postgresql/contrib/bloom/bloom.h
2017-01-03 13:48:53 -05:00

213 lines
6.8 KiB
C

/*-------------------------------------------------------------------------
*
* bloom.h
* Header for bloom index.
*
* Copyright (c) 2016-2017, 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 "nodes/relation.h"
#include "fmgr.h"
/* Support procedures numbers */
#define BLOOM_HASH_PROC 1
#define BLOOM_NPROC 1
/* 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];
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);
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);
#endif