summaryrefslogtreecommitdiffstats
path: root/contrib/bloom/bloom.h
blob: 23aa7ac4416cc87c1bcd3508151e35b58f1559f0 (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
/*-------------------------------------------------------------------------
 *
 * bloom.h
 *	  Header for bloom index.
 *
 * Copyright (c) 2016-2020, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *	  contrib/bloom/bloom.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef _BLOOM_H_
#define _BLOOM_H_

#include "access/amapi.h"
#include "access/generic_xlog.h"
#include "access/itup.h"
#include "access/xlog.h"
#include "fmgr.h"
#include "nodes/pathnodes.h"

/* Support procedures numbers */
#define BLOOM_HASH_PROC			1
#define BLOOM_OPTIONS_PROC		2
#define BLOOM_NPROC				2

/* Scan strategies */
#define BLOOM_EQUAL_STRATEGY	1
#define BLOOM_NSTRATEGIES		1

/* Opaque for bloom pages */
typedef struct BloomPageOpaqueData
{
	OffsetNumber maxoff;		/* number of index tuples on page */
	uint16		flags;			/* see bit definitions below */
	uint16		unused;			/* placeholder to force maxaligning of size of
								 * BloomPageOpaqueData and to place
								 * bloom_page_id exactly at the end of page */
	uint16		bloom_page_id;	/* for identification of BLOOM indexes */
} BloomPageOpaqueData;

typedef BloomPageOpaqueData *BloomPageOpaque;

/* Bloom page flags */
#define BLOOM_META		(1<<0)
#define BLOOM_DELETED	(2<<0)

/*
 * The page ID is for the convenience of pg_filedump and similar utilities,
 * which otherwise would have a hard time telling pages of different index
 * types apart.  It should be the last 2 bytes on the page.  This is more or
 * less "free" due to alignment considerations.
 *
 * See comments above GinPageOpaqueData.
 */
#define BLOOM_PAGE_ID		0xFF83

/* Macros for accessing bloom page structures */
#define BloomPageGetOpaque(page) ((BloomPageOpaque) PageGetSpecialPointer(page))
#define BloomPageGetMaxOffset(page) (BloomPageGetOpaque(page)->maxoff)
#define BloomPageIsMeta(page) \
	((BloomPageGetOpaque(page)->flags & BLOOM_META) != 0)
#define BloomPageIsDeleted(page) \
	((BloomPageGetOpaque(page)->flags & BLOOM_DELETED) != 0)
#define BloomPageSetDeleted(page) \
	(BloomPageGetOpaque(page)->flags |= BLOOM_DELETED)
#define BloomPageSetNonDeleted(page) \
	(BloomPageGetOpaque(page)->flags &= ~BLOOM_DELETED)
#define BloomPageGetData(page)		((BloomTuple *)PageGetContents(page))
#define BloomPageGetTuple(state, page, offset) \
	((BloomTuple *)(PageGetContents(page) \
		+ (state)->sizeOfBloomTuple * ((offset) - 1)))
#define BloomPageGetNextTuple(state, tuple) \
	((BloomTuple *)((Pointer)(tuple) + (state)->sizeOfBloomTuple))

/* Preserved page numbers */
#define BLOOM_METAPAGE_BLKNO	(0)
#define BLOOM_HEAD_BLKNO		(1) /* first data page */

/*
 * We store Bloom signatures as arrays of uint16 words.
 */
typedef uint16 BloomSignatureWord;

#define SIGNWORDBITS ((int) (BITS_PER_BYTE * sizeof(BloomSignatureWord)))

/*
 * Default and maximum Bloom signature length in bits.
 */
#define DEFAULT_BLOOM_LENGTH	(5 * SIGNWORDBITS)
#define MAX_BLOOM_LENGTH		(256 * SIGNWORDBITS)

/*
 * Default and maximum signature bits generated per index key.
 */
#define DEFAULT_BLOOM_BITS		2
#define MAX_BLOOM_BITS			(MAX_BLOOM_LENGTH - 1)

/* Bloom index options */
typedef struct BloomOptions
{
	int32		vl_len_;		/* varlena header (do not touch directly!) */
	int			bloomLength;	/* length of signature in words (not bits!) */
	int			bitSize[INDEX_MAX_KEYS];	/* # of bits generated for each
											 * index key */
} BloomOptions;

