summaryrefslogtreecommitdiffstats
path: root/sql/handler.cc
blob: 230bcf5e38af92b54300367707b5bcf82efe864d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
6678
6679
6680
6681
6682
6683
6684
6685
6686
6687
6688
6689
6690
6691
6692
6693
6694
6695
6696
6697
6698
6699
6700
6701
6702
6703
6704
6705
6706
6707
6708
6709
6710
6711
6712
6713
6714
6715
6716
6717
6718
6719
6720
6721
6722
6723
6724
6725
6726
6727
6728
6729
6730
6731
6732
6733
6734
6735
6736
6737
6738
6739
6740
6741
6742
6743
6744
6745
6746
6747
6748
6749
6750
6751
6752
6753
6754
6755
6756
6757
6758
6759
6760
6761
6762
6763
6764
6765
6766
6767
6768
6769
6770
6771
6772
6773
6774
6775
6776
6777
6778
6779
6780
6781
6782
6783
6784
6785
6786
6787
6788
6789
6790
6791
6792
6793
6794
6795
6796
6797
6798
6799
6800
6801
6802
6803
6804
6805
6806
6807
6808
6809
6810
6811
6812
6813
6814
6815
6816
6817
6818
6819
6820
6821
6822
6823
6824
6825
6826
6827
6828
6829
6830
6831
6832
6833
6834
6835
6836
6837
6838
6839
6840
6841
6842
6843
6844
6845
6846
6847
6848
6849
6850
6851
6852
6853
6854
6855
6856
6857
6858
6859
6860
6861
6862
6863
6864
6865
6866
6867
6868
6869
6870
6871
6872
6873
6874
6875
6876
6877
6878
6879
6880
6881
6882
6883
6884
6885
6886
6887
6888
6889
6890
6891
6892
6893
6894
6895
6896
6897
6898
6899
6900
6901
6902
6903
6904
6905
6906
6907
6908
6909
6910
6911
6912
6913
6914
6915
6916
6917
6918
6919
6920
6921
6922
6923
6924
6925
6926
6927
6928
6929
6930
6931
6932
6933
6934
6935
6936
6937
6938
6939
6940
6941
6942
6943
6944
6945
6946
6947
6948
6949
6950
6951
6952
6953
6954
6955
6956
6957
6958
6959
6960
6961
6962
6963
6964
6965
6966
6967
6968
6969
6970
6971
6972
6973
6974
6975
6976
6977
6978
6979
6980
6981
6982
6983
6984
6985
6986
6987
6988
6989
6990
6991
6992
6993
6994
6995
6996
6997
6998
6999
7000
7001
7002
7003
7004
7005
7006
7007
7008
7009
7010
7011
7012
7013
7014
7015
7016
7017
7018
7019
7020
7021
7022
7023
7024
7025
7026
7027
7028
7029
7030
7031
7032
7033
7034
7035
7036
7037
7038
7039
7040
7041
7042
7043
7044
7045
7046
7047
7048
7049
7050
7051
7052
7053
7054
7055
7056
7057
7058
7059
7060
7061
7062
7063
7064
7065
7066
7067
7068
7069
7070
7071
7072
7073
7074
7075
7076
7077
7078
7079
7080
7081
7082
7083
7084
7085
7086
7087
7088
7089
7090
7091
7092
7093
7094
7095
7096
7097
7098
7099
7100
7101
7102
7103
7104
7105
7106
7107
7108
7109
7110
7111
7112
7113
7114
7115
7116
7117
7118
7119
7120
7121
7122
7123
7124
7125
7126
7127
7128
7129
7130
7131
7132
7133
7134
7135
7136
7137
7138
7139
7140
7141
7142
7143
7144
7145
7146
7147
7148
7149
7150
7151
7152
7153
7154
7155
7156
7157
7158
7159
7160
7161
7162
7163
7164
7165
7166
7167
7168
7169
7170
7171
7172
7173
7174
7175
7176
7177
7178
7179
7180
7181
7182
7183
7184
7185
7186
7187
7188
7189
7190
7191
7192
7193
7194
7195
7196
7197
7198
7199
7200
7201
7202
7203
7204
7205
7206
7207
7208
7209
7210
7211
7212
7213
7214
7215
7216
7217
7218
7219
7220
7221
7222
7223
7224
7225
7226
7227
7228
7229
7230
7231
7232
7233
7234
7235
7236
7237
7238
7239
7240
7241
7242
7243
7244
7245
7246
7247
7248
7249
7250
7251
7252
7253
7254
7255
7256
7257
7258
7259
7260
7261
7262
7263
7264
7265
7266
7267
7268
7269
7270
7271
7272
7273
7274
7275
7276
7277
7278
7279
7280
7281
7282
7283
7284
7285
7286
7287
7288
7289
7290
7291
7292
7293
7294
7295
7296
7297
7298
7299
7300
7301
7302
7303
7304
7305
7306
7307
7308
7309
7310
7311
7312
7313
7314
7315
7316
7317
7318
7319
7320
7321
7322
7323
7324
7325
7326
7327
7328
7329
7330
7331
7332
7333
7334
7335
7336
7337
7338
7339
7340
7341
7342
7343
7344
7345
7346
7347
7348
7349
7350
7351
7352
7353
7354
7355
7356
7357
7358
7359
7360
7361
7362
7363
7364
7365
7366
7367
7368
7369
7370
7371
7372
7373
7374
7375
7376
7377
7378
7379
7380
7381
7382
7383
7384
7385
7386
7387
7388
7389
7390
7391
7392
7393
7394
7395
7396
7397
7398
7399
7400
7401
7402
7403
7404
7405
7406
7407
7408
7409
7410
7411
7412
7413
7414
7415
7416
7417
7418
7419
7420
7421
7422
7423
7424
7425
7426
7427
7428
7429
7430
7431
7432
7433
7434
7435
7436
7437
7438
7439
7440
7441
7442
7443
7444
7445
7446
7447
7448
7449
7450
7451
7452
7453
7454
7455
7456
7457
7458
7459
7460
7461
7462
7463
7464
7465
7466
7467
7468
7469
7470
7471
7472
7473
7474
7475
7476
7477
7478
7479
7480
7481
7482
7483
7484
7485
7486
7487
7488
7489
7490
7491
7492
7493
7494
7495
7496
7497
7498
7499
7500
7501
7502
7503
7504
7505
7506
7507
7508
7509
7510
7511
7512
7513
7514
7515
7516
7517
7518
7519
7520
7521
7522
7523
7524
7525
7526
7527
7528
7529
7530
7531
7532
7533
7534
7535
7536
7537
7538
7539
7540
7541
7542
7543
7544
7545
7546
7547
7548
7549
7550
7551
7552
7553
7554
7555
7556
7557
7558
7559
7560
7561
7562
7563
7564
7565
7566
7567
7568
7569
7570
7571
7572
7573
7574
7575
7576
7577
7578
7579
7580
7581
7582
7583
7584
7585
7586
7587
7588
7589
7590
7591
7592
7593
7594
7595
7596
7597
7598
7599
7600
7601
7602
7603
7604
7605
7606
7607
7608
7609
7610
7611
7612
7613
7614
7615
7616
7617
7618
7619
7620
7621
7622
7623
7624
7625
7626
7627
7628
7629
7630
7631
7632
7633
7634
7635
7636
7637
7638
7639
7640
7641
7642
7643
7644
7645
7646
7647
7648
7649
7650
7651
7652
7653
7654
7655
7656
7657
7658
7659
7660
7661
7662
7663
7664
7665
7666
7667
7668
7669
7670
7671
7672
7673
7674
7675
7676
7677
7678
7679
7680
7681
7682
7683
7684
7685
7686
7687
7688
7689
7690
7691
7692
7693
7694
7695
7696
7697
7698
7699
7700
7701
7702
7703
7704
7705
7706
7707
7708
7709
7710
7711
7712
7713
7714
7715
7716
7717
7718
7719
7720
7721
7722
7723
7724
7725
7726
7727
7728
7729
7730
7731
7732
7733
7734
7735
7736
7737
7738
7739
7740
7741
7742
7743
7744
7745
7746
7747
7748
7749
7750
7751
7752
7753
7754
7755
7756
7757
7758
7759
7760
7761
7762
7763
7764
7765
7766
7767
7768
7769
7770
7771
7772
7773
7774
7775
7776
7777
7778
7779
7780
7781
7782
7783
7784
7785
7786
7787
7788
7789
7790
7791
7792
7793
7794
7795
7796
7797
7798
7799
7800
7801
7802
7803
7804
7805
7806
7807
7808
7809
7810
7811
7812
7813
7814
7815
7816
7817
7818
7819
7820
7821
7822
7823
7824
7825
7826
7827
7828
7829
7830
7831
7832
7833
7834
7835
7836
7837
7838
7839
7840
7841
7842
7843
7844
7845
7846
7847
7848
7849
7850
7851
7852
7853
7854
7855
7856
7857
7858
7859
7860
7861
7862
7863
7864
7865
7866
7867
7868
7869
7870
7871
7872
7873
7874
7875
7876
7877
7878
7879
7880
7881
7882
7883
7884
7885
7886
7887
7888
7889
7890
7891
7892
7893
7894
7895
7896
7897
7898
7899
7900
7901
7902
7903
7904
7905
7906
7907
7908
7909
7910
7911
7912
7913
7914
7915
7916
7917
7918
7919
7920
7921
7922
7923
7924
7925
7926
7927
7928
7929
7930
7931
7932
7933
7934
7935
7936
7937
7938
7939
7940
7941
7942
7943
7944
7945
7946
7947
7948
7949
7950
7951
7952
7953
7954
7955
7956
7957
7958
7959
7960
7961
7962
7963
7964
7965
7966
7967
7968
7969
7970
7971
7972
7973
7974
7975
7976
7977
7978
7979
7980
7981
7982
7983
7984
7985
7986
7987
7988
7989
7990
7991
7992
7993
7994
7995
7996
7997
7998
7999
8000
8001
8002
8003
8004
8005
8006
8007
8008
8009
8010
8011
8012
8013
8014
8015
8016
8017
8018
8019
8020
8021
8022
8023
8024
8025
8026
8027
8028
8029
8030
8031
8032
8033
8034
8035
8036
8037
8038
8039
8040
8041
8042
8043
8044
8045
8046
8047
8048
8049
8050
8051
8052
8053
8054
8055
8056
8057
8058
8059
8060
8061
8062
8063
8064
8065
8066
8067
8068
8069
8070
8071
8072
8073
8074
8075
8076
8077
8078
8079
8080
8081
8082
8083
8084
8085
8086
8087
8088
8089
8090
8091
8092
8093
8094
8095
8096
8097
8098
8099
8100
8101
8102
8103
8104
8105
8106
8107
8108
8109
8110
8111
8112
8113
8114
8115
8116
8117
8118
8119
8120
8121
8122
8123
8124
8125
8126
8127
8128
8129
8130
8131
8132
8133
8134
8135
8136
8137
8138
8139
8140
8141
8142
8143
8144
8145
8146
8147
8148
8149
8150
8151
8152
8153
8154
8155
8156
8157
8158
8159
8160
8161
8162
8163
8164
8165
8166
8167
8168
8169
8170
8171
8172
8173
8174
8175
8176
8177
8178
8179
8180
8181
8182
8183
8184
8185
8186
8187
8188
8189
8190
8191
8192
8193
8194
8195
8196
8197
8198
8199
8200
8201
8202
8203
8204
8205
8206
8207
8208
8209
8210
8211
8212
8213
8214
8215
8216
8217
8218
8219
8220
8221
8222
8223
8224
8225
8226
8227
8228
8229
8230
8231
8232
8233
8234
8235
8236
8237
8238
8239
8240
8241
8242
8243
8244
8245
8246
8247
8248
8249
8250
8251
8252
8253
8254
8255
8256
8257
8258
8259
8260
8261
8262
8263
8264
8265
8266
8267
8268
8269
8270
8271
8272
8273
8274
8275
8276
8277
8278
8279
8280
8281
8282
8283
8284
8285
8286
8287
8288
8289
8290
8291
8292
8293
8294
8295
8296
8297
8298
8299
8300
8301
8302
8303
8304
8305
8306
8307
8308
8309
8310
8311
8312
8313
8314
8315
8316
8317
8318
8319
8320
8321
8322
8323
8324
8325
8326
8327
8328
8329
8330
8331
8332
8333
8334
8335
8336
8337
8338
8339
8340
8341
8342
8343
8344
8345
8346
8347
8348
8349
8350
8351
8352
8353
8354
8355
8356
8357
8358
8359
8360
8361
8362
8363
8364
8365
8366
8367
8368
8369
8370
8371
8372
8373
8374
8375
8376
8377
8378
8379
8380
8381
8382
8383
8384
8385
8386
8387
8388
8389
8390
8391
8392
8393
8394
8395
8396
8397
8398
8399
8400
8401
8402
8403
8404
8405
8406
8407
8408
8409
8410
8411
8412
8413
8414
8415
8416
8417
8418
8419
8420
8421
8422
8423
8424
8425
8426
8427
8428
8429
8430
8431
8432
8433
8434
8435
8436
8437
8438
8439
8440
8441
8442
8443
8444
8445
8446
8447
8448
8449
8450
8451
8452
8453
8454
8455
8456
8457
8458
8459
8460
8461
8462
8463
8464
8465
8466
8467
8468
8469
8470
8471
8472
8473
8474
8475
8476
8477
8478
8479
8480
8481
8482
8483
8484
8485
8486
8487
8488
8489
8490
8491
8492
8493
8494
8495
8496
8497
8498
8499
8500
8501
8502
8503
8504
8505
8506
8507
8508
8509
8510
8511
8512
8513
8514
8515
8516
8517
8518
8519
8520
8521
8522
8523
8524
8525
8526
8527
8528
8529
8530
8531
8532
8533
8534
8535
8536
8537
8538
8539
8540
8541
8542
8543
8544
8545
8546
8547
8548
8549
8550
8551
8552
8553
8554
8555
8556
8557
8558
8559
8560
8561
8562
8563
8564
8565
8566
8567
8568
8569
8570
8571
8572
8573
8574
8575
8576
8577
8578
8579
8580
8581
8582
8583
8584
8585
8586
8587
8588
8589
8590
8591
8592
8593
8594
8595
8596
8597
8598
8599
8600
8601
8602
8603
8604
8605
8606
8607
8608
8609
8610
8611
8612
8613
8614
8615
8616
8617
8618
8619
8620
8621
8622
8623
8624
8625
8626
8627
8628
8629
8630
8631
8632
8633
8634
8635
8636
8637
8638
8639
8640
8641
8642
8643
8644
8645
8646
8647
8648
8649
8650
8651
8652
8653
8654
8655
8656
8657
8658
8659
8660
8661
8662
8663
8664
8665
8666
8667
8668
8669
8670
8671
8672
8673
8674
8675
8676
8677
8678
8679
8680
8681
8682
8683
8684
8685
8686
8687
8688
8689
8690
8691
8692
8693
8694
8695
8696
8697
8698
8699
8700
8701
8702
8703
8704
8705
8706
8707
8708
8709
8710
8711
8712
8713
8714
8715
8716
8717
8718
8719
8720
8721
8722
8723
8724
8725
8726
8727
8728
8729
8730
8731
8732
8733
8734
8735
8736
8737
8738
8739
8740
8741
8742
8743
8744
8745
8746
8747
8748
8749
8750
8751
8752
8753
8754
8755
8756
8757
8758
8759
8760
8761
8762
8763
8764
8765
8766
8767
8768
8769
8770
8771
8772
8773
8774
8775
8776
8777
8778
8779
8780
8781
8782
8783
8784
8785
8786
8787
8788
8789
/* Copyright (c) 2000, 2016, Oracle and/or its affiliates.
   Copyright (c) 2009, 2023, MariaDB Corporation.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */

/** @file handler.cc

    @brief
  Handler-calling-functions
*/

#include "mariadb.h"
#include <inttypes.h>
#include "sql_priv.h"
#include "unireg.h"
#include "rpl_rli.h"
#include "sql_cache.h"                   // query_cache, query_cache_*
#include "sql_connect.h"                 // global_table_stats
#include "key.h"     // key_copy, key_unpack, key_cmp_if_same, key_cmp
#include "sql_table.h"                   // build_table_filename
#include "sql_parse.h"                          // check_stack_overrun
#include "sql_base.h"           // TDC_element
#include "discover.h"           // extension_based_table_discovery, etc
#include "log_event.h"          // *_rows_log_event
#include "create_options.h"
#include <myisampack.h>
#include "transaction.h"
#include "myisam.h"
#include "probes_mysql.h"
#include <mysql/psi/mysql_table.h>
#include <pfs_transaction_provider.h>
#include <mysql/psi/mysql_transaction.h>
#include "debug_sync.h"         // DEBUG_SYNC
#include "sql_audit.h"
#include "ha_sequence.h"
#include "rowid_filter.h"
#include "mysys_err.h"

#ifdef WITH_PARTITION_STORAGE_ENGINE
#include "ha_partition.h"
#endif

#ifdef WITH_ARIA_STORAGE_ENGINE
#include "../storage/maria/ha_maria.h"
#endif
#include "semisync_master.h"

#include "wsrep_mysqld.h"
#ifdef WITH_WSREP
#include "wsrep_binlog.h"
#include "wsrep_xid.h"
#include "wsrep_thd.h"
#include "wsrep_trans_observer.h" /* wsrep transaction hooks */
#include "wsrep_var.h"            /* wsrep_hton_check() */
#endif /* WITH_WSREP */

/**
  @def MYSQL_TABLE_LOCK_WAIT
  Instrumentation helper for table io_waits.
  @param OP the table operation to be performed
  @param FLAGS per table operation flags.
  @param PAYLOAD the code to instrument.
  @sa MYSQL_END_TABLE_WAIT.
*/
#ifdef HAVE_PSI_TABLE_INTERFACE
  #define MYSQL_TABLE_LOCK_WAIT(OP, FLAGS, PAYLOAD)    \
    {                                                  \
      if (m_psi != NULL)                               \
      {                                                \
        PSI_table_locker *locker;                      \
        PSI_table_locker_state state;                  \
        locker= PSI_TABLE_CALL(start_table_lock_wait)  \
          (& state, m_psi, OP, FLAGS,                  \
          __FILE__, __LINE__);                         \
        PAYLOAD                                        \
        if (locker != NULL)                            \
          PSI_TABLE_CALL(end_table_lock_wait)(locker); \
      }                                                \
      else                                             \
      {                                                \
        PAYLOAD                                        \
      }                                                \
    }
#else
  #define MYSQL_TABLE_LOCK_WAIT(OP, FLAGS, PAYLOAD) \
    PAYLOAD
#endif


/*
  While we have legacy_db_type, we have this array to
  check for dups and to find handlerton from legacy_db_type.
  Remove when legacy_db_type is finally gone
*/
st_plugin_int *hton2plugin[MAX_HA];

static handlerton *installed_htons[128];

#define BITMAP_STACKBUF_SIZE (128/8)

KEY_CREATE_INFO default_key_create_info=
{ HA_KEY_ALG_UNDEF, 0, 0, {NullS, 0}, {NullS, 0}, false };

/* number of entries in handlertons[] */
ulong total_ha= 0;
/* number of storage engines (from handlertons[]) that support 2pc */
ulong total_ha_2pc= 0;
#ifdef DBUG_ASSERT_EXISTS
/*
  Number of non-mandatory 2pc handlertons whose initialization failed
  to estimate total_ha_2pc value under supposition of the failures
  have not occcured.
*/
ulong failed_ha_2pc= 0;
#endif
/* size of savepoint storage area (see ha_init) */
ulong savepoint_alloc_size= 0;

static const LEX_CSTRING sys_table_aliases[]=
{
  { STRING_WITH_LEN("INNOBASE") },  { STRING_WITH_LEN("INNODB") },
  { STRING_WITH_LEN("HEAP") },      { STRING_WITH_LEN("MEMORY") },
  { STRING_WITH_LEN("MERGE") },     { STRING_WITH_LEN("MRG_MYISAM") },
  { STRING_WITH_LEN("Maria") },     { STRING_WITH_LEN("Aria") },
  {NullS, 0}
};

const LEX_CSTRING ha_row_type[]=
{
  { STRING_WITH_LEN("") },
  { STRING_WITH_LEN("FIXED") },
  { STRING_WITH_LEN("DYNAMIC") },
  { STRING_WITH_LEN("COMPRESSED") },
  { STRING_WITH_LEN("REDUNDANT") },
  { STRING_WITH_LEN("COMPACT") },
  { STRING_WITH_LEN("PAGE") }
};

const char *tx_isolation_names[]=
{ "READ-UNCOMMITTED", "READ-COMMITTED", "REPEATABLE-READ", "SERIALIZABLE",
  NullS};
TYPELIB tx_isolation_typelib= {array_elements(tx_isolation_names)-1,"",
			       tx_isolation_names, NULL};

static TYPELIB known_extensions= {0,"known_exts", NULL, NULL};
uint known_extensions_id= 0;


class Table_exists_error_handler : public Internal_error_handler
{
public:
  Table_exists_error_handler()
    : m_handled_errors(0), m_unhandled_errors(0)
  {}

  bool handle_condition(THD *thd,
                        uint sql_errno,
                        const char* sqlstate,
                        Sql_condition::enum_warning_level *level,
                        const char* msg,
                        Sql_condition ** cond_hdl)
  {
    *cond_hdl= NULL;
    if (non_existing_table_error(sql_errno))
    {
      m_handled_errors++;
      return TRUE;
    }

    if (*level == Sql_condition::WARN_LEVEL_ERROR)
      m_unhandled_errors++;
    return FALSE;
  }

  bool safely_trapped_errors()
  {
    return ((m_handled_errors > 0) && (m_unhandled_errors == 0));
  }

private:
  int m_handled_errors;
  int m_unhandled_errors;
};


static int commit_one_phase_2(THD *thd, bool all, THD_TRANS *trans,
                              bool is_real_trans);


static plugin_ref ha_default_plugin(THD *thd)
{
  if (thd->variables.table_plugin)
    return thd->variables.table_plugin;
  return my_plugin_lock(thd, global_system_variables.table_plugin);
}

static plugin_ref ha_default_tmp_plugin(THD *thd)
{
  if (thd->variables.tmp_table_plugin)
    return thd->variables.tmp_table_plugin;
  if (global_system_variables.tmp_table_plugin)
    return my_plugin_lock(thd, global_system_variables.tmp_table_plugin);
  return ha_default_plugin(thd);
}


/** @brief
  Return the default storage engine handlerton for thread

  SYNOPSIS
    ha_default_handlerton(thd)
    thd         current thread

  RETURN
    pointer to handlerton
*/
handlerton *ha_default_handlerton(THD *thd)
{
  plugin_ref plugin= ha_default_plugin(thd);
  DBUG_ASSERT(plugin);
  handlerton *hton= plugin_hton(plugin);
  DBUG_ASSERT(hton);
  return hton;
}


handlerton *ha_default_tmp_handlerton(THD *thd)
{
  plugin_ref plugin= ha_default_tmp_plugin(thd);
  DBUG_ASSERT(plugin);
  handlerton *hton= plugin_hton(plugin);
  DBUG_ASSERT(hton);
  return hton;
}


/** @brief
  Return the storage engine handlerton for the supplied name
  
  SYNOPSIS
    ha_resolve_by_name(thd, name)
    thd         current thread
    name        name of storage engine
  
  RETURN
    pointer to storage engine plugin handle
*/
plugin_ref ha_resolve_by_name(THD *thd, const LEX_CSTRING *name,
                              bool tmp_table)
{
  const LEX_CSTRING *table_alias;
  plugin_ref plugin;

redo:
  if (thd && !my_charset_latin1.strnncoll(
                           (const uchar *)name->str, name->length,
                           (const uchar *)STRING_WITH_LEN("DEFAULT"), 0))
    return tmp_table ?  ha_default_tmp_plugin(thd) : ha_default_plugin(thd);

  if ((plugin= my_plugin_lock_by_name(thd, name, MYSQL_STORAGE_ENGINE_PLUGIN)))
  {
    handlerton *hton= plugin_hton(plugin);
    if (hton && !(hton->flags & HTON_NOT_USER_SELECTABLE))
      return plugin;
      
    /*
      unlocking plugin immediately after locking is relatively low cost.
    */
    plugin_unlock(thd, plugin);
  }

  /*
    We check for the historical aliases.
  */
  for (table_alias= sys_table_aliases; table_alias->str; table_alias+= 2)
  {
    if (!my_charset_latin1.strnncoll(
                      (const uchar *)name->str, name->length,
                      (const uchar *)table_alias->str, table_alias->length))
    {
      name= table_alias + 1;
      goto redo;
    }
  }

  return NULL;
}


bool
Storage_engine_name::resolve_storage_engine_with_error(THD *thd,
                                                       handlerton **ha,
                                                       bool tmp_table)
{
  if (plugin_ref plugin= ha_resolve_by_name(thd, &m_storage_engine_name,
                                            tmp_table))
  {
    *ha= plugin_hton(plugin);
    return false;
  }

  *ha= NULL;
  if (thd->variables.sql_mode & MODE_NO_ENGINE_SUBSTITUTION)
  {
    my_error(ER_UNKNOWN_STORAGE_ENGINE, MYF(0), m_storage_engine_name.str);
    return true;
  }
  push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
                      ER_UNKNOWN_STORAGE_ENGINE,
                      ER_THD(thd, ER_UNKNOWN_STORAGE_ENGINE),
                      m_storage_engine_name.str);
  return false;
}


plugin_ref ha_lock_engine(THD *thd, const handlerton *hton)
{
  if (hton)
  {
    st_plugin_int *plugin= hton2plugin[hton->slot];
    return my_plugin_lock(thd, plugin_int_to_ref(plugin));
  }
  return NULL;
}


handlerton *ha_resolve_by_legacy_type(THD *thd, enum legacy_db_type db_type)
{
  plugin_ref plugin;
  switch (db_type) {
  case DB_TYPE_DEFAULT:
    return ha_default_handlerton(thd);
  default:
    if (db_type > DB_TYPE_UNKNOWN && db_type < DB_TYPE_DEFAULT &&
        (plugin= ha_lock_engine(thd, installed_htons[db_type])))
      return plugin_hton(plugin);
    /* fall through */
  case DB_TYPE_UNKNOWN:
    return NULL;
  }
}


/**
  Use other database handler if databasehandler is not compiled in.
*/
handlerton *ha_checktype(THD *thd, handlerton *hton, bool no_substitute)
{
  if (ha_storage_engine_is_enabled(hton))
    return hton;

  if (no_substitute)
    return NULL;

  return ha_default_handlerton(thd);
} /* ha_checktype */


handler *get_new_handler(TABLE_SHARE *share, MEM_ROOT *alloc,
                         handlerton *db_type)
{
  handler *file;
  DBUG_ENTER("get_new_handler");
  DBUG_PRINT("enter", ("alloc: %p", alloc));

  if (ha_storage_engine_is_enabled(db_type))
  {
    if ((file= db_type->create(db_type, share, alloc)))
      file->init();
    DBUG_RETURN(file);
  }
  /*
    Try the default table type
    Here the call to current_thd() is ok as we call this function a lot of
    times but we enter this branch very seldom.
  */
  file= get_new_handler(share, alloc, ha_default_handlerton(current_thd));
  DBUG_RETURN(file);
}


#ifdef WITH_PARTITION_STORAGE_ENGINE
handler *get_ha_partition(partition_info *part_info)
{
  ha_partition *partition;
  DBUG_ENTER("get_ha_partition");
  if ((partition= new ha_partition(partition_hton, part_info)))
  {
    if (partition->initialize_partition(current_thd->mem_root))
    {
      delete partition;
      partition= 0;
    }
    else
      partition->init();
  }
  else
  {
    my_error(ER_OUTOFMEMORY, MYF(ME_FATAL), 
             static_cast<int>(sizeof(ha_partition)));
  }
  DBUG_RETURN(((handler*) partition));
}
#endif

static const char **handler_errmsgs;

C_MODE_START
static const char **get_handler_errmsgs(int nr)
{
  return handler_errmsgs;
}
C_MODE_END


/**
  Register handler error messages for use with my_error().

  @retval
    0           OK
  @retval
    !=0         Error
*/

int ha_init_errors(void)
{
#define SETMSG(nr, msg) handler_errmsgs[(nr) - HA_ERR_FIRST]= (msg)

  /* Allocate a pointer array for the error message strings. */
  /* Zerofill it to avoid uninitialized gaps. */
  if (! (handler_errmsgs= (const char**) my_malloc(key_memory_handler_errmsgs,
                                                   HA_ERR_ERRORS * sizeof(char*),
                                                   MYF(MY_WME | MY_ZEROFILL))))
    return 1;

  /* Set the dedicated error messages. */
  SETMSG(HA_ERR_KEY_NOT_FOUND,          ER_DEFAULT(ER_KEY_NOT_FOUND));
  SETMSG(HA_ERR_FOUND_DUPP_KEY,         ER_DEFAULT(ER_DUP_KEY));
  SETMSG(HA_ERR_RECORD_CHANGED,         "Update which is recoverable");
  SETMSG(HA_ERR_WRONG_INDEX,            "Wrong index given to function");
  SETMSG(HA_ERR_CRASHED,                ER_DEFAULT(ER_NOT_KEYFILE));
  SETMSG(HA_ERR_WRONG_IN_RECORD,        ER_DEFAULT(ER_CRASHED_ON_USAGE));
  SETMSG(HA_ERR_OUT_OF_MEM,             "Table handler out of memory");
  SETMSG(HA_ERR_NOT_A_TABLE,            "Incorrect file format '%.64s'");
  SETMSG(HA_ERR_WRONG_COMMAND,          "Command not supported");
  SETMSG(HA_ERR_OLD_FILE,               ER_DEFAULT(ER_OLD_KEYFILE));
  SETMSG(HA_ERR_NO_ACTIVE_RECORD,       "No record read in update");
  SETMSG(HA_ERR_RECORD_DELETED,         "Intern record deleted");
  SETMSG(HA_ERR_RECORD_FILE_FULL,       ER_DEFAULT(ER_RECORD_FILE_FULL));
  SETMSG(HA_ERR_INDEX_FILE_FULL,        "No more room in index file '%.64s'");
  SETMSG(HA_ERR_END_OF_FILE,            "End in next/prev/first/last");
  SETMSG(HA_ERR_UNSUPPORTED,            ER_DEFAULT(ER_ILLEGAL_HA));
  SETMSG(HA_ERR_TO_BIG_ROW,             "Too big row");
  SETMSG(HA_WRONG_CREATE_OPTION,        "Wrong create option");
  SETMSG(HA_ERR_FOUND_DUPP_UNIQUE,      ER_DEFAULT(ER_DUP_UNIQUE));
  SETMSG(HA_ERR_UNKNOWN_CHARSET,        "Can't open charset");
  SETMSG(HA_ERR_WRONG_MRG_TABLE_DEF,    ER_DEFAULT(ER_WRONG_MRG_TABLE));
  SETMSG(HA_ERR_CRASHED_ON_REPAIR,      ER_DEFAULT(ER_CRASHED_ON_REPAIR));
  SETMSG(HA_ERR_CRASHED_ON_USAGE,       ER_DEFAULT(ER_CRASHED_ON_USAGE));
  SETMSG(HA_ERR_LOCK_WAIT_TIMEOUT,      ER_DEFAULT(ER_LOCK_WAIT_TIMEOUT));
  SETMSG(HA_ERR_LOCK_TABLE_FULL,        ER_DEFAULT(ER_LOCK_TABLE_FULL));
  SETMSG(HA_ERR_READ_ONLY_TRANSACTION,  ER_DEFAULT(ER_READ_ONLY_TRANSACTION));
  SETMSG(HA_ERR_LOCK_DEADLOCK,          ER_DEFAULT(ER_LOCK_DEADLOCK));
  SETMSG(HA_ERR_CANNOT_ADD_FOREIGN,     ER_DEFAULT(ER_CANNOT_ADD_FOREIGN));
  SETMSG(HA_ERR_NO_REFERENCED_ROW,      ER_DEFAULT(ER_NO_REFERENCED_ROW_2));
  SETMSG(HA_ERR_ROW_IS_REFERENCED,      ER_DEFAULT(ER_ROW_IS_REFERENCED_2));
  SETMSG(HA_ERR_NO_SAVEPOINT,           "No savepoint with that name");
  SETMSG(HA_ERR_NON_UNIQUE_BLOCK_SIZE,  "Non unique key block size");
  SETMSG(HA_ERR_NO_SUCH_TABLE,          "No such table: '%.64s'");
  SETMSG(HA_ERR_TABLE_EXIST,            ER_DEFAULT(ER_TABLE_EXISTS_ERROR));
  SETMSG(HA_ERR_NO_CONNECTION,          "Could not connect to storage engine");
  SETMSG(HA_ERR_TABLE_DEF_CHANGED,      ER_DEFAULT(ER_TABLE_DEF_CHANGED));
  SETMSG(HA_ERR_FOREIGN_DUPLICATE_KEY,  "FK constraint would lead to duplicate key");
  SETMSG(HA_ERR_TABLE_NEEDS_UPGRADE,    ER_DEFAULT(ER_TABLE_NEEDS_UPGRADE));
  SETMSG(HA_ERR_TABLE_READONLY,         ER_DEFAULT(ER_OPEN_AS_READONLY));
  SETMSG(HA_ERR_AUTOINC_READ_FAILED,    ER_DEFAULT(ER_AUTOINC_READ_FAILED));
  SETMSG(HA_ERR_AUTOINC_ERANGE,         ER_DEFAULT(ER_WARN_DATA_OUT_OF_RANGE));
  SETMSG(HA_ERR_TOO_MANY_CONCURRENT_TRXS, ER_DEFAULT(ER_TOO_MANY_CONCURRENT_TRXS));
  SETMSG(HA_ERR_INDEX_COL_TOO_LONG,	ER_DEFAULT(ER_INDEX_COLUMN_TOO_LONG));
  SETMSG(HA_ERR_INDEX_CORRUPT,		ER_DEFAULT(ER_INDEX_CORRUPT));
  SETMSG(HA_FTS_INVALID_DOCID,		"Invalid InnoDB FTS Doc ID");
  SETMSG(HA_ERR_DISK_FULL,              ER_DEFAULT(ER_DISK_FULL));
  SETMSG(HA_ERR_FTS_TOO_MANY_WORDS_IN_PHRASE,  "Too many words in a FTS phrase or proximity search");
  SETMSG(HA_ERR_FK_DEPTH_EXCEEDED,      "Foreign key cascade delete/update exceeds");
  SETMSG(HA_ERR_TABLESPACE_MISSING,     ER_DEFAULT(ER_TABLESPACE_MISSING));

  /* Register the error messages for use with my_error(). */
  return my_error_register(get_handler_errmsgs, HA_ERR_FIRST, HA_ERR_LAST);
}


/**
  Unregister handler error messages.

