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
|
/*
* brin_tuple.h
* Declarations for dealing with BRIN-specific tuples.
*
* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/include/access/brin_tuple.h
*/
#ifndef BRIN_TUPLE_H
#define BRIN_TUPLE_H
#include "access/brin_internal.h"
#include "access/tupdesc.h"
/*
* A BRIN index stores one index tuple per page range. Each index tuple
* has one BrinValues struct for each indexed column; in turn, each BrinValues
* has (besides the null flags) an array of Datum whose size is determined by
* the opclass.
*/
typedef struct BrinValues
{
AttrNumber bv_attno; /* index attribute number */
bool bv_hasnulls; /* are there any nulls in the page range? */
bool bv_allnulls; /* are all values nulls in the page range? */
Datum *bv_values; /* current accumulated values */
} BrinValues;
/*
* This struct is used to represent an in-memory index tuple. The values can
* only be meaningfully decoded with an appropriate BrinDesc.
*/
typedef struct BrinMemTuple
{
bool bt_placeholder; /* this is a placeholder tuple */
BlockNumber bt_blkno; /* heap blkno that the tuple is for */
MemoryContext bt_context; /* memcxt holding the bt_columns values */
/* output arrays for brin_deform_tuple: */
Datum *bt_values; /* values array */
bool *bt_allnulls; /* allnulls array */
bool *bt_hasnulls; /* hasnulls array */
/* not an output array, but must be last */
BrinValues bt_columns[FLEXIBLE_ARRAY_MEMBER];
} BrinMemTuple;
/*
* An on-disk BRIN tuple. This is possibly followed by a nulls bitmask, with
* room for 2 null bits (two bits for each indexed column); an opclass-defined
* number of Datum values for each column follow.
*/
typedef struct BrinTuple
{
/* heap block number that the tuple is for */
BlockNumber bt_blkno;
/* ---------------
* bt_info is laid out in the following fashion:
*
* 7th (high) bit: has nulls
* 6th bit: is placeholder tuple
* 5th bit: unused
* 4-0 bit: offset of data
* ---------------
*/
uint8 bt_info;
} BrinTuple;
#define SizeOfBrinTuple (offsetof(BrinTuple, bt_info) + sizeof(uint8))
/*
* bt_info manipulation macros
*/
#define BRIN_OFFSET_MASK 0x1F
/* bit 0x20 is not used at present */
#define BRIN_PLACEHOLDER_MASK 0x40
#define BRIN_NULLS_MASK 0x80
#define BrinTupleDataOffset(tup) ((Size) (((BrinTuple *) (tup))->bt_info & BRIN_OFFSET_MASK))
#define BrinTupleHasNulls(tup) (((((BrinTuple *) (tup))->bt_info & BRIN_NULLS_MASK)) != 0)
#define BrinTupleIsPlaceholder(tup) (((((BrinTuple *) (tup))->bt_info & BRIN_PLACEHOLDER_MASK)) != 0)
extern BrinTuple *brin_form_tuple(BrinDesc *brdesc, BlockNumber blkno,
BrinMemTuple *tuple, Size *size);
extern BrinTuple *brin_form_placeholder_tuple(BrinDesc *brdesc,
BlockNumber blkno, Size *size);
extern void brin_free_tuple(BrinTuple *tuple);
extern BrinTuple *brin_copy_tuple(BrinTuple *tuple, Size len,
BrinTuple *dest, Size *destsz);
extern bool brin_tuples_equal(const BrinTuple *a, Size alen,
const BrinTuple *b, Size blen);
extern BrinMemTuple *brin_new_memtuple(BrinDesc *brdesc);
extern BrinMemTuple *brin_memtuple_initialize(BrinMemTuple *dtuple,
BrinDesc *brdesc);
extern BrinMemTuple *brin_deform_tuple(BrinDesc *brdesc,
BrinTuple *tuple, BrinMemTuple *dMemtuple);
#endif /* BRIN_TUPLE_H */
|