/*
 * FreeBlockNumberArray - array of block numbers sized so that metadata fill
 * all space in metapage.
 */
typedef BlockNumber FreeBlockNumberArray[
										 MAXALIGN_DOWN(
													   BLCKSZ - SizeOfPageHeaderData - MAXALIGN(sizeof(BloomPageOpaqueData))
													   - MAXALIGN(sizeof(uint16) * 2 + sizeof(uint32) + sizeof(BloomOptions))
													   ) / sizeof(BlockNumber)
];

/* Metadata of bloom index */
typedef struct BloomMetaPageData
{
	uint32		magickNumber;
	uint16		nStart;
	uint16		nEnd;
	BloomOptions opts;
	FreeBlockNumberArray notFullPage;
} BloomMetaPageData;

/* Magic number to distinguish bloom pages among anothers */
#define BLOOM_MAGICK_NUMBER (0xDBAC0DED)

/* Number of blocks numbers fit in BloomMetaPageData */
#define BloomMetaBlockN		(sizeof(FreeBlockNumberArray) / sizeof(BlockNumber))

#define BloomPageGetMeta(page)	((BloomMetaPageData *) PageGetContents(page))

typedef struct BloomState
{
	FmgrInfo	hashFn[INDEX_MAX_KEYS];
	Oid			collations[INDEX_MAX_KEYS];
	BloomOptions opts;			/* copy of options on index's metapage */
	int32		nColumns;

	/*
	 * sizeOfBloomTuple is index-specific, and it depends on reloptions, so
	 * precompute it
	 */
	Size		sizeOfBloomTuple;
} BloomState;

#define BloomPageGetFreeSpace(state, page) \
	(BLCKSZ - MAXALIGN(SizeOfPageHeaderData) \
		- BloomPageGetMaxOffset(page) * (state)->sizeOfBloomTuple \
		- MAXALIGN(sizeof(BloomPageOpaqueData)))

/*
 * Tuples are very different from all other relations
 */
typedef struct BloomTuple
{
	ItemPointerData heapPtr;
	BloomSignatureWord sign[FLEXIBLE_ARRAY_MEMBER];
} BloomTuple;

#define BLOOMTUPLEHDRSZ offsetof(BloomTuple, sign)

/* Opaque data structure for bloom index scan */
typedef struct BloomScanOpaqueData
{
	BloomSignatureWord *sign;	/* Scan signature */
	BloomState	state;
} BloomScanOpaqueData;

typedef BloomScanOpaqueData *BloomScanOpaque;

/* blutils.c */
extern void _PG_init(void);
extern void initBloomState(BloomState *state, Relation index);
extern void BloomFillMetapage(Relation index, Page metaPage);
extern void BloomInitMetapage(Relation index);
extern void BloomInitPage(Page page, uint16 flags);
extern Buffer BloomNewBuffer(Relation index);
extern void signValue(BloomState *state, BloomSignatureWord *sign, Datum value, int attno);
extern BloomTuple *BloomFormTuple(BloomState *state, ItemPointer iptr, Datum *values, bool *isnull);
extern bool BloomPageAddItem(BloomState *state, Page page, BloomTuple *tuple);

/* blvalidate.c */
extern bool blvalidate(Oid opclassoid);

/* index access method interface functions */
extern bool blinsert(Relation index, Datum *values, bool *isnull,
					 ItemPointer ht_ctid, Relation heapRel,
					 IndexUniqueCheck checkUnique,
					 struct IndexInfo *indexInfo);
extern IndexScanDesc blbeginscan(Relation r, int nkeys, int norderbys);
extern int64 blgetbitmap(IndexScanDesc scan, TIDBitmap *tbm);
extern void blrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
					 ScanKey orderbys, int norderbys);
extern void blendscan(IndexScanDesc scan);
extern IndexBuildResult *blbuild(Relation heap, Relation index,
								 struct IndexInfo *indexInfo);
extern void blbuildempty(Relation index);
extern IndexBulkDeleteResult *blbulkdelete(IndexVacuumInfo *info,
										   IndexBulkDeleteResult *stats, IndexBulkDeleteCallback callback,
										   void *callback_state);
extern IndexBulkDeleteResult *blvacuumcleanup(IndexVacuumInfo *info,
											  IndexBulkDeleteResult *stats);
extern bytea *bloptions(Datum reloptions, bool validate);
extern void blcostestimate(PlannerInfo *root, IndexPath *path,
						   double loop_count, Cost *indexStartupCost,
						   Cost *indexTotalCost, Selectivity *indexSelectivity,
						   double *indexCorrelation, double *indexPages);

#endif