  @retval
    0           OK
  @retval
    !=0         Error
*/
static int ha_finish_errors(void)
{
  /* Allocate a pointer array for the error message strings. */
  my_error_unregister(HA_ERR_FIRST, HA_ERR_LAST);
  my_free(handler_errmsgs);
  handler_errmsgs= 0;
  return 0;
}

static Atomic_counter<int32> need_full_discover_for_existence(0);
static Atomic_counter<int32> engines_with_discover_file_names(0);
static Atomic_counter<int32> engines_with_discover(0);

static int full_discover_for_existence(handlerton *, const char *, const char *)
{ return 0; }

static int ext_based_existence(handlerton *, const char *, const char *)
{ return 0; }

static int hton_ext_based_table_discovery(handlerton *hton, LEX_CSTRING *db,
                             MY_DIR *dir, handlerton::discovered_list *result)
{
  /*
    tablefile_extensions[0] is the metadata file, see
    the comment above tablefile_extensions declaration
  */
  return extension_based_table_discovery(dir, hton->tablefile_extensions[0],
                                         result);
}

static void update_discovery_counters(handlerton *hton, int val)
{
  if (hton->discover_table_existence == full_discover_for_existence)
    need_full_discover_for_existence+= val;

  if (hton->discover_table_names && hton->tablefile_extensions[0])
    engines_with_discover_file_names+= val;

  if (hton->discover_table)
    engines_with_discover+= val;
}

int ha_drop_table(THD *thd, handlerton *hton, const char *path)
{
  if (ha_check_if_updates_are_ignored(thd, hton, "DROP"))
    return 0;                                   // Simulate dropped
  return hton->drop_table(hton, path);
}

static int hton_drop_table(handlerton *hton, const char *path)
{
  char tmp_path[FN_REFLEN];
  handler *file= get_new_handler(nullptr, current_thd->mem_root, hton);
  if (!file)
  {
    /*
      If file is not defined it means that the engine can't create a
      handler if share is not set or we got an out of memory error
    */
    return my_errno == ENOMEM ? ENOMEM : ENOENT;
  }
  path= get_canonical_filename(file, path, tmp_path);
  int error= file->delete_table(path);
  delete file;
  return error;
}


int ha_finalize_handlerton(st_plugin_int *plugin)
{
  int deinit_status= 0;
  handlerton *hton= (handlerton *)plugin->data;
  DBUG_ENTER("ha_finalize_handlerton");

  /* hton can be NULL here, if ha_initialize_handlerton() failed. */
  if (!hton)
    goto end;

  if (installed_htons[hton->db_type] == hton)
    installed_htons[hton->db_type]= NULL;

  if (hton->panic)
    hton->panic(hton, HA_PANIC_CLOSE);

  if (plugin->plugin->deinit)
    deinit_status= plugin->plugin->deinit(NULL);

  free_sysvar_table_options(hton);
  update_discovery_counters(hton, -1);

  /*
    In case a plugin is uninstalled and re-installed later, it should
    reuse an array slot. Otherwise the number of uninstall/install
    cycles would be limited.
  */
  if (hton->slot != HA_SLOT_UNDEF)
  {
    /* Make sure we are not unpluging another plugin */
    DBUG_ASSERT(hton2plugin[hton->slot] == plugin);
    DBUG_ASSERT(hton->slot < MAX_HA);
    hton2plugin[hton->slot]= NULL;
  }

  my_free(hton);

 end:
  DBUG_RETURN(deinit_status);
}


const char *hton_no_exts[]= { 0 };


int ha_initialize_handlerton(st_plugin_int *plugin)
{
  handlerton *hton;
  int ret= 0;
  DBUG_ENTER("ha_initialize_handlerton");
  DBUG_PRINT("plugin", ("initialize plugin: '%s'", plugin->name.str));

  hton= (handlerton *)my_malloc(key_memory_handlerton, sizeof(handlerton),
                                MYF(MY_WME | MY_ZEROFILL));
  if (hton == NULL)
  {
    sql_print_error("Unable to allocate memory for plugin '%s' handlerton.",
                    plugin->name.str);
    ret= 1;
    goto err_no_hton_memory;
  }

  hton->tablefile_extensions= hton_no_exts;
  hton->discover_table_names= hton_ext_based_table_discovery;
  hton->drop_table= hton_drop_table;

  hton->slot= HA_SLOT_UNDEF;
  /* Historical Requirement */
  plugin->data= hton; // shortcut for the future
  /* [remove after merge] notes on merge conflict (MDEV-31400):
  10.6-10.11: 13ba00ff4933cfc1712676f323587504e453d1b5
  11.0-11.2: 42f8be10f18163c4025710cf6a212e82bddb2f62
  The 10.11->11.0 conflict is trivial, but the reference commit also
  contains different non-conflict changes needs to be applied to 11.0
  (and beyond).
  */
  if (plugin->plugin->init && (ret= plugin->plugin->init(hton)))
    goto err;

  // hton_ext_based_table_discovery() works only when discovery
  // is supported and the engine if file-based.
  if (hton->discover_table_names == hton_ext_based_table_discovery &&
      (!hton->discover_table || !hton->tablefile_extensions[0]))
    hton->discover_table_names= NULL;

  // default discover_table_existence implementation
  if (!hton->discover_table_existence && hton->discover_table)
  {
    if (hton->tablefile_extensions[0])
      hton->discover_table_existence= ext_based_existence;
    else
      hton->discover_table_existence= full_discover_for_existence;
  }

  uint tmp;
  ulong fslot;

  DBUG_EXECUTE_IF("unstable_db_type", {
                    static int i= (int) DB_TYPE_FIRST_DYNAMIC;
                    hton->db_type= (enum legacy_db_type)++i;
                  });

  /* now check the db_type for conflict */
  if (hton->db_type <= DB_TYPE_UNKNOWN ||
      hton->db_type >= DB_TYPE_DEFAULT ||
      installed_htons[hton->db_type])
  {
    int idx= (int) DB_TYPE_FIRST_DYNAMIC;

    while (idx < (int) DB_TYPE_DEFAULT && installed_htons[idx])
      idx++;

    if (idx == (int) DB_TYPE_DEFAULT)
    {
      sql_print_warning("Too many storage engines!");
      ret= 1;
      goto err_deinit;
    }
    if (hton->db_type != DB_TYPE_UNKNOWN)
      sql_print_warning("Storage engine '%s' has conflicting typecode. "
                        "Assigning value %d.", plugin->plugin->name, idx);
    hton->db_type= (enum legacy_db_type) idx;
  }

  /*
    In case a plugin is uninstalled and re-installed later, it should
    reuse an array slot. Otherwise the number of uninstall/install
    cycles would be limited. So look for a free slot.
  */
  DBUG_PRINT("plugin", ("total_ha: %lu", total_ha));
  for (fslot= 0; fslot < total_ha; fslot++)
  {
    if (!hton2plugin[fslot])
      break;
  }
  if (fslot < total_ha)
    hton->slot= fslot;
  else
  {
    if (total_ha >= MAX_HA)
    {
      sql_print_error("Too many plugins loaded. Limit is %lu. "
                      "Failed on '%s'", (ulong) MAX_HA, plugin->name.str);
      ret= 1;
      goto err_deinit;
    }
    hton->slot= total_ha++;
  }
  installed_htons[hton->db_type]= hton;
  tmp= hton->savepoint_offset;
  hton->savepoint_offset= savepoint_alloc_size;
  savepoint_alloc_size+= tmp;
  hton2plugin[hton->slot]=plugin;
  if (hton->prepare)
  {
    total_ha_2pc++;
    if (tc_log && tc_log != get_tc_log_implementation())
    {
      total_ha_2pc--;
      hton->prepare= 0;
      push_warning_printf(current_thd, Sql_condition::WARN_LEVEL_WARN,
                          ER_UNKNOWN_ERROR,
                          "Cannot enable tc-log at run-time. "
                          "XA features of %s are disabled",
                          plugin->name.str);
    }
  }

  /* 
    This is entirely for legacy. We will create a new "disk based" hton and a 
    "memory" hton which will be configurable longterm. We should be able to 
    remove partition.
  */
  switch (hton->db_type) {
  case DB_TYPE_HEAP:
    heap_hton= hton;
    break;
  case DB_TYPE_MYISAM:
    myisam_hton= hton;
    break;
  case DB_TYPE_PARTITION_DB:
    partition_hton= hton;
    break;
  case DB_TYPE_SEQUENCE:
    sql_sequence_hton= hton;
    break;
  default:
    break;
  };

  resolve_sysvar_table_options(hton);
  update_discovery_counters(hton, 1);

  DBUG_RETURN(ret);

err_deinit:
  /* 
    Let plugin do its inner deinitialization as plugin->init() 
    was successfully called before.
  */
  if (plugin->plugin->deinit)
    (void) plugin->plugin->deinit(NULL);

err:
#ifdef DBUG_ASSERT_EXISTS
  if (hton->prepare)
    failed_ha_2pc++;
#endif
  my_free(hton);
err_no_hton_memory:
  plugin->data= NULL;
  DBUG_RETURN(ret);
}

int ha_init()
{
  int error= 0;
  DBUG_ENTER("ha_init");

  DBUG_ASSERT(total_ha < MAX_HA);
  /*
    Check if there is a transaction-capable storage engine besides the
    binary log (which is considered a transaction-capable storage engine in
    counting total_ha)
  */
  opt_using_transactions= total_ha > (ulong) opt_bin_log;
  savepoint_alloc_size+= sizeof(SAVEPOINT);
  DBUG_RETURN(error);
}

int ha_end()
{
  int error= 0;
  DBUG_ENTER("ha_end");

  /* 
    This should be eventually based on the graceful shutdown flag.
    So if flag is equal to HA_PANIC_CLOSE, the deallocate
    the errors.
  */
  if (unlikely(ha_finish_errors()))
    error= 1;

  DBUG_RETURN(error);
}

static my_bool dropdb_handlerton(THD *unused1, plugin_ref plugin,
                                 void *path)
{
  handlerton *hton= plugin_hton(plugin);
  if (hton->drop_database)
    hton->drop_database(hton, (char *)path);
  return FALSE;
}


void ha_drop_database(const char* path)
{
  plugin_foreach(NULL, dropdb_handlerton, MYSQL_STORAGE_ENGINE_PLUGIN,
                 (char*) path);
}


static my_bool checkpoint_state_handlerton(THD *unused1, plugin_ref plugin,
                                           void *disable)
{
  handlerton *hton= plugin_hton(plugin);
  if (hton->checkpoint_state)
    hton->checkpoint_state(hton, (int) *(bool*) disable);
  return FALSE;
}


void ha_checkpoint_state(bool disable)
{
  plugin_foreach(NULL, checkpoint_state_handlerton, MYSQL_STORAGE_ENGINE_PLUGIN, &disable);
}


struct st_commit_checkpoint_request {
  void *cookie;
  void (*pre_hook)(void *);
};

static my_bool commit_checkpoint_request_handlerton(THD *unused1, plugin_ref plugin,
                                           void *data)
{
  st_commit_checkpoint_request *st= (st_commit_checkpoint_request *)data;
  handlerton *hton= plugin_hton(plugin);
  if (hton->commit_checkpoint_request)
  {
    void *cookie= st->cookie;
    if (st->pre_hook)
      (*st->pre_hook)(cookie);
    (*hton->commit_checkpoint_request)(cookie);
  }
  return FALSE;
}


/*
  Invoke commit_checkpoint_request() in all storage engines that implement it.

  If pre_hook is non-NULL, the hook will be called prior to each invocation.
*/
void
ha_commit_checkpoint_request(void *cookie, void (*pre_hook)(void *))
{
  st_commit_checkpoint_request st;
  st.cookie= cookie;
  st.pre_hook= pre_hook;
  plugin_foreach(NULL, commit_checkpoint_request_handlerton,
                 MYSQL_STORAGE_ENGINE_PLUGIN, &st);
}


/**
  @note
    don't bother to rollback here, it's done already

  there's no need to rollback here as all transactions must
  be rolled back already
*/
void ha_close_connection(THD* thd)
{
  for (auto i= 0; i < MAX_HA; i++)
  {
    if (plugin_ref plugin= thd->ha_data[i].lock)
    {
      thd->ha_data[i].lock= NULL;
      handlerton *hton= plugin_hton(plugin);
      if (hton->close_connection)
        hton->close_connection(hton, thd);
      thd_set_ha_data(thd, hton, 0);
      plugin_unlock(NULL, plugin);
    }
    DBUG_ASSERT(!thd->ha_data[i].ha_ptr);
  }
}

static my_bool kill_handlerton(THD *thd, plugin_ref plugin,
                               void *level)
{
  handlerton *hton= plugin_hton(plugin);

  mysql_mutex_assert_owner(&thd->LOCK_thd_data);
  if (hton->kill_query && thd_get_ha_data(thd, hton))
    hton->kill_query(hton, thd, *(enum thd_kill_levels *) level);
  return FALSE;
}

void ha_kill_query(THD* thd, enum thd_kill_levels level)
{
  DBUG_ENTER("ha_kill_query");
  plugin_foreach(thd, kill_handlerton, MYSQL_STORAGE_ENGINE_PLUGIN, &level);
  DBUG_VOID_RETURN;
}


static my_bool plugin_disable_internal_writes(THD *, plugin_ref plugin,
                                              void *disable)
{
  if (void(*diw)(bool)= plugin_hton(plugin)->disable_internal_writes)
    diw(*static_cast<bool*>(disable));
  return FALSE;
}


void ha_disable_internal_writes(bool disable)
{
  plugin_foreach(NULL, plugin_disable_internal_writes,
                 MYSQL_STORAGE_ENGINE_PLUGIN, &disable);
}


static my_bool signal_ddl_recovery_done(THD *, plugin_ref plugin, void *)
{
  handlerton *hton= plugin_hton(plugin);
  if (hton->signal_ddl_recovery_done)
    (hton->signal_ddl_recovery_done)(hton);
  return 0;
}


void ha_signal_ddl_recovery_done()
{
  DBUG_ENTER("ha_signal_ddl_recovery_done");
  plugin_foreach(NULL, signal_ddl_recovery_done, MYSQL_STORAGE_ENGINE_PLUGIN,
                 NULL);
  DBUG_VOID_RETURN;
}


/*****************************************************************************
  Backup functions
******************************************************************************/

static my_bool plugin_prepare_for_backup(THD *unused1, plugin_ref plugin,
                                         void *not_used)
{
  handlerton *hton= plugin_hton(plugin);
  if (hton->prepare_for_backup)
    hton->prepare_for_backup();
  return FALSE;
}

void ha_prepare_for_backup()
{
  plugin_foreach_with_mask(0, plugin_prepare_for_backup,
                           MYSQL_STORAGE_ENGINE_PLUGIN,
                           PLUGIN_IS_DELETED|PLUGIN_IS_READY, 0);
}

static my_bool plugin_end_backup(THD *unused1, plugin_ref plugin,
                                 void *not_used)
{
  handlerton *hton= plugin_hton(plugin);
  if (hton->end_backup)
    hton->end_backup();
  return FALSE;
}

void ha_end_backup()
{
  plugin_foreach_with_mask(0, plugin_end_backup,
                           MYSQL_STORAGE_ENGINE_PLUGIN,
                           PLUGIN_IS_DELETED|PLUGIN_IS_READY, 0);
}

/*
  Take a lock to block MDL_BACKUP_DDL (used by maria-backup) until
  the DDL operation is taking place
*/

bool handler::log_not_redoable_operation(const char *operation)
{
  DBUG_ENTER("log_not_redoable_operation");
  if (table->s->tmp_table == NO_TMP_TABLE)
  {
    /*
      Take a lock to ensure that mariadb-backup will notice the
      new log entry (and re-copy the table if needed).
    */
    THD *thd= table->in_use;
    MDL_request mdl_backup;
    backup_log_info ddl_log;

    MDL_REQUEST_INIT(&mdl_backup, MDL_key::BACKUP, "", "", MDL_BACKUP_DDL,
                     MDL_STATEMENT);
    if (thd->mdl_context.acquire_lock(&mdl_backup,
                                      thd->variables.lock_wait_timeout))
      DBUG_RETURN(1);

    bzero(&ddl_log, sizeof(ddl_log));
    lex_string_set(&ddl_log.query, operation);
    /*
      We can't use partition_engine() here as this function is called
      directly by the handler for the underlaying partition table
    */
#ifdef WITH_PARTITION_STORAGE_ENGINE
    ddl_log.org_partitioned= table->s->partition_info_str != 0;
#endif
    lex_string_set(&ddl_log.org_storage_engine_name, table_type());
    ddl_log.org_database=     table->s->db;
    ddl_log.org_table=        table->s->table_name;
    ddl_log.org_table_id=     table->s->tabledef_version;
    backup_log_ddl(&ddl_log);
  }
  DBUG_RETURN(0);
}

/*
  Inform plugin of the server shutdown.
  Called after all connections are down.

  Under some circumstances, storage engine might need to
  so some work, before deinit() can be safely called.
  (an example is Innodb purge that might call into server
   to calculate virtual columns, which might potentially also
  invoke other plugins, such as audit
*/
static my_bool plugin_pre_shutdown(THD *, plugin_ref plugin, void *)
{
  handlerton *hton= plugin_hton(plugin);
  if (hton->pre_shutdown)
    hton->pre_shutdown();
  return FALSE;
}


void ha_pre_shutdown()
{
  plugin_foreach_with_mask(0, plugin_pre_shutdown,
    MYSQL_STORAGE_ENGINE_PLUGIN,
    PLUGIN_IS_DELETED | PLUGIN_IS_READY, 0);
}


/* ========================================================================
 ======================= TRANSACTIONS ===================================*/

/**
  Transaction handling in the server
  ==================================

  In each client connection, MySQL maintains two transactional
  states:
  - a statement transaction,
  - a standard, also called normal transaction.

  Historical note
  ---------------
  "Statement transaction" is a non-standard term that comes
  from the times when MySQL supported BerkeleyDB storage engine.

  First of all, it should be said that in BerkeleyDB auto-commit
  mode auto-commits operations that are atomic to the storage
  engine itself, such as a write of a record, and are too
  high-granular to be atomic from the application perspective
  (MySQL). One SQL statement could involve many BerkeleyDB
  auto-committed operations and thus BerkeleyDB auto-commit was of
  little use to MySQL.

  Secondly, instead of SQL standard savepoints, BerkeleyDB
  provided the concept of "nested transactions". In a nutshell,
  transactions could be arbitrarily nested, but when the parent
  transaction was committed or aborted, all its child (nested)
  transactions were handled committed or aborted as well.
  Commit of a nested transaction, in turn, made its changes
  visible, but not durable: it destroyed the nested transaction,
  all its changes would become available to the parent and
  currently active nested transactions of this parent.

  So the mechanism of nested transactions was employed to
  provide "all or nothing" guarantee of SQL statements
  required by the standard.
  A nested transaction would be created at start of each SQL
  statement, and destroyed (committed or aborted) at statement
  end. Such nested transaction was internally referred to as
  a "statement transaction" and gave birth to the term.

  (Historical note ends)

  Since then a statement transaction is started for each statement
  that accesses transactional tables or uses the binary log.  If
  the statement succeeds, the statement transaction is committed.
  If the statement fails, the transaction is rolled back. Commits
  of statement transactions are not durable -- each such
  transaction is nested in the normal transaction, and if the
  normal transaction is rolled back, the effects of all enclosed
  statement transactions are undone as well.  Technically,
  a statement transaction can be viewed as a savepoint which is
  maintained automatically in order to make effects of one
  statement atomic.

  The normal transaction is started by the user and is ended
  usually upon a user request as well. The normal transaction
  encloses transactions of all statements issued between
  its beginning and its end.
  In autocommit mode, the normal transaction is equivalent
  to the statement transaction.

  Since MySQL supports PSEA (pluggable storage engine
  architecture), more than one transactional engine can be
  active at a time. Hence transactions, from the server
  point of view, are always distributed. In particular,
  transactional state is maintained independently for each
  engine. In order to commit a transaction the two phase
  commit protocol is employed.

  Not all statements are executed in context of a transaction.
  Administrative and status information statements do not modify
  engine data, and thus do not start a statement transaction and
  also have no effect on the normal transaction. Examples of such
  statements are SHOW STATUS and RESET SLAVE.

  Similarly DDL statements are not transactional,
  and therefore a transaction is [almost] never started for a DDL
  statement. The difference between a DDL statement and a purely
  administrative statement though is that a DDL statement always
  commits the current transaction before proceeding, if there is
  any.

  At last, SQL statements that work with non-transactional
  engines also have no effect on the transaction state of the
  connection. Even though they are written to the binary log,
  and the binary log is, overall, transactional, the writes
  are done in "write-through" mode, directly to the binlog
  file, followed with a OS cache sync, in other words,
  bypassing the binlog undo log (translog).
  They do not commit the current normal transaction.
  A failure of a statement that uses non-transactional tables
  would cause a rollback of the statement transaction, but
  in case there no non-transactional tables are used,
  no statement transaction is started.

  Data layout
  -----------

  The server stores its transaction-related data in
  thd->transaction. This structure has two members of type
  THD_TRANS. These members correspond to the statement and
  normal transactions respectively:

  - thd->transaction.stmt contains a list of engines
  that are participating in the given statement
  - thd->transaction.all contains a list of engines that
  have participated in any of the statement transactions started
  within the context of the normal transaction.
  Each element of the list contains a pointer to the storage
  engine, engine-specific transactional data, and engine-specific
  transaction flags.

  In autocommit mode thd->transaction.all is empty.
  Instead, data of thd->transaction.stmt is
  used to commit/rollback the normal transaction.

  The list of registered engines has a few important properties:
  - no engine is registered in the list twice
  - engines are present in the list a reverse temporal order --
  new participants are always added to the beginning of the list.

  Transaction life cycle
  ----------------------

  When a new connection is established, thd->transaction
  members are initialized to an empty state.
  If a statement uses any tables, all affected engines
  are registered in the statement engine list. In
  non-autocommit mode, the same engines are registered in
  the normal transaction list.
  At the end of the statement, the server issues a commit
  or a roll back for all engines in the statement list.
  At this point transaction flags of an engine, if any, are
  propagated from the statement list to the list of the normal
  transaction.
  When commit/rollback is finished, the statement list is
  cleared. It will be filled in again by the next statement,
  and emptied again at the next statement's end.

  The normal transaction is committed in a similar way
  (by going over all engines in thd->transaction.all list)
  but at different times:
  - upon COMMIT SQL statement is issued by the user
  - implicitly, by the server, at the beginning of a DDL statement
  or SET AUTOCOMMIT={0|1} statement.

  The normal transaction can be rolled back as well:
  - if the user has requested so, by issuing ROLLBACK SQL
  statement
  - if one of the storage engines requested a rollback
  by setting thd->transaction_rollback_request. This may
  happen in case, e.g., when the transaction in the engine was
  chosen a victim of the internal deadlock resolution algorithm
  and rolled back internally. When such a situation happens, there
  is little the server can do and the only option is to rollback
  transactions in all other participating engines.  In this case
  the rollback is accompanied by an error sent to the user.

  As follows from the use cases above, the normal transaction
  is never committed when there is an outstanding statement
  transaction. In most cases there is no conflict, since
  commits of the normal transaction are issued by a stand-alone
  administrative or DDL statement, thus no outstanding statement
  transaction of the previous statement exists. Besides,
  all statements that manipulate with the normal transaction
  are prohibited in stored functions and triggers, therefore
  no conflicting situation can occur in a sub-statement either.
  The remaining rare cases when the server explicitly has
  to commit the statement transaction prior to committing the normal
  one cover error-handling scenarios (see for example
  SQLCOM_LOCK_TABLES).

  When committing a statement or a normal transaction, the server
  either uses the two-phase commit protocol, or issues a commit
  in each engine independently. The two-phase commit protocol
  is used only if:
  - all participating engines support two-phase commit (provide
    handlerton::prepare PSEA API call) and
  - transactions in at least two engines modify data (i.e. are
  not read-only).

  Note that the two phase commit is used for
  statement transactions, even though they are not durable anyway.
  This is done to ensure logical consistency of data in a multiple-
  engine transaction.
  For example, imagine that some day MySQL supports unique
  constraint checks deferred till the end of statement. In such
  case a commit in one of the engines may yield ER_DUP_KEY,
  and MySQL should be able to gracefully abort statement
  transactions of other participants.

  After the normal transaction has been committed,
  thd->transaction.all list is cleared.

  When a connection is closed, the current normal transaction, if
  any, is rolled back.

  Roles and responsibilities
  --------------------------

  The server has no way to know that an engine participates in
  the statement and a transaction has been started
  in it unless the engine says so. Thus, in order to be
  a part of a transaction, the engine must "register" itself.
  This is done by invoking trans_register_ha() server call.
  Normally the engine registers itself whenever handler::external_lock()
  is called. trans_register_ha() can be invoked many times: if
  an engine is already registered, the call does nothing.
  In case autocommit is not set, the engine must register itself
  twice -- both in the statement list and in the normal transaction
  list.
  In which list to register is a parameter of trans_register_ha().

  Note, that although the registration interface in itself is
  fairly clear, the current usage practice often leads to undesired
  effects. E.g. since a call to trans_register_ha() in most engines
  is embedded into implementation of handler::external_lock(), some
  DDL statements start a transaction (at least from the server
  point of view) even though they are not expected to. E.g.
  CREATE TABLE does not start a transaction, since
  handler::external_lock() is never called during CREATE TABLE. But
  CREATE TABLE ... SELECT does, since handler::external_lock() is
  called for the table that is being selected from. This has no
  practical effects currently, but must be kept in mind
  nevertheless.

  Once an engine is registered, the server will do the rest
  of the work.

  During statement execution, whenever any of data-modifying
  PSEA API methods is used, e.g. handler::write_row() or
  handler::update_row(), the read-write flag is raised in the
  statement transaction for the involved engine.
  Currently All PSEA calls are "traced", and the data can not be
  changed in a way other than issuing a PSEA call. Important:
  unless this invariant is preserved the server will not know that
  a transaction in a given engine is read-write and will not
  involve the two-phase commit protocol!

  At the end of a statement, server call trans_commit_stmt is
  invoked. This call in turn invokes handlerton::prepare()
  for every involved engine. Prepare is followed by a call
  to handlerton::commit_one_phase() If a one-phase commit
  will suffice, handlerton::prepare() is not invoked and
  the server only calls handlerton::commit_one_phase().
  At statement commit, the statement-related read-write
  engine flag is propagated to the corresponding flag in the
  normal transaction.  When the commit is complete, the list
  of registered engines is cleared.

  Rollback is handled in a similar fashion.

  Additional notes on DDL and the normal transaction.
  ---------------------------------------------------

  DDLs and operations with non-transactional engines
  do not "register" in thd->transaction lists, and thus do not
  modify the transaction state. Besides, each DDL in
  MySQL is prefixed with an implicit normal transaction commit
  (a call to trans_commit_implicit()), and thus leaves nothing
  to modify.
  However, as it has been pointed out with CREATE TABLE .. SELECT,
  some DDL statements can start a *new* transaction.

  Behaviour of the server in this case is currently badly
  defined.
  DDL statements use a form of "semantic" logging
  to maintain atomicity: if CREATE TABLE .. SELECT failed,
  the newly created table is deleted.
  In addition, some DDL statements issue interim transaction
  commits: e.g. ALTER TABLE issues a commit after data is copied
  from the original table to the internal temporary table. Other
  statements, e.g. CREATE TABLE ... SELECT do not always commit
  after itself.
  And finally there is a group of DDL statements such as
  RENAME/DROP TABLE that doesn't start a new transaction
  and doesn't commit.

  This diversity makes it hard to say what will happen if
  by chance a stored function is invoked during a DDL --
  whether any modifications it makes will be committed or not
  is not clear. Fortunately, SQL grammar of few DDLs allows
  invocation of a stored function.

  A consistent behaviour is perhaps to always commit the normal
  transaction after all DDLs, just like the statement transaction
  is always committed at the end of all statements.
*/

/**
  Register a storage engine for a transaction.

  Every storage engine MUST call this function when it starts
  a transaction or a statement (that is it must be called both for the
  "beginning of transaction" and "beginning of statement").
  Only storage engines registered for the transaction/statement
  will know when to commit/rollback it.

  @note
    trans_register_ha is idempotent - storage engine may register many
    times per transaction.

*/
void trans_register_ha(THD *thd, bool all, handlerton *ht_arg, ulonglong trxid)
{
  THD_TRANS *trans;
  Ha_trx_info *ha_info;
  DBUG_ENTER("trans_register_ha");
  DBUG_PRINT("enter",("%s", all ? "all" : "stmt"));

  if (all)
  {
    trans= &thd->transaction->all;
    thd->server_status|= SERVER_STATUS_IN_TRANS;
    if (thd->tx_read_only)
      thd->server_status|= SERVER_STATUS_IN_TRANS_READONLY;
    DBUG_PRINT("info", ("setting SERVER_STATUS_IN_TRANS"));
  }
  else
    trans= &thd->transaction->stmt;

  ha_info= thd->ha_data[ht_arg->slot].ha_info + (all ? 1 : 0);

  if (ha_info->is_started())
    DBUG_VOID_RETURN; /* already registered, return */

  ha_info->register_ha(trans, ht_arg);

  trans->no_2pc|=(ht_arg->prepare==0);

  /* Set implicit xid even if there's explicit XA, it will be ignored anyway. */
  if (thd->transaction->implicit_xid.is_null())
    thd->transaction->implicit_xid.set(thd->query_id);

/*
  Register transaction start in performance schema if not done already.
  By doing this, we handle cases when the transaction is started implicitly in
  autocommit=0 mode, and cases when we are in normal autocommit=1 mode and the
  executed statement is a single-statement transaction.

  Explicitly started transactions are handled in trans_begin().

  Do not register transactions in which binary log is the only participating
  transactional storage engine.
*/
  if (thd->m_transaction_psi == NULL && ht_arg->db_type != DB_TYPE_BINLOG)
  {
    thd->m_transaction_psi= MYSQL_START_TRANSACTION(&thd->m_transaction_state,
          thd->get_xid(), trxid, thd->tx_isolation, thd->tx_read_only,
          !thd->in_multi_stmt_transaction_mode());
    DEBUG_SYNC(thd, "after_set_transaction_psi_before_set_transaction_gtid");
    //gtid_set_performance_schema_values(thd);
  }
  DBUG_VOID_RETURN;
}


static int prepare_or_error(handlerton *ht, THD *thd, bool all)
{
#ifdef WITH_WSREP
  const bool run_wsrep_hooks= wsrep_run_commit_hook(thd, all);
  if (run_wsrep_hooks && ht->flags & HTON_WSREP_REPLICATION &&
      wsrep_before_prepare(thd, all))
  {
    return(1);
  }
#endif /* WITH_WSREP */

  int err= ht->prepare(ht, thd, all);
  status_var_increment(thd->status_var.ha_prepare_count);
  if (err)
  {
      my_error(ER_ERROR_DURING_COMMIT, MYF(0), err);
  }
#ifdef WITH_WSREP
  if (run_wsrep_hooks && !err && ht->flags & HTON_WSREP_REPLICATION &&
      wsrep_after_prepare(thd, all))
  {
    err= 1;
  }
#endif /* WITH_WSREP */

  return err;
}


/**
  @retval
    0   ok
  @retval
    1   error, transaction was rolled back
*/
int ha_prepare(THD *thd)
{
  int error=0, all=1;
  THD_TRANS *trans=all ? &thd->transaction->all : &thd->transaction->stmt;
  Ha_trx_info *ha_info= trans->ha_list;
  DBUG_ENTER("ha_prepare");

  if (ha_info)
  {
    for (; ha_info; ha_info= ha_info->next())
    {
      handlerton *ht= ha_info->ht();
      if (ht->prepare)
      {
        if (unlikely(prepare_or_error(ht, thd, all)))
        {
          ha_rollback_trans(thd, all);
          error=1;
          break;
        }
      }
      else
      {
        push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
                            ER_GET_ERRNO, ER_THD(thd, ER_GET_ERRNO),
                            HA_ERR_WRONG_COMMAND,
                            ha_resolve_storage_engine_name(ht));

      }
    }

    DEBUG_SYNC(thd, "at_unlog_xa_prepare");

    if (tc_log->unlog_xa_prepare(thd, all))
    {
      ha_rollback_trans(thd, all);
      error=1;
    }
  }

  DBUG_RETURN(error);
}

/*
  Like ha_check_and_coalesce_trx_read_only to return counted number of
  read-write transaction participants limited to two, but works in the 'all'
  context.
  Also returns the last found rw ha_info through the 2nd argument.
*/
uint ha_count_rw_all(THD *thd, Ha_trx_info **ptr_ha_info)
{
  unsigned rw_ha_count= 0;

  for (auto ha_info= thd->transaction->all.ha_list; ha_info;
       ha_info= ha_info->next())
  {
    if (ha_info->is_trx_read_write())
    {
      *ptr_ha_info= ha_info;
      if (++rw_ha_count > 1)
        break;
    }
  }
  return rw_ha_count;
}

/*
  Returns counted number of
  read-write recoverable transaction participants.
*/
uint ha_count_rw_2pc(THD *thd, bool all)
{
  unsigned rw_ha_count= 0;
  THD_TRANS *trans=all ? &thd->transaction->all : &thd->transaction->stmt;

  for (Ha_trx_info * ha_info= trans->ha_list; ha_info;
       ha_info= ha_info->next())
  {
    if (ha_info->is_trx_read_write() && ha_info->ht()->recover)
      ++rw_ha_count;
  }
  return rw_ha_count;
}

/**
  Check if we can skip the two-phase commit.

  A helper function to evaluate if two-phase commit is mandatory.
  As a side effect, propagates the read-only/read-write flags
  of the statement transaction to its enclosing normal transaction.
  
  If we have at least two engines with read-write changes we must
  run a two-phase commit. Otherwise we can run several independent
  commits as the only transactional engine has read-write changes
  and others are read-only.

  @retval   0   All engines are read-only.
  @retval   1   We have the only engine with read-write changes.
  @retval   >1  More than one engine have read-write changes.
                Note: return value might NOT be the exact number of
                engines with read-write changes.
*/

uint
ha_check_and_coalesce_trx_read_only(THD *thd, Ha_trx_info *ha_list,
                                    bool all)
{
  /* The number of storage engines that have actual changes. */
  unsigned rw_ha_count= 0;
  Ha_trx_info *ha_info;

  for (ha_info= ha_list; ha_info; ha_info= ha_info->next())
  {
    if (ha_info->is_trx_read_write())
      ++rw_ha_count;

    if (! all)
    {
      Ha_trx_info *ha_info_all= &thd->ha_data[ha_info->ht()->slot].ha_info[1];
      DBUG_ASSERT(ha_info != ha_info_all);
      /*
        Merge read-only/read-write information about statement
        transaction to its enclosing normal transaction. Do this
        only if in a real transaction -- that is, if we know
        that ha_info_all is registered in thd->transaction.all.
        Since otherwise we only clutter the normal transaction flags.
      */
      if (ha_info_all->is_started()) /* FALSE if autocommit. */
        ha_info_all->coalesce_trx_with(ha_info);
    }
    else if (rw_ha_count > 1)
    {
      /*
        It is a normal transaction, so we don't need to merge read/write
        information up, and the need for two-phase commit has been
        already established. Break the loop prematurely.
      */
      break;
    }
  }
  return rw_ha_count;
}


/**
  @retval
    0   ok
  @retval
    1   transaction was rolled back
  @retval
    2   error during commit, data may be inconsistent

  @todo
    Since we don't support nested statement transactions in 5.0,
    we can't commit or rollback stmt transactions while we are inside
    stored functions or triggers. So we simply do nothing now.
    TODO: This should be fixed in later ( >= 5.1) releases.
*/
int ha_commit_trans(THD *thd, bool all)
{
  int error= 0, cookie;
  /*
    'all' means that this is either an explicit commit issued by
    user, or an implicit commit issued by a DDL.
  */
  THD_TRANS *trans= all ? &thd->transaction->all : &thd->transaction->stmt;
  /*
    "real" is a nick name for a transaction for which a commit will
    make persistent changes. E.g. a 'stmt' transaction inside an 'all'
    transaction is not 'real': even though it's possible to commit it,
    the changes are not durable as they might be rolled back if the
    enclosing 'all' transaction is rolled back.
  */
  bool is_real_trans= ((all || thd->transaction->all.ha_list == 0) &&
                       !(thd->variables.option_bits & OPTION_GTID_BEGIN));
  Ha_trx_info *ha_info= trans->ha_list;
  bool need_prepare_ordered, need_commit_ordered;
  my_xid xid;
#ifdef WITH_WSREP
  const bool run_wsrep_hooks= wsrep_run_commit_hook(thd, all);
#endif /* WITH_WSREP */
  DBUG_ENTER("ha_commit_trans");
  DBUG_PRINT("info",("thd: %p  option_bits: %lu  all: %d",
                     thd, (ulong) thd->variables.option_bits, all));

  /* Just a random warning to test warnings pushed during autocommit. */
  DBUG_EXECUTE_IF("warn_during_ha_commit_trans",
    push_warning(thd, Sql_condition::WARN_LEVEL_WARN,
                 ER_WARNING_NOT_COMPLETE_ROLLBACK,
                 ER_THD(thd, ER_WARNING_NOT_COMPLETE_ROLLBACK)););

  DBUG_PRINT("info",
             ("all: %d  thd->in_sub_stmt: %d  ha_info: %p  is_real_trans: %d",
              all, thd->in_sub_stmt, ha_info, is_real_trans));
  /*
    We must not commit the normal transaction if a statement
    transaction is pending. Otherwise statement transaction
    flags will not get propagated to its normal transaction's
    counterpart.
  */
  DBUG_ASSERT(thd->transaction->stmt.ha_list == NULL ||
              trans == &thd->transaction->stmt);

  DBUG_ASSERT(!thd->in_sub_stmt);

  if (thd->in_sub_stmt)
  {
    /*
      Since we don't support nested statement transactions in 5.0,
      we can't commit or rollback stmt transactions while we are inside
      stored functions or triggers. So we simply do nothing now.
      TODO: This should be fixed in later ( >= 5.1) releases.
    */
    if (!all)
      DBUG_RETURN(0);
    /*
      We assume that all statements which commit or rollback main transaction
      are prohibited inside of stored functions or triggers. So they should
      bail out with error even before ha_commit_trans() call. To be 100% safe
      let us throw error in non-debug builds.
    */
    my_error(ER_COMMIT_NOT_ALLOWED_IN_SF_OR_TRG, MYF(0));
    DBUG_RETURN(2);
  }

  if (!ha_info)
  {
    /*
      Free resources and perform other cleanup even for 'empty' transactions.
    */
    if (is_real_trans)
    {
      thd->transaction->cleanup();
      MYSQL_COMMIT_TRANSACTION(thd->m_transaction_psi);
      thd->m_transaction_psi= NULL;
    }
#ifdef WITH_WSREP
    if (wsrep_is_active(thd) && is_real_trans && !error)
      wsrep_commit_empty(thd, all);
#endif /* WITH_WSREP */

    DBUG_RETURN(0);
  }

  DBUG_EXECUTE_IF("crash_commit_before", DBUG_SUICIDE(););

  /* Close all cursors that can not survive COMMIT */
  if (is_real_trans)                          /* not a statement commit */
    thd->stmt_map.close_transient_cursors();

  uint rw_ha_count= ha_check_and_coalesce_trx_read_only(thd, ha_info, all);
  /* rw_trans is TRUE when we in a transaction changing data */
  bool rw_trans= is_real_trans && rw_ha_count > 0;
  MDL_request mdl_backup;
  DBUG_PRINT("info", ("is_real_trans: %d  rw_trans:  %d  rw_ha_count: %d",
                      is_real_trans, rw_trans, rw_ha_count));

  if (rw_trans)
  {
    /*
      Acquire a metadata lock which will ensure that COMMIT is blocked
      by an active FLUSH TABLES WITH READ LOCK (and vice versa:
      COMMIT in progress blocks FTWRL).

