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buf_table.c File Reference

#include "postgres.h"
#include "storage/buf_internals.h"

Include dependency graph for buf_table.c:

Go to the source code of this file.

Data Structures

struct BufferLookupEnt

Functions

Size BufTableShmemSize (int size)

void InitBufTable (int size)

uint32 BufTableHashCode (BufferTag *tagPtr)

int BufTableLookup (BufferTag *tagPtr, uint32 hashcode)

int BufTableInsert (BufferTag *tagPtr, uint32 hashcode, int buf_id)

void BufTableDelete (BufferTag *tagPtr, uint32 hashcode)

Variables

static HTAB * SharedBufHash

Function Documentation

◆ BufTableDelete()

void BufTableDelete ( BufferTag * tagPtr,

uint32 hashcode

)

Definition at line 148 of file buf_table.c.

149{

150 BufferLookupEnt *result;

151

152 result = (BufferLookupEnt *)

153 hash_search_with_hash_value(SharedBufHash,

154 tagPtr,

155 hashcode,

156 HASH_REMOVE,

157 NULL);

158

159 if (!result) /* shouldn't happen */

160 elog(ERROR, "shared buffer hash table corrupted");

161}

SharedBufHash

static HTAB * SharedBufHash

Definition: buf_table.c:33

hash_search_with_hash_value

void * hash_search_with_hash_value(HTAB *hashp, const void *keyPtr, uint32 hashvalue, HASHACTION action, bool *foundPtr)

Definition: dynahash.c:965

ERROR

#define ERROR

Definition: elog.h:39

elog

#define elog(elevel,...)

Definition: elog.h:226

HASH_REMOVE

@ HASH_REMOVE

Definition: hsearch.h:115

BufferLookupEnt

Definition: buf_table.c:28

References elog, ERROR, HASH_REMOVE, hash_search_with_hash_value(), and SharedBufHash.

Referenced by InvalidateBuffer(), and InvalidateVictimBuffer().

◆ BufTableHashCode()

uint32 BufTableHashCode ( BufferTag * tagPtr )

Definition at line 78 of file buf_table.c.

79{

80 return get_hash_value(SharedBufHash, tagPtr);

81}

get_hash_value

uint32 get_hash_value(HTAB *hashp, const void *keyPtr)

Definition: dynahash.c:908

References get_hash_value(), and SharedBufHash.

Referenced by BufferAlloc(), ExtendBufferedRelShared(), FindAndDropRelationBuffers(), InvalidateBuffer(), InvalidateVictimBuffer(), and PrefetchSharedBuffer().

◆ BufTableInsert()

int BufTableInsert ( BufferTag * tagPtr,

uint32 hashcode,

int buf_id

)

Definition at line 118 of file buf_table.c.

119{

120 BufferLookupEnt *result;

121 bool found;

122

123 Assert(buf_id >= 0); /* -1 is reserved for not-in-table */

124 Assert(tagPtr->blockNum != P_NEW); /* invalid tag */

125

126 result = (BufferLookupEnt *)

127 hash_search_with_hash_value(SharedBufHash,

128 tagPtr,

129 hashcode,

130 HASH_ENTER,

131 &found);

132

133 if (found) /* found something already in the table */

134 return result->id;

135

136 result->id = buf_id;

137

138 return -1;

139}

P_NEW

#define P_NEW

Definition: bufmgr.h:191

Assert

Assert(PointerIsAligned(start, uint64))

HASH_ENTER

@ HASH_ENTER

Definition: hsearch.h:114

BufferLookupEnt::id

int id

Definition: buf_table.c:30

buftag::blockNum

BlockNumber blockNum

Definition: buf_internals.h:111

References Assert(), buftag::blockNum, HASH_ENTER, hash_search_with_hash_value(), BufferLookupEnt::id, P_NEW, and SharedBufHash.

Referenced by BufferAlloc(), and ExtendBufferedRelShared().

◆ BufTableLookup()

int BufTableLookup ( BufferTag * tagPtr,

uint32 hashcode

)

Definition at line 90 of file buf_table.c.

91{

92 BufferLookupEnt *result;

93

94 result = (BufferLookupEnt *)

95 hash_search_with_hash_value(SharedBufHash,

96 tagPtr,

97 hashcode,

98 HASH_FIND,

99 NULL);

100

101 if (!result)

102 return -1;

103

104 return result->id;

105}

HASH_FIND

@ HASH_FIND

Definition: hsearch.h:113

References HASH_FIND, hash_search_with_hash_value(), BufferLookupEnt::id, and SharedBufHash.

Referenced by BufferAlloc(), FindAndDropRelationBuffers(), and PrefetchSharedBuffer().

◆ BufTableShmemSize()

Size BufTableShmemSize ( int size )

Definition at line 41 of file buf_table.c.

42{

43 return hash_estimate_size(size, sizeof(BufferLookupEnt));

44}

hash_estimate_size

Size hash_estimate_size(int64 num_entries, Size entrysize)

Definition: dynahash.c:783

References hash_estimate_size().

Referenced by StrategyShmemSize().

◆ InitBufTable()

void InitBufTable ( int size )

Definition at line 51 of file buf_table.c.

52{

53 HASHCTL info;

54

55 /* assume no locking is needed yet */

56

57 /* BufferTag maps to Buffer */

58 info.keysize = sizeof(BufferTag);

59 info.entrysize = sizeof(BufferLookupEnt);

60 info.num_partitions = NUM_BUFFER_PARTITIONS;

61

62 SharedBufHash = ShmemInitHash("Shared Buffer Lookup Table",

63 size, size,

64 &info,

65 HASH_ELEM | HASH_BLOBS | HASH_PARTITION | HASH_FIXED_SIZE);

66}

BufferTag

struct buftag BufferTag

HASH_ELEM

#define HASH_ELEM

Definition: hsearch.h:95

HASH_BLOBS

#define HASH_BLOBS

Definition: hsearch.h:97

HASH_FIXED_SIZE

#define HASH_FIXED_SIZE

Definition: hsearch.h:105

HASH_PARTITION

#define HASH_PARTITION

Definition: hsearch.h:92

NUM_BUFFER_PARTITIONS

#define NUM_BUFFER_PARTITIONS

Definition: lwlock.h:91

ShmemInitHash

HTAB * ShmemInitHash(const char *name, int64 init_size, int64 max_size, HASHCTL *infoP, int hash_flags)

Definition: shmem.c:332

HASHCTL

Definition: hsearch.h:66

HASHCTL::keysize

Size keysize

Definition: hsearch.h:75

HASHCTL::entrysize

Size entrysize

Definition: hsearch.h:76

HASHCTL::num_partitions

int64 num_partitions

Definition: hsearch.h:68

References HASHCTL::entrysize, HASH_BLOBS, HASH_ELEM, HASH_FIXED_SIZE, HASH_PARTITION, HASHCTL::keysize, NUM_BUFFER_PARTITIONS, HASHCTL::num_partitions, SharedBufHash, and ShmemInitHash().

Referenced by StrategyInitialize().

Variable Documentation

◆ SharedBufHash

HTAB* SharedBufHash

static

Definition at line 33 of file buf_table.c.

Referenced by BufTableDelete(), BufTableHashCode(), BufTableInsert(), BufTableLookup(), and InitBufTable().