      We allow the owner of FTWRL to COMMIT; we assume that it knows
      what it does.
    */
    MDL_REQUEST_INIT(&mdl_backup, MDL_key::BACKUP, "", "", MDL_BACKUP_COMMIT,
                     MDL_EXPLICIT);

    if (!WSREP(thd))
    {
      if (thd->mdl_context.acquire_lock(&mdl_backup,
                                        thd->variables.lock_wait_timeout))
      {
        my_error(ER_ERROR_DURING_COMMIT, MYF(0), 1);
        ha_rollback_trans(thd, all);
        DBUG_RETURN(1);
      }
      thd->backup_commit_lock= &mdl_backup;
    }
    DEBUG_SYNC(thd, "ha_commit_trans_after_acquire_commit_lock");
  }

  if (rw_trans && thd->is_read_only_ctx())
  {
    my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0), "--read-only");
    goto err;
  }

#if 1 // FIXME: This should be done in ha_prepare().
  if (rw_trans || (thd->lex->sql_command == SQLCOM_ALTER_TABLE &&
                   thd->lex->alter_info.flags & ALTER_ADD_SYSTEM_VERSIONING &&
                   is_real_trans))
  {
    ulonglong trx_start_id= 0, trx_end_id= 0;
    for (Ha_trx_info *ha_info= trans->ha_list; ha_info; ha_info= ha_info->next())
    {
      if (ha_info->ht()->prepare_commit_versioned)
      {
        trx_end_id= ha_info->ht()->prepare_commit_versioned(thd, &trx_start_id);

        if (trx_end_id == ULONGLONG_MAX)
        {
          my_error(ER_ERROR_DURING_COMMIT, MYF(0), 1);
          goto err;
        }

        if (trx_end_id)
          break; // FIXME: use a common ID for cross-engine transactions
      }
    }

    if (trx_end_id)
    {
      if (!TR_table::use_transaction_registry)
      {
        my_error(ER_VERS_TRT_IS_DISABLED, MYF(0));
        goto err;
      }
      DBUG_ASSERT(trx_start_id);
#ifdef WITH_WSREP
      bool saved_wsrep_on= thd->variables.wsrep_on;
      thd->variables.wsrep_on= false;
#endif
      TR_table trt(thd, true);
      if (trt.update(trx_start_id, trx_end_id))
      {
#ifdef WITH_WSREP
        thd->variables.wsrep_on= saved_wsrep_on;
#endif
        (void) trans_rollback_stmt(thd);
        goto err;
      }
      trt.table->file->extra(HA_EXTRA_RESET_STATE);
      // Here, the call will not commit inside InnoDB. It is only working
      // around closing thd->transaction.stmt open by TR_table::open().
      if (all)
        commit_one_phase_2(thd, false, &thd->transaction->stmt, false);
#ifdef WITH_WSREP
      thd->variables.wsrep_on= saved_wsrep_on;
#endif
    }
  }
#endif

  if (trans->no_2pc || (rw_ha_count <= 1))
  {
#ifdef WITH_WSREP
    /*
      This commit will not go through log_and_order() where wsrep commit
      ordering is normally done. Commit ordering must be done here.
    */
    if (run_wsrep_hooks)
    {
      // This commit involves more than one storage engine and requires
      // two phases, but some engines don't support it.
      // Issue a message to the client and roll back the transaction.
      if (trans->no_2pc && rw_ha_count > 1)
      {
        my_message(ER_ERROR_DURING_COMMIT, "Transactional commit not supported "
                   "by involved engine(s)", MYF(0));
        error= 1;
      }
      else
        error= wsrep_before_commit(thd, all);
    }
    if (error)
    {
      ha_rollback_trans(thd, FALSE);
      goto wsrep_err;
    }
#endif /* WITH_WSREP */
    error= ha_commit_one_phase(thd, all);
#ifdef WITH_WSREP
    // Here in case of error we must return 2 for inconsistency
    if (run_wsrep_hooks && !error)
      error= wsrep_after_commit(thd, all) ? 2 : 0;
#endif /* WITH_WSREP */
    goto done;
  }

  need_prepare_ordered= FALSE;
  need_commit_ordered= FALSE;

  for (Ha_trx_info *hi= ha_info; hi; hi= hi->next())
  {
    handlerton *ht= hi->ht();
    /*
      Do not call two-phase commit if this particular
      transaction is read-only. This allows for simpler
      implementation in engines that are always read-only.
    */
    if (! hi->is_trx_read_write())
      continue;
    /*
      Sic: we know that prepare() is not NULL since otherwise
      trans->no_2pc would have been set.
    */
    if (unlikely(prepare_or_error(ht, thd, all)))
      goto err;

    need_prepare_ordered|= (ht->prepare_ordered != NULL);
    need_commit_ordered|= (ht->commit_ordered != NULL);
  }
  DEBUG_SYNC(thd, "ha_commit_trans_after_prepare");
  DBUG_EXECUTE_IF("crash_commit_after_prepare", DBUG_SUICIDE(););

  if (!is_real_trans)
  {
    error= commit_one_phase_2(thd, all, trans, is_real_trans);
    goto done;
  }

  DBUG_ASSERT(thd->transaction->implicit_xid.get_my_xid() ==
              thd->transaction->implicit_xid.quick_get_my_xid());
  DBUG_ASSERT(!thd->transaction->xid_state.is_explicit_XA() ||
              thd->lex->xa_opt == XA_ONE_PHASE);
  xid= thd->transaction->implicit_xid.quick_get_my_xid();

#ifdef WITH_WSREP
  if (run_wsrep_hooks && !error)
  {
    wsrep::seqno const s= wsrep_xid_seqno(thd->wsrep_xid);
    if (!s.is_undefined())
    {
      // xid was rewritten by wsrep
      xid= s.get();
    }
  }
  if (run_wsrep_hooks && (error = wsrep_before_commit(thd, all)))
    goto wsrep_err;
#endif /* WITH_WSREP */
  DEBUG_SYNC(thd, "ha_commit_trans_before_log_and_order");
  cookie= tc_log->log_and_order(thd, xid, all, need_prepare_ordered,
                                need_commit_ordered);
  if (!cookie)
  {
    WSREP_DEBUG("log_and_order has failed %llu %d", thd->thread_id, cookie);
    goto err;
  }
  DEBUG_SYNC(thd, "ha_commit_trans_after_log_and_order");
  DBUG_EXECUTE_IF("crash_commit_after_log", DBUG_SUICIDE(););

  error= commit_one_phase_2(thd, all, trans, is_real_trans) ? 2 : 0;
#ifdef WITH_WSREP
  if (run_wsrep_hooks &&
      (error || (error = wsrep_after_commit(thd, all))))
  {
    error = 2;
    mysql_mutex_lock(&thd->LOCK_thd_data);
    if (wsrep_must_abort(thd))
    {
      mysql_mutex_unlock(&thd->LOCK_thd_data);
      (void)tc_log->unlog(cookie, xid);
      goto wsrep_err;
    }
    mysql_mutex_unlock(&thd->LOCK_thd_data);
  }
#endif /* WITH_WSREP */
  DBUG_EXECUTE_IF("crash_commit_before_unlog", DBUG_SUICIDE(););
  if (tc_log->unlog(cookie, xid))
    error= 2;                                /* Error during commit */

done:
  if (is_real_trans)
  {
    MYSQL_COMMIT_TRANSACTION(thd->m_transaction_psi);
    thd->m_transaction_psi= NULL;
  }

  DBUG_EXECUTE_IF("crash_commit_after", DBUG_SUICIDE(););

  mysql_mutex_assert_not_owner(&LOCK_prepare_ordered);
  mysql_mutex_assert_not_owner(mysql_bin_log.get_log_lock());
  mysql_mutex_assert_not_owner(&LOCK_after_binlog_sync);
  mysql_mutex_assert_not_owner(&LOCK_commit_ordered);
#ifdef HAVE_REPLICATION
  repl_semisync_master.wait_after_commit(thd, all);
  DEBUG_SYNC(thd, "after_group_after_commit");
#endif
  goto end;

  /* Come here if error and we need to rollback. */
#ifdef WITH_WSREP
wsrep_err:
  mysql_mutex_lock(&thd->LOCK_thd_data);
  if (run_wsrep_hooks && wsrep_must_abort(thd))
  {
    WSREP_DEBUG("BF abort has happened after prepare & certify");
    mysql_mutex_unlock(&thd->LOCK_thd_data);
    ha_rollback_trans(thd, TRUE);
  }
  else
    mysql_mutex_unlock(&thd->LOCK_thd_data);

#endif /* WITH_WSREP */
err:
  error= 1;                                  /* Transaction was rolled back */
  /*
    In parallel replication, rollback is delayed, as there is extra replication
    book-keeping to be done before rolling back and allowing a conflicting
    transaction to continue (MDEV-7458).
  */
  if (!(thd->rgi_slave && thd->rgi_slave->is_parallel_exec))
    ha_rollback_trans(thd, all);
  else
  {
    /*
      We are not really doing a rollback here, but the code in trans_commit()
      requres that m_transaction_psi is 0 when we return from this function.
    */
    MYSQL_ROLLBACK_TRANSACTION(thd->m_transaction_psi);
    thd->m_transaction_psi= NULL;
    WSREP_DEBUG("rollback skipped %p %d",thd->rgi_slave,
                thd->rgi_slave->is_parallel_exec);
  }
end:
  if (mdl_backup.ticket)
  {
    /*
      We do not always immediately release transactional locks
      after ha_commit_trans() (see uses of ha_enable_transaction()),
      thus we release the commit blocker lock as soon as it's
      not needed.
    */
    thd->mdl_context.release_lock(mdl_backup.ticket);
  }
  thd->backup_commit_lock= 0;
#ifdef WITH_WSREP
  if (wsrep_is_active(thd) && is_real_trans && !error &&
      (rw_ha_count == 0 || all) &&
      wsrep_not_committed(thd))
  {
    wsrep_commit_empty(thd, all);
  }
#endif /* WITH_WSREP */

  DBUG_RETURN(error);
}

/**
  @note
  This function does not care about global read lock or backup locks,
  the caller should.

  @param[in]  all  Is set in case of explicit commit
                   (COMMIT statement), or implicit commit
                   issued by DDL. Is not set when called
                   at the end of statement, even if
                   autocommit=1.
*/

int ha_commit_one_phase(THD *thd, bool all)
{
  THD_TRANS *trans=all ? &thd->transaction->all : &thd->transaction->stmt;
  /*
    "real" is a nick name for a transaction for which a commit will
    make persistent changes. E.g. a 'stmt' transaction inside a 'all'
    transaction is not 'real': even though it's possible to commit it,
    the changes are not durable as they might be rolled back if the
    enclosing 'all' transaction is rolled back.
    We establish the value of 'is_real_trans' by checking
    if it's an explicit COMMIT/BEGIN statement, or implicit
    commit issued by DDL (all == TRUE), or if we're running
    in autocommit mode (it's only in the autocommit mode
    ha_commit_one_phase() can be called with an empty
    transaction.all.ha_list, see why in trans_register_ha()).
  */
  bool is_real_trans= ((all || thd->transaction->all.ha_list == 0) &&
                       !(thd->variables.option_bits & OPTION_GTID_BEGIN));
  int res;
  DBUG_ENTER("ha_commit_one_phase");
  if (is_real_trans)
  {
    DEBUG_SYNC(thd, "ha_commit_one_phase");
    if ((res= thd->wait_for_prior_commit()))
      DBUG_RETURN(res);
  }
  res= commit_one_phase_2(thd, all, trans, is_real_trans);
  DBUG_RETURN(res);
}

static bool is_ro_1pc_trans(THD *thd, Ha_trx_info *ha_info, bool all,
                            bool is_real_trans)
{
  uint rw_ha_count= ha_check_and_coalesce_trx_read_only(thd, ha_info, all);
  bool rw_trans= is_real_trans &&
    (rw_ha_count > (thd->is_current_stmt_binlog_disabled()?0U:1U));

  return !rw_trans;
}

static bool has_binlog_hton(Ha_trx_info *ha_info)
{
  bool rc;
  for (rc= false; ha_info && !rc; ha_info= ha_info->next())
    rc= ha_info->ht() == binlog_hton;

  return rc;
}

static int
commit_one_phase_2(THD *thd, bool all, THD_TRANS *trans, bool is_real_trans)
{
  int error= 0;
  uint count= 0;
  Ha_trx_info *ha_info= trans->ha_list, *ha_info_next;
  DBUG_ENTER("commit_one_phase_2");
  if (is_real_trans)
    DEBUG_SYNC(thd, "commit_one_phase_2");

  if (ha_info)
  {
    int err;

    if (has_binlog_hton(ha_info) &&
        (err= binlog_commit(thd, all,
                            is_ro_1pc_trans(thd, ha_info, all, is_real_trans))))
    {
      my_error(ER_ERROR_DURING_COMMIT, MYF(0), err);
      error= 1;
    }
    for (; ha_info; ha_info= ha_info_next)
    {
      handlerton *ht= ha_info->ht();
      if ((err= ht->commit(ht, thd, all)))
      {
        my_error(ER_ERROR_DURING_COMMIT, MYF(0), err);
        error=1;
      }
      /* Should this be done only if is_real_trans is set ? */
      status_var_increment(thd->status_var.ha_commit_count);
      if (is_real_trans && ht != binlog_hton && ha_info->is_trx_read_write())
        ++count;
      ha_info_next= ha_info->next();
      ha_info->reset(); /* keep it conveniently zero-filled */
    }
    trans->ha_list= 0;
    trans->no_2pc=0;
    if (all)
    {
#ifdef HAVE_QUERY_CACHE
      if (thd->transaction->changed_tables)
        query_cache.invalidate(thd, thd->transaction->changed_tables);
#endif
    }
  }

  /* Free resources and perform other cleanup even for 'empty' transactions. */
  if (is_real_trans)
  {
    thd->has_waiter= false;
    thd->transaction->cleanup();
    if (count >= 2)
      statistic_increment(transactions_multi_engine, LOCK_status);
  }

  DBUG_RETURN(error);
}


int ha_rollback_trans(THD *thd, bool all)
{
  int error=0;
  THD_TRANS *trans=all ? &thd->transaction->all : &thd->transaction->stmt;
  Ha_trx_info *ha_info= trans->ha_list, *ha_info_next;
  /*
    "real" is a nick name for a transaction for which a commit will
    make persistent changes. E.g. a 'stmt' transaction inside a 'all'
    transaction is not 'real': even though it's possible to commit it,
    the changes are not durable as they might be rolled back if the
    enclosing 'all' transaction is rolled back.
    We establish the value of 'is_real_trans' by checking
    if it's an explicit COMMIT or BEGIN statement, or implicit
    commit issued by DDL (in these cases all == TRUE),
    or if we're running in autocommit mode (it's only in the autocommit mode
    ha_commit_one_phase() is called with an empty
    transaction.all.ha_list, see why in trans_register_ha()).
  */
  bool is_real_trans=all || thd->transaction->all.ha_list == 0;
  DBUG_ENTER("ha_rollback_trans");

  /*
    We must not rollback the normal transaction if a statement
    transaction is pending.
  */
  DBUG_ASSERT(thd->transaction->stmt.ha_list == NULL ||
              trans == &thd->transaction->stmt);

#ifdef HAVE_REPLICATION
  if (is_real_trans)
  {
    /*
      In parallel replication, if we need to rollback during commit, we must
      first inform following transactions that we are going to abort our commit
      attempt. Otherwise those following transactions can run too early, and
      possibly cause replication to fail. See comments in retry_event_group().

      (This concerns rollbacks due to temporary errors where the transaction
      will be retried afterwards. For non-recoverable errors, following
      transactions will not start but just be skipped as the worker threads
      perform the error stop).

      There were several bugs with this in the past that were very hard to
      track down (MDEV-7458, MDEV-8302). So we add here an assertion for
      rollback without signalling following transactions. And in release
      builds, we explicitly do the signalling before rolling back.
    */
    DBUG_ASSERT(
        !(thd->rgi_slave &&
          !thd->rgi_slave->worker_error &&
          thd->rgi_slave->did_mark_start_commit) ||
        (thd->transaction->xid_state.is_explicit_XA() ||
         (thd->rgi_slave->gtid_ev_flags2 & Gtid_log_event::FL_PREPARED_XA)));

    if (thd->rgi_slave &&
        !thd->rgi_slave->worker_error &&
        thd->rgi_slave->did_mark_start_commit)
      thd->rgi_slave->unmark_start_commit();
  }
#endif

  if (thd->in_sub_stmt)
  {
    DBUG_ASSERT(0);
    /*
      If we are inside stored function or trigger we should not commit or
      rollback current statement transaction. See comment in ha_commit_trans()
      call for more information.
    */
    if (!all)
      DBUG_RETURN(0);
    my_error(ER_COMMIT_NOT_ALLOWED_IN_SF_OR_TRG, MYF(0));
    DBUG_RETURN(1);
  }

#ifdef WITH_WSREP
  (void) wsrep_before_rollback(thd, all);
#endif /* WITH_WSREP */
  if (ha_info)
  {
    /* Close all cursors that can not survive ROLLBACK */
    if (is_real_trans)                          /* not a statement commit */
      thd->stmt_map.close_transient_cursors();

    for (; ha_info; ha_info= ha_info_next)
    {
      int err;
      handlerton *ht= ha_info->ht();
      if ((err= ht->rollback(ht, thd, all)))
      {
        // cannot happen
        my_error(ER_ERROR_DURING_ROLLBACK, MYF(0), err);
        error=1;
#ifdef WITH_WSREP
        WSREP_WARN("handlerton rollback failed, thd %lld %lld conf %d SQL %s",
                   thd->thread_id, thd->query_id, thd->wsrep_trx().state(),
                   thd->query());
#endif /* WITH_WSREP */
      }
      status_var_increment(thd->status_var.ha_rollback_count);
      ha_info_next= ha_info->next();
      ha_info->reset(); /* keep it conveniently zero-filled */
    }
    trans->ha_list= 0;
    trans->no_2pc=0;
  }

#ifdef WITH_WSREP
  if (thd->is_error())
  {
    WSREP_DEBUG("ha_rollback_trans(%lld, %s) rolled back: %s: %s; is_real %d",
                thd->thread_id, all?"TRUE":"FALSE", wsrep_thd_query(thd),
                thd->get_stmt_da()->message(), is_real_trans);
  }
  (void) wsrep_after_rollback(thd, all);
#endif /* WITH_WSREP */

  if (all || !thd->in_active_multi_stmt_transaction())
  {
    MYSQL_ROLLBACK_TRANSACTION(thd->m_transaction_psi);
    thd->m_transaction_psi= NULL;
  }

  /* Always cleanup. Even if nht==0. There may be savepoints. */
  if (is_real_trans)
  {
    /*
      Thanks to possibility of MDL deadlock rollback request can come even if
      transaction hasn't been started in any transactional storage engine.
    */
    if (thd->transaction_rollback_request &&
        thd->transaction->xid_state.is_explicit_XA())
      thd->transaction->xid_state.set_error(thd->get_stmt_da()->sql_errno());

    thd->has_waiter= false;
    thd->transaction->cleanup();
  }
  if (all)
    thd->transaction_rollback_request= FALSE;

  /*
    If a non-transactional table was updated, warn; don't warn if this is a
    slave thread (because when a slave thread executes a ROLLBACK, it has
    been read from the binary log, so it's 100% sure and normal to produce
    error ER_WARNING_NOT_COMPLETE_ROLLBACK. If we sent the warning to the
    slave SQL thread, it would not stop the thread but just be printed in
    the error log; but we don't want users to wonder why they have this
    message in the error log, so we don't send it.

    We don't have to test for thd->killed == KILL_SYSTEM_THREAD as
    it doesn't matter if a warning is pushed to a system thread or not:
    No one will see it...
  */
  if (is_real_trans && thd->transaction->all.modified_non_trans_table &&
      !thd->slave_thread && thd->killed < KILL_CONNECTION)
    push_warning(thd, Sql_condition::WARN_LEVEL_WARN,
                 ER_WARNING_NOT_COMPLETE_ROLLBACK,
                 ER_THD(thd, ER_WARNING_NOT_COMPLETE_ROLLBACK));
#ifdef HAVE_REPLICATION
  repl_semisync_master.wait_after_rollback(thd, all);
#endif
  DBUG_RETURN(error);
}


struct xahton_st {
  XID *xid;
  int result;
};

static my_bool xacommit_handlerton(THD *unused1, plugin_ref plugin,
                                   void *arg)
{
  handlerton *hton= plugin_hton(plugin);
  if (hton->recover)
  {
    hton->commit_by_xid(hton, ((struct xahton_st *)arg)->xid);
    ((struct xahton_st *)arg)->result= 0;
  }
  return FALSE;
}

static my_bool xarollback_handlerton(THD *unused1, plugin_ref plugin,
                                     void *arg)
{
  handlerton *hton= plugin_hton(plugin);
  if (hton->recover)
  {
    hton->rollback_by_xid(hton, ((struct xahton_st *)arg)->xid);
    ((struct xahton_st *)arg)->result= 0;
  }
  return FALSE;
}


int ha_commit_or_rollback_by_xid(XID *xid, bool commit)
{
  struct xahton_st xaop;
  xaop.xid= xid;
  xaop.result= 1;

  /*
    When the binlogging service is enabled complete the transaction
    by it first.
  */
  if (commit)
    binlog_commit_by_xid(binlog_hton, xid);
  else
    binlog_rollback_by_xid(binlog_hton, xid);

  plugin_foreach(NULL, commit ? xacommit_handlerton : xarollback_handlerton,
                 MYSQL_STORAGE_ENGINE_PLUGIN, &xaop);

  return xaop.result;
}


#ifndef DBUG_OFF
/** Converts XID to string.

@param[out] buf output buffer
@param[in] xid XID to convert

@return pointer to converted string

@note This does not need to be multi-byte safe or anything */
static char *xid_to_str(char *buf, const XID &xid)
{
  int i;
  char *s=buf;
  *s++='\'';
  for (i= 0; i < xid.gtrid_length + xid.bqual_length; i++)
  {
    uchar c= (uchar) xid.data[i];
    /* is_next_dig is set if next character is a number */
    bool is_next_dig= FALSE;
    if (i < XIDDATASIZE)
    {
      char ch= xid.data[i + 1];
      is_next_dig= (ch >= '0' && ch <='9');
    }
    if (i == xid.gtrid_length)
    {
      *s++='\'';
      if (xid.bqual_length)
      {
        *s++='.';
        *s++='\'';
      }
    }
    if (c < 32 || c > 126)
    {
      *s++='\\';
      /*
        If next character is a number, write current character with
        3 octal numbers to ensure that the next number is not seen
        as part of the octal number
      */
      if (c > 077 || is_next_dig)
        *s++=_dig_vec_lower[c >> 6];
      if (c > 007 || is_next_dig)
        *s++=_dig_vec_lower[(c >> 3) & 7];
      *s++=_dig_vec_lower[c & 7];
    }
    else
    {
      if (c == '\'' || c == '\\')
        *s++='\\';
      *s++=c;
    }
  }
  *s++='\'';
  *s=0;
  return buf;
}
#endif

static my_xid wsrep_order_and_check_continuity(XID *list, int len)
{
#ifdef WITH_WSREP
  wsrep_sort_xid_array(list, len);
  wsrep::gtid cur_position= wsrep_get_SE_checkpoint<wsrep::gtid>();
  long long cur_seqno= cur_position.seqno().get();
  for (int i= 0; i < len; ++i)
  {
    if (!wsrep_is_wsrep_xid(list + i) ||
        wsrep_xid_seqno(list + i) != cur_seqno + 1)
    {
      WSREP_WARN("Discovered discontinuity in recovered wsrep "
                 "transaction XIDs. Truncating the recovery list to "
                 "%d entries", i);
      break;
    }
    ++cur_seqno;
  }
  WSREP_INFO("Last wsrep seqno to be recovered %lld", cur_seqno);
  return (cur_seqno < 0 ? 0 : cur_seqno);
#else
  return 0;
#endif /* WITH_WSREP */
}
/**
  recover() step of xa.

  @note
    there are four modes of operation:
    - automatic recover after a crash
    in this case commit_list != 0, tc_heuristic_recover==0
    all xids from commit_list are committed, others are rolled back
    - manual (heuristic) recover
    in this case commit_list==0, tc_heuristic_recover != 0
    DBA has explicitly specified that all prepared transactions should
    be committed (or rolled back).
    - no recovery (MySQL did not detect a crash)
    in this case commit_list==0, tc_heuristic_recover == 0
    there should be no prepared transactions in this case.
    - automatic recovery for the semisync slave server: uncommitted
    transactions are rolled back and when they are in binlog it gets
    truncated to the first uncommitted transaction start offset.
*/
struct xarecover_st
{
  int len, found_foreign_xids, found_my_xids;
  XID *list;
  HASH *commit_list;
  bool dry_run;
  MEM_ROOT *mem_root;
  bool error;
};

/**
  Inserts a new hash member.

  returns a successfully created and inserted @c xid_recovery_member
           into hash @c hash_arg,
           or NULL.
*/
static xid_recovery_member*
xid_member_insert(HASH *hash_arg, my_xid xid_arg, MEM_ROOT *ptr_mem_root,
                  XID *full_xid_arg, decltype(::server_id) server_id_arg)
{
  xid_recovery_member *member= (xid_recovery_member *)
    alloc_root(ptr_mem_root, sizeof(xid_recovery_member));
  XID *xid_full= NULL;

  if (full_xid_arg)
    xid_full= (XID*) alloc_root(ptr_mem_root, sizeof(XID));

  if (!member || (full_xid_arg && !xid_full))
    return NULL;

  if (full_xid_arg)
    *xid_full= *full_xid_arg;
  *member= xid_recovery_member(xid_arg, 1, false, xid_full, server_id_arg);

  return
    my_hash_insert(hash_arg, (uchar*) member) ? NULL : member;
}

/*
  Inserts a new or updates an existing hash member to increment
  the member's prepare counter.

  returns false  on success,
           true   otherwise.
*/
static bool xid_member_replace(HASH *hash_arg, my_xid xid_arg,
                               MEM_ROOT *ptr_mem_root,
                               XID *full_xid_arg,
                               decltype(::server_id) server_id_arg)
{
  xid_recovery_member* member;
  if ((member= (xid_recovery_member *)
       my_hash_search(hash_arg, (uchar *)& xid_arg, sizeof(xid_arg))))
    member->in_engine_prepare++;
  else
    member= xid_member_insert(hash_arg, xid_arg, ptr_mem_root, full_xid_arg,  server_id_arg);

  return member == NULL;
}

/*
  A "transport" type for recovery completion with ha_recover_complete()
*/
struct xarecover_complete_arg
{
  xid_recovery_member* member;
  Binlog_offset *binlog_coord;
  uint count;
};

/*
  Flagged to commit member confirms to get committed.
  Otherwise when
    A. ptr_commit_max is NULL (implies the normal recovery), or
    B. it's not NULL (can only be so in the semisync slave case)
       and the value referenced is not greater than the member's coordinate
       the decision is to rollback.
  When both A,B do not hold - which is the semisync slave recovery
  case - the decision is to commit.

  Returns  true  as commmit decision
           false as rollback one
*/
static bool xarecover_decide_to_commit(xid_recovery_member* member,
                                       Binlog_offset *ptr_commit_max)
{
  return
    member->decided_to_commit ? true :
    !ptr_commit_max ? false :
    (member->binlog_coord < *ptr_commit_max ?  // semisync slave recovery
     true : false);
}

/*
  Helper function for xarecover_do_commit_or_rollback_handlerton.
  For a given hton decides what to do with a xid passed in the 2nd arg
  and carries out the decision.
*/
static void xarecover_do_commit_or_rollback(handlerton *hton,
                                            xarecover_complete_arg *arg)
{
  xid_t x;
  my_bool rc;
  xid_recovery_member *member= arg->member;
  Binlog_offset *ptr_commit_max= arg->binlog_coord;

  if (!member->full_xid)
    // Populate xid using the server_id from original transaction
    x.set(member->xid, member->server_id);
  else
    x= *member->full_xid;

  rc= xarecover_decide_to_commit(member, ptr_commit_max) ?
    hton->commit_by_xid(hton, &x) : hton->rollback_by_xid(hton, &x);

  /*
    It's fine to have non-zero rc which would be from transaction
    non-participant hton:s.
  */
  DBUG_ASSERT(rc || member->in_engine_prepare > 0);

  if (!rc)
  {
    /*
      This block relies on Engine to report XAER_NOTA at
      "complete"_by_xid for unknown xid.
    */
    member->in_engine_prepare--;
    if (global_system_variables.log_warnings > 2)
      sql_print_information("%s transaction with xid %llu",
                            member->decided_to_commit ? "Committed" :
                            "Rolled back", (ulonglong) member->xid);
  }
}

/*
  Per hton recovery decider function.
*/
static my_bool xarecover_do_commit_or_rollback_handlerton(THD *unused,
                                                          plugin_ref plugin,
                                                          void *arg)
{
  handlerton *hton= plugin_hton(plugin);

  if (hton->recover)
  {
    xarecover_do_commit_or_rollback(hton, (xarecover_complete_arg *) arg);
  }

  return FALSE;
}

/*
  Completes binlog recovery for an input xid in the passed
  member_arg to invoke decider functions for each handlerton.

  Returns always FALSE.
*/
static my_bool xarecover_complete_and_count(void *member_arg,
                                            void *param_arg)
{
  xid_recovery_member *member= (xid_recovery_member*) member_arg;
  xarecover_complete_arg *complete_params=
    (xarecover_complete_arg*) param_arg;
  complete_params->member= member;

  (void) plugin_foreach(NULL, xarecover_do_commit_or_rollback_handlerton,
                        MYSQL_STORAGE_ENGINE_PLUGIN, complete_params);

  if (member->in_engine_prepare)
  {
    complete_params->count++;
    if (global_system_variables.log_warnings > 2)
      sql_print_warning("Found prepared transaction with xid %llu",
                        (ulonglong) member->xid);
  }

  return false;
}

/*
  Completes binlog recovery to invoke decider functions for
  each xid.
  Returns the number of transactions remained doubtful.
*/
uint ha_recover_complete(HASH *commit_list, Binlog_offset *coord)
{
  xarecover_complete_arg complete= { NULL, coord, 0 };
  (void) my_hash_iterate(commit_list, xarecover_complete_and_count, &complete);

  return complete.count;
}

static my_bool xarecover_handlerton(THD *unused, plugin_ref plugin,
                                    void *arg)
{
  handlerton *hton= plugin_hton(plugin);
  struct xarecover_st *info= (struct xarecover_st *) arg;
  int got;

  if (hton->recover)
  {
    while ((got= hton->recover(hton, info->list, info->len)) > 0 )
    {
      sql_print_information("Found %d prepared transaction(s) in %s",
                            got, hton_name(hton)->str);
      /* If wsrep_on=ON, XIDs are first ordered and then the range of
         recovered XIDs is checked for continuity. All the XIDs which
         are in continuous range can be safely committed if binlog
         is off since they have already ordered and certified in the
         cluster.

         The discontinuity of wsrep XIDs may happen because the GTID
         is assigned for transaction in wsrep_before_prepare(), but the
         commit order is entered in wsrep_before_commit(). This means that
         transactions may run prepare step out of order and may
         result in gap in wsrep XIDs. This can be the case for example
         if we have T1 with seqno 1 and T2 with seqno 2 and the server
         crashes after T2 finishes prepare step but before T1 starts
         the prepare.
      */
      my_xid wsrep_limit __attribute__((unused))= 0;

      /* Note that we could call this for binlog also that
         will not have WSREP(thd) but global wsrep on might
         be true.
      */
      if (WSREP_ON)
        wsrep_limit= wsrep_order_and_check_continuity(info->list, got);

      for (int i=0; i < got; i ++)
      {
        my_xid x= info->list[i].get_my_xid();
        bool is_server_xid= x > 0;

#ifdef WITH_WSREP
        if (!is_server_xid && wsrep_is_wsrep_xid(&info->list[i]))
          x= wsrep_xid_seqno(&info->list[i]);
#endif
        if (!x) // not "mine" - that is generated by external TM
        {
          DBUG_EXECUTE("info",{
            char buf[XIDDATASIZE*4+6];
            _db_doprnt_("ignore xid %s", xid_to_str(buf, info->list[i]));
            });
          xid_cache_insert(info->list + i);
          info->found_foreign_xids++;
          continue;
        }
        if (IF_WSREP(!(wsrep_emulate_bin_log &&
                       wsrep_is_wsrep_xid(info->list + i) &&
                       x <= wsrep_limit) && info->dry_run,
                     info->dry_run))
        {
          info->found_my_xids++;
          continue;
        }

        /*
          Regular and semisync slave server recovery only collects
          xids to make decisions on them later by the caller.
        */
        if (info->mem_root)
        {
          // remember "full" xid too when it's not in mysql format.
          // Also record the transaction's original server_id. It will be used for
          // populating the input XID to be searched in hash.
          if (xid_member_replace(info->commit_list, x, info->mem_root,
                                 is_server_xid? NULL : &info->list[i],
                                 is_server_xid? info->list[i].get_trx_server_id() : server_id))
          {
            info->error= true;
            sql_print_error("Error in memory allocation at xarecover_handlerton");
            break;
          }
        }
        if (IF_WSREP((wsrep_emulate_bin_log &&
                      wsrep_is_wsrep_xid(info->list + i) &&
                      x <= wsrep_limit), false) ||
            tc_heuristic_recover == TC_HEURISTIC_RECOVER_COMMIT)
        {
          int rc= hton->commit_by_xid(hton, info->list+i);
          if (rc == 0)
          {
            DBUG_EXECUTE("info",{
              char buf[XIDDATASIZE*4+6];
              _db_doprnt_("commit xid %s", xid_to_str(buf, info->list[i]));
              });
          }
        }
        else if (!info->mem_root)
        {
          int rc= hton->rollback_by_xid(hton, info->list+i);
          if (rc == 0)
          {
            DBUG_EXECUTE("info",{
              char buf[XIDDATASIZE*4+6];
              _db_doprnt_("rollback xid %s", xid_to_str(buf, info->list[i]));
              });
          }
        }
      }
      if (got < info->len)
        break;
    }
  }
  return FALSE;
}

int ha_recover(HASH *commit_list, MEM_ROOT *arg_mem_root)
{
  struct xarecover_st info;
  DBUG_ENTER("ha_recover");
  info.found_foreign_xids= info.found_my_xids= 0;
  info.commit_list= commit_list;
  info.dry_run= (info.commit_list==0 && tc_heuristic_recover==0);
  info.list= NULL;
  info.mem_root= arg_mem_root;
  info.error= false;

  /* commit_list and tc_heuristic_recover cannot be set both */
  DBUG_ASSERT(info.commit_list==0 || tc_heuristic_recover==0);
  /* if either is set, total_ha_2pc must be set too */
  DBUG_ASSERT(info.dry_run ||
              (failed_ha_2pc + total_ha_2pc) > (ulong)opt_bin_log);

  if (total_ha_2pc <= (ulong)opt_bin_log)
    DBUG_RETURN(0);

  if (info.commit_list)
    sql_print_information("Starting table crash recovery...");

  for (info.len= MAX_XID_LIST_SIZE ; 
       info.list==0 && info.len > MIN_XID_LIST_SIZE; info.len/=2)
  {
    DBUG_EXECUTE_IF("min_xa_len", info.len = 16;);
    info.list=(XID *)my_malloc(key_memory_XID, info.len*sizeof(XID), MYF(0));
  }
  if (!info.list)
  {
    sql_print_error(ER(ER_OUTOFMEMORY),
                    static_cast<int>(info.len*sizeof(XID)));
    DBUG_RETURN(1);
  }

  plugin_foreach(NULL, xarecover_handlerton, 
                 MYSQL_STORAGE_ENGINE_PLUGIN, &info);

  my_free(info.list);
  if (info.found_foreign_xids)
    sql_print_warning("Found %d prepared XA transactions", 
                      info.found_foreign_xids);
  if (info.dry_run && info.found_my_xids)
  {
    sql_print_error("Found %d prepared transactions! It means that server was "
                    "not shut down properly last time and critical recovery "
                    "information (last binlog or %s file) was manually deleted "
                    "after a crash. You have to start server with "
                    "--tc-heuristic-recover switch to commit or rollback "
                    "pending transactions.",
                    info.found_my_xids, opt_tc_log_file);
    DBUG_RETURN(1);
  }
  if (info.error)
    DBUG_RETURN(1);

  if (info.commit_list)
    sql_print_information("Crash table recovery finished.");
  DBUG_RETURN(0);
}


/*
  Called by engine to notify TC that a new commit checkpoint has been reached.
  See comments on handlerton method commit_checkpoint_request() for details.
*/
void commit_checkpoint_notify_ha(void *cookie)
{
  tc_log->commit_checkpoint_notify(cookie);
}


/**
  Check if all storage engines used in transaction agree that after
  rollback to savepoint it is safe to release MDL locks acquired after
  savepoint creation.

  @param thd   The client thread that executes the transaction.

  @return true  - It is safe to release MDL locks.
          false - If it is not.
*/
bool ha_rollback_to_savepoint_can_release_mdl(THD *thd)
{
  Ha_trx_info *ha_info;
  THD_TRANS *trans= (thd->in_sub_stmt ? &thd->transaction->stmt :
                                        &thd->transaction->all);

  DBUG_ENTER("ha_rollback_to_savepoint_can_release_mdl");

  /**
    Checking whether it is safe to release metadata locks after rollback to
    savepoint in all the storage engines that are part of the transaction.
  */
  for (ha_info= trans->ha_list; ha_info; ha_info= ha_info->next())
  {
    handlerton *ht= ha_info->ht();
    DBUG_ASSERT(ht);

    if (ht->savepoint_rollback_can_release_mdl == 0 ||
        ht->savepoint_rollback_can_release_mdl(ht, thd) == false)
      DBUG_RETURN(false);
  }

  DBUG_RETURN(true);
}

int ha_rollback_to_savepoint(THD *thd, SAVEPOINT *sv)
{
  int error=0;
  THD_TRANS *trans= (thd->in_sub_stmt ? &thd->transaction->stmt :
                                        &thd->transaction->all);
  Ha_trx_info *ha_info, *ha_info_next;

  DBUG_ENTER("ha_rollback_to_savepoint");

  trans->no_2pc=0;
  /*
    rolling back to savepoint in all storage engines that were part of the
    transaction when the savepoint was set
  */
  for (ha_info= sv->ha_list; ha_info; ha_info= ha_info->next())
  {
    int err;
    handlerton *ht= ha_info->ht();
    DBUG_ASSERT(ht);
    DBUG_ASSERT(ht->savepoint_set != 0);
    if ((err= ht->savepoint_rollback(ht, thd,
                                     (uchar *)(sv+1)+ht->savepoint_offset)))
    { // cannot happen
      my_error(ER_ERROR_DURING_ROLLBACK, MYF(0), err);
      error=1;
    }
    status_var_increment(thd->status_var.ha_savepoint_rollback_count);
    trans->no_2pc|= ht->prepare == 0;
  }
  /*
    rolling back the transaction in all storage engines that were not part of
    the transaction when the savepoint was set
  */
  for (ha_info= trans->ha_list; ha_info != sv->ha_list;
       ha_info= ha_info_next)
  {
    int err;
    handlerton *ht= ha_info->ht();
#ifdef WITH_WSREP
    if (WSREP(thd) && ht->flags & HTON_WSREP_REPLICATION)
    {
      WSREP_DEBUG("ha_rollback_to_savepoint: run before_rollbackha_rollback_trans hook");
      (void) wsrep_before_rollback(thd, !thd->in_sub_stmt);

    }
#endif // WITH_WSREP
    if ((err= ht->rollback(ht, thd, !thd->in_sub_stmt)))
    { // cannot happen
      my_error(ER_ERROR_DURING_ROLLBACK, MYF(0), err);
      error=1;
    }
#ifdef WITH_WSREP
    if (WSREP(thd) && ht->flags & HTON_WSREP_REPLICATION)
    {
      WSREP_DEBUG("ha_rollback_to_savepoint: run after_rollback hook");
      (void) wsrep_after_rollback(thd, !thd->in_sub_stmt);
    }
#endif // WITH_WSREP
    status_var_increment(thd->status_var.ha_rollback_count);
    ha_info_next= ha_info->next();
    ha_info->reset(); /* keep it conveniently zero-filled */
  }
  trans->ha_list= sv->ha_list;

  if (thd->m_transaction_psi != NULL)
    MYSQL_INC_TRANSACTION_ROLLBACK_TO_SAVEPOINT(thd->m_transaction_psi, 1);

  DBUG_RETURN(error);
}

/**
  @note
  according to the sql standard (ISO/IEC 9075-2:2003)
  section "4.33.4 SQL-statements and transaction states",
  SAVEPOINT is *not* transaction-initiating SQL-statement
*/
int ha_savepoint(THD *thd, SAVEPOINT *sv)
{
#ifdef WITH_WSREP
  /*
    Register binlog hton for savepoint processing if wsrep binlog
    emulation is on.
   */
  if (WSREP_EMULATE_BINLOG(thd) && wsrep_thd_is_local(thd))
  {
    wsrep_register_binlog_handler(thd, thd->in_multi_stmt_transaction_mode());
  }
#endif /* WITH_WSREP */
  int error=0;
  THD_TRANS *trans= (thd->in_sub_stmt ? &thd->transaction->stmt :
                                        &thd->transaction->all);
  Ha_trx_info *ha_info= trans->ha_list;
  DBUG_ENTER("ha_savepoint");

  for (; ha_info; ha_info= ha_info->next())
  {
    int err;
    handlerton *ht= ha_info->ht();
    DBUG_ASSERT(ht);
    if (! ht->savepoint_set)
    {
      my_error(ER_CHECK_NOT_IMPLEMENTED, MYF(0), "SAVEPOINT");
      error=1;
      break;
    }
    if ((err= ht->savepoint_set(ht, thd, (uchar *)(sv+1)+ht->savepoint_offset)))
    { // cannot happen
      my_error(ER_GET_ERRNO, MYF(0), err, hton_name(ht)->str);
      error=1;
    }
    status_var_increment(thd->status_var.ha_savepoint_count);
  }
  /*
    Remember the list of registered storage engines. All new
    engines are prepended to the beginning of the list.
  */
  sv->ha_list= trans->ha_list;

  if (!error && thd->m_transaction_psi != NULL)
    MYSQL_INC_TRANSACTION_SAVEPOINTS(thd->m_transaction_psi, 1);

  DBUG_RETURN(error);
}

int ha_release_savepoint(THD *thd, SAVEPOINT *sv)
{
  int error=0;
  Ha_trx_info *ha_info= sv->ha_list;
  DBUG_ENTER("ha_release_savepoint");

  for (; ha_info; ha_info= ha_info->next())
  {
    int err;
    handlerton *ht= ha_info->ht();
    /* Savepoint life time is enclosed into transaction life time. */
    DBUG_ASSERT(ht);
    if (!ht->savepoint_release)
      continue;
    if ((err= ht->savepoint_release(ht, thd,
                                    (uchar *)(sv+1) + ht->savepoint_offset)))
    { // cannot happen
      my_error(ER_GET_ERRNO, MYF(0), err, hton_name(ht)->str);
      error=1;
    }
  }

  if (thd->m_transaction_psi != NULL)
    MYSQL_INC_TRANSACTION_RELEASE_SAVEPOINT(thd->m_transaction_psi, 1);

  DBUG_RETURN(error);
}


static my_bool snapshot_handlerton(THD *thd, plugin_ref plugin,
                                   void *arg)
{
  handlerton *hton= plugin_hton(plugin);
  if (hton->start_consistent_snapshot)
  {
    if (hton->start_consistent_snapshot(hton, thd))
      return TRUE;
    *((bool *)arg)= false;
  }
  return FALSE;
}

int ha_start_consistent_snapshot(THD *thd)
{
  bool err, warn= true;

  /*
    Holding the LOCK_commit_ordered mutex ensures that we get the same
    snapshot for all engines (including the binary log).  This allows us
    among other things to do backups with
    START TRANSACTION WITH CONSISTENT SNAPSHOT and
    have a consistent binlog position.
  */
  mysql_mutex_lock(&LOCK_commit_ordered);
  err= plugin_foreach(thd, snapshot_handlerton, MYSQL_STORAGE_ENGINE_PLUGIN, &warn);
  mysql_mutex_unlock(&LOCK_commit_ordered);

  if (err)
  {
    ha_rollback_trans(thd, true);
    return 1;
  }

  /*
    Same idea as when one wants to CREATE TABLE in one engine which does not
    exist:
  */
  if (warn)
    push_warning(thd, Sql_condition::WARN_LEVEL_WARN, ER_UNKNOWN_ERROR,
                 "This MariaDB server does not support any "
                 "consistent-read capable storage engine");
  return 0;
}


static my_bool flush_handlerton(THD *thd, plugin_ref plugin,
                                void *arg)
{
  handlerton *hton= plugin_hton(plugin);
  return hton->flush_logs && hton->flush_logs(hton);
}


bool ha_flush_logs()
{
  return plugin_foreach(NULL, flush_handlerton,
                        MYSQL_STORAGE_ENGINE_PLUGIN, 0);
}


/**
  @brief make canonical filename

  @param[in]  file     table handler
  @param[in]  path     original path
  @param[out] tmp_path buffer for canonized path

  @details Lower case db name and table name path parts for
           non file based tables when lower_case_table_names
           is 2 (store as is, compare in lower case).
           Filesystem path prefix (mysql_data_home or tmpdir)
           is left intact.

  @note tmp_path may be left intact if no conversion was
        performed.

  @retval canonized path

  @todo This may be done more efficiently when table path
        gets built. Convert this function to something like
        ASSERT_CANONICAL_FILENAME.
*/
const char *get_canonical_filename(handler *file, const char *path,
                                   char *tmp_path)
{
  uint i;
  if (!file->needs_lower_case_filenames())
    return path;

  for (i= 0; i <= mysql_tmpdir_list.max; i++)
  {
    if (is_prefix(path, mysql_tmpdir_list.list[i]))
      return path;
  }

  /* Ensure that table handler get path in lower case */
  if (tmp_path != path)
    strmov(tmp_path, path);

  /*
    we only should turn into lowercase database/table part
    so start the process after homedirectory
  */
  my_casedn_str(files_charset_info, tmp_path + mysql_data_home_len);
  return tmp_path;
}


/**
   Delete a table in the engine

   @return 0   Table was deleted
   @return -1  Table didn't exists, no error given
   @return #   Error from table handler

  @note
  ENOENT and HA_ERR_NO_SUCH_TABLE are not considered errors.
  The .frm file should be deleted by the caller only if we return <= 0.
*/

int ha_delete_table(THD *thd, handlerton *hton, const char *path,
                    const LEX_CSTRING *db, const LEX_CSTRING *alias,
                    bool generate_warning)
{
  int error;
  bool is_error= thd->is_error();
  DBUG_ENTER("ha_delete_table");

  /* hton is NULL in ALTER TABLE when renaming only .frm files */
  if (hton == NULL || hton == view_pseudo_hton)
    DBUG_RETURN(0);

  if (ha_check_if_updates_are_ignored(thd, hton, "DROP"))
    DBUG_RETURN(0);

  error= hton->drop_table(hton, path);
  if (error > 0)
  {
    /*
      It's not an error if the table doesn't exist in the engine.
      warn the user, but still report DROP being a success
    */
    bool intercept= non_existing_table_error(error);

    if ((!intercept || generate_warning) && ! thd->is_error())
    {
      TABLE dummy_table;
      TABLE_SHARE dummy_share;
      handler *file= get_new_handler(nullptr, thd->mem_root, hton);
      if (file) {
        bzero((char*) &dummy_table, sizeof(dummy_table));
        bzero((char*) &dummy_share, sizeof(dummy_share));
        dummy_share.path.str= (char*) path;
        dummy_share.path.length= strlen(path);
        dummy_share.normalized_path= dummy_share.path;
        dummy_share.db= *db;
        dummy_share.table_name= *alias;
        dummy_table.s= &dummy_share;
        dummy_table.alias.set(alias->str, alias->length, table_alias_charset);
        file->change_table_ptr(&dummy_table, &dummy_share);
        file->print_error(error, MYF(intercept ? ME_WARNING : 0));
        delete file;
      }
    }
    if (intercept)
    {
      /* Clear error if we got it in this function */
      if (!is_error)
        thd->clear_error();
      error= -1;
    }
  }
  if (error)
    DBUG_PRINT("exit", ("error: %d", error));
  DBUG_RETURN(error);
}

/****************************************************************************
** General handler functions
****************************************************************************/


/**
   Clone a handler

   @param name     name of new table instance
   @param mem_root Where 'this->ref' should be allocated. It can't be
                   in this->table->mem_root as otherwise we will not be
                   able to reclaim that memory when the clone handler
                   object is destroyed.
*/

handler *handler::clone(const char *name, MEM_ROOT *mem_root)
{
  handler *new_handler= get_new_handler(table->s, mem_root, ht);

  if (!new_handler)
    return NULL;
  if (new_handler->set_ha_share_ref(ha_share))
    goto err;

  /*
    TODO: Implement a more efficient way to have more than one index open for
    the same table instance. The ha_open call is not cacheable for clone.

    This is not critical as the engines already have the table open
    and should be able to use the original instance of the table.
  */
  if (new_handler->ha_open(table, name, table->db_stat,
                           HA_OPEN_IGNORE_IF_LOCKED, mem_root))
    goto err;
  new_handler->handler_stats= handler_stats;

  return new_handler;

err:
  delete new_handler;
  return NULL;
}


/**
  clone of current handler.

  Creates a clone of handler used for unique hash key and WITHOUT OVERLAPS.
  @return error code
*/
int handler::create_lookup_handler()
{
  handler *tmp;
  if (lookup_handler != this)
    return 0;
  if (!(tmp= clone(table->s->normalized_path.str, table->in_use->mem_root)))
    return 1;
  lookup_handler= tmp;
  return lookup_handler->ha_external_lock(table->in_use, F_RDLCK);
}

LEX_CSTRING *handler::engine_name()
{
  return hton_name(ht);
}


/*
  It is assumed that the value of the parameter 'ranges' can be only 0 or 1.
  If ranges == 1 then the function returns the cost of index only scan
  by index 'keyno' of one range containing 'rows' key entries.
  If ranges == 0 then the function returns only the cost of copying
  those key entries into the engine buffers.
*/

double handler::keyread_time(uint index, uint ranges, ha_rows rows)
{
  DBUG_ASSERT(ranges == 0 || ranges == 1);
  size_t len= table->key_info[index].key_length + ref_length;
  if (table->file->is_clustering_key(index))
    len= table->s->stored_rec_length;
  double cost= (double)rows*len/(stats.block_size+1)*IDX_BLOCK_COPY_COST;
  if (ranges)
  {
    uint keys_per_block= (uint) (stats.block_size*3/4/len+1);
    ulonglong blocks= (rows+ keys_per_block- 1)/keys_per_block;
    cost+= blocks;
  }
  return cost;
}


THD *handler::ha_thd(void) const
{
  DBUG_ASSERT(!table || !table->in_use || table->in_use == current_thd);
  return (table && table->in_use) ? table->in_use : current_thd;
}

void handler::unbind_psi()
{
  /*
    Notify the instrumentation that this table is not owned
    by this thread any more.
  */
  PSI_CALL_unbind_table(m_psi);
}

void handler::rebind_psi()
{
  /*
    Notify the instrumentation that this table is now owned
    by this thread.
  */
  m_psi= PSI_CALL_rebind_table(ha_table_share_psi(), this, m_psi);
}


void handler::start_psi_batch_mode()
{
#ifdef HAVE_PSI_TABLE_INTERFACE
  DBUG_ASSERT(m_psi_batch_mode == PSI_BATCH_MODE_NONE);
  DBUG_ASSERT(m_psi_locker == NULL);
  m_psi_batch_mode= PSI_BATCH_MODE_STARTING;
  m_psi_numrows= 0;
#endif
}

void handler::end_psi_batch_mode()
{
#ifdef HAVE_PSI_TABLE_INTERFACE
  DBUG_ASSERT(m_psi_batch_mode != PSI_BATCH_MODE_NONE);
  if (m_psi_locker != NULL)
  {
    DBUG_ASSERT(m_psi_batch_mode == PSI_BATCH_MODE_STARTED);
    PSI_TABLE_CALL(end_table_io_wait)(m_psi_locker, m_psi_numrows);
    m_psi_locker= NULL;
  }
  m_psi_batch_mode= PSI_BATCH_MODE_NONE;
#endif
}

PSI_table_share *handler::ha_table_share_psi() const
{
  return table_share->m_psi;
}

/** @brief
  Open database-handler.

  IMPLEMENTATION
    Try O_RDONLY if cannot open as O_RDWR
    Don't wait for locks if not HA_OPEN_WAIT_IF_LOCKED is set
*/
int handler::ha_open(TABLE *table_arg, const char *name, int mode,
                     uint test_if_locked, MEM_ROOT *mem_root,
                     List<String> *partitions_to_open)
{
  int error;
  DBUG_ENTER("handler::ha_open");
  DBUG_PRINT("enter",
             ("name: %s  db_type: %d  db_stat: %d  mode: %d  lock_test: %d",
              name, ht->db_type, table_arg->db_stat, mode,
              test_if_locked));

  table= table_arg;
  DBUG_ASSERT(table->s == table_share);
  DBUG_ASSERT(m_lock_type == F_UNLCK);
  DBUG_PRINT("info", ("old m_lock_type: %d F_UNLCK %d", m_lock_type, F_UNLCK));
  DBUG_ASSERT(alloc_root_inited(&table->mem_root));

  set_partitions_to_open(partitions_to_open);

  if (unlikely((error=open(name,mode,test_if_locked))))
  {
    if ((error == EACCES || error == EROFS) && mode == O_RDWR &&
	(table->db_stat & HA_TRY_READ_ONLY))
    {
      table->db_stat|=HA_READ_ONLY;
      error=open(name,O_RDONLY,test_if_locked);
    }
  }
  if (unlikely(error))
  {
    my_errno= error;                            /* Safeguard */
    DBUG_PRINT("error",("error: %d  errno: %d",error,errno));
  }
  else
  {
    DBUG_ASSERT(m_psi == NULL);
    DBUG_ASSERT(table_share != NULL);
    /*
      Do not call this for partitions handlers, since it may take too much
      resources.
      So only use the m_psi on table level, not for individual partitions.
    */
    if (!(test_if_locked & HA_OPEN_NO_PSI_CALL))
    {
      m_psi= PSI_CALL_open_table(ha_table_share_psi(), this);
    }

    if (table->s->db_options_in_use & HA_OPTION_READ_ONLY_DATA)
      table->db_stat|=HA_READ_ONLY;
    (void) extra(HA_EXTRA_NO_READCHECK);	// Not needed in SQL

    /* Allocate ref in thd or on the table's mem_root */
    if (!(ref= (uchar*) alloc_root(mem_root ? mem_root : &table->mem_root, 
                                   ALIGN_SIZE(ref_length)*2)))
    {
      ha_close();
      error=HA_ERR_OUT_OF_MEM;
    }
    else
      dup_ref=ref+ALIGN_SIZE(ref_length);
    cached_table_flags= table_flags();
  }
  reset_statistics();
  internal_tmp_table= MY_TEST(test_if_locked & HA_OPEN_INTERNAL_TABLE);
  DBUG_RETURN(error);
}

int handler::ha_close(void)
{
  DBUG_ENTER("ha_close");
  /*
    Increment global statistics for temporary tables.
    In_use is 0 for tables that was closed from the table cache.
  */
  if (table->in_use)
    status_var_add(table->in_use->status_var.rows_tmp_read, rows_tmp_read);
  PSI_CALL_close_table(table_share, m_psi);
  m_psi= NULL; /* instrumentation handle, invalid after close_table() */
  DBUG_ASSERT(m_psi_batch_mode == PSI_BATCH_MODE_NONE);
  DBUG_ASSERT(m_psi_locker == NULL);

  /* Detach from ANALYZE tracker */
  tracker= NULL;
  /* We use ref as way to check that open succeded */
  ref= 0;
  
  DBUG_ASSERT(m_lock_type == F_UNLCK);
  DBUG_ASSERT(inited == NONE);
  DBUG_RETURN(close());
}


int handler::ha_rnd_next(uchar *buf)
{
  int result;
  DBUG_ENTER("handler::ha_rnd_next");
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  DBUG_ASSERT(inited == RND);

  do
  {
    TABLE_IO_WAIT(tracker, PSI_TABLE_FETCH_ROW, MAX_KEY, result,
      { result= rnd_next(buf); })
    if (result != HA_ERR_RECORD_DELETED)
      break;
    status_var_increment(table->in_use->status_var.ha_read_rnd_deleted_count);
  } while (!table->in_use->check_killed(1));

  if (result == HA_ERR_RECORD_DELETED)
    result= HA_ERR_ABORTED_BY_USER;
  else
  {
    if (!result)
    {
      update_rows_read();
      if (table->vfield && buf == table->record[0])
        table->update_virtual_fields(this, VCOL_UPDATE_FOR_READ);
    }
    increment_statistics(&SSV::ha_read_rnd_next_count);
  }

  table->status=result ? STATUS_NOT_FOUND: 0;
  DBUG_RETURN(result);
}

int handler::ha_rnd_pos(uchar *buf, uchar *pos)
{
  int result;
  DBUG_ENTER("handler::ha_rnd_pos");
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  DBUG_ASSERT(inited == RND);

  TABLE_IO_WAIT(tracker, PSI_TABLE_FETCH_ROW, MAX_KEY, result,
    { result= rnd_pos(buf, pos); })
  increment_statistics(&SSV::ha_read_rnd_count);
  if (result == HA_ERR_RECORD_DELETED)
    result= HA_ERR_KEY_NOT_FOUND;
  else if (!result)
  {
    update_rows_read();
    if (table->vfield && buf == table->record[0])
      table->update_virtual_fields(this, VCOL_UPDATE_FOR_READ);
  }
  table->status=result ? STATUS_NOT_FOUND: 0;
  DBUG_RETURN(result);
}

int handler::ha_index_read_map(uchar *buf, const uchar *key,
                                      key_part_map keypart_map,
                                      enum ha_rkey_function find_flag)
{
  int result;
  DBUG_ENTER("handler::ha_index_read_map");
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  DBUG_ASSERT(inited==INDEX);

  TABLE_IO_WAIT(tracker, PSI_TABLE_FETCH_ROW, active_index, result,
    { result= index_read_map(buf, key, keypart_map, find_flag); })
  increment_statistics(&SSV::ha_read_key_count);
  if (!result)
  {
    update_index_statistics();
    if (table->vfield && buf == table->record[0])
      table->update_virtual_fields(this, VCOL_UPDATE_FOR_READ);
  }
  table->status=result ? STATUS_NOT_FOUND: 0;
  DBUG_RETURN(result);
}

/*
  @note: Other index lookup/navigation functions require prior
  handler->index_init() call. This function is different, it requires
  that the scan is not initialized, and accepts "uint index" as an argument.
*/

int handler::ha_index_read_idx_map(uchar *buf, uint index, const uchar *key,
                                          key_part_map keypart_map,
                                          enum ha_rkey_function find_flag)
{
  int result;
  DBUG_ASSERT(inited==NONE);
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  DBUG_ASSERT(end_range == NULL);
  TABLE_IO_WAIT(tracker, PSI_TABLE_FETCH_ROW, index, result,
    { result= index_read_idx_map(buf, index, key, keypart_map, find_flag); })
  increment_statistics(&SSV::ha_read_key_count);
  if (!result)
  {
    update_rows_read();
    index_rows_read[index]++;
    if (table->vfield && buf == table->record[0])
      table->update_virtual_fields(this, VCOL_UPDATE_FOR_READ);
  }
  table->status=result ? STATUS_NOT_FOUND: 0;
  return result;
}

int handler::ha_index_next(uchar * buf)
{
  int result;
  DBUG_ENTER("handler::ha_index_next");
 DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  DBUG_ASSERT(inited==INDEX);

  TABLE_IO_WAIT(tracker, PSI_TABLE_FETCH_ROW, active_index, result,
    { result= index_next(buf); })
  increment_statistics(&SSV::ha_read_next_count);
  if (!result)
  {
    update_index_statistics();
    if (table->vfield && buf == table->record[0])
      table->update_virtual_fields(this, VCOL_UPDATE_FOR_READ);
  }
  table->status=result ? STATUS_NOT_FOUND: 0;

  DEBUG_SYNC(ha_thd(), "handler_ha_index_next_end");

  DBUG_RETURN(result);
}

int handler::ha_index_prev(uchar * buf)
{
  int result;
  DBUG_ENTER("handler::ha_index_prev");
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  DBUG_ASSERT(inited==INDEX);

  TABLE_IO_WAIT(tracker, PSI_TABLE_FETCH_ROW, active_index, result,
    { result= index_prev(buf); })
  increment_statistics(&SSV::ha_read_prev_count);
  if (!result)
  {
    update_index_statistics();
    if (table->vfield && buf == table->record[0])
      table->update_virtual_fields(this, VCOL_UPDATE_FOR_READ);
  }
  table->status=result ? STATUS_NOT_FOUND: 0;
  DBUG_RETURN(result);
}

int handler::ha_index_first(uchar * buf)
{
  int result;
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  DBUG_ASSERT(inited==INDEX);

  TABLE_IO_WAIT(tracker, PSI_TABLE_FETCH_ROW, active_index, result,
    { result= index_first(buf); })
  increment_statistics(&SSV::ha_read_first_count);
  if (!result)
  {
    update_index_statistics();
    if (table->vfield && buf == table->record[0])
      table->update_virtual_fields(this, VCOL_UPDATE_FOR_READ);
  }
  table->status=result ? STATUS_NOT_FOUND: 0;
  return result;
}

int handler::ha_index_last(uchar * buf)
{
  int result;
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  DBUG_ASSERT(inited==INDEX);

  TABLE_IO_WAIT(tracker, PSI_TABLE_FETCH_ROW, active_index, result,
    { result= index_last(buf); })
  increment_statistics(&SSV::ha_read_last_count);
  if (!result)
  {
    update_index_statistics();
    if (table->vfield && buf == table->record[0])
      table->update_virtual_fields(this, VCOL_UPDATE_FOR_READ);
  }
  table->status=result ? STATUS_NOT_FOUND: 0;
  return result;
}

int handler::ha_index_next_same(uchar *buf, const uchar *key, uint keylen)
{
  int result;
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  DBUG_ASSERT(inited==INDEX);

  TABLE_IO_WAIT(tracker, PSI_TABLE_FETCH_ROW, active_index, result,
    { result= index_next_same(buf, key, keylen); })
  increment_statistics(&SSV::ha_read_next_count);
  if (!result)
  {
    update_index_statistics();
    if (table->vfield && buf == table->record[0])
      table->update_virtual_fields(this, VCOL_UPDATE_FOR_READ);
  }
  table->status=result ? STATUS_NOT_FOUND: 0;
  return result;
}


bool handler::ha_was_semi_consistent_read()
{
  bool result= was_semi_consistent_read();
  if (result)
    increment_statistics(&SSV::ha_read_retry_count);
  return result;
}

/* Initialize handler for random reading, with error handling */

int handler::ha_rnd_init_with_error(bool scan)
{
  int error;
  if (likely(!(error= ha_rnd_init(scan))))
    return 0;
  table->file->print_error(error, MYF(0));
  return error;
}


/**
  Read first row (only) from a table. Used for reading tables with
  only one row, either based on table statistics or if table is a SEQUENCE.

  This is never called for normal InnoDB tables, as these table types
  does not have HA_STATS_RECORDS_IS_EXACT set.
*/
int handler::read_first_row(uchar * buf, uint primary_key)
{
  int error;
  DBUG_ENTER("handler::read_first_row");

  /*
    If there is very few deleted rows in the table, find the first row by
    scanning the table.
    TODO remove the test for HA_READ_ORDER
  */
  if (stats.deleted < 10 || primary_key >= MAX_KEY ||
      !(index_flags(primary_key, 0, 0) & HA_READ_ORDER))
  {
    if (likely(!(error= ha_rnd_init(1))))
    {
      error= ha_rnd_next(buf);
      const int end_error= ha_rnd_end();
      if (likely(!error))
        error= end_error;
    }
  }
  else
  {
    /* Find the first row through the primary key */
    if (likely(!(error= ha_index_init(primary_key, 0))))
    {
      error= ha_index_first(buf);
      const int end_error= ha_index_end();
      if (likely(!error))
        error= end_error;
    }
  }
  DBUG_RETURN(error);
}

/**
  Generate the next auto-increment number based on increment and offset.
  computes the lowest number
  - strictly greater than "nr"
  - of the form: auto_increment_offset + N * auto_increment_increment
  If overflow happened then return MAX_ULONGLONG value as an
  indication of overflow.
  In most cases increment= offset= 1, in which case we get:
  @verbatim 1,2,3,4,5,... @endverbatim
    If increment=10 and offset=5 and previous number is 1, we get:
  @verbatim 1,5,15,25,35,... @endverbatim
*/
inline ulonglong
compute_next_insert_id(ulonglong nr,struct system_variables *variables)
{
  const ulonglong save_nr= nr;

  if (variables->auto_increment_increment == 1)
    nr= nr + 1; // optimization of the formula below
  else
  {
    /*
       Calculating the number of complete auto_increment_increment extents:
    */
    nr= (nr + variables->auto_increment_increment -
         variables->auto_increment_offset) /
        (ulonglong) variables->auto_increment_increment;
    /*
       Adding an offset to the auto_increment_increment extent boundary:
    */
    nr= nr * (ulonglong) variables->auto_increment_increment +
        variables->auto_increment_offset;
  }

  if (unlikely(nr <= save_nr))
    return ULONGLONG_MAX;

  return nr;
}


void handler::adjust_next_insert_id_after_explicit_value(ulonglong nr)
{
  /*
    If we have set THD::next_insert_id previously and plan to insert an
    explicitly-specified value larger than this, we need to increase
    THD::next_insert_id to be greater than the explicit value.
  */
  if ((next_insert_id > 0) && (nr >= next_insert_id))
    set_next_insert_id(compute_next_insert_id(nr, &table->in_use->variables));
}


/** @brief
  Computes the largest number X:
  - smaller than or equal to "nr"
  - of the form: auto_increment_offset + N * auto_increment_increment
  where N>=0.

  SYNOPSIS
    prev_insert_id
      nr            Number to "round down"
      variables     variables struct containing auto_increment_increment and
                    auto_increment_offset

  RETURN
    The number X if it exists, "nr" otherwise.
*/
inline ulonglong
prev_insert_id(ulonglong nr, struct system_variables *variables)
{
  if (unlikely(nr < variables->auto_increment_offset))
  {
    /*
      There's nothing good we can do here. That is a pathological case, where
      the offset is larger than the column's max possible value, i.e. not even
      the first sequence value may be inserted. User will receive warning.
    */
    DBUG_PRINT("info",("auto_increment: nr: %lu cannot honour "
                       "auto_increment_offset: %lu",
                       (ulong) nr, variables->auto_increment_offset));
    return nr;
  }
  if (variables->auto_increment_increment == 1)
    return nr; // optimization of the formula below
  /*
     Calculating the number of complete auto_increment_increment extents:
  */
  nr= (nr - variables->auto_increment_offset) /
      (ulonglong) variables->auto_increment_increment;
  /*
     Adding an offset to the auto_increment_increment extent boundary:
  */
  return (nr * (ulonglong) variables->auto_increment_increment +
          variables->auto_increment_offset);
}


/**
  Update the auto_increment field if necessary.

  Updates columns with type NEXT_NUMBER if:

  - If column value is set to NULL (in which case
    auto_increment_field_not_null is 0)
  - If column is set to 0 and (sql_mode & MODE_NO_AUTO_VALUE_ON_ZERO) is not
    set. In the future we will only set NEXT_NUMBER fields if one sets them
    to NULL (or they are not included in the insert list).

    In those cases, we check if the currently reserved interval still has
    values we have not used. If yes, we pick the smallest one and use it.
    Otherwise:

  - If a list of intervals has been provided to the statement via SET
    INSERT_ID or via an Intvar_log_event (in a replication slave), we pick the
    first unused interval from this list, consider it as reserved.

  - Otherwise we set the column for the first row to the value
    next_insert_id(get_auto_increment(column))) which is usually
    max-used-column-value+1.
    We call get_auto_increment() for the first row in a multi-row
    statement. get_auto_increment() will tell us the interval of values it
    reserved for us.

  - In both cases, for the following rows we use those reserved values without
    calling the handler again (we just progress in the interval, computing
    each new value from the previous one). Until we have exhausted them, then
    we either take the next provided interval or call get_auto_increment()
    again to reserve a new interval.

  - In both cases, the reserved intervals are remembered in
    thd->auto_inc_intervals_in_cur_stmt_for_binlog if statement-based
    binlogging; the last reserved interval is remembered in
    auto_inc_interval_for_cur_row. The number of reserved intervals is
    remembered in auto_inc_intervals_count. It differs from the number of
    elements in thd->auto_inc_intervals_in_cur_stmt_for_binlog() because the
    latter list is cumulative over all statements forming one binlog event
    (when stored functions and triggers are used), and collapses two
    contiguous intervals in one (see its append() method).

    The idea is that generated auto_increment values are predictable and
    independent of the column values in the table.  This is needed to be
    able to replicate into a table that already has rows with a higher
    auto-increment value than the one that is inserted.

    After we have already generated an auto-increment number and the user
    inserts a column with a higher value than the last used one, we will
    start counting from the inserted value.

    This function's "outputs" are: the table's auto_increment field is filled
    with a value, thd->next_insert_id is filled with the value to use for the
    next row, if a value was autogenerated for the current row it is stored in
    thd->insert_id_for_cur_row, if get_auto_increment() was called
    thd->auto_inc_interval_for_cur_row is modified, if that interval is not
    present in thd->auto_inc_intervals_in_cur_stmt_for_binlog it is added to
    this list.

  @todo
    Replace all references to "next number" or NEXT_NUMBER to
    "auto_increment", everywhere (see below: there is
    table->auto_increment_field_not_null, and there also exists
    table->next_number_field, it's not consistent).

  @retval
    0	ok
  @retval
    HA_ERR_AUTOINC_READ_FAILED  get_auto_increment() was called and
    returned ~(ulonglong) 0
  @retval
    HA_ERR_AUTOINC_ERANGE storing value in field caused strict mode
    failure.
*/

#define AUTO_INC_DEFAULT_NB_ROWS 1 // Some prefer 1024 here
#define AUTO_INC_DEFAULT_NB_MAX_BITS 16
#define AUTO_INC_DEFAULT_NB_MAX ((1 << AUTO_INC_DEFAULT_NB_MAX_BITS) - 1)

int handler::update_auto_increment()
{
  ulonglong nr, nb_reserved_values;
  bool append= FALSE;
  THD *thd= table->in_use;
  struct system_variables *variables= &thd->variables;
  int result=0, tmp;
  DBUG_ENTER("handler::update_auto_increment");

  /*
    next_insert_id is a "cursor" into the reserved interval, it may go greater
    than the interval, but not smaller.
  */
  DBUG_ASSERT(next_insert_id >= auto_inc_interval_for_cur_row.minimum());

  if ((nr= table->next_number_field->val_int()) != 0 ||
      (table->auto_increment_field_not_null &&
       thd->variables.sql_mode & MODE_NO_AUTO_VALUE_ON_ZERO))
  {

    /*
      There could be an error reported because value was truncated
      when strict mode is enabled.
    */
    if (thd->is_error())
      DBUG_RETURN(HA_ERR_AUTOINC_ERANGE);
    /*
      Update next_insert_id if we had already generated a value in this
      statement (case of INSERT VALUES(null),(3763),(null):
      the last NULL needs to insert 3764, not the value of the first NULL plus
      1).
      Ignore negative values.
    */
    if ((longlong) nr > 0 || (table->next_number_field->flags & UNSIGNED_FLAG))
      adjust_next_insert_id_after_explicit_value(nr);
    insert_id_for_cur_row= 0; // didn't generate anything
    DBUG_RETURN(0);
  }

  if (table->versioned())
  {
    Field *end= table->vers_end_field();
    DBUG_ASSERT(end);
    bitmap_set_bit(table->read_set, end->field_index);
    if (!end->is_max())
    {
      if (thd->lex->sql_command == SQLCOM_ALTER_TABLE)
      {
        if (!table->next_number_field->real_maybe_null())
          DBUG_RETURN(HA_ERR_UNSUPPORTED);
        table->next_number_field->set_null();
      }
      DBUG_RETURN(0);
    }
  }

  // ALTER TABLE ... ADD COLUMN ... AUTO_INCREMENT
  if (thd->lex->sql_command == SQLCOM_ALTER_TABLE)
    table->next_number_field->set_notnull();

  if ((nr= next_insert_id) >= auto_inc_interval_for_cur_row.maximum())
  {
    /* next_insert_id is beyond what is reserved, so we reserve more. */
    const Discrete_interval *forced=
      thd->auto_inc_intervals_forced.get_next();
    if (forced != NULL)
    {
      nr= forced->minimum();
      nb_reserved_values= forced->values();
    }
    else
    {
      /*
        handler::estimation_rows_to_insert was set by
        handler::ha_start_bulk_insert(); if 0 it means "unknown".
      */
      ulonglong nb_desired_values;
      /*
        If an estimation was given to the engine:
        - use it.
        - if we already reserved numbers, it means the estimation was
        not accurate, then we'll reserve 2*AUTO_INC_DEFAULT_NB_ROWS the 2nd
        time, twice that the 3rd time etc.
        If no estimation was given, use those increasing defaults from the
        start, starting from AUTO_INC_DEFAULT_NB_ROWS.
        Don't go beyond a max to not reserve "way too much" (because
        reservation means potentially losing unused values).
        Note that in prelocked mode no estimation is given.
      */

      if ((auto_inc_intervals_count == 0) && (estimation_rows_to_insert > 0))
        nb_desired_values= estimation_rows_to_insert;
      else if ((auto_inc_intervals_count == 0) &&
               (thd->lex->many_values.elements > 0))
      {
        /*
          For multi-row inserts, if the bulk inserts cannot be started, the
          handler::estimation_rows_to_insert will not be set. But we still
          want to reserve the autoinc values.
        */
        nb_desired_values= thd->lex->many_values.elements;
      }
      else /* go with the increasing defaults */
      {
        /* avoid overflow in formula, with this if() */
        if (auto_inc_intervals_count <= AUTO_INC_DEFAULT_NB_MAX_BITS)
        {
          nb_desired_values= AUTO_INC_DEFAULT_NB_ROWS *
            (1 << auto_inc_intervals_count);
          set_if_smaller(nb_desired_values, AUTO_INC_DEFAULT_NB_MAX);
        }
        else
          nb_desired_values= AUTO_INC_DEFAULT_NB_MAX;
      }
      get_auto_increment(variables->auto_increment_offset,
                         variables->auto_increment_increment,
                         nb_desired_values, &nr,
                         &nb_reserved_values);
      if (nr == ULONGLONG_MAX)
        DBUG_RETURN(HA_ERR_AUTOINC_READ_FAILED);  // Mark failure

      /*
        That rounding below should not be needed when all engines actually
        respect offset and increment in get_auto_increment(). But they don't
        so we still do it. Wonder if for the not-first-in-index we should do
        it. Hope that this rounding didn't push us out of the interval; even
        if it did we cannot do anything about it (calling the engine again
        will not help as we inserted no row).
      */
      nr= compute_next_insert_id(nr-1, variables);
    }

    if (table->s->next_number_keypart == 0)
    {
      /* We must defer the appending until "nr" has been possibly truncated */
      append= TRUE;
    }
    else
    {
      /*
        For such auto_increment there is no notion of interval, just a
        singleton. The interval is not even stored in
        thd->auto_inc_interval_for_cur_row, so we are sure to call the engine
        for next row.
      */
      DBUG_PRINT("info",("auto_increment: special not-first-in-index"));
    }
  }

  if (unlikely(nr == ULONGLONG_MAX))
      DBUG_RETURN(HA_ERR_AUTOINC_ERANGE);

  DBUG_ASSERT(nr != 0);
  DBUG_PRINT("info",("auto_increment: %llu  nb_reserved_values: %llu",
                     nr, append ? nb_reserved_values : 0));

  /* Store field without warning (Warning will be printed by insert) */
  {
    Check_level_instant_set check_level_save(thd, CHECK_FIELD_IGNORE);
    tmp= table->next_number_field->store((longlong)nr, TRUE);
  }

  if (unlikely(tmp))                            // Out of range value in store
  {
    /*
      First, test if the query was aborted due to strict mode constraints
      or new field value greater than maximum integer value:
    */
    if (thd->killed == KILL_BAD_DATA ||
        nr > table->next_number_field->get_max_int_value())
    {
      /*
        It's better to return an error here than getting a confusing
        'duplicate key error' later.
      */
      result= HA_ERR_AUTOINC_ERANGE;
    }
    else
    {
      /*
        Field refused this value (overflow) and truncated it, use the result
        of the truncation (which is going to be inserted); however we try to
        decrease it to honour auto_increment_* variables.
        That will shift the left bound of the reserved interval, we don't
        bother shifting the right bound (anyway any other value from this
        interval will cause a duplicate key).
      */
      nr= prev_insert_id(table->next_number_field->val_int(), variables);
      if (unlikely(table->next_number_field->store((longlong)nr, TRUE)))
        nr= table->next_number_field->val_int();
    }
  }
  if (append)
  {
    auto_inc_interval_for_cur_row.replace(nr, nb_reserved_values,
                                          variables->auto_increment_increment);
    auto_inc_intervals_count++;
    /* Row-based replication does not need to store intervals in binlog */
    if (((WSREP_NNULL(thd) && wsrep_emulate_bin_log) ||
         mysql_bin_log.is_open()) &&
        !thd->is_current_stmt_binlog_format_row())
      thd->auto_inc_intervals_in_cur_stmt_for_binlog.
        append(auto_inc_interval_for_cur_row.minimum(),
               auto_inc_interval_for_cur_row.values(),
               variables->auto_increment_increment);
  }

  /*
    Record this autogenerated value. If the caller then
    succeeds to insert this value, it will call
    record_first_successful_insert_id_in_cur_stmt()
    which will set first_successful_insert_id_in_cur_stmt if it's not
    already set.
  */
  insert_id_for_cur_row= nr;

  if (result)                                   // overflow
    DBUG_RETURN(result);

  /*
    Set next insert id to point to next auto-increment value to be able to
    handle multi-row statements.
  */
  set_next_insert_id(compute_next_insert_id(nr, variables));

  DBUG_RETURN(0);
}


/** @brief
  MySQL signal that it changed the column bitmap

  USAGE
    This is for handlers that needs to setup their own column bitmaps.
    Normally the handler should set up their own column bitmaps in
    index_init() or rnd_init() and in any column_bitmaps_signal() call after
    this.

    The handler is allowed to do changes to the bitmap after a index_init or
    rnd_init() call is made as after this, MySQL will not use the bitmap
    for any program logic checking.
*/
void handler::column_bitmaps_signal()
{
  DBUG_ENTER("column_bitmaps_signal");
  if (table)
    DBUG_PRINT("info", ("read_set: %p  write_set: %p",
                        table->read_set, table->write_set));
  DBUG_VOID_RETURN;
}


/** @brief
  Reserves an interval of auto_increment values from the handler.

  SYNOPSIS
    get_auto_increment()
    offset              
    increment
    nb_desired_values   how many values we want
    first_value         (OUT) the first value reserved by the handler
    nb_reserved_values  (OUT) how many values the handler reserved

  offset and increment means that we want values to be of the form
  offset + N * increment, where N>=0 is integer.
  If the function sets *first_value to ~(ulonglong)0 it means an error.
  If the function sets *nb_reserved_values to ULONGLONG_MAX it means it has
  reserved to "positive infinite".
*/
void handler::get_auto_increment(ulonglong offset, ulonglong increment,
                                 ulonglong nb_desired_values,
                                 ulonglong *first_value,
                                 ulonglong *nb_reserved_values)
{
  ulonglong nr;
  int error;
  MY_BITMAP *old_read_set;
  bool rnd_inited= (inited ==  RND);
  bool rev= table->key_info[table->s->next_number_index].
              key_part[table->s->next_number_keypart].key_part_flag &
                HA_REVERSE_SORT;

  if (rnd_inited && ha_rnd_end())
    return;

  old_read_set= table->prepare_for_keyread(table->s->next_number_index);

  if (ha_index_init(table->s->next_number_index, 1))
  {
    /* This should never happen, assert in debug, and fail in release build */
    DBUG_ASSERT(0);
    (void) extra(HA_EXTRA_NO_KEYREAD);
    *first_value= ULONGLONG_MAX;
    if (rnd_inited && ha_rnd_init_with_error(0))
    {
      //TODO: it would be nice to return here an error
    }
    return;
  }

  if (table->s->next_number_keypart == 0)
  {						// Autoincrement at key-start
    error= rev ? ha_index_first(table->record[1])
               : ha_index_last(table->record[1]);
    /*
      MySQL implicitly assumes such method does locking (as MySQL decides to
      use nr+increment without checking again with the handler, in
      handler::update_auto_increment()), so reserves to infinite.
    */
    *nb_reserved_values= ULONGLONG_MAX;
  }
  else
  {
    uchar key[MAX_KEY_LENGTH];
    key_copy(key, table->record[0],
             table->key_info + table->s->next_number_index,
             table->s->next_number_key_offset);
    error= ha_index_read_map(table->record[1], key,
                          make_prev_keypart_map(table->s->next_number_keypart),
                          rev ? HA_READ_KEY_EXACT : HA_READ_PREFIX_LAST);
    /*
      MySQL needs to call us for next row: assume we are inserting ("a",null)
      here, we return 3, and next this statement will want to insert
      ("b",null): there is no reason why ("b",3+1) would be the good row to
      insert: maybe it already exists, maybe 3+1 is too large...
    */
    *nb_reserved_values= 1;
  }

  if (unlikely(error))
  {
    if (error == HA_ERR_END_OF_FILE || error == HA_ERR_KEY_NOT_FOUND)
      /* No entry found, that's fine */;
    else
      print_error(error, MYF(0));
    nr= 1;
  }
  else
    nr= ((ulonglong) table->next_number_field->
         val_int_offset(table->s->rec_buff_length)+1);
  ha_index_end();
  table->restore_column_maps_after_keyread(old_read_set);
  *first_value= nr;
  if (rnd_inited && ha_rnd_init_with_error(0))
  {
    //TODO: it would be nice to return here an error
  }
  return;
}


void handler::ha_release_auto_increment()
{
  DBUG_ENTER("ha_release_auto_increment");
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK ||
              (!next_insert_id && !insert_id_for_cur_row));
  release_auto_increment();
  insert_id_for_cur_row= 0;
  auto_inc_interval_for_cur_row.replace(0, 0, 0);
  auto_inc_intervals_count= 0;
  if (next_insert_id > 0)
  {
    next_insert_id= 0;
    /*
      this statement used forced auto_increment values if there were some,
      wipe them away for other statements.
    */
    table->in_use->auto_inc_intervals_forced.empty();
  }
  DBUG_VOID_RETURN;
}


/**
  Construct and emit duplicate key error message using information
  from table's record buffer.

  @param table    TABLE object which record buffer should be used as
                  source for column values.
  @param key      Key description.
  @param msg      Error message template to which key value should be
                  added.
  @param errflag  Flags for my_error() call.

  @notes
    The error message is from ER_DUP_ENTRY_WITH_KEY_NAME but to keep things compatibly
    with old code, the error number is ER_DUP_ENTRY
*/

void print_keydup_error(TABLE *table, KEY *key, const char *msg, myf errflag)
{
  /* Write the duplicated key in the error message */
  char key_buff[MAX_KEY_LENGTH];
  String str(key_buff,sizeof(key_buff),system_charset_info);

  if (key == NULL)
  {
    /*
      Key is unknown. Should only happen if storage engine reports wrong
      duplicate key number.
    */
    my_printf_error(ER_DUP_ENTRY, msg, errflag, "", "*UNKNOWN*");
  }
  else
  {
    if (key->algorithm == HA_KEY_ALG_LONG_HASH)
      setup_keyinfo_hash(key);
    /* Table is opened and defined at this point */
    key_unpack(&str,table, key);
    uint max_length=MYSQL_ERRMSG_SIZE-(uint) strlen(msg);
    if (str.length() >= max_length)
    {
      str.length(max_length-4);
      str.append(STRING_WITH_LEN("..."));
    }
    my_printf_error(ER_DUP_ENTRY, msg, errflag, str.c_ptr_safe(),
                    key->name.str);
    if (key->algorithm == HA_KEY_ALG_LONG_HASH)
      re_setup_keyinfo_hash(key);
  }
}

/**
  Construct and emit duplicate key error message using information
  from table's record buffer.

  @sa print_keydup_error(table, key, msg, errflag).
*/

void print_keydup_error(TABLE *table, KEY *key, myf errflag)
{
  print_keydup_error(table, key,
                     ER_THD(table->in_use, ER_DUP_ENTRY_WITH_KEY_NAME),
                     errflag);
}

/**
  Print error that we got from handler function.

  @note
    In case of delete table it's only safe to use the following parts of
    the 'table' structure:
    - table->s->path
    - table->alias
*/

#define SET_FATAL_ERROR fatal_error=1

void handler::print_error(int error, myf errflag)
{
  bool fatal_error= 0;
  DBUG_ENTER("handler::print_error");
  DBUG_PRINT("enter",("error: %d",error));

  if (ha_thd()->transaction_rollback_request)
  {
    /* Ensure this becomes a true error */
    errflag&= ~(ME_WARNING | ME_NOTE);
  }

  int textno= -1; // impossible value
  switch (error) {
  case EACCES:
    textno=ER_OPEN_AS_READONLY;
    break;
  case EAGAIN:
    textno=ER_FILE_USED;
    break;
  case ENOENT:
  case ENOTDIR:
  case ELOOP:
    textno=ER_FILE_NOT_FOUND;
    break;
  case ENOSPC:
  case HA_ERR_DISK_FULL:
    textno= ER_DISK_FULL;
    SET_FATAL_ERROR;                            // Ensure error is logged
    break;
  case HA_ERR_KEY_NOT_FOUND:
  case HA_ERR_NO_ACTIVE_RECORD:
  case HA_ERR_RECORD_DELETED:
  case HA_ERR_END_OF_FILE:
    /*
      This errors is not not normally fatal (for example for reads). However
      if you get it during an update or delete, then its fatal.
      As the user is calling print_error() (which is not done on read), we
      assume something when wrong with the update or delete.
    */
    SET_FATAL_ERROR;
    textno=ER_KEY_NOT_FOUND;
    break;
  case HA_ERR_ABORTED_BY_USER:
  {
    DBUG_ASSERT(ha_thd()->killed);
    ha_thd()->send_kill_message();
    DBUG_VOID_RETURN;
  }
  case HA_ERR_WRONG_MRG_TABLE_DEF:
    textno=ER_WRONG_MRG_TABLE;
    break;
  case HA_ERR_FOUND_DUPP_KEY:
  {
    if (table)
    {
      uint key_nr=get_dup_key(error);
      if ((int) key_nr >= 0 && key_nr < table->s->keys)
      {
        print_keydup_error(table, &table->key_info[key_nr], errflag);
        table->file->lookup_errkey= -1;
        DBUG_VOID_RETURN;
      }
    }
    textno=ER_DUP_KEY;
    break;
  }
  case HA_ERR_FOREIGN_DUPLICATE_KEY:
  {
    char rec_buf[MAX_KEY_LENGTH];
    String rec(rec_buf, sizeof(rec_buf), system_charset_info);
    /* Table is opened and defined at this point */

    /*
      Just print the subset of fields that are part of the first index,
      printing the whole row from there is not easy.
    */
    key_unpack(&rec, table, &table->key_info[0]);

    char child_table_name[NAME_LEN + 1];
    char child_key_name[NAME_LEN + 1];
    if (get_foreign_dup_key(child_table_name, sizeof(child_table_name),
                            child_key_name, sizeof(child_key_name)))
    {
      my_error(ER_FOREIGN_DUPLICATE_KEY_WITH_CHILD_INFO, errflag,
               table_share->table_name.str, rec.c_ptr_safe(),
               child_table_name, child_key_name);
      }
    else
    {
      my_error(ER_FOREIGN_DUPLICATE_KEY_WITHOUT_CHILD_INFO, errflag,
               table_share->table_name.str, rec.c_ptr_safe());
    }
    DBUG_VOID_RETURN;
  }
  case HA_ERR_NULL_IN_SPATIAL:
    my_error(ER_CANT_CREATE_GEOMETRY_OBJECT, errflag);
    DBUG_VOID_RETURN;
  case HA_ERR_FOUND_DUPP_UNIQUE:
    textno=ER_DUP_UNIQUE;
    break;
  case HA_ERR_RECORD_CHANGED:
    /*
      This is not fatal error when using HANDLER interface
      SET_FATAL_ERROR;
    */
    textno=ER_CHECKREAD;
    break;
  case HA_ERR_CRASHED:
    SET_FATAL_ERROR;
    textno=ER_NOT_KEYFILE;
    break;
  case HA_ERR_WRONG_IN_RECORD:
    SET_FATAL_ERROR;
    textno= ER_CRASHED_ON_USAGE;
    break;
  case HA_ERR_CRASHED_ON_USAGE:
    SET_FATAL_ERROR;
    textno=ER_CRASHED_ON_USAGE;
    break;
  case HA_ERR_NOT_A_TABLE:
    textno= error;
    break;
  case HA_ERR_CRASHED_ON_REPAIR:
    SET_FATAL_ERROR;
    textno=ER_CRASHED_ON_REPAIR;
    break;
  case HA_ERR_OUT_OF_MEM:
    textno=ER_OUT_OF_RESOURCES;
    break;
  case HA_ERR_WRONG_COMMAND:
    my_error(ER_ILLEGAL_HA, MYF(0), table_type(), table_share->db.str,
             table_share->table_name.str);
    DBUG_VOID_RETURN;
    break;
  case HA_ERR_OLD_FILE:
    textno=ER_OLD_KEYFILE;
    break;
  case HA_ERR_UNSUPPORTED:
    textno=ER_UNSUPPORTED_EXTENSION;
    break;
  case HA_ERR_RECORD_FILE_FULL:
  {
    textno=ER_RECORD_FILE_FULL;
    /* Write the error message to error log */
    errflag|= ME_ERROR_LOG;
    break;
  }
  case HA_ERR_INDEX_FILE_FULL:
  {
    textno=ER_INDEX_FILE_FULL;
    /* Write the error message to error log */
    errflag|= ME_ERROR_LOG;
    break;
  }
  case HA_ERR_LOCK_WAIT_TIMEOUT:
    textno=ER_LOCK_WAIT_TIMEOUT;
    break;
  case HA_ERR_LOCK_TABLE_FULL:
    textno=ER_LOCK_TABLE_FULL;
    break;
  case HA_ERR_LOCK_DEADLOCK:
  {
    String str, full_err_msg(ER_DEFAULT(ER_LOCK_DEADLOCK),
                             strlen(ER_DEFAULT(ER_LOCK_DEADLOCK)),
                             system_charset_info);

    get_error_message(error, &str);
    full_err_msg.append(str);
    my_printf_error(ER_LOCK_DEADLOCK, "%s", errflag, full_err_msg.c_ptr_safe());
    DBUG_VOID_RETURN;
  }
  case HA_ERR_READ_ONLY_TRANSACTION:
    textno=ER_READ_ONLY_TRANSACTION;
    break;
  case HA_ERR_CANNOT_ADD_FOREIGN:
    textno=ER_CANNOT_ADD_FOREIGN;
    break;
  case HA_ERR_ROW_IS_REFERENCED:
  {
    String str;
    get_error_message(error, &str);
    my_printf_error(ER_ROW_IS_REFERENCED_2,
                    ER(str.length() ? ER_ROW_IS_REFERENCED_2 : ER_ROW_IS_REFERENCED),
                    errflag, str.c_ptr_safe());
    DBUG_VOID_RETURN;
  }
  case HA_ERR_NO_REFERENCED_ROW:
  {
    String str;
    get_error_message(error, &str);
    my_printf_error(ER_NO_REFERENCED_ROW_2,
                    ER(str.length() ? ER_NO_REFERENCED_ROW_2 : ER_NO_REFERENCED_ROW),
                    errflag, str.c_ptr_safe());
    DBUG_VOID_RETURN;
  }
  case HA_ERR_TABLE_DEF_CHANGED:
    textno=ER_TABLE_DEF_CHANGED;
    break;
  case HA_ERR_NO_SUCH_TABLE:
    my_error(ER_NO_SUCH_TABLE_IN_ENGINE, errflag, table_share->db.str,
             table_share->table_name.str);
    DBUG_VOID_RETURN;
  case HA_ERR_RBR_LOGGING_FAILED:
    textno= ER_BINLOG_ROW_LOGGING_FAILED;
    break;
  case HA_ERR_DROP_INDEX_FK:
  {
    const char *ptr= "???";
    uint key_nr= get_dup_key(error);
    if ((int) key_nr >= 0)
      ptr= table->key_info[key_nr].name.str;
    my_error(ER_DROP_INDEX_FK, errflag, ptr);
    DBUG_VOID_RETURN;
  }
  case HA_ERR_TABLE_NEEDS_UPGRADE:
    textno= ER_TABLE_NEEDS_UPGRADE;
    my_error(ER_TABLE_NEEDS_UPGRADE, errflag,
             "TABLE", table_share->table_name.str);
    DBUG_VOID_RETURN;
  case HA_ERR_NO_PARTITION_FOUND:
    textno=ER_WRONG_PARTITION_NAME;
    break;
  case HA_ERR_TABLE_READONLY:
    textno= ER_OPEN_AS_READONLY;
    break;
  case HA_ERR_AUTOINC_READ_FAILED:
    textno= ER_AUTOINC_READ_FAILED;
    break;
  case HA_ERR_AUTOINC_ERANGE:
    textno= error;
    my_error(textno, errflag, table->found_next_number_field->field_name.str,
             table->in_use->get_stmt_da()->current_row_for_warning());
    DBUG_VOID_RETURN;
    break;
  case HA_ERR_TOO_MANY_CONCURRENT_TRXS:
    textno= ER_TOO_MANY_CONCURRENT_TRXS;
    break;
  case HA_ERR_INDEX_COL_TOO_LONG:
    textno= ER_INDEX_COLUMN_TOO_LONG;
    break;
  case HA_ERR_NOT_IN_LOCK_PARTITIONS:
    textno=ER_ROW_DOES_NOT_MATCH_GIVEN_PARTITION_SET;
    break;
  case HA_ERR_INDEX_CORRUPT:
    textno= ER_INDEX_CORRUPT;
    break;
  case HA_ERR_UNDO_REC_TOO_BIG:
    textno= ER_UNDO_RECORD_TOO_BIG;
    break;
  case HA_ERR_COMMIT_ERROR:
    textno= ER_ERROR_DURING_COMMIT;
    break;
  case HA_ERR_PARTITION_LIST:
    my_error(ER_VERS_NOT_ALLOWED, errflag, table->s->db.str, table->s->table_name.str);
    DBUG_VOID_RETURN;
  default:
    {
      /* The error was "unknown" to this function.
	 Ask handler if it has got a message for this error */
      bool temporary= FALSE;
      String str;
      temporary= get_error_message(error, &str);
      if (!str.is_empty())
      {
	const char* engine= table_type();
	if (temporary)
	  my_error(ER_GET_TEMPORARY_ERRMSG, errflag, error, str.c_ptr(),
                   engine);
	else
        {
          SET_FATAL_ERROR;
	  my_error(ER_GET_ERRMSG, errflag, error, str.c_ptr(), engine);
        }
      }
      else
      {
        if (!temporary)
          my_error(ER_GET_ERRNO, errflag, error, table_type());
        /* else no error message. */
      }
      DBUG_VOID_RETURN;
    }
  }
  DBUG_ASSERT(textno > 0);
  if (unlikely(fatal_error))
  {
    /* Ensure this becomes a true error */
    errflag&= ~(ME_WARNING | ME_NOTE);
    if ((debug_assert_if_crashed_table ||
                      global_system_variables.log_warnings > 1))
    {
      /*
        Log error to log before we crash or if extended warnings are requested
      */
      errflag|= ME_ERROR_LOG;
    }
  }

  /* if we got an OS error from a file-based engine, specify a path of error */
  if (error < HA_ERR_FIRST && bas_ext()[0])
  {
    char buff[FN_REFLEN];
    strxnmov(buff, sizeof(buff),
             table_share->normalized_path.str, bas_ext()[0], NULL);
    my_error(textno, errflag, buff, error);
  }
  else
    my_error(textno, errflag, table_share->table_name.str, error);
  DBUG_VOID_RETURN;
}


/**
  Return an error message specific to this handler.

  @param error  error code previously returned by handler
  @param buf    pointer to String where to add error message

  @return
    Returns true if this is a temporary error
*/
bool handler::get_error_message(int error, String* buf)
{
  DBUG_EXECUTE_IF("external_lock_failure",
                  buf->set_ascii(STRING_WITH_LEN("KABOOM!")););
  return FALSE;
}

/**
  Check for incompatible collation changes.
   
  @retval
    HA_ADMIN_NEEDS_UPGRADE   Table may have data requiring upgrade.
  @retval
    0                        No upgrade required.
*/

int handler::check_collation_compatibility()
{
  ulong mysql_version= table->s->mysql_version;

  if (mysql_version < Charset::latest_mariadb_version_with_collation_change())
  {
    KEY *key= table->key_info;
    KEY *key_end= key + table->s->keys;
    for (; key < key_end; key++)
    {
      KEY_PART_INFO *key_part= key->key_part;
      KEY_PART_INFO *key_part_end= key_part + key->user_defined_key_parts;
      for (; key_part < key_part_end; key_part++)
      {
        if (!key_part->fieldnr)
          continue;
        Field *field= table->field[key_part->fieldnr - 1];
        uint cs_number= field->charset()->number;
        if (Charset::collation_changed_order(mysql_version, cs_number))
          return HA_ADMIN_NEEDS_UPGRADE;
      }
    }
  }

  return 0;
}


int handler::check_long_hash_compatibility() const
{
  if (!table->s->old_long_hash_function())
    return 0;
  KEY *key= table->key_info;
  KEY *key_end= key + table->s->keys;
  for ( ; key < key_end; key++)
  {
    if (key->algorithm == HA_KEY_ALG_LONG_HASH)
    {
      /*
        The old (pre-MDEV-27653)  hash function was wrong.
        So the long hash unique constraint can have some
        duplicate records. REPAIR TABLE can't fix this,
        it will fail on a duplicate key error.
        Only "ALTER IGNORE TABLE .. FORCE" can fix this.
        So we need to return HA_ADMIN_NEEDS_ALTER here,
        (not HA_ADMIN_NEEDS_UPGRADE which is used elsewhere),
        to properly send the error message text corresponding
        to ER_TABLE_NEEDS_REBUILD (rather than to ER_TABLE_NEEDS_UPGRADE)
        to the user.
      */
      return HA_ADMIN_NEEDS_ALTER;
    }
  }
  return 0;
}


int handler::ha_check_for_upgrade(HA_CHECK_OPT *check_opt)
{
  int error;
  KEY *keyinfo, *keyend;
  KEY_PART_INFO *keypart, *keypartend;

  if (table->s->incompatible_version)
    return HA_ADMIN_NEEDS_ALTER;

  if (!table->s->mysql_version)
  {
    /* check for blob-in-key error */
    keyinfo= table->key_info;
    keyend= table->key_info + table->s->keys;
    for (; keyinfo < keyend; keyinfo++)
    {
      keypart= keyinfo->key_part;
      keypartend= keypart + keyinfo->user_defined_key_parts;
      for (; keypart < keypartend; keypart++)
      {
        if (!keypart->fieldnr)
          continue;
        Field *field= table->field[keypart->fieldnr-1];
        if (field->type() == MYSQL_TYPE_BLOB)
        {
          if (check_opt->sql_flags & TT_FOR_UPGRADE)
            check_opt->flags= T_MEDIUM;
          return HA_ADMIN_NEEDS_CHECK;
        }
      }
    }
  }
  if (table->s->frm_version < FRM_VER_TRUE_VARCHAR)
    return HA_ADMIN_NEEDS_ALTER;

  if (unlikely((error= check_collation_compatibility())))
    return error;

  if (unlikely((error= check_long_hash_compatibility())))
    return error;
    
  return check_for_upgrade(check_opt);
}


int handler::check_old_types()
{
  Field** field;

  if (!table->s->mysql_version)
  {
    /* check for bad DECIMAL field */
    for (field= table->field; (*field); field++)
    {
      if ((*field)->type() == MYSQL_TYPE_NEWDECIMAL)
      {
        return HA_ADMIN_NEEDS_ALTER;
      }
      if ((*field)->type() == MYSQL_TYPE_VAR_STRING)
      {
        return HA_ADMIN_NEEDS_ALTER;
      }
    }
  }
  return 0;
}


static bool update_frm_version(TABLE *table)
{
  char path[FN_REFLEN];
  File file;
  int result= 1;
  DBUG_ENTER("update_frm_version");

  /*
    No need to update frm version in case table was created or checked
    by server with the same version. This also ensures that we do not
    update frm version for temporary tables as this code doesn't support
    temporary tables.

    keep_original_mysql_version is set if the table version cannot be
    changed without rewriting the frm file.
  */
  if (table->s->mysql_version == MYSQL_VERSION_ID ||
      table->s->keep_original_mysql_version)
    DBUG_RETURN(0);

  strxmov(path, table->s->normalized_path.str, reg_ext, NullS);

  if ((file= mysql_file_open(key_file_frm,
                             path, O_RDWR|O_BINARY, MYF(MY_WME))) >= 0)
  {
    uchar version[4];

    int4store(version, MYSQL_VERSION_ID);

    if ((result= (int)mysql_file_pwrite(file, (uchar*) version, 4, 51L,
                                        MYF(MY_WME+MY_NABP))))
      goto err;

    table->s->mysql_version= MYSQL_VERSION_ID;
  }
err:
  if (file >= 0)
    (void) mysql_file_close(file, MYF(MY_WME));
  DBUG_RETURN(result);
}



/**
  @return
    key if error because of duplicated keys
*/
uint handler::get_dup_key(int error)
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE || m_lock_type != F_UNLCK);
  DBUG_ENTER("handler::get_dup_key");

  if (lookup_errkey != (uint)-1)
    DBUG_RETURN(errkey= lookup_errkey);

  errkey= (uint)-1;
  if (error == HA_ERR_FOUND_DUPP_KEY ||
      error == HA_ERR_FOREIGN_DUPLICATE_KEY ||
      error == HA_ERR_FOUND_DUPP_UNIQUE || error == HA_ERR_NULL_IN_SPATIAL ||
      error == HA_ERR_DROP_INDEX_FK)
    info(HA_STATUS_ERRKEY | HA_STATUS_NO_LOCK);
  DBUG_RETURN(errkey);
}


/**
  Delete all files with extension from bas_ext().

  @param name		Base name of table

  @note
    We assume that the handler may return more extensions than
    was actually used for the file. We also assume that the first
    extension is the most important one (see the comment near
    handlerton::tablefile_extensions). If this exist and we can't delete
    that it, we will abort the delete.
    If the first one doesn't exists, we have to try to delete all other
    extension as there is chance that the server had crashed between
    the delete of the first file and the next

  @retval
    0   If we successfully deleted at least one file from base_ext and
        didn't get any other errors than ENOENT

  @retval
    !0  Error
*/

int handler::delete_table(const char *name)
{
  int saved_error= ENOENT;
  bool abort_if_first_file_error= 1;
  bool some_file_deleted= 0;
  DBUG_ENTER("handler::delete_table");

  for (const char **ext= bas_ext(); *ext ; ext++)
  {
    int err= mysql_file_delete_with_symlink(key_file_misc, name, *ext, MYF(0));
    if (err)
    {
      if (my_errno != ENOENT)
      {
        saved_error= my_errno;
        /*
          If error other than file not found on the first existing file,
          return the error.
          Otherwise delete as much as possible.
        */
        if (abort_if_first_file_error)
          DBUG_RETURN(saved_error);
      }
    }
    else
      some_file_deleted= 1;
    abort_if_first_file_error= 0;
  }
  DBUG_RETURN(some_file_deleted && saved_error == ENOENT ? 0 : saved_error);
}


int handler::rename_table(const char * from, const char * to)
{
  int error= 0;
  const char **ext, **start_ext;
  start_ext= bas_ext();
  for (ext= start_ext; *ext ; ext++)
  {
    if (unlikely(rename_file_ext(from, to, *ext)))
    {
      if ((error=my_errno) != ENOENT)
	break;
      error= 0;
    }
  }
  if (unlikely(error))
  {
    /* Try to revert the rename. Ignore errors. */
    for (; ext >= start_ext; ext--)
      rename_file_ext(to, from, *ext);
  }
  return error;
}


void handler::drop_table(const char *name)
{
  ha_close();
  delete_table(name);
}


/**
   Return true if the error from drop table means that the
   table didn't exists
*/

bool non_existing_table_error(int error)
{
  return (error == ENOENT ||
          (error == EE_DELETE && my_errno == ENOENT) ||
          error == EE_FILENOTFOUND ||
          error == HA_ERR_NO_SUCH_TABLE ||
          error == HA_ERR_UNSUPPORTED ||
          error == ER_NO_SUCH_TABLE ||
          error == ER_NO_SUCH_TABLE_IN_ENGINE ||
          error == ER_WRONG_OBJECT);
}


/**
  Performs checks upon the table.

  @param thd                thread doing CHECK TABLE operation
  @param check_opt          options from the parser

  @retval
    HA_ADMIN_OK               Successful upgrade
  @retval
    HA_ADMIN_NEEDS_UPGRADE    Table has structures requiring upgrade
  @retval
    HA_ADMIN_NEEDS_ALTER      Table has structures requiring ALTER TABLE
  @retval
    HA_ADMIN_NOT_IMPLEMENTED
*/

int handler::ha_check(THD *thd, HA_CHECK_OPT *check_opt)
{
  int error;
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);

  if ((table->s->mysql_version >= MYSQL_VERSION_ID) &&
      (check_opt->sql_flags & TT_FOR_UPGRADE))
    return 0;

  if (table->s->mysql_version < MYSQL_VERSION_ID)
  {
    if (unlikely((error= check_old_types())))
      return error;
    error= ha_check_for_upgrade(check_opt);
    if (unlikely(error && (error != HA_ADMIN_NEEDS_CHECK)))
      return error;
    if (unlikely(!error && (check_opt->sql_flags & TT_FOR_UPGRADE)))
      return 0;
  }
  if (unlikely((error= check(thd, check_opt))))
    return error;
  /* Skip updating frm version if not main handler. */
  if (table->file != this)
    return error;
  return update_frm_version(table);
}

/**
  A helper function to mark a transaction read-write,
  if it is started.
*/

void handler::mark_trx_read_write_internal()
{
  Ha_trx_info *ha_info= &ha_thd()->ha_data[ht->slot].ha_info[0];
  /*
    When a storage engine method is called, the transaction must
    have been started, unless it's a DDL call, for which the
    storage engine starts the transaction internally, and commits
    it internally, without registering in the ha_list.
    Unfortunately here we can't know know for sure if the engine
    has registered the transaction or not, so we must check.
  */
  if (ha_info->is_started())
  {
    /*
      table_share can be NULL, for example, in ha_delete_table() or
      ha_rename_table().
    */
    if (table_share == NULL || table_share->tmp_table == NO_TMP_TABLE)
      ha_info->set_trx_read_write();
  }
}


/**
  Repair table: public interface.

  @sa handler::repair()
*/

int handler::ha_repair(THD* thd, HA_CHECK_OPT* check_opt)
{
  int result;

  mark_trx_read_write();

  result= repair(thd, check_opt);
  DBUG_ASSERT(result == HA_ADMIN_NOT_IMPLEMENTED ||
              ha_table_flags() & HA_CAN_REPAIR);

  if (result == HA_ADMIN_OK)
    result= update_frm_version(table);
  return result;
}


/**
   End bulk insert
*/

int handler::ha_end_bulk_insert()
{
  DBUG_ENTER("handler::ha_end_bulk_insert");
  DBUG_EXECUTE_IF("crash_end_bulk_insert",
                  { extra(HA_EXTRA_FLUSH) ; DBUG_SUICIDE();});
  estimation_rows_to_insert= 0;
  DBUG_RETURN(end_bulk_insert());
}

/**
  Bulk update row: public interface.

  @sa handler::bulk_update_row()
*/

int
handler::ha_bulk_update_row(const uchar *old_data, const uchar *new_data,
                            ha_rows *dup_key_found)
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type == F_WRLCK);
  mark_trx_read_write();

  return bulk_update_row(old_data, new_data, dup_key_found);
}


/**
  Delete all rows: public interface.

  @sa handler::delete_all_rows()
*/

int
handler::ha_delete_all_rows()
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type == F_WRLCK);
  mark_trx_read_write();

  return delete_all_rows();
}


/**
  Truncate table: public interface.

  @sa handler::truncate()
*/

int
handler::ha_truncate()
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type == F_WRLCK);
  mark_trx_read_write();

  return truncate();
}


/**
  Reset auto increment: public interface.

  @sa handler::reset_auto_increment()
*/

int
handler::ha_reset_auto_increment(ulonglong value)
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type == F_WRLCK);
  mark_trx_read_write();

  return reset_auto_increment(value);
}


/**
  Optimize table: public interface.

  @sa handler::optimize()
*/

int
handler::ha_optimize(THD* thd, HA_CHECK_OPT* check_opt)
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type == F_WRLCK);
  mark_trx_read_write();

  return optimize(thd, check_opt);
}


/**
  Analyze table: public interface.

  @sa handler::analyze()
*/

int
handler::ha_analyze(THD* thd, HA_CHECK_OPT* check_opt)
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  mark_trx_read_write();

  return analyze(thd, check_opt);
}


/**
  Check and repair table: public interface.

  @sa handler::check_and_repair()
*/

bool
handler::ha_check_and_repair(THD *thd)
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type == F_UNLCK);
  mark_trx_read_write();

  return check_and_repair(thd);
}


/**
  Disable indexes: public interface.

  @sa handler::disable_indexes()
*/

int
handler::ha_disable_indexes(uint mode)
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  mark_trx_read_write();

  return disable_indexes(mode);
}


/**
  Enable indexes: public interface.

  @sa handler::enable_indexes()
*/

int
handler::ha_enable_indexes(uint mode)
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  mark_trx_read_write();

  return enable_indexes(mode);
}


/**
  Discard or import tablespace: public interface.

  @sa handler::discard_or_import_tablespace()
*/

int
handler::ha_discard_or_import_tablespace(my_bool discard)
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type == F_WRLCK);
  mark_trx_read_write();

  return discard_or_import_tablespace(discard);
}


bool handler::ha_prepare_inplace_alter_table(TABLE *altered_table,
                                             Alter_inplace_info *ha_alter_info)
{
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);
  mark_trx_read_write();

  return prepare_inplace_alter_table(altered_table, ha_alter_info);
}


bool handler::ha_commit_inplace_alter_table(TABLE *altered_table,
                                            Alter_inplace_info *ha_alter_info,
                                            bool commit)
{
   /*
     At this point we should have an exclusive metadata lock on the table.
     The exception is if we're about to roll back changes (commit= false).
     In this case, we might be rolling back after a failed lock upgrade,
     so we could be holding the same lock level as for inplace_alter_table().
   */
   DBUG_ASSERT(ha_thd()->mdl_context.is_lock_owner(MDL_key::TABLE,
                                                   table->s->db.str,
                                                   table->s->table_name.str,
                                                   MDL_EXCLUSIVE) ||
               !commit);

   return commit_inplace_alter_table(altered_table, ha_alter_info, commit);
}


/*
   Default implementation to support in-place alter table
   and old online add/drop index API
*/

enum_alter_inplace_result
handler::check_if_supported_inplace_alter(TABLE *altered_table,
                                          Alter_inplace_info *ha_alter_info)
{
  DBUG_ENTER("handler::check_if_supported_inplace_alter");

  HA_CREATE_INFO *create_info= ha_alter_info->create_info;

  if (altered_table->versioned(VERS_TIMESTAMP))
    DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED);

  alter_table_operations inplace_offline_operations=
    ALTER_COLUMN_TYPE_CHANGE_BY_ENGINE |
    ALTER_COLUMN_NAME |
    ALTER_RENAME_COLUMN |
    ALTER_CHANGE_COLUMN_DEFAULT |
    ALTER_COLUMN_DEFAULT |
    ALTER_COLUMN_OPTION |
    ALTER_CHANGE_CREATE_OPTION |
    ALTER_DROP_CHECK_CONSTRAINT |
    ALTER_PARTITIONED |
    ALTER_VIRTUAL_GCOL_EXPR |
    ALTER_RENAME |
    ALTER_RENAME_INDEX |
    ALTER_INDEX_IGNORABILITY;

  /* Is there at least one operation that requires copy algorithm? */
  if (ha_alter_info->handler_flags & ~inplace_offline_operations)
    DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED);

  /*
    The following checks for changes related to ALTER_OPTIONS

    ALTER TABLE tbl_name CONVERT TO CHARACTER SET .. and
    ALTER TABLE table_name DEFAULT CHARSET = .. most likely
    change column charsets and so not supported in-place through
    old API.

    Changing of PACK_KEYS, MAX_ROWS and ROW_FORMAT options were
    not supported as in-place operations in old API either.
  */
  if (create_info->used_fields & (HA_CREATE_USED_CHARSET |
                                  HA_CREATE_USED_DEFAULT_CHARSET |
                                  HA_CREATE_USED_PACK_KEYS |
                                  HA_CREATE_USED_CHECKSUM |
                                  HA_CREATE_USED_MAX_ROWS) ||
      (table->s->row_type != create_info->row_type))
    DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED);

  uint table_changes= (ha_alter_info->handler_flags &
                       ALTER_COLUMN_TYPE_CHANGE_BY_ENGINE) ?
    IS_EQUAL_PACK_LENGTH : IS_EQUAL_YES;
  if (table->file->check_if_incompatible_data(create_info, table_changes)
      == COMPATIBLE_DATA_YES)
    DBUG_RETURN(HA_ALTER_INPLACE_NO_LOCK);

  DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED);
}

Alter_inplace_info::Alter_inplace_info(HA_CREATE_INFO *create_info_arg,
                     Alter_info *alter_info_arg,
                     KEY *key_info_arg, uint key_count_arg,
                     partition_info *modified_part_info_arg,
                     bool ignore_arg, bool error_non_empty)
    : create_info(create_info_arg),
    alter_info(alter_info_arg),
    key_info_buffer(key_info_arg),
    key_count(key_count_arg),
    rename_keys(current_thd->mem_root),
    modified_part_info(modified_part_info_arg),
    ignore(ignore_arg),
    error_if_not_empty(error_non_empty)
  {}

void Alter_inplace_info::report_unsupported_error(const char *not_supported,
                                                  const char *try_instead) const
{
  if (unsupported_reason == NULL)
    my_error(ER_ALTER_OPERATION_NOT_SUPPORTED, MYF(0),
             not_supported, try_instead);
  else
    my_error(ER_ALTER_OPERATION_NOT_SUPPORTED_REASON, MYF(0),
             not_supported, unsupported_reason, try_instead);
}


/**
  Rename table: public interface.

  @sa handler::rename_table()
*/

int
handler::ha_rename_table(const char *from, const char *to)
{
  DBUG_ASSERT(m_lock_type == F_UNLCK);
  mark_trx_read_write();

  return rename_table(from, to);
}


/**
  Drop table in the engine: public interface.

  @sa handler::drop_table()

  The difference between this and delete_table() is that the table is open in
  drop_table().
*/

void
handler::ha_drop_table(const char *name)
{
  DBUG_ASSERT(m_lock_type == F_UNLCK);
  if (check_if_updates_are_ignored("DROP"))
    return;

  mark_trx_read_write();
  drop_table(name);
}


/**
   Structure used during force drop table.
*/

struct st_force_drop_table_params
{
  const char *path;
  const LEX_CSTRING *db;
  const LEX_CSTRING *alias;
  int error;
  bool discovering;
};


/**
   Try to delete table from a given plugin
   Table types with discovery is ignored as these .frm files would have
   been created during discovery and thus doesn't need to be found
   for drop table force
*/

static my_bool delete_table_force(THD *thd, plugin_ref plugin, void *arg)
{
  handlerton *hton = plugin_hton(plugin);
  st_force_drop_table_params *param = (st_force_drop_table_params *)arg;

  if (param->discovering == (hton->discover_table != NULL) &&
      !(thd->slave_thread && (hton->flags & HTON_IGNORE_UPDATES)))
  {
    int error;
    error= ha_delete_table(thd, hton, param->path, param->db, param->alias, 0);
    if (error > 0 && !non_existing_table_error(error))
      param->error= error;
    if (error == 0)
    {
      if (hton && hton->flags & HTON_TABLE_MAY_NOT_EXIST_ON_SLAVE)
        thd->replication_flags |= OPTION_IF_EXISTS;
      param->error= 0;
      return TRUE;                                // Table was deleted
    }
  }
  return FALSE;
}

/**
   @brief
   Traverse all plugins to delete table when .frm file is missing.

   @return -1  Table was not found in any engine
   @return 0  Table was found in some engine and delete succeded
   @return #  Error from first engine that had a table but didn't succeed to
              delete the table
   @return HA_ERR_ROW_IS_REFERENCED if foreign key reference is encountered,

*/

int ha_delete_table_force(THD *thd, const char *path, const LEX_CSTRING *db,
                          const LEX_CSTRING *alias)
{
  st_force_drop_table_params param;
  Table_exists_error_handler no_such_table_handler;
  DBUG_ENTER("ha_delete_table_force");

  param.path=        path;
  param.db=          db;
  param.alias=       alias;
  param.error=       -1;                   // Table not found
  param.discovering= true;

  thd->push_internal_handler(&no_such_table_handler);
  if (plugin_foreach(thd, delete_table_force, MYSQL_STORAGE_ENGINE_PLUGIN,
                     &param))
    param.error= 0;                            // Delete succeded
  else
  {
    param.discovering= false;
    if (plugin_foreach(thd, delete_table_force, MYSQL_STORAGE_ENGINE_PLUGIN,
                       &param))
      param.error= 0;                            // Delete succeded
  }
  thd->pop_internal_handler();
  DBUG_RETURN(param.error);
}


/**
  Create a table in the engine: public interface.

  @sa handler::create()
*/

int
handler::ha_create(const char *name, TABLE *form, HA_CREATE_INFO *info_arg)
{
  DBUG_ASSERT(m_lock_type == F_UNLCK);
  mark_trx_read_write();
  int error= create(name, form, info_arg);
  if (!error &&
      !(info_arg->options & (HA_LEX_CREATE_TMP_TABLE | HA_CREATE_TMP_ALTER)))
    mysql_audit_create_table(form);
  return error;
}


/**
  Create handler files for CREATE TABLE: public interface.

  @sa handler::create_partitioning_metadata()
*/

int
handler::ha_create_partitioning_metadata(const char *name,
                                         const char *old_name,
                                         chf_create_flags action_flag)
{
  /*
    Normally this is done when unlocked, but in fast_alter_partition_table,
    it is done on an already locked handler when preparing to alter/rename
    partitions.
  */
  DBUG_ASSERT(m_lock_type == F_UNLCK ||
              (!old_name && strcmp(name, table_share->path.str)));


  mark_trx_read_write();
  return create_partitioning_metadata(name, old_name, action_flag);
}


/**
  Change partitions: public interface.

  @sa handler::change_partitions()
*/

int
handler::ha_change_partitions(HA_CREATE_INFO *create_info,
                              const char *path,
                              ulonglong * const copied,
                              ulonglong * const deleted,
                              const uchar *pack_frm_data,
                              size_t pack_frm_len)
{
  /*
    Must have at least RDLCK or be a TMP table. Read lock is needed to read
    from current partitions and write lock will be taken on new partitions.
  */
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type != F_UNLCK);

  mark_trx_read_write();

  return change_partitions(create_info, path, copied, deleted,
                           pack_frm_data, pack_frm_len);
}


/**
  Drop partitions: public interface.

  @sa handler::drop_partitions()
*/

int
handler::ha_drop_partitions(const char *path)
{
  DBUG_ASSERT(!table->db_stat);

  mark_trx_read_write();

  return drop_partitions(path);
}


/**
  Rename partitions: public interface.

  @sa handler::rename_partitions()
*/

int
handler::ha_rename_partitions(const char *path)
{
  DBUG_ASSERT(!table->db_stat);

  mark_trx_read_write();

  return rename_partitions(path);
}


/**
  Tell the storage engine that it is allowed to "disable transaction" in the
  handler. It is a hint that ACID is not required - it was used in NDB for
  ALTER TABLE, for example, when data are copied to temporary table.
  A storage engine may treat this hint any way it likes. NDB for example
  started to commit every now and then automatically.
  This hint can be safely ignored.
*/
int ha_enable_transaction(THD *thd, bool on)
{
  int error=0;
  DBUG_ENTER("ha_enable_transaction");
  DBUG_PRINT("enter", ("on: %d", (int) on));

  if ((thd->transaction->on= on))
  {
    /*
      Now all storage engines should have transaction handling enabled.
      But some may have it enabled all the time - "disabling" transactions
      is an optimization hint that storage engine is free to ignore.
      So, let's commit an open transaction (if any) now.
    */
    if (likely(!(error= ha_commit_trans(thd, 0))))
      error= trans_commit_implicit(thd);
  }
  DBUG_RETURN(error);
}

int handler::index_next_same(uchar *buf, const uchar *key, uint keylen)
{
  int error;
  DBUG_ENTER("handler::index_next_same");
  if (!(error=index_next(buf)))
  {
    my_ptrdiff_t ptrdiff= buf - table->record[0];
    uchar *UNINIT_VAR(save_record_0);
    KEY *UNINIT_VAR(key_info);
    KEY_PART_INFO *UNINIT_VAR(key_part);
    KEY_PART_INFO *UNINIT_VAR(key_part_end);

    /*
      key_cmp_if_same() compares table->record[0] against 'key'.
      In parts it uses table->record[0] directly, in parts it uses
      field objects with their local pointers into table->record[0].
      If 'buf' is distinct from table->record[0], we need to move
      all record references. This is table->record[0] itself and
      the field pointers of the fields used in this key.
    */
    if (ptrdiff)
    {
      save_record_0= table->record[0];
      table->record[0]= buf;
      key_info= table->key_info + active_index;
      key_part= key_info->key_part;
      key_part_end= key_part + key_info->user_defined_key_parts;
      for (; key_part < key_part_end; key_part++)
      {
        DBUG_ASSERT(key_part->field);
        key_part->field->move_field_offset(ptrdiff);
      }
    }

    if (key_cmp_if_same(table, key, active_index, keylen))
    {
      table->status=STATUS_NOT_FOUND;
      error=HA_ERR_END_OF_FILE;
    }

    /* Move back if necessary. */
    if (ptrdiff)
    {
      table->record[0]= save_record_0;
      for (key_part= key_info->key_part; key_part < key_part_end; key_part++)
        key_part->field->move_field_offset(-ptrdiff);
    }
  }
  DBUG_PRINT("return",("%i", error));
  DBUG_RETURN(error);
}


void handler::get_dynamic_partition_info(PARTITION_STATS *stat_info,
                                         uint part_id)
{
  info(HA_STATUS_CONST | HA_STATUS_TIME | HA_STATUS_VARIABLE |
       HA_STATUS_NO_LOCK);
  stat_info->records=              stats.records;
  stat_info->mean_rec_length=      stats.mean_rec_length;
  stat_info->data_file_length=     stats.data_file_length;
  stat_info->max_data_file_length= stats.max_data_file_length;
  stat_info->index_file_length=    stats.index_file_length;
  stat_info->max_index_file_length=stats.max_index_file_length;
  stat_info->delete_length=        stats.delete_length;
  stat_info->create_time=          stats.create_time;
  stat_info->update_time=          stats.update_time;
  stat_info->check_time=           stats.check_time;
  stat_info->check_sum=            stats.checksum;
  stat_info->check_sum_null=       stats.checksum_null;
}


/*
  Updates the global table stats with the TABLE this handler represents
*/

void handler::update_global_table_stats()
{
  TABLE_STATS * table_stats;

  status_var_add(table->in_use->status_var.rows_read, rows_read);
  DBUG_ASSERT(rows_tmp_read == 0);

  if (!table->in_use->userstat_running)
  {
    rows_read= rows_changed= 0;
    return;
  }

  if (rows_read + rows_changed == 0)
    return;                                     // Nothing to update.

  DBUG_ASSERT(table->s);
  DBUG_ASSERT(table->s->table_cache_key.str);

  mysql_mutex_lock(&LOCK_global_table_stats);
  /* Gets the global table stats, creating one if necessary. */
  if (!(table_stats= (TABLE_STATS*)
        my_hash_search(&global_table_stats,
                    (uchar*) table->s->table_cache_key.str,
                    table->s->table_cache_key.length)))
  {
    if (!(table_stats = ((TABLE_STATS*)
                         my_malloc(PSI_INSTRUMENT_ME, sizeof(TABLE_STATS),
                                   MYF(MY_WME | MY_ZEROFILL)))))
    {
      /* Out of memory error already given */
      goto end;
    }
    memcpy(table_stats->table, table->s->table_cache_key.str,
           table->s->table_cache_key.length);
    table_stats->table_name_length= (uint)table->s->table_cache_key.length;
    table_stats->engine_type= ht->db_type;
    /* No need to set variables to 0, as we use MY_ZEROFILL above */

    if (my_hash_insert(&global_table_stats, (uchar*) table_stats))
    {
      /* Out of memory error is already given */
      my_free(table_stats);
      goto end;
    }
  }
  // Updates the global table stats.
  table_stats->rows_read+=    rows_read;
  table_stats->rows_changed+= rows_changed;
  table_stats->rows_changed_x_indexes+= (rows_changed *
                                         (table->s->keys ? table->s->keys :
                                          1));
  rows_read= rows_changed= 0;
end:
  mysql_mutex_unlock(&LOCK_global_table_stats);
}


/*
  Updates the global index stats with this handler's accumulated index reads.
*/

void handler::update_global_index_stats()
{
  DBUG_ASSERT(table->s);

  if (!table->in_use->userstat_running)
  {
    /* Reset all index read values */
    bzero(index_rows_read, sizeof(index_rows_read[0]) * table->s->keys);
    return;
  }

  for (uint index = 0; index < table->s->keys; index++)
  {
    if (index_rows_read[index])
    {
      INDEX_STATS* index_stats;
      size_t key_length;
      KEY *key_info = &table->key_info[index];  // Rows were read using this

      DBUG_ASSERT(key_info->cache_name);
      if (!key_info->cache_name)
        continue;
      key_length= table->s->table_cache_key.length + key_info->name.length + 1;
      mysql_mutex_lock(&LOCK_global_index_stats);
      // Gets the global index stats, creating one if necessary.
      if (!(index_stats= (INDEX_STATS*) my_hash_search(&global_index_stats,
                                                    key_info->cache_name,
                                                    key_length)))
      {
        if (!(index_stats = ((INDEX_STATS*)
                             my_malloc(PSI_INSTRUMENT_ME, sizeof(INDEX_STATS),
                                       MYF(MY_WME | MY_ZEROFILL)))))
          goto end;                             // Error is already given

        memcpy(index_stats->index, key_info->cache_name, key_length);
        index_stats->index_name_length= key_length;
        if (my_hash_insert(&global_index_stats, (uchar*) index_stats))
        {
          my_free(index_stats);
          goto end;
        }
      }
      /* Updates the global index stats. */
      index_stats->rows_read+= index_rows_read[index];
      index_rows_read[index]= 0;
end:
      mysql_mutex_unlock(&LOCK_global_index_stats);
    }
  }
}


static void flush_checksum(ha_checksum *row_crc, uchar **checksum_start,
                           size_t *checksum_length)
{
  if (*checksum_start)
  {
    *row_crc= my_checksum(*row_crc, *checksum_start, *checksum_length);
    *checksum_start= NULL;
    *checksum_length= 0;
  }
}


/* calculating table's checksum */
int handler::calculate_checksum()
{
  int error;
  THD *thd=ha_thd();
  DBUG_ASSERT(table->s->last_null_bit_pos < 8);
  uchar null_mask= table->s->last_null_bit_pos
                   ? 256 -  (1 << table->s->last_null_bit_pos) : 0;

  table->use_all_stored_columns();
  stats.checksum= 0;

  if ((error= ha_rnd_init(1)))
    return error;

  for (;;)
  {
    if (thd->killed)
      return HA_ERR_ABORTED_BY_USER;

    ha_checksum row_crc= 0;
    error= ha_rnd_next(table->record[0]);
    if (error)
      break;

    if (table->s->null_bytes)
    {
      /* fix undefined null bits */
      table->record[0][table->s->null_bytes-1] |= null_mask;
      if (!(table->s->db_create_options & HA_OPTION_PACK_RECORD))
        table->record[0][0] |= 1;

      row_crc= my_checksum(row_crc, table->record[0], table->s->null_bytes);
    }

    uchar *checksum_start= NULL;
    size_t checksum_length= 0;
    for (uint i= 0; i < table->s->fields; i++ )
    {
      Field *f= table->field[i];
      if (!f->stored_in_db())
        continue;


      if (! (thd->variables.old_behavior & OLD_MODE_COMPAT_5_1_CHECKSUM) &&
            f->is_real_null(0))
      {
        flush_checksum(&row_crc, &checksum_start, &checksum_length);
        continue;
      }
     /*
       BLOB and VARCHAR have pointers in their field, we must convert
       to string; GEOMETRY is implemented on top of BLOB.
       BIT may store its data among NULL bits, convert as well.
     */
      switch (f->type()) {
        case MYSQL_TYPE_BLOB:
        case MYSQL_TYPE_VARCHAR:
        case MYSQL_TYPE_GEOMETRY:
        case MYSQL_TYPE_BIT:
        {
          flush_checksum(&row_crc, &checksum_start, &checksum_length);
          String tmp;
          f->val_str(&tmp);
          row_crc= my_checksum(row_crc, (uchar*) tmp.ptr(), tmp.length());
          break;
        }
        default:
          if (!checksum_start)
            checksum_start= f->ptr;
          DBUG_ASSERT(checksum_start + checksum_length == f->ptr);
          checksum_length+= f->pack_length();
          break;
      }
    }
    flush_checksum(&row_crc, &checksum_start, &checksum_length);

    stats.checksum+= row_crc;
  }
  ha_rnd_end();
  return error == HA_ERR_END_OF_FILE ? 0 : error;
}


/****************************************************************************
** Some general functions that isn't in the handler class
****************************************************************************/

/**
  Initiates table-file and calls appropriate database-creator.

  @retval
   0  ok
  @retval
   1  error
*/
int ha_create_table(THD *thd, const char *path, const char *db,
                    const char *table_name, HA_CREATE_INFO *create_info,
                    LEX_CUSTRING *frm, bool skip_frm_file)
{
  int error= 1;
  TABLE table;
  char name_buff[FN_REFLEN];
  const char *name;
  TABLE_SHARE share;
  Abort_on_warning_instant_set old_abort_on_warning(thd, 0);
  bool temp_table __attribute__((unused)) =
    create_info->options & (HA_LEX_CREATE_TMP_TABLE | HA_CREATE_TMP_ALTER);
  DBUG_ENTER("ha_create_table");

  init_tmp_table_share(thd, &share, db, 0, table_name, path);

  if (frm)
  {
    bool write_frm_now= (!create_info->db_type->discover_table &&
                         !create_info->tmp_table() && !skip_frm_file);

    share.frm_image= frm;

    // open an frm image
    if (share.init_from_binary_frm_image(thd, write_frm_now,
                                         frm->str, frm->length))
      goto err;
  }
  else
  {
    // open an frm file
    share.db_plugin= ha_lock_engine(thd, create_info->db_type);

    if (open_table_def(thd, &share))
      goto err;
  }

  share.m_psi= PSI_CALL_get_table_share(temp_table, &share);

  if (open_table_from_share(thd, &share, &empty_clex_str, 0, READ_ALL, 0,
                            &table, true))
    goto err;

  update_create_info_from_table(create_info, &table);

  name= get_canonical_filename(table.file, share.path.str, name_buff);

  error= table.file->ha_create(name, &table, create_info);

  if (unlikely(error))
  {
    if (!thd->is_error())
      my_error(ER_CANT_CREATE_TABLE, MYF(0), db, table_name, error);
    table.file->print_error(error, MYF(ME_WARNING));
    PSI_CALL_drop_table_share(temp_table, share.db.str, (uint)share.db.length,
                              share.table_name.str, (uint)share.table_name.length);
  }

  (void) closefrm(&table);
 
err:
  free_table_share(&share);
  DBUG_RETURN(error != 0);
}

void st_ha_check_opt::init()
{
  flags= sql_flags= 0;
  start_time= my_time(0);
}


/*****************************************************************************
  Key cache handling.

  This code is only relevant for ISAM/MyISAM tables

  key_cache->cache may be 0 only in the case where a key cache is not
  initialized or when we where not able to init the key cache in a previous
  call to ha_init_key_cache() (probably out of memory)
*****************************************************************************/

/**
  Init a key cache if it has not been initied before.
*/
int ha_init_key_cache(const char *name, KEY_CACHE *key_cache, void *unused
                      __attribute__((unused)))
{
  DBUG_ENTER("ha_init_key_cache");

  if (!key_cache->key_cache_inited)
  {
    mysql_mutex_lock(&LOCK_global_system_variables);
    size_t tmp_buff_size= (size_t) key_cache->param_buff_size;
    uint tmp_block_size= (uint) key_cache->param_block_size;
    uint division_limit= (uint)key_cache->param_division_limit;
    uint age_threshold=  (uint)key_cache->param_age_threshold;
    uint partitions=     (uint)key_cache->param_partitions;
    uint changed_blocks_hash_size=  (uint)key_cache->changed_blocks_hash_size;
    mysql_mutex_unlock(&LOCK_global_system_variables);
    DBUG_RETURN(!init_key_cache(key_cache,
				tmp_block_size,
				tmp_buff_size,
				division_limit, age_threshold,
                                changed_blocks_hash_size,
                                partitions));
  }
  DBUG_RETURN(0);
}


/**
  Resize key cache.
*/
int ha_resize_key_cache(KEY_CACHE *key_cache)
{
  DBUG_ENTER("ha_resize_key_cache");

  if (key_cache->key_cache_inited)
  {
    mysql_mutex_lock(&LOCK_global_system_variables);
    size_t tmp_buff_size= (size_t) key_cache->param_buff_size;
    long tmp_block_size= (long) key_cache->param_block_size;
    uint division_limit= (uint)key_cache->param_division_limit;
    uint age_threshold=  (uint)key_cache->param_age_threshold;
    uint changed_blocks_hash_size=  (uint)key_cache->changed_blocks_hash_size;
    mysql_mutex_unlock(&LOCK_global_system_variables);
    DBUG_RETURN(!resize_key_cache(key_cache, tmp_block_size,
				  tmp_buff_size,
				  division_limit, age_threshold,
                                  changed_blocks_hash_size));
  }
  DBUG_RETURN(0);
}


/**
  Change parameters for key cache (like division_limit)
*/
int ha_change_key_cache_param(KEY_CACHE *key_cache)
{
  DBUG_ENTER("ha_change_key_cache_param");

  if (key_cache->key_cache_inited)
  {
    mysql_mutex_lock(&LOCK_global_system_variables);
    uint division_limit= (uint)key_cache->param_division_limit;
    uint age_threshold=  (uint)key_cache->param_age_threshold;
    mysql_mutex_unlock(&LOCK_global_system_variables);
    change_key_cache_param(key_cache, division_limit, age_threshold);
  }
  DBUG_RETURN(0);
}


/**
  Repartition key cache 
*/
int ha_repartition_key_cache(KEY_CACHE *key_cache)
{
  DBUG_ENTER("ha_repartition_key_cache");

  if (key_cache->key_cache_inited)
  {
    mysql_mutex_lock(&LOCK_global_system_variables);
    size_t tmp_buff_size= (size_t) key_cache->param_buff_size;
    long tmp_block_size= (long) key_cache->param_block_size;
    uint division_limit= (uint)key_cache->param_division_limit;
    uint age_threshold=  (uint)key_cache->param_age_threshold;
    uint partitions=     (uint)key_cache->param_partitions;
    uint changed_blocks_hash_size=  (uint)key_cache->changed_blocks_hash_size;
    mysql_mutex_unlock(&LOCK_global_system_variables);
    DBUG_RETURN(!repartition_key_cache(key_cache, tmp_block_size,
				       tmp_buff_size,
				       division_limit, age_threshold,
                                       changed_blocks_hash_size,
                                       partitions));
  }
  DBUG_RETURN(0);
}


/**
  Move all tables from one key cache to another one.
*/
int ha_change_key_cache(KEY_CACHE *old_key_cache,
			KEY_CACHE *new_key_cache)
{
  mi_change_key_cache(old_key_cache, new_key_cache);
  return 0;
}


static my_bool discover_handlerton(THD *thd, plugin_ref plugin,
                                   void *arg)
{
  TABLE_SHARE *share= (TABLE_SHARE *)arg;
  handlerton *hton= plugin_hton(plugin);
  if (hton->discover_table)
  {
    share->db_plugin= plugin;
    int error= hton->discover_table(hton, thd, share);
    if (error != HA_ERR_NO_SUCH_TABLE)
    {
      if (unlikely(error))
      {
        if (!share->error)
        {
          share->error= OPEN_FRM_ERROR_ALREADY_ISSUED;
          plugin_unlock(0, share->db_plugin);
        }

        /*
          report an error, unless it is "generic" and a more
          specific one was already reported
        */
        if (error != HA_ERR_GENERIC || !thd->is_error())
          my_error(ER_GET_ERRNO, MYF(0), error, plugin_name(plugin)->str);
        share->db_plugin= 0;
      }
      else
        share->error= OPEN_FRM_OK;

      status_var_increment(thd->status_var.ha_discover_count);
      return TRUE; // abort the search
    }
    share->db_plugin= 0;
  }

  DBUG_ASSERT(share->error == OPEN_FRM_OPEN_ERROR);
  return FALSE;    // continue with the next engine
}

int ha_discover_table(THD *thd, TABLE_SHARE *share)
{
  DBUG_ENTER("ha_discover_table");
  int found;

  DBUG_ASSERT(share->error == OPEN_FRM_OPEN_ERROR);   // share is not OK yet

  if (!engines_with_discover)
    found= FALSE;
  else if (share->db_plugin)
    found= discover_handlerton(thd, share->db_plugin, share);
  else
    found= plugin_foreach(thd, discover_handlerton,
                        MYSQL_STORAGE_ENGINE_PLUGIN, share);

  if (thd->lex->query_tables && thd->lex->query_tables->sequence && !found)
    my_error(ER_UNKNOWN_SEQUENCES, MYF(0),share->table_name.str);
  if (!found)
    open_table_error(share, OPEN_FRM_OPEN_ERROR, ENOENT); // not found

  DBUG_RETURN(share->error != OPEN_FRM_OK);
}

static my_bool file_ext_exists(char *path, size_t path_len, const char *ext)
{
  strmake(path + path_len, ext, FN_REFLEN - path_len);
  return !access(path, F_OK);
}

struct st_discover_existence_args
{
  char *path;
  size_t  path_len;
  const char *db, *table_name;
  handlerton *hton;
  bool frm_exists;
};

static my_bool discover_existence(THD *thd, plugin_ref plugin,
                                  void *arg)
{
  st_discover_existence_args *args= (st_discover_existence_args*)arg;
  handlerton *ht= plugin_hton(plugin);
  if (!ht->discover_table_existence)
    return args->frm_exists;

  args->hton= ht;

  if (ht->discover_table_existence == ext_based_existence)
    return file_ext_exists(args->path, args->path_len,
                           ht->tablefile_extensions[0]);

  return ht->discover_table_existence(ht, args->db, args->table_name);
}


/**
  Check if a given table exists, without doing a full discover, if possible

  If the 'hton' is not NULL, it's set to the handlerton of the storage engine
  of this table, or to view_pseudo_hton if the frm belongs to a view.

  This function takes discovery correctly into account. If frm is found,
  it discovers the table to make sure it really exists in the engine.
  If no frm is found it discovers the table, in case it still exists in
  the engine.

  While it tries to cut corners (don't open .frm if no discovering engine is
  enabled, no full discovery if all discovering engines support
  discover_table_existence, etc), it still *may* be quite expensive
  and must be used sparingly.

  @retval true    Table exists (even if the error occurred, like bad frm)
  @retval false   Table does not exist (one can do CREATE TABLE table_name)

  @note if frm exists and the table in engine doesn't, *hton will be set,
        but the return value will be false.

  @note if frm file exists, but the table cannot be opened (engine not
        loaded, frm is invalid), the return value will be true, but
        *hton will be NULL.
*/

bool ha_table_exists(THD *thd, const LEX_CSTRING *db,
                     const LEX_CSTRING *table_name, LEX_CUSTRING *table_id,
                     LEX_CSTRING *partition_engine_name,
                     handlerton **hton, bool *is_sequence)
{
  handlerton *dummy;
  bool dummy2;
  DBUG_ENTER("ha_table_exists");

  if (hton)
    *hton= 0;
  else if (engines_with_discover)
    hton= &dummy;
  if (!is_sequence)
    is_sequence= &dummy2;
  *is_sequence= 0;
  if (table_id)
  {
    table_id->str= 0;
    table_id->length= 0;
  }

  TDC_element *element= tdc_lock_share(thd, db->str, table_name->str);
  if (element && element != MY_ERRPTR)
  {
    if (!hton)
      hton= &dummy;
    *hton= element->share->db_type();
#ifdef WITH_PARTITION_STORAGE_ENGINE
    if (partition_engine_name && element->share->db_type() == partition_hton)
    {
      if (!static_cast<Partition_share *>(element->share->ha_share)->
          partition_engine_name)
      {
        /* Partition engine found, but table has never been opened */
        tdc_unlock_share(element);
        goto retry_from_frm;
      }
      lex_string_set(partition_engine_name,
        static_cast<Partition_share *>(element->share->ha_share)->
          partition_engine_name);
    }
#endif
    *is_sequence= element->share->table_type == TABLE_TYPE_SEQUENCE;
    if (*hton != view_pseudo_hton && element->share->tabledef_version.length &&
        table_id &&
        (table_id->str= (uchar*)
         thd->memdup(element->share->tabledef_version.str, MY_UUID_SIZE)))
      table_id->length= MY_UUID_SIZE;
    tdc_unlock_share(element);
    DBUG_RETURN(TRUE);
  }

#ifdef WITH_PARTITION_STORAGE_ENGINE
retry_from_frm:
#endif
  char path[FN_REFLEN + 1];
  size_t path_len = build_table_filename(path, sizeof(path) - 1,
                                         db->str, table_name->str, "", 0);
  st_discover_existence_args args= {path, path_len, db->str, table_name->str, 0, true};

  if (file_ext_exists(path, path_len, reg_ext))
  {
    bool exists= true;
    if (hton)
    {
      char engine_buf[NAME_CHAR_LEN + 1];
      LEX_CSTRING engine= { engine_buf, 0 };
      Table_type type= dd_frm_type(thd, path, &engine,
                                   partition_engine_name,
                                   table_id);

      switch (type) {
      case TABLE_TYPE_UNKNOWN:
        DBUG_PRINT("exit", ("Exist, cannot be opened"));
        DBUG_RETURN(true);                      // Frm exists
      case TABLE_TYPE_VIEW:
        *hton= view_pseudo_hton;
        DBUG_PRINT("exit", ("Exist, view"));
        DBUG_RETURN(true);                      // Frm exists
      case TABLE_TYPE_SEQUENCE:
        *is_sequence= true;
        /* fall through */
      case TABLE_TYPE_NORMAL:
        {
          plugin_ref p=  plugin_lock_by_name(thd, &engine,
                                             MYSQL_STORAGE_ENGINE_PLUGIN);
          *hton= p ? plugin_hton(p) : NULL;
          if (*hton)      // verify that the table really exists
            exists= discover_existence(thd, p, &args);
        }
      }
    }
    DBUG_PRINT("exit", (exists ? "Exists" : "Does not exist"));
    DBUG_RETURN(exists);
  }

  args.frm_exists= false;
  if (plugin_foreach(thd, discover_existence, MYSQL_STORAGE_ENGINE_PLUGIN,
                     &args))
  {
    if (hton)
      *hton= args.hton;
    DBUG_PRINT("exit", ("discovery found file"));
    DBUG_RETURN(TRUE);
  }

  if (need_full_discover_for_existence)
  {
    TABLE_LIST table;
    bool exists;
    uint flags = GTS_TABLE | GTS_VIEW;

    if (!hton)
      flags|= GTS_NOLOCK;

    Table_exists_error_handler no_such_table_handler;
    thd->push_internal_handler(&no_such_table_handler);
    table.init_one_table(db, table_name, 0, TL_READ);
    TABLE_SHARE *share= tdc_acquire_share(thd, &table, flags);
    thd->pop_internal_handler();

    if (hton && share)
    {
      *hton= share->db_type();
      if (table_id && share->tabledef_version.length &&
          (table_id->str=
           (uchar*) thd->memdup(share->tabledef_version.str, MY_UUID_SIZE)))
        table_id->length= MY_UUID_SIZE;
      tdc_release_share(share);
    }

    // the table doesn't exist if we've caught ER_NO_SUCH_TABLE and nothing else
    exists= !no_such_table_handler.safely_trapped_errors();
    DBUG_PRINT("exit", (exists ? "Exists" : "Does not exist"));
    DBUG_RETURN(exists);
  }

  DBUG_PRINT("exit", ("Does not exist"));
  DBUG_RETURN(FALSE);
}


/*
  Check if the CREATE/ALTER table should be ignored
  This could happen for slaves where the table is shared between master
  and slave

  If statement is ignored, write a note
*/

bool handler::check_if_updates_are_ignored(const char *op) const
{
  return ha_check_if_updates_are_ignored(table->in_use, ht, op);
}


bool ha_check_if_updates_are_ignored(THD *thd, handlerton *hton,
                                     const char *op)
{
  DBUG_ENTER("ha_check_if_updates_are_ignored");
  if (!thd->slave_thread || !(hton= ha_checktype(thd, hton, 1)))
    DBUG_RETURN(0);                                   // Not slave or no engine
  if (!(hton->flags & HTON_IGNORE_UPDATES))
    DBUG_RETURN(0);                                   // Not shared table
  my_error(ER_SLAVE_IGNORED_SHARED_TABLE, MYF(ME_NOTE), op);
  DBUG_RETURN(1);
}


/**
  Discover all table names in a given database
*/
extern "C" {

static int cmp_file_names(const void *a, const void *b)
{
  CHARSET_INFO *cs= character_set_filesystem;
  char *aa= ((FILEINFO *)a)->name;
  char *bb= ((FILEINFO *)b)->name;
  return cs->strnncoll(aa, strlen(aa), bb, strlen(bb));
}

static int cmp_table_names(LEX_CSTRING * const *a, LEX_CSTRING * const *b)
{
  return my_charset_bin.strnncoll((*a)->str, (*a)->length,
                                  (*b)->str, (*b)->length);
}

#ifndef DBUG_OFF
static int cmp_table_names_desc(LEX_CSTRING * const *a, LEX_CSTRING * const *b)
{
  return -cmp_table_names(a, b);
}
#endif

}

Discovered_table_list::Discovered_table_list(THD *thd_arg,
                 Dynamic_array<LEX_CSTRING*> *tables_arg,
                 const LEX_CSTRING *wild_arg) :
  thd(thd_arg), with_temps(false), tables(tables_arg)
{
  if (wild_arg->str && wild_arg->str[0])
  {
    wild= wild_arg->str;
    wend= wild + wild_arg->length;
  }
  else
    wild= 0;
}

bool Discovered_table_list::add_table(const char *tname, size_t tlen)
{
  /*
    TODO Check with_temps and filter out temp tables.
    Implement the check, when we'll have at least one affected engine (with
    custom discover_table_names() method, that calls add_table() directly).
    Note: avoid comparing the same name twice (here and in add_file).
  */
  if (wild && table_alias_charset->wildcmp(tname, tname + tlen, wild, wend,
                                           wild_prefix, wild_one, wild_many))
      return 0;

  LEX_CSTRING *name= thd->make_clex_string(tname, tlen);
  if (!name || tables->append(name))
    return 1;
  return 0;
}

bool Discovered_table_list::add_file(const char *fname)
{
  bool is_temp= strncmp(fname, STRING_WITH_LEN(tmp_file_prefix)) == 0;

  if (is_temp && !with_temps)
    return 0;

  char tname[SAFE_NAME_LEN + 1];
  size_t tlen= filename_to_tablename(fname, tname, sizeof(tname), is_temp);
  return add_table(tname, tlen);
}


void Discovered_table_list::sort()
{
  tables->sort(cmp_table_names);
}


#ifndef DBUG_OFF
void Discovered_table_list::sort_desc()
{
  tables->sort(cmp_table_names_desc);
}
#endif


void Discovered_table_list::remove_duplicates()
{
  LEX_CSTRING **src= tables->front();
  LEX_CSTRING **dst= src;
  sort();
  while (++dst <= tables->back())
  {
    LEX_CSTRING *s= *src, *d= *dst;
    DBUG_ASSERT(strncmp(s->str, d->str, MY_MIN(s->length, d->length)) <= 0);
    if ((s->length != d->length || strncmp(s->str, d->str, d->length)))
    {
      src++;
      if (src != dst)
        *src= *dst;
    }
  }
  tables->elements(src - tables->front() + 1);
}

struct st_discover_names_args
{
  LEX_CSTRING *db;
  MY_DIR *dirp;
  Discovered_table_list *result;
  uint possible_duplicates;
};

static my_bool discover_names(THD *thd, plugin_ref plugin,
                              void *arg)
{
  st_discover_names_args *args= (st_discover_names_args *)arg;
  handlerton *ht= plugin_hton(plugin);

  if (ht->discover_table_names)
  {
    size_t old_elements= args->result->tables->elements();
    if (ht->discover_table_names(ht, args->db, args->dirp, args->result))
      return 1;

    /*
      hton_ext_based_table_discovery never discovers a table that has
      a corresponding .frm file; but custom engine discover methods might
    */
    if (ht->discover_table_names != hton_ext_based_table_discovery)
      args->possible_duplicates+= (uint)(args->result->tables->elements() - old_elements);
  }

  return 0;
}

/**
  Return the list of tables

  @param thd
  @param db         database to look into
  @param dirp       list of files in this database (as returned by my_dir())
  @param result     the object to return the list of files in
  @param reusable   if true, on return, 'dirp' will be a valid list of all
                    non-table files. If false, discovery will work much faster,
                    but it will leave 'dirp' corrupted and completely unusable,
                    only good for my_dirend().

  Normally, reusable=false for SHOW and INFORMATION_SCHEMA, and reusable=true
  for DROP DATABASE (as it needs to know and delete non-table files).
*/

int ha_discover_table_names(THD *thd, LEX_CSTRING *db, MY_DIR *dirp,
                            Discovered_table_list *result, bool reusable)
{
  int error;
  DBUG_ENTER("ha_discover_table_names");

  if (engines_with_discover_file_names == 0 && !reusable)
  {
    st_discover_names_args args= {db, NULL, result, 0};
    error= ext_table_discovery_simple(dirp, result) ||
           plugin_foreach(thd, discover_names,
                            MYSQL_STORAGE_ENGINE_PLUGIN, &args);
    if (args.possible_duplicates > 0)
      result->remove_duplicates();
  }
  else
  {
    st_discover_names_args args= {db, dirp, result, 0};

    /* extension_based_table_discovery relies on dirp being sorted */
    my_qsort(dirp->dir_entry, dirp->number_of_files,
             sizeof(FILEINFO), cmp_file_names);

    error= extension_based_table_discovery(dirp, reg_ext, result) ||
           plugin_foreach(thd, discover_names,
                            MYSQL_STORAGE_ENGINE_PLUGIN, &args);
    if (args.possible_duplicates > 0)
      result->remove_duplicates();
  }

  DBUG_RETURN(error);
}


/*
int handler::pre_read_multi_range_first(KEY_MULTI_RANGE **found_range_p,
                                        KEY_MULTI_RANGE *ranges,
                                        uint range_count,
                                        bool sorted, HANDLER_BUFFER *buffer,
                                        bool use_parallel)
{
  int result;
  DBUG_ENTER("handler::pre_read_multi_range_first");
  result = pre_read_range_first(ranges->start_key.keypart_map ?
                                &ranges->start_key : 0,
                                ranges->end_key.keypart_map ?
                                &ranges->end_key : 0,
                                test(ranges->range_flag & EQ_RANGE),
                                sorted,
                                use_parallel);
  DBUG_RETURN(result);
}
*/


/**
  Read first row between two ranges.
  Store ranges for future calls to read_range_next.

  @param start_key		Start key. Is 0 if no min range
  @param end_key		End key.  Is 0 if no max range
  @param eq_range_arg	        Set to 1 if start_key == end_key
  @param sorted		Set to 1 if result should be sorted per key

  @note
    Record is read into table->record[0]

  @retval
    0			Found row
  @retval
    HA_ERR_END_OF_FILE	No rows in range
  @retval
    \#			Error code
*/
int handler::read_range_first(const key_range *start_key,
			      const key_range *end_key,
			      bool eq_range_arg, bool sorted)
{
  int result;
  DBUG_ENTER("handler::read_range_first");

  eq_range= eq_range_arg;
  set_end_range(end_key);
  range_key_part= table->key_info[active_index].key_part;

  if (!start_key)			// Read first record
    result= ha_index_first(table->record[0]);
  else
    result= ha_index_read_map(table->record[0],
                              start_key->key,
                              start_key->keypart_map,
                              start_key->flag);
  if (result)
    DBUG_RETURN((result == HA_ERR_KEY_NOT_FOUND) 
		? HA_ERR_END_OF_FILE
		: result);

  if (compare_key(end_range) <= 0)
  {
    DBUG_RETURN(0);
  }
  else
  {
    /*
      The last read row does not fall in the range. So request
      storage engine to release row lock if possible.
    */
    unlock_row();
    DBUG_RETURN(HA_ERR_END_OF_FILE);
  }
}


/**
  Read next row between two ranges.

  @note
    Record is read into table->record[0]

  @retval
    0			Found row
  @retval
    HA_ERR_END_OF_FILE	No rows in range
  @retval
    \#			Error code
*/
int handler::read_range_next()
{
  int result;
  DBUG_ENTER("handler::read_range_next");

  if (eq_range)
  {
    /* We trust that index_next_same always gives a row in range */
    DBUG_RETURN(ha_index_next_same(table->record[0],
                                   end_range->key,
                                   end_range->length));
  }
  result= ha_index_next(table->record[0]);
  if (result)
    DBUG_RETURN(result);

  if (compare_key(end_range) <= 0)
  {
    DBUG_RETURN(0);
  }
  else
  {
    /*
      The last read row does not fall in the range. So request
      storage engine to release row lock if possible.
    */
    unlock_row();
    DBUG_RETURN(HA_ERR_END_OF_FILE);
  }
}


void handler::set_end_range(const key_range *end_key)
{
  end_range= 0;
  if (end_key)
  {
    end_range= &save_end_range;
    save_end_range= *end_key;
    key_compare_result_on_equal=
      ((end_key->flag == HA_READ_BEFORE_KEY) ? 1 :
       (end_key->flag == HA_READ_AFTER_KEY) ? -1 : 0);
  }
}


/**
  Compare if found key (in row) is over max-value.

  @param range		range to compare to row. May be 0 for no range

  @see also
    key.cc::key_cmp()

  @return
    The return value is SIGN(key_in_row - range_key):

    - 0   : Key is equal to range or 'range' == 0 (no range)
    - -1  : Key is less than range
    - 1   : Key is larger than range
*/
int handler::compare_key(key_range *range)
{
  int cmp;
  if (!range || in_range_check_pushed_down)
    return 0;					// No max range
  cmp= key_cmp(range_key_part, range->key, range->length);
  if (!cmp)
    cmp= key_compare_result_on_equal;
  return cmp;
}


/*
  Same as compare_key() but doesn't check have in_range_check_pushed_down.
  This is used by index condition pushdown implementation.
*/

int handler::compare_key2(key_range *range) const
{
  int cmp;
  if (!range)
    return 0;					// no max range
  cmp= key_cmp(range_key_part, range->key, range->length);
  if (!cmp)
    cmp= key_compare_result_on_equal;
  return cmp;
}


/**
  ICP callback - to be called by an engine to check the pushed condition
*/
extern "C" check_result_t handler_index_cond_check(void* h_arg)
{
  handler *h= (handler*)h_arg;
  THD *thd= h->table->in_use;
  check_result_t res;

  DEBUG_SYNC(thd, "handler_index_cond_check");
  enum thd_kill_levels abort_at= h->has_rollback() ?
    THD_ABORT_SOFTLY : THD_ABORT_ASAP;
  if (thd_kill_level(thd) > abort_at)
    return CHECK_ABORTED_BY_USER;

  if (h->end_range && h->compare_key2(h->end_range) > 0)
    return CHECK_OUT_OF_RANGE;
  h->increment_statistics(&SSV::ha_icp_attempts);
  if ((res= h->pushed_idx_cond->val_int()? CHECK_POS : CHECK_NEG) ==
      CHECK_POS)
    h->increment_statistics(&SSV::ha_icp_match);
  return res;
}


/**
  Rowid filter callback - to be called by an engine to check rowid / primary
  keys of the rows whose data is to be fetched against the used rowid filter
*/

extern "C"
check_result_t handler_rowid_filter_check(void *h_arg)
{
  handler *h= (handler*) h_arg;
  TABLE *tab= h->get_table();

  /*
    Check for out-of-range and killed conditions only if we haven't done it
    already in the pushed index condition check
  */
  if (!h->pushed_idx_cond)
  {
    THD *thd= h->table->in_use;
    DEBUG_SYNC(thd, "handler_rowid_filter_check");
    enum thd_kill_levels abort_at= h->has_transactions() ?
      THD_ABORT_SOFTLY : THD_ABORT_ASAP;
    if (thd_kill_level(thd) > abort_at)
      return CHECK_ABORTED_BY_USER;

    if (h->end_range && h->compare_key2(h->end_range) > 0)
      return CHECK_OUT_OF_RANGE;
  }

  h->position(tab->record[0]);
  return h->pushed_rowid_filter->check((char*)h->ref)? CHECK_POS: CHECK_NEG;
}


/**
  Callback function for an engine to check whether the used rowid filter
  has been already built
*/

extern "C" int handler_rowid_filter_is_active(void *h_arg)
{
  if (!h_arg)
    return false;
  handler *h= (handler*) h_arg;
  return h->rowid_filter_is_active;
}


int handler::index_read_idx_map(uchar * buf, uint index, const uchar * key,
                                key_part_map keypart_map,
                                enum ha_rkey_function find_flag)
{
  int error, UNINIT_VAR(error1);

  error= ha_index_init(index, 0);
  if (likely(!error))
  {
    error= index_read_map(buf, key, keypart_map, find_flag);
    error1= ha_index_end();
  }
  return error ? error : error1;
}


/**
  Returns a list of all known extensions.

    No mutexes, worst case race is a minor surplus memory allocation
    We have to recreate the extension map if mysqld is restarted (for example
    within libmysqld)

  @retval
    pointer		pointer to TYPELIB structure
*/
static my_bool exts_handlerton(THD *unused, plugin_ref plugin,
                               void *arg)
{
  List<char> *found_exts= (List<char> *) arg;
  handlerton *hton= plugin_hton(plugin);
  List_iterator_fast<char> it(*found_exts);
  const char **ext, *old_ext;

  for (ext= hton->tablefile_extensions; *ext; ext++)
  {
    while ((old_ext= it++))
    {
      if (!strcmp(old_ext, *ext))
        break;
    }
    if (!old_ext)
      found_exts->push_back((char *) *ext);

    it.rewind();
  }
  return FALSE;
}

TYPELIB *ha_known_exts(void)
{
  if (!known_extensions.type_names || mysys_usage_id != known_extensions_id)
  {
    List<char> found_exts;
    const char **ext, *old_ext;

    known_extensions_id= mysys_usage_id;
    found_exts.push_back((char*) TRG_EXT);
    found_exts.push_back((char*) TRN_EXT);

    plugin_foreach(NULL, exts_handlerton,
                   MYSQL_STORAGE_ENGINE_PLUGIN, &found_exts);

    ext= (const char **) my_once_alloc(sizeof(char *)*
                                       (found_exts.elements+1),
                                       MYF(MY_WME | MY_FAE));

    DBUG_ASSERT(ext != 0);
    known_extensions.count= found_exts.elements;
    known_extensions.type_names= ext;

    List_iterator_fast<char> it(found_exts);
    while ((old_ext= it++))
      *ext++= old_ext;
    *ext= 0;
  }
  return &known_extensions;
}


static bool stat_print(THD *thd, const char *type, size_t type_len,
                       const char *file, size_t file_len,
                       const char *status, size_t status_len)
{
  Protocol *protocol= thd->protocol;
  protocol->prepare_for_resend();
  protocol->store(type, type_len, system_charset_info);
  protocol->store(file, file_len, system_charset_info);
  protocol->store(status, status_len, system_charset_info);
  if (protocol->write())
    return TRUE;
  return FALSE;
}


static my_bool showstat_handlerton(THD *thd, plugin_ref plugin,
                                   void *arg)
{
  enum ha_stat_type stat= *(enum ha_stat_type *) arg;
  handlerton *hton= plugin_hton(plugin);
  if (hton->show_status &&
      hton->show_status(hton, thd, stat_print, stat))
    return TRUE;
  return FALSE;
}

bool ha_show_status(THD *thd, handlerton *db_type, enum ha_stat_type stat)
{
  List<Item> field_list;
  Protocol *protocol= thd->protocol;
  MEM_ROOT *mem_root= thd->mem_root;
  bool result;

  field_list.push_back(new (mem_root) Item_empty_string(thd, "Type", 10),
                       mem_root);
  field_list.push_back(new (mem_root)
                       Item_empty_string(thd, "Name", FN_REFLEN), mem_root);
  field_list.push_back(new (mem_root)
                       Item_empty_string(thd, "Status", 10),
                       mem_root);

  if (protocol->send_result_set_metadata(&field_list,
                            Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF))
    return TRUE;

  if (db_type == NULL)
  {
    result= plugin_foreach(thd, showstat_handlerton,
                           MYSQL_STORAGE_ENGINE_PLUGIN, &stat);
  }
  else
  {
    result= db_type->show_status &&
            db_type->show_status(db_type, thd, stat_print, stat) ? 1 : 0;
  }

  /*
    We also check thd->is_error() as Innodb may return 0 even if
    there was an error.
  */
  if (likely(!result && !thd->is_error()))
    my_eof(thd);
  else if (!thd->is_error())
    my_error(ER_GET_ERRNO, MYF(0), errno, hton_name(db_type)->str);
  return result;
}

/*
  Function to check if the conditions for row-based binlogging is
  correct for the table.

  A row in the given table should be replicated if:
  - It's not called by partition engine
  - Row-based replication is enabled in the current thread
  - The binlog is enabled
  - It is not a temporary table
  - The binary log is open
  - The database the table resides in shall be binlogged (binlog_*_db rules)
  - table is not mysql.event

  RETURN VALUE
    0  No binary logging in row format
    1  Row needs to be logged
*/

bool handler::check_table_binlog_row_based()
{
  if (unlikely((!check_table_binlog_row_based_done)))
  {
    check_table_binlog_row_based_done= 1;
    check_table_binlog_row_based_result=
      check_table_binlog_row_based_internal();
  }
  return check_table_binlog_row_based_result;
}

bool handler::check_table_binlog_row_based_internal()
{
  THD *thd= table->in_use;

#ifdef WITH_WSREP
  if (!thd->variables.sql_log_bin &&
      wsrep_thd_is_applying(table->in_use))
  {
    /*
      wsrep patch sets sql_log_bin to silence binlogging from high
      priority threads
    */
    return 0;
  }
#endif
  return (table->s->can_do_row_logging &&
          !table->versioned(VERS_TRX_ID) &&
          !(thd->variables.option_bits & OPTION_BIN_TMP_LOG_OFF) &&
          thd->is_current_stmt_binlog_format_row() &&
          /*
            Wsrep partially enables binary logging if it have not been
            explicitly turned on. As a result we return 'true' if we are in
            wsrep binlog emulation mode and the current thread is not a wsrep
            applier or replayer thread. This decision is not affected by
            @@sql_log_bin as we want the events to make into the binlog
            cache only to filter them later before they make into binary log
            file.

            However, we do return 'false' if binary logging was temporarily
            turned off (see tmp_disable_binlog(A)).

            Otherwise, return 'true' if binary logging is on.
          */
          IF_WSREP(((WSREP_EMULATE_BINLOG_NNULL(thd) &&
                     wsrep_thd_is_local(thd)) ||
                    ((WSREP_NNULL(thd) ||
                      (thd->variables.option_bits & OPTION_BIN_LOG)) &&
                     mysql_bin_log.is_open())),
                    (thd->variables.option_bits & OPTION_BIN_LOG) &&
                    mysql_bin_log.is_open()));
}


int handler::binlog_log_row(TABLE *table,
                            const uchar *before_record,
                            const uchar *after_record,
                            Log_func *log_func)
{
  bool error;
  THD *thd= table->in_use;
  DBUG_ENTER("binlog_log_row");

  if (!thd->binlog_table_maps &&
      thd->binlog_write_table_maps())
    DBUG_RETURN(HA_ERR_RBR_LOGGING_FAILED);

  error= (*log_func)(thd, table, row_logging_has_trans,
                     before_record, after_record);
  DBUG_RETURN(error ? HA_ERR_RBR_LOGGING_FAILED : 0);
}


int handler::ha_external_lock(THD *thd, int lock_type)
{
  int error;
  DBUG_ENTER("handler::ha_external_lock");
  /*
    Whether this is lock or unlock, this should be true, and is to verify that
    if get_auto_increment() was called (thus may have reserved intervals or
    taken a table lock), ha_release_auto_increment() was too.
  */
  DBUG_ASSERT(next_insert_id == 0);
  /* Consecutive calls for lock without unlocking in between is not allowed */
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              ((lock_type != F_UNLCK && m_lock_type == F_UNLCK) ||
               lock_type == F_UNLCK));
  /* SQL HANDLER call locks/unlock while scanning (RND/INDEX). */
  DBUG_ASSERT(inited == NONE || table->open_by_handler);

  if (MYSQL_HANDLER_RDLOCK_START_ENABLED() ||
      MYSQL_HANDLER_WRLOCK_START_ENABLED() ||
      MYSQL_HANDLER_UNLOCK_START_ENABLED())
  {
    if (lock_type == F_RDLCK)
    {
      MYSQL_HANDLER_RDLOCK_START(table_share->db.str,
                                 table_share->table_name.str);
    }
    else if (lock_type == F_WRLCK)
    {
      MYSQL_HANDLER_WRLOCK_START(table_share->db.str,
                                 table_share->table_name.str);
    }
    else if (lock_type == F_UNLCK)
    {
      MYSQL_HANDLER_UNLOCK_START(table_share->db.str,
                                 table_share->table_name.str);
    }
  }

  /*
    We cache the table flags if the locking succeeded. Otherwise, we
    keep them as they were when they were fetched in ha_open().
  */
  MYSQL_TABLE_LOCK_WAIT(PSI_TABLE_EXTERNAL_LOCK, lock_type,
    { error= external_lock(thd, lock_type); })

  DBUG_EXECUTE_IF("external_lock_failure", error= HA_ERR_GENERIC;);

  if (likely(error == 0 || lock_type == F_UNLCK))
  {
    m_lock_type= lock_type;
    cached_table_flags= table_flags();
    if (table_share->tmp_table == NO_TMP_TABLE)
      mysql_audit_external_lock(thd, table_share, lock_type);
  }

  if (MYSQL_HANDLER_RDLOCK_DONE_ENABLED() ||
      MYSQL_HANDLER_WRLOCK_DONE_ENABLED() ||
      MYSQL_HANDLER_UNLOCK_DONE_ENABLED())
  {
    if (lock_type == F_RDLCK)
    {
      MYSQL_HANDLER_RDLOCK_DONE(error);
    }
    else if (lock_type == F_WRLCK)
    {
      MYSQL_HANDLER_WRLOCK_DONE(error);
    }
    else if (lock_type == F_UNLCK)
    {
      MYSQL_HANDLER_UNLOCK_DONE(error);
    }
  }
  DBUG_RETURN(error);
}


/** @brief
  Check handler usage and reset state of file to after 'open'
*/
int handler::ha_reset()
{
  DBUG_ENTER("ha_reset");

  /* Check that we have called all proper deallocation functions */
  DBUG_ASSERT((uchar*) table->def_read_set.bitmap +
              table->s->column_bitmap_size ==
              (uchar*) table->def_write_set.bitmap);
  DBUG_ASSERT(bitmap_is_set_all(&table->s->all_set));
  DBUG_ASSERT(!table->file->keyread_enabled());
  /* ensure that ha_index_end / ha_rnd_end has been called */
  DBUG_ASSERT(inited == NONE);
  /* reset the bitmaps to point to defaults */
  table->default_column_bitmaps();
  pushed_cond= NULL;
  tracker= NULL;
  mark_trx_read_write_done= 0;
  /*
    Disable row logging.
  */
  row_logging= row_logging_init= 0;
  clear_cached_table_binlog_row_based_flag();
  /* Reset information about pushed engine conditions */
  cancel_pushed_idx_cond();
  /* Reset information about pushed index conditions */
  cancel_pushed_rowid_filter();
  if (lookup_handler != this)
  {
    lookup_handler->ha_external_unlock(table->in_use);
    lookup_handler->close();
    delete lookup_handler;
    lookup_handler= this;
  }
  DBUG_RETURN(reset());
}

#ifdef WITH_WSREP
static int wsrep_after_row(THD *thd)
{
  DBUG_ENTER("wsrep_after_row");
  if (thd->internal_transaction())
    DBUG_RETURN(0);

  /* enforce wsrep_max_ws_rows */
  thd->wsrep_affected_rows++;
  if (wsrep_max_ws_rows &&
      thd->wsrep_affected_rows > wsrep_max_ws_rows &&
      wsrep_thd_is_local(thd))
  {
    /*
      If we are inside stored function or trigger we should not commit or
      rollback current statement transaction. See comment in ha_commit_trans()
      call for more information.
    */
    if (!thd->in_sub_stmt)
      trans_rollback_stmt(thd) || trans_rollback(thd);
    my_message(ER_ERROR_DURING_COMMIT, "wsrep_max_ws_rows exceeded", MYF(0));
    DBUG_RETURN(ER_ERROR_DURING_COMMIT);
  }
  else if (wsrep_after_row_internal(thd))
  {
    DBUG_RETURN(ER_LOCK_DEADLOCK);
  }
  DBUG_RETURN(0);
}
#endif /* WITH_WSREP */


/**
   Check if there is a conflicting unique hash key
*/

int handler::check_duplicate_long_entry_key(const uchar *new_rec, uint key_no)
{
  int result, error= 0;
  KEY *key_info= table->key_info + key_no;
  Field *hash_field= key_info->key_part->field;
  uchar ptr[HA_HASH_KEY_LENGTH_WITH_NULL];
  String *blob_storage;
  DBUG_ENTER("handler::check_duplicate_long_entry_key");

  DBUG_ASSERT((key_info->flags & HA_NULL_PART_KEY &&
               key_info->key_length == HA_HASH_KEY_LENGTH_WITH_NULL) ||
              key_info->key_length == HA_HASH_KEY_LENGTH_WITHOUT_NULL);

  if (hash_field->is_real_null())
    DBUG_RETURN(0);

  key_copy(ptr, new_rec, key_info, key_info->key_length, false);

  result= lookup_handler->ha_index_init(key_no, 0);
  if (result)
    DBUG_RETURN(result);
  blob_storage= (String*)alloca(sizeof(String)*table->s->virtual_not_stored_blob_fields);
  table->remember_blob_values(blob_storage);
  store_record(table, file->lookup_buffer);
  result= lookup_handler->ha_index_read_map(table->record[0], ptr,
                                            HA_WHOLE_KEY, HA_READ_KEY_EXACT);
  if (!result)
  {
    bool is_same;
    Field * t_field;
    Item_func_hash * temp= (Item_func_hash *)hash_field->vcol_info->expr;
    Item ** arguments= temp->arguments();
    uint arg_count= temp->argument_count();
    // restore pointers after swap_values in TABLE::update_virtual_fields()
    for (Field **vf= table->vfield; *vf; vf++)
    {
      if (!(*vf)->stored_in_db() && (*vf)->flags & BLOB_FLAG &&
          bitmap_is_set(table->read_set, (*vf)->field_index))
        ((Field_blob*)*vf)->swap_value_and_read_value();
    }
    do
    {
      my_ptrdiff_t diff= table->file->lookup_buffer - new_rec;
      is_same= true;
      for (uint j=0; is_same && j < arg_count; j++)
      {
        DBUG_ASSERT(arguments[j]->type() == Item::FIELD_ITEM ||
                    // this one for left(fld_name,length)
                    arguments[j]->type() == Item::FUNC_ITEM);
        if (arguments[j]->type() == Item::FIELD_ITEM)
        {
          t_field= static_cast<Item_field *>(arguments[j])->field;
          if (t_field->cmp_offset(diff))
            is_same= false;
        }
        else
        {
          Item_func_left *fnc= static_cast<Item_func_left *>(arguments[j]);
          DBUG_ASSERT(!my_strcasecmp(system_charset_info, "left", fnc->func_name()));
          DBUG_ASSERT(fnc->arguments()[0]->type() == Item::FIELD_ITEM);
          t_field= static_cast<Item_field *>(fnc->arguments()[0])->field;
          uint length= (uint)fnc->arguments()[1]->val_int();
          if (t_field->cmp_prefix(t_field->ptr, t_field->ptr + diff, length))
            is_same= false;
        }
      }
    }
    while (!is_same &&
           !(result= lookup_handler->ha_index_next_same(table->record[0],
                                                ptr, key_info->key_length)));
    if (is_same)
      error= HA_ERR_FOUND_DUPP_KEY;
    goto exit;
  }
  if (result != HA_ERR_KEY_NOT_FOUND)
    error= result;
exit:
  if (error == HA_ERR_FOUND_DUPP_KEY)
  {
    table->file->lookup_errkey= key_no;
    if (ha_table_flags() & HA_DUPLICATE_POS)
    {
      lookup_handler->position(table->record[0]);
      memcpy(table->file->dup_ref, lookup_handler->ref, ref_length);
    }
  }
  restore_record(table, file->lookup_buffer);
  table->restore_blob_values(blob_storage);
  lookup_handler->ha_index_end();
  DBUG_RETURN(error);
}

void handler::alloc_lookup_buffer()
{
  if (!lookup_buffer)
    lookup_buffer= (uchar*)alloc_root(&table->mem_root,
                                      table_share->max_unique_length
                                      + table_share->null_fields
                                      + table_share->reclength);
}

/** @brief
    check whether inserted records breaks the
    unique constraint on long columns.
    @returns 0 if no duplicate else returns error
  */
int handler::check_duplicate_long_entries(const uchar *new_rec)
{
  lookup_errkey= (uint)-1;
  for (uint i= 0; i < table->s->keys; i++)
  {
    int result;
    if (table->key_info[i].algorithm == HA_KEY_ALG_LONG_HASH &&
        (result= check_duplicate_long_entry_key(new_rec, i)))
      return result;
  }
  return 0;
}


/** @brief
    check whether updated records breaks the
    unique constraint on long columns.
    In the case of update we just need to check the specic key
    reason for that is consider case
    create table t1(a blob , b blob , x blob , y blob ,unique(a,b)
                                                    ,unique(x,y))
    and update statement like this
    update t1 set a=23+a; in this case if we try to scan for
    whole keys in table then index scan on x_y will return 0
    because data is same so in the case of update we take
    key as a parameter in normal insert key should be -1
    @returns 0 if no duplicate else returns error
  */
int handler::check_duplicate_long_entries_update(const uchar *new_rec)
{
  Field *field;
  uint key_parts;
  KEY *keyinfo;
  KEY_PART_INFO *keypart;
  /*
     Here we are comparing whether new record and old record are same
     with respect to fields in hash_str
   */
  uint reclength= (uint) (table->record[1] - table->record[0]);

  for (uint i= 0; i < table->s->keys; i++)
  {
    keyinfo= table->key_info + i;
    if (keyinfo->algorithm == HA_KEY_ALG_LONG_HASH)
    {
      key_parts= fields_in_hash_keyinfo(keyinfo);
      keypart= keyinfo->key_part - key_parts;
      for (uint j= 0; j < key_parts; j++, keypart++)
      {
        int error;
        field= keypart->field;
        /*
          Compare fields if they are different then check for duplicates
          cmp_binary_offset cannot differentiate between null and empty string
          So also check for that too
        */
        if((field->is_null(0) != field->is_null(reclength)) ||
                               field->cmp_binary_offset(reclength))
        {
          if((error= check_duplicate_long_entry_key(new_rec, i)))
            return error;
          /*
            break because check_duplicate_long_entries_key will
            take care of remaining fields
           */
          break;
        }
      }
    }
  }
  return 0;
}


int handler::ha_check_overlaps(const uchar *old_data, const uchar* new_data)
{
  DBUG_ASSERT(new_data);
  if (this != table->file)
    return 0;
  if (!table_share->period.unique_keys)
    return 0;
  if (table->versioned() && !table->vers_end_field()->is_max())
    return 0;

  const bool is_update= old_data != NULL;
  uchar *record_buffer= lookup_buffer + table_share->max_unique_length
                                      + table_share->null_fields;

  // Needed to compare record refs later
  if (is_update)
    position(old_data);

  DBUG_ASSERT(!keyread_enabled());

  int error= 0;
  lookup_errkey= (uint)-1;

  for (uint key_nr= 0; key_nr < table_share->keys && !error; key_nr++)
  {
    const KEY &key_info= table->key_info[key_nr];
    const uint key_parts= key_info.user_defined_key_parts;
    if (!key_info.without_overlaps)
      continue;

    if (is_update)
    {
      bool key_used= false;
      for (uint k= 0; k < key_parts && !key_used; k++)
        key_used= bitmap_is_set(table->write_set,
                                key_info.key_part[k].fieldnr - 1);
      if (!key_used)
        continue;
    }

    error= lookup_handler->ha_index_init(key_nr, 0);
    if (error)
      return error;

    error= lookup_handler->ha_start_keyread(key_nr);
    DBUG_ASSERT(!error);

    const uint period_field_length= key_info.key_part[key_parts - 1].length;
    const uint key_base_length= key_info.key_length - 2 * period_field_length;

    key_copy(lookup_buffer, new_data, &key_info, 0);

    /* Copy period_start to period_end.
       the value in period_start field is not significant, but anyway let's leave
       it defined to avoid uninitialized memory access
     */
    memcpy(lookup_buffer + key_base_length,
           lookup_buffer + key_base_length + period_field_length,
           period_field_length);

    /* Find row with period_end > (period_start of new_data) */
    error = lookup_handler->ha_index_read_map(record_buffer, lookup_buffer,
                                       key_part_map((1 << (key_parts - 1)) - 1),
                                       HA_READ_AFTER_KEY);

    if (!error && is_update)
    {
      /* In case of update it could happen that the nearest neighbour is
         a record we are updating. It means, that there are no overlaps
         from this side.
      */
      DBUG_ASSERT(lookup_handler != this);
      DBUG_ASSERT(ref_length == lookup_handler->ref_length);

      lookup_handler->position(record_buffer);
      if (memcmp(ref, lookup_handler->ref, ref_length) == 0)
        error= lookup_handler->ha_index_next(record_buffer);
    }

    if (!error && table->check_period_overlaps(key_info, new_data, record_buffer))
      error= HA_ERR_FOUND_DUPP_KEY;

    if (error == HA_ERR_KEY_NOT_FOUND || error == HA_ERR_END_OF_FILE)
      error= 0;

    if (error == HA_ERR_FOUND_DUPP_KEY)
      lookup_errkey= key_nr;

    int end_error= lookup_handler->ha_end_keyread();
    DBUG_ASSERT(!end_error);

    end_error= lookup_handler->ha_index_end();
    if (!error && end_error)
      error= end_error;
  }

  return error;
}


/**
  Check if galera disables binary logging for this table

  @return 0  Binary logging disabled
  @return 1  Binary logging can be enabled
*/


static inline bool wsrep_check_if_binlog_row(TABLE *table)
{
#ifdef WITH_WSREP
  THD *const thd= table->in_use;

  /* only InnoDB tables will be replicated through binlog emulation */
  if ((WSREP_EMULATE_BINLOG(thd) &&
       !(table->file->partition_ht()->flags & HTON_WSREP_REPLICATION)) ||
      thd->wsrep_ignore_table == true)
    return 0;
#endif
  return 1;
}


/**
   Prepare handler for row logging

   @return 0 if handler will not participate in row logging
   @return 1 handler will participate in row logging

   This function is always safe to call on an opened table.
*/

bool handler::prepare_for_row_logging()
{
  DBUG_ENTER("handler::prepare_for_row_logging");

  /* Check if we should have row logging */
  if (wsrep_check_if_binlog_row(table) &&
      check_table_binlog_row_based())
  {
    /*
      Row logging enabled. Intialize all variables and write
      annotated and table maps
    */
    row_logging= row_logging_init= 1;

    /*
      We need to have a transactional behavior for SQLCOM_CREATE_TABLE
      (e.g. CREATE TABLE... SELECT * FROM TABLE) in order to keep a
      compatible behavior with the STMT based replication even when
      the table is not transactional. In other words, if the operation
      fails while executing the insert phase nothing is written to the
      binlog.
    */
    row_logging_has_trans=
      ((sql_command_flags[table->in_use->lex->sql_command] &
        (CF_SCHEMA_CHANGE | CF_ADMIN_COMMAND)) ||
       table->file->has_transactions_and_rollback());
  }
  else
  {
    /* Check row_logging has not been properly cleared from previous command */
    DBUG_ASSERT(row_logging == 0);
  }
  DBUG_RETURN(row_logging);
}


/*
  Do all initialization needed for insert
*/

int handler::prepare_for_insert(bool do_create)
{
  /* Preparation for unique of blob's */
  if (table->s->long_unique_table || table->s->period.unique_keys)
  {
    if (do_create && create_lookup_handler())
      return 1;
    alloc_lookup_buffer();
  }
  return 0;
}


int handler::ha_write_row(const uchar *buf)
{
  int error;
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type == F_WRLCK);
  DBUG_ENTER("handler::ha_write_row");
  DEBUG_SYNC_C("ha_write_row_start");

  if ((error= ha_check_overlaps(NULL, buf)))
    DBUG_RETURN(error);

  /*
    NOTE: this != table->file is true in 3 cases:

    1. under copy_partitions() (REORGANIZE PARTITION): that does not
       require long unique check as it does not introduce new rows or new index.
    2. under partition's ha_write_row() (INSERT): check_duplicate_long_entries()
       was already done by ha_partition::ha_write_row(), no need to check it
       again for each single partition.
    3. under ha_mroonga::wrapper_write_row()
  */

  if (table->s->long_unique_table && this == table->file)
  {
    DBUG_ASSERT(inited == NONE || lookup_handler != this);
    if ((error= check_duplicate_long_entries(buf)))
      DBUG_RETURN(error);
  }

  MYSQL_INSERT_ROW_START(table_share->db.str, table_share->table_name.str);
  mark_trx_read_write();
  increment_statistics(&SSV::ha_write_count);

  TABLE_IO_WAIT(tracker, PSI_TABLE_WRITE_ROW, MAX_KEY, error,
                      { error= write_row(buf); })

  MYSQL_INSERT_ROW_DONE(error);
  if (likely(!error))
  {
    rows_changed++;
    if (row_logging)
    {
      Log_func *log_func= Write_rows_log_event::binlog_row_logging_function;
      error= binlog_log_row(table, 0, buf, log_func);
    }
#ifdef WITH_WSREP
    if (WSREP_NNULL(ha_thd()) && table_share->tmp_table == NO_TMP_TABLE &&
        ht->flags & HTON_WSREP_REPLICATION &&
        !error && (error= wsrep_after_row(ha_thd())))
    {
      DBUG_RETURN(error);
    }
#endif /* WITH_WSREP */
  }

  DEBUG_SYNC_C("ha_write_row_end");
  DBUG_RETURN(error);
}


int handler::ha_update_row(const uchar *old_data, const uchar *new_data)
{
  int error;
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type == F_WRLCK);
  /*
    Some storage engines require that the new record is in record[0]
    (and the old record is in record[1]).
   */
  DBUG_ASSERT(new_data == table->record[0]);
  DBUG_ASSERT(old_data == table->record[1]);

  uint saved_status= table->status;
  error= ha_check_overlaps(old_data, new_data);

  /*
    NOTE: this != table->file is true under partition's ha_update_row():
    check_duplicate_long_entries_update() was already done by
    ha_partition::ha_update_row(), no need to check it again for each single
    partition. Same applies to ha_mroonga wrapper.
  */

  if (!error && table->s->long_unique_table && this == table->file)
    error= check_duplicate_long_entries_update(new_data);
  table->status= saved_status;

  if (error)
    return error;

  MYSQL_UPDATE_ROW_START(table_share->db.str, table_share->table_name.str);
  mark_trx_read_write();
  increment_statistics(&SSV::ha_update_count);

  TABLE_IO_WAIT(tracker, PSI_TABLE_UPDATE_ROW, active_index, 0,
                      { error= update_row(old_data, new_data);})

  MYSQL_UPDATE_ROW_DONE(error);
  if (likely(!error))
  {
    rows_changed++;
    if (row_logging)
    {
      Log_func *log_func= Update_rows_log_event::binlog_row_logging_function;
      error= binlog_log_row(table, old_data, new_data, log_func);
    }
#ifdef WITH_WSREP
    THD *thd= ha_thd();
    if (WSREP_NNULL(thd))
    {
      /* for streaming replication, the following wsrep_after_row()
      may replicate a fragment, so we have to declare potential PA
      unsafe before that */
      if (table->s->primary_key == MAX_KEY && wsrep_thd_is_local(thd))
      {
        WSREP_DEBUG("marking trx as PA unsafe pk %d", table->s->primary_key);
        if (thd->wsrep_cs().mark_transaction_pa_unsafe())
          WSREP_DEBUG("session does not have active transaction,"
                      " can not mark as PA unsafe");
      }

      if (!error && table_share->tmp_table == NO_TMP_TABLE &&
          ht->flags & HTON_WSREP_REPLICATION)
        error= wsrep_after_row(thd);
    }
#endif /* WITH_WSREP */
  }
  return error;
}

/*
  Update first row. Only used by sequence tables
*/

int handler::update_first_row(const uchar *new_data)
{
  int error;
  if (likely(!(error= ha_rnd_init(1))))
  {
    int end_error;
    if (likely(!(error= ha_rnd_next(table->record[1]))))
    {
      /*
        We have to do the memcmp as otherwise we may get error 169 from InnoDB
      */
      if (memcmp(new_data, table->record[1], table->s->reclength))
        error= update_row(table->record[1], new_data);
    }
    end_error= ha_rnd_end();
    if (likely(!error))
      error= end_error;
    /* Logging would be wrong if update_row works but ha_rnd_end fails */
    DBUG_ASSERT(!end_error || error != 0);
  }
  return error;
}


int handler::ha_delete_row(const uchar *buf)
{
  int error;
  DBUG_ASSERT(table_share->tmp_table != NO_TMP_TABLE ||
              m_lock_type == F_WRLCK);
  /*
    Normally table->record[0] is used, but sometimes table->record[1] is used.
  */
  DBUG_ASSERT(buf == table->record[0] ||
              buf == table->record[1]);

  MYSQL_DELETE_ROW_START(table_share->db.str, table_share->table_name.str);
  mark_trx_read_write();
  increment_statistics(&SSV::ha_delete_count);

  TABLE_IO_WAIT(tracker, PSI_TABLE_DELETE_ROW, active_index, error,
    { error= delete_row(buf);})
  MYSQL_DELETE_ROW_DONE(error);
  if (likely(!error))
  {
    rows_changed++;
    if (row_logging)
    {
      Log_func *log_func= Delete_rows_log_event::binlog_row_logging_function;
      error= binlog_log_row(table, buf, 0, log_func);
    }
#ifdef WITH_WSREP
    THD *thd= ha_thd();
    if (WSREP_NNULL(thd))
    {
      /* for streaming replication, the following wsrep_after_row()
      may replicate a fragment, so we have to declare potential PA
      unsafe before that */
      if (table->s->primary_key == MAX_KEY && wsrep_thd_is_local(thd))
      {
        WSREP_DEBUG("marking trx as PA unsafe pk %d", table->s->primary_key);
        if (thd->wsrep_cs().mark_transaction_pa_unsafe())
          WSREP_DEBUG("session does not have active transaction,"
                      " can not mark as PA unsafe");
      }

      if (!error && table_share->tmp_table == NO_TMP_TABLE &&
          ht->flags & HTON_WSREP_REPLICATION)
        error= wsrep_after_row(thd);
    }
#endif /* WITH_WSREP */
  }
  return error;
}


/**
  Execute a direct update request.  A direct update request updates all
  qualified rows in a single operation, rather than one row at a time.
  In a Spider cluster the direct update operation is pushed down to the
  child levels of the cluster.

  Note that this can't be used in case of statment logging

  @param  update_rows   Number of updated rows.

  @retval 0             Success.
  @retval != 0          Failure.
*/

int handler::ha_direct_update_rows(ha_rows *update_rows, ha_rows *found_rows)
{
  int error;
  MYSQL_UPDATE_ROW_START(table_share->db.str, table_share->table_name.str);
  mark_trx_read_write();

  error= direct_update_rows(update_rows, found_rows);
  MYSQL_UPDATE_ROW_DONE(error);
  return error;
}


/**
  Execute a direct delete request.  A direct delete request deletes all
  qualified rows in a single operation, rather than one row at a time.
  In a Spider cluster the direct delete operation is pushed down to the
  child levels of the cluster.

  @param  delete_rows   Number of deleted rows.

  @retval 0             Success.
  @retval != 0          Failure.
*/

int handler::ha_direct_delete_rows(ha_rows *delete_rows)
{
  int error;
  /* Ensure we are not using binlog row */
  DBUG_ASSERT(!table->in_use->is_current_stmt_binlog_format_row());

  MYSQL_DELETE_ROW_START(table_share->db.str, table_share->table_name.str);
  mark_trx_read_write();

  error = direct_delete_rows(delete_rows);
  MYSQL_DELETE_ROW_DONE(error);
  return error;
}


/** @brief
  use_hidden_primary_key() is called in case of an update/delete when
  (table_flags() and HA_PRIMARY_KEY_REQUIRED_FOR_DELETE) is defined
  but we don't have a primary key
*/
void handler::use_hidden_primary_key()
{
  /* fallback to use all columns in the table to identify row */
  table->column_bitmaps_set(&table->s->all_set, table->write_set);
}


/**
  Get an initialized ha_share.

  @return Initialized ha_share
    @retval NULL    ha_share is not yet initialized.
    @retval != NULL previous initialized ha_share.

  @note
  If not a temp table, then LOCK_ha_data must be held.
*/

Handler_share *handler::get_ha_share_ptr()
{
  DBUG_ENTER("handler::get_ha_share_ptr");
  DBUG_ASSERT(ha_share);
  DBUG_ASSERT(table_share);

#ifndef DBUG_OFF
  if (table_share->tmp_table == NO_TMP_TABLE)
    mysql_mutex_assert_owner(&table_share->LOCK_ha_data);
#endif

  DBUG_RETURN(*ha_share);
}


/**
  Set ha_share to be used by all instances of the same table/partition.

  @param ha_share    Handler_share to be shared.

  @note
  If not a temp table, then LOCK_ha_data must be held.
*/

void handler::set_ha_share_ptr(Handler_share *arg_ha_share)
{
  DBUG_ENTER("handler::set_ha_share_ptr");
  DBUG_ASSERT(ha_share);
#ifndef DBUG_OFF
  if (table_share->tmp_table == NO_TMP_TABLE)
    mysql_mutex_assert_owner(&table_share->LOCK_ha_data);
#endif

  *ha_share= arg_ha_share;
  DBUG_VOID_RETURN;
}


/**
  Take a lock for protecting shared handler data.
*/

void handler::lock_shared_ha_data()
{
  DBUG_ASSERT(table_share);
  if (table_share->tmp_table == NO_TMP_TABLE)
    mysql_mutex_lock(&table_share->LOCK_ha_data);
}


/**
  Release lock for protecting ha_share.
*/

void handler::unlock_shared_ha_data()
{
  DBUG_ASSERT(table_share);
  if (table_share->tmp_table == NO_TMP_TABLE)
    mysql_mutex_unlock(&table_share->LOCK_ha_data);
}

void handler::set_lock_type(enum thr_lock_type lock)
{
  table->reginfo.lock_type= lock;
}

Compare_keys handler::compare_key_parts(const Field &old_field,
                                        const Column_definition &new_field,
                                        const KEY_PART_INFO &old_part,
                                        const KEY_PART_INFO &new_part) const
{
  if (!old_field.is_equal(new_field))
    return Compare_keys::NotEqual;

  if (old_part.length != new_part.length)
    return Compare_keys::NotEqual;

  return Compare_keys::Equal;
}

#ifdef WITH_WSREP
/**
  @details
  This function makes the storage engine to force the victim transaction
  to abort. Currently, only innodb has this functionality, but any SE
  implementing the wsrep API should provide this service to support
  multi-master operation.

  @note Aborting the transaction does NOT end it, it still has to
  be rolled back with hton->rollback().

  @note It is safe to abort from one thread (bf_thd) the transaction,
  running in another thread (victim_thd), because InnoDB's lock_sys and
  trx_mutex guarantee the necessary protection. However, its not safe
  to access victim_thd->transaction, because it's not protected from
  concurrent accesses. And it's an overkill to take LOCK_plugin and
  iterate the whole installed_htons[] array every time.

  @note Object victim_thd is not guaranteed to exist after this
        function returns.

  @param bf_thd       brute force THD asking for the abort
  @param victim_thd   victim THD to be aborted

  @return
    always 0
*/

int ha_abort_transaction(THD *bf_thd, THD *victim_thd, my_bool signal)
{
  DBUG_ENTER("ha_abort_transaction");
  if (!WSREP(bf_thd) &&
      !(bf_thd->variables.wsrep_OSU_method == WSREP_OSU_RSU &&
        wsrep_thd_is_toi(bf_thd))) {
    mysql_mutex_unlock(&victim_thd->LOCK_thd_data);
    mysql_mutex_unlock(&victim_thd->LOCK_thd_kill);
    DBUG_RETURN(0);
  }

  handlerton *hton= installed_htons[DB_TYPE_INNODB];
  if (hton && hton->abort_transaction)
  {
    hton->abort_transaction(hton, bf_thd, victim_thd, signal);
  }
  else
  {
    WSREP_WARN("Cannot abort InnoDB transaction");
    mysql_mutex_unlock(&victim_thd->LOCK_thd_data);
    mysql_mutex_unlock(&victim_thd->LOCK_thd_kill);
  }

  DBUG_RETURN(0);
}
#endif /* WITH_WSREP */


/* Remove all indexes for a given table from global index statistics */

static
int del_global_index_stats_for_table(THD *thd, uchar* cache_key, size_t cache_key_length)
{
  int res = 0;
  uint to_delete_counter= 0;
  INDEX_STATS *index_stats_to_delete[MAX_INDEXES];
  DBUG_ENTER("del_global_index_stats_for_table");

  mysql_mutex_lock(&LOCK_global_index_stats);

  for (uint i= 0; i < global_index_stats.records; i++)
  {
    INDEX_STATS *index_stats =
      (INDEX_STATS*) my_hash_element(&global_index_stats, i);

    /* We search correct db\0table_name\0 string */
    if (index_stats &&
	index_stats->index_name_length >= cache_key_length &&
	!memcmp(index_stats->index, cache_key, cache_key_length))
    {
      index_stats_to_delete[to_delete_counter++]= index_stats;
    }
  }

  for (uint i= 0; i < to_delete_counter; i++)
    res= my_hash_delete(&global_index_stats, (uchar*)index_stats_to_delete[i]);

  mysql_mutex_unlock(&LOCK_global_index_stats);
  DBUG_RETURN(res);
}

/* Remove a table from global table statistics */

int del_global_table_stat(THD *thd, const LEX_CSTRING *db, const LEX_CSTRING *table)
{
  TABLE_STATS *table_stats;
  int res = 0;
  uchar *cache_key;
  size_t cache_key_length;
  DBUG_ENTER("del_global_table_stat");

  cache_key_length= db->length + 1 + table->length + 1;

  if(!(cache_key= (uchar *)my_malloc(PSI_INSTRUMENT_ME, cache_key_length,
                                     MYF(MY_WME | MY_ZEROFILL))))
  {
    /* Out of memory error already given */
    res = 1;
    goto end;
  }

  memcpy(cache_key, db->str, db->length);
  memcpy(cache_key + db->length + 1, table->str, table->length);

  res= del_global_index_stats_for_table(thd, cache_key, cache_key_length);

  mysql_mutex_lock(&LOCK_global_table_stats);

  if((table_stats= (TABLE_STATS*) my_hash_search(&global_table_stats,
                                                cache_key,
                                                cache_key_length)))
    res= my_hash_delete(&global_table_stats, (uchar*)table_stats);

  my_free(cache_key);
  mysql_mutex_unlock(&LOCK_global_table_stats);

end:
  DBUG_RETURN(res);
}

/* Remove a index from global index statistics */

int del_global_index_stat(THD *thd, TABLE* table, KEY* key_info)
{
  INDEX_STATS *index_stats;
  size_t key_length= table->s->table_cache_key.length + key_info->name.length + 1;
  int res = 0;
  DBUG_ENTER("del_global_index_stat");
  mysql_mutex_lock(&LOCK_global_index_stats);

  if((index_stats= (INDEX_STATS*) my_hash_search(&global_index_stats,
                                                key_info->cache_name,
                                                key_length)))
    res= my_hash_delete(&global_index_stats, (uchar*)index_stats);

  mysql_mutex_unlock(&LOCK_global_index_stats);
  DBUG_RETURN(res);
}

/*****************************************************************************
  VERSIONING functions
******************************************************************************/

bool Vers_parse_info::is_start(const char *name) const
{
  DBUG_ASSERT(name);
  return as_row.start && as_row.start.streq(name);
}
bool Vers_parse_info::is_end(const char *name) const
{
  DBUG_ASSERT(name);
  return as_row.end && as_row.end.streq(name);
}
bool Vers_parse_info::is_start(const Create_field &f) const
{
  return f.flags & VERS_ROW_START;
}
bool Vers_parse_info::is_end(const Create_field &f) const
{
  return f.flags & VERS_ROW_END;
}

static Create_field *vers_init_sys_field(THD *thd, const char *field_name, int flags, bool integer)
{
  Create_field *f= new (thd->mem_root) Create_field();
  if (!f)
    return NULL;

  f->field_name.str= field_name;
  f->field_name.length= strlen(field_name);
  f->charset= system_charset_info;
  f->flags= flags | NO_DEFAULT_VALUE_FLAG | NOT_NULL_FLAG;
  if (integer)
  {
    f->set_handler(&type_handler_vers_trx_id);
    f->length= MY_INT64_NUM_DECIMAL_DIGITS - 1;
    f->flags|= UNSIGNED_FLAG;
  }
  else
  {
    f->set_handler(&type_handler_timestamp2);
    f->length= MAX_DATETIME_PRECISION;
  }
  f->invisible= DBUG_IF("sysvers_show") ? VISIBLE : INVISIBLE_SYSTEM;

  if (f->check(thd))
    return NULL;

  return f;
}

bool Vers_parse_info::create_sys_field(THD *thd, const char *field_name,
                                       Alter_info *alter_info, int flags)
{
  DBUG_ASSERT(can_native >= 0); /* Requires vers_check_native() called */
  Create_field *f= vers_init_sys_field(thd, field_name, flags,
                                       DBUG_IF("sysvers_force_trx") &&
                                       can_native);
  if (!f)
    return true;

  alter_info->flags|= ALTER_PARSER_ADD_COLUMN;
  alter_info->create_list.push_back(f);

  return false;
}

const Lex_ident Vers_parse_info::default_start= "row_start";
const Lex_ident Vers_parse_info::default_end= "row_end";

bool Vers_parse_info::fix_implicit(THD *thd, Alter_info *alter_info)
{
  // If user specified some of these he must specify the others too. Do nothing.
  if (*this)
    return false;

  alter_info->flags|= ALTER_PARSER_ADD_COLUMN;

  period= start_end_t(default_start, default_end);
  as_row= period;

  if (create_sys_field(thd, default_start, alter_info, VERS_ROW_START) ||
      create_sys_field(thd, default_end, alter_info, VERS_ROW_END))
  {
    return true;
  }
  return false;
}


void Table_scope_and_contents_source_st::vers_check_native()
{
  vers_info.can_native= (db_type->db_type == DB_TYPE_PARTITION_DB ||
                         ha_check_storage_engine_flag(db_type,
                                                      HTON_NATIVE_SYS_VERSIONING));
}


bool Table_scope_and_contents_source_st::vers_fix_system_fields(
  THD *thd, Alter_info *alter_info, const TABLE_LIST &create_table)
{
  DBUG_ASSERT(!(alter_info->flags & ALTER_DROP_SYSTEM_VERSIONING));

  if (DBUG_IF("sysvers_force") || DBUG_IF("sysvers_force_trx"))
  {
    alter_info->flags|= ALTER_ADD_SYSTEM_VERSIONING;
    options|= HA_VERSIONED_TABLE;
  }

  if (!vers_info.need_check(alter_info))
    return false;

  const bool add_versioning= alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING;

  if (!vers_info.versioned_fields && vers_info.unversioned_fields && !add_versioning)
  {
    // All is correct but this table is not versioned.
    options&= ~HA_VERSIONED_TABLE;
    return false;
  }

  if (!add_versioning && vers_info && !vers_info.versioned_fields)
  {
    my_error(ER_MISSING, MYF(0), create_table.table_name.str,
             "WITH SYSTEM VERSIONING");
    return true;
  }

  List_iterator<Create_field> it(alter_info->create_list);
  while (Create_field *f= it++)
  {
    if (f->vers_sys_field())
      continue;
    if ((f->versioning == Column_definition::VERSIONING_NOT_SET && !add_versioning) ||
        f->versioning == Column_definition::WITHOUT_VERSIONING)
    {
      f->flags|= VERS_UPDATE_UNVERSIONED_FLAG;
    }
  } // while

  vers_check_native();

  if (vers_info.fix_implicit(thd, alter_info))
    return true;

  return false;
}


bool Table_scope_and_contents_source_st::vers_check_system_fields(
        THD *thd, Alter_info *alter_info, const Lex_table_name &table_name,
        const Lex_table_name &db, int select_count)
{
  if (!(options & HA_VERSIONED_TABLE))
    return false;

  uint versioned_fields= 0;

  if (!(alter_info->flags & ALTER_DROP_SYSTEM_VERSIONING))
  {
    uint fieldnr= 0;
    List_iterator<Create_field> field_it(alter_info->create_list);
    while (Create_field *f= field_it++)
    {
      /*
         The field from the CREATE part can be duplicated in the SELECT part of
         CREATE...SELECT. In that case double counts should be avoided.
         select_create::create_table_from_items just pushes the fields back into
         the create_list, without additional manipulations, so the fields from
         SELECT go last there.
       */
      bool is_dup= false;
      if (fieldnr >= alter_info->create_list.elements - select_count)
      {
        List_iterator<Create_field> dup_it(alter_info->create_list);
        for (Create_field *dup= dup_it++; !is_dup && dup != f; dup= dup_it++)
          is_dup= Lex_ident(dup->field_name).streq(f->field_name);
      }

      if (!(f->flags & VERS_UPDATE_UNVERSIONED_FLAG) && !is_dup)
        versioned_fields++;
      fieldnr++;
    }
    if (versioned_fields == VERSIONING_FIELDS)
    {
      my_error(ER_VERS_TABLE_MUST_HAVE_COLUMNS, MYF(0), table_name.str);
      return true;
    }
  }

  if (!(alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING) && !versioned_fields)
    return false;

  return vers_info.check_sys_fields(table_name, db, alter_info);
}


bool Vers_parse_info::fix_alter_info(THD *thd, Alter_info *alter_info,
                                     HA_CREATE_INFO *create_info, TABLE *table)
{
  TABLE_SHARE *share= table->s;
  const char *table_name= share->table_name.str;

  if (!need_check(alter_info) && !share->versioned)
    return false;

  if (share->tmp_table &&
      !DBUG_IF("sysvers_force") && !DBUG_IF("sysvers_force_trx"))
  {
    my_error(ER_VERS_NOT_SUPPORTED, MYF(0), "CREATE TEMPORARY TABLE");
    return true;
  }

  if (alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING &&
      table->versioned())
  {
    my_error(ER_VERS_ALREADY_VERSIONED, MYF(0), table_name);
    return true;
  }

  if (alter_info->flags & ALTER_DROP_SYSTEM_VERSIONING)
  {
    if (!share->versioned)
    {
      my_error(ER_VERS_NOT_VERSIONED, MYF(0), table_name);
      return true;
    }
#ifdef WITH_PARTITION_STORAGE_ENGINE
    if (table->part_info &&
        table->part_info->part_type == VERSIONING_PARTITION)
    {
      my_error(ER_DROP_VERSIONING_SYSTEM_TIME_PARTITION, MYF(0), table_name);
      return true;
    }
#endif

    return false;
  }

  if (!(alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING))
  {
    List_iterator_fast<Create_field> it(alter_info->create_list);
    while (Create_field *f= it++)
    {
      if (f->flags & VERS_SYSTEM_FIELD)
      {
        if (!table->versioned())
        {
          my_error(ER_VERS_NOT_VERSIONED, MYF(0), table->s->table_name.str);
          return true;
        }
        my_error(ER_VERS_DUPLICATE_ROW_START_END, MYF(0),
                 f->flags & VERS_ROW_START ? "START" : "END", f->field_name.str);
        return true;
      }
    }
  }

  if ((alter_info->flags & ALTER_DROP_PERIOD ||
       versioned_fields || unversioned_fields) && !share->versioned)
  {
    my_error(ER_VERS_NOT_VERSIONED, MYF(0), table_name);
    return true;
  }

  if (share->versioned)
  {
    if (alter_info->flags & ALTER_ADD_PERIOD)
    {
      my_error(ER_VERS_ALREADY_VERSIONED, MYF(0), table_name);
      return true;
    }

    // copy info from existing table
    create_info->options|= HA_VERSIONED_TABLE;

    DBUG_ASSERT(share->vers_start_field());
    DBUG_ASSERT(share->vers_end_field());
    Lex_ident start(share->vers_start_field()->field_name);
    Lex_ident end(share->vers_end_field()->field_name);
    DBUG_ASSERT(start.str);
    DBUG_ASSERT(end.str);

    as_row= start_end_t(start, end);
    period= as_row;

    if (alter_info->create_list.elements)
    {
      List_iterator_fast<Create_field> it(alter_info->create_list);
      while (Create_field *f= it++)
      {
        if (f->versioning == Column_definition::WITHOUT_VERSIONING)
          f->flags|= VERS_UPDATE_UNVERSIONED_FLAG;

        if (f->change.str && (start.streq(f->change) || end.streq(f->change)))
        {
          my_error(ER_VERS_ALTER_SYSTEM_FIELD, MYF(0), f->change.str);
          return true;
        }
      }
    }

    return false;
  }

  if (fix_implicit(thd, alter_info))
    return true;

  if (alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING)
  {
    if (check_sys_fields(table_name, share->db, alter_info))
      return true;
  }

  return false;
}

bool
Vers_parse_info::fix_create_like(Alter_info &alter_info, HA_CREATE_INFO &create_info,
                                 TABLE_LIST &src_table, TABLE_LIST &table)
{
  List_iterator<Create_field> it(alter_info.create_list);
  List_iterator<Key> key_it(alter_info.key_list);
  List_iterator<Key_part_spec> kp_it;
  Create_field *f, *f_start=NULL, *f_end= NULL;

  DBUG_ASSERT(alter_info.create_list.elements > 2);

  if (create_info.tmp_table())
  {
    int remove= 2;
    while (remove && (f= it++))
    {
      if (f->flags & VERS_SYSTEM_FIELD)
      {
        it.remove();
        remove--;
      }
      key_it.rewind();
      while (Key *key= key_it++)
      {
        kp_it.init(key->columns);
        while (Key_part_spec *kp= kp_it++)
        {
          if (0 == lex_string_cmp(system_charset_info, &kp->field_name,
                                  &f->field_name))
          {
            kp_it.remove();
          }
        }
        if (0 == key->columns.elements)
        {
          key_it.remove();
        }
      }
    }
    DBUG_ASSERT(remove == 0);
    push_warning_printf(current_thd, Sql_condition::WARN_LEVEL_WARN,
                        ER_UNKNOWN_ERROR,
                        "System versioning is stripped from temporary `%s.%s`",
                        table.db.str, table.table_name.str);
    return false;
  }

  while ((f= it++))
  {
    if (f->flags & VERS_ROW_START)
    {
      f_start= f;
      if (f_end)
        break;
    }
    else if (f->flags & VERS_ROW_END)
    {
      f_end= f;
      if (f_start)
        break;
    }
  }

  if (!f_start || !f_end)
  {
    my_error(ER_MISSING, MYF(0), src_table.table_name.str,
             f_start ? "AS ROW END" : "AS ROW START");
    return true;
  }

  as_row= start_end_t(f_start->field_name, f_end->field_name);
  period= as_row;

  create_info.options|= HA_VERSIONED_TABLE;
  return false;
}

bool Vers_parse_info::need_check(const Alter_info *alter_info) const
{
  return versioned_fields || unversioned_fields ||
         alter_info->flags & ALTER_ADD_PERIOD ||
         alter_info->flags & ALTER_DROP_PERIOD ||
         alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING ||
         alter_info->flags & ALTER_DROP_SYSTEM_VERSIONING || *this;
}

bool Vers_parse_info::check_conditions(const Lex_table_name &table_name,
                                       const Lex_table_name &db) const
{
  if (!as_row.start || !as_row.end)
  {
    my_error(ER_MISSING, MYF(0), table_name.str,
                as_row.start ? "AS ROW END" : "AS ROW START");
    return true;
  }

  if (!period.start || !period.end)
  {
    my_error(ER_MISSING, MYF(0), table_name.str, "PERIOD FOR SYSTEM_TIME");
    return true;
  }

  if (!as_row.start.streq(period.start) ||
      !as_row.end.streq(period.end))
  {
    my_error(ER_VERS_PERIOD_COLUMNS, MYF(0), as_row.start.str, as_row.end.str);
    return true;
  }

  if (db.streq(MYSQL_SCHEMA_NAME))
  {
    my_error(ER_VERS_DB_NOT_SUPPORTED, MYF(0), MYSQL_SCHEMA_NAME.str);
    return true;
  }
  return false;
}

static bool is_versioning_timestamp(const Column_definition *f)
{
  return f->type_handler() == &type_handler_timestamp2 &&
         f->length == MAX_DATETIME_FULL_WIDTH;
}

static bool is_some_bigint(const Column_definition *f)
{
  return f->type_handler() == &type_handler_slonglong ||
         f->type_handler() == &type_handler_ulonglong ||
         f->type_handler() == &type_handler_vers_trx_id;
}

static bool is_versioning_bigint(const Column_definition *f)
{
  return is_some_bigint(f) && f->flags & UNSIGNED_FLAG &&
         f->length == MY_INT64_NUM_DECIMAL_DIGITS - 1;
}

static void require_timestamp_error(const char *field, const char *table)
{
  my_error(ER_VERS_FIELD_WRONG_TYPE, MYF(0), field, "TIMESTAMP(6)", table);
}

static void require_trx_id_error(const char *field, const char *table)
{
  my_error(ER_VERS_FIELD_WRONG_TYPE, MYF(0), field, "BIGINT(20) UNSIGNED",
           table);
}


bool Vers_type_timestamp::check_sys_fields(const LEX_CSTRING &table_name,
                                           const Column_definition *row_start,
                                           const Column_definition *row_end) const
{
  if (!is_versioning_timestamp(row_start))
  {
    require_timestamp_error(row_start->field_name.str, table_name.str);
    return true;
  }

  if (row_end->type_handler()->vers() != this ||
      !is_versioning_timestamp(row_end))
  {
    require_timestamp_error(row_end->field_name.str, table_name.str);
    return true;
  }

  return false;
}


bool Vers_type_trx::check_sys_fields(const LEX_CSTRING &table_name,
                                     const Column_definition *row_start,
                                     const Column_definition *row_end) const
{
  if (!is_versioning_bigint(row_start))
  {
    require_trx_id_error(row_start->field_name.str, table_name.str);
    return true;
  }

  if (row_end->type_handler()->vers() != this ||
      !is_versioning_bigint(row_end))
  {
    require_trx_id_error(row_end->field_name.str, table_name.str);
    return true;
  }

  if (!is_some_bigint(row_start))
  {
    require_timestamp_error(row_start->field_name.str, table_name.str);
    return true;
  }

  if (!TR_table::use_transaction_registry)
  {
    my_error(ER_VERS_TRT_IS_DISABLED, MYF(0));
    return true;
  }

  return false;
}


bool Vers_parse_info::check_sys_fields(const Lex_table_name &table_name,
                                       const Lex_table_name &db,
                                       Alter_info *alter_info) const
{
  if (check_conditions(table_name, db))
    return true;

  List_iterator<Create_field> it(alter_info->create_list);
  const Create_field *row_start= nullptr;
  const Create_field *row_end= nullptr;
  while (const Create_field *f= it++)
  {
    if (f->flags & VERS_ROW_START && !row_start)
      row_start= f;
    if (f->flags & VERS_ROW_END && !row_end)
      row_end= f;
  }

  if (!row_start || !row_end)
  {
    my_error(ER_VERS_PERIOD_COLUMNS, MYF(0), as_row.start.str, as_row.end.str);
    return true;
  }

  const Vers_type_handler *row_start_vers= row_start->type_handler()->vers();

  if (!row_start_vers)
  {
    require_timestamp_error(row_start->field_name.str, table_name);
    return true;
  }

  return row_start_vers->check_sys_fields(table_name, row_start, row_end);
}

bool Table_period_info::check_field(const Create_field* f,
                                    const Lex_ident& f_name) const
{
  bool res= false;
  if (!f)
  {
    my_error(ER_BAD_FIELD_ERROR, MYF(0), f_name.str, name.str);
    res= true;
  }
  else if (f->type_handler()->mysql_timestamp_type() != MYSQL_TIMESTAMP_DATE &&
           f->type_handler()->mysql_timestamp_type() != MYSQL_TIMESTAMP_DATETIME)
  {
    my_error(ER_WRONG_FIELD_SPEC, MYF(0), f->field_name.str);
    res= true;
  }
  else if (f->vcol_info || f->flags & VERS_SYSTEM_FIELD)
  {
    my_error(ER_PERIOD_FIELD_WRONG_ATTRIBUTES, MYF(0),
             f->field_name.str, "GENERATED ALWAYS AS");
    res= true;
  }

  return res;
}

bool Table_scope_and_contents_source_st::check_fields(
  THD *thd, Alter_info *alter_info,
  const Lex_table_name &table_name, const Lex_table_name &db, int select_count)
{
  return vers_check_system_fields(thd, alter_info,
                                  table_name, db, select_count) ||
    check_period_fields(thd, alter_info);
}

bool Table_scope_and_contents_source_st::check_period_fields(
                THD *thd, Alter_info *alter_info)
{
  if (!period_info.name)
    return false;

  if (tmp_table())
  {
    my_error(ER_PERIOD_TEMPORARY_NOT_ALLOWED, MYF(0));
    return true;
  }

  Table_period_info::start_end_t &period= period_info.period;
  const Create_field *row_start= NULL;
  const Create_field *row_end= NULL;
  List_iterator<Create_field> it(alter_info->create_list);
  while (const Create_field *f= it++)
  {
    if (period.start.streq(f->field_name)) row_start= f;
    else if (period.end.streq(f->field_name)) row_end= f;

    if (period_info.name.streq(f->field_name))
    {
      my_error(ER_DUP_FIELDNAME, MYF(0), f->field_name.str);
      return true;
    }
  }

  bool res= period_info.check_field(row_start, period.start.str)
            || period_info.check_field(row_end, period.end.str);
  if (res)
    return true;

  if (row_start->type_handler() != row_end->type_handler()
      || row_start->length != row_end->length)
  {
    my_error(ER_PERIOD_TYPES_MISMATCH, MYF(0), period_info.name.str);
    res= true;
  }

  return res;
}

bool
Table_scope_and_contents_source_st::fix_create_fields(THD *thd,
                                                      Alter_info *alter_info,
                                                      const TABLE_LIST &create_table)
{
  return vers_fix_system_fields(thd, alter_info, create_table)
         || fix_period_fields(thd, alter_info);
}

bool
Table_scope_and_contents_source_st::fix_period_fields(THD *thd,
                                                      Alter_info *alter_info)
{
  if (!period_info.name)
    return false;

  Table_period_info::start_end_t &period= period_info.period;
  List_iterator<Create_field> it(alter_info->create_list);
  while (Create_field *f= it++)
  {
    if (period.start.streq(f->field_name) || period.end.streq(f->field_name))
    {
      f->period= &period_info;
      f->flags|= NOT_NULL_FLAG;
    }
  }
  return false;
}