contrib/bloom/bloom.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * bloom.h
   4  *        Header for bloom index.
   5  *
   6  * Copyright (c) 2016-2020, PostgreSQL Global Development Group
   7  *
   8  * IDENTIFICATION
   9  *        contrib/bloom/bloom.h
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13 #ifndef _BLOOM_H_
  14 #define _BLOOM_H_
  15
  16 #include "access/amapi.h"
  17 #include "access/generic_xlog.h"
  18 #include "access/itup.h"
  19 #include "access/xlog.h"
  20 #include "fmgr.h"
  21 #include "nodes/pathnodes.h"
  22
  23 /* Support procedures numbers */
  24 #define BLOOM_HASH_PROC                 1
  25 #define BLOOM_OPTIONS_PROC              2
  26 #define BLOOM_NPROC                             2
  27
  28 /* Scan strategies */
  29 #define BLOOM_EQUAL_STRATEGY    1
  30 #define BLOOM_NSTRATEGIES               1
  31
  32 /* Opaque for bloom pages */
  33 typedef struct BloomPageOpaqueData
  34 {
  35         OffsetNumber maxoff;            /* number of index tuples on page */
  36         uint16          flags;                  /* see bit definitions below */
  37         uint16          unused;                 /* placeholder to force maxaligning of size of
  38                                                                  * BloomPageOpaqueData and to place
  39                                                                  * bloom_page_id exactly at the end of page */
  40         uint16          bloom_page_id;  /* for identification of BLOOM indexes */
  41 } BloomPageOpaqueData;
  42
  43 typedef BloomPageOpaqueData *BloomPageOpaque;
  44
  45 /* Bloom page flags */
  46 #define BLOOM_META              (1<<0)
  47 #define BLOOM_DELETED   (2<<0)
  48
  49 /*
  50  * The page ID is for the convenience of pg_filedump and similar utilities,
  51  * which otherwise would have a hard time telling pages of different index
  52  * types apart.  It should be the last 2 bytes on the page.  This is more or
  53  * less "free" due to alignment considerations.
  54  *
  55  * See comments above GinPageOpaqueData.
  56  */
  57 #define BLOOM_PAGE_ID           0xFF83
  58
  59 /* Macros for accessing bloom page structures */
  60 #define BloomPageGetOpaque(page) ((BloomPageOpaque) PageGetSpecialPointer(page))
  61 #define BloomPageGetMaxOffset(page) (BloomPageGetOpaque(page)->maxoff)
  62 #define BloomPageIsMeta(page) \
  63         ((BloomPageGetOpaque(page)->flags & BLOOM_META) != 0)
  64 #define BloomPageIsDeleted(page) \
  65         ((BloomPageGetOpaque(page)->flags & BLOOM_DELETED) != 0)
  66 #define BloomPageSetDeleted(page) \
  67         (BloomPageGetOpaque(page)->flags |= BLOOM_DELETED)
  68 #define BloomPageSetNonDeleted(page) \
  69         (BloomPageGetOpaque(page)->flags &= ~BLOOM_DELETED)
  70 #define BloomPageGetData(page)          ((BloomTuple *)PageGetContents(page))
  71 #define BloomPageGetTuple(state, page, offset) \
  72         ((BloomTuple *)(PageGetContents(page) \
  73                 + (state)->sizeOfBloomTuple * ((offset) - 1)))
  74 #define BloomPageGetNextTuple(state, tuple) \
  75         ((BloomTuple *)((Pointer)(tuple) + (state)->sizeOfBloomTuple))
  76
  77 /* Preserved page numbers */
  78 #define BLOOM_METAPAGE_BLKNO    (0)
  79 #define BLOOM_HEAD_BLKNO                (1) /* first data page */
  80
  81 /*
  82  * We store Bloom signatures as arrays of uint16 words.
  83  */
  84 typedef uint16 BloomSignatureWord;
  85
  86 #define SIGNWORDBITS ((int) (BITS_PER_BYTE * sizeof(BloomSignatureWord)))
  87
  88 /*
  89  * Default and maximum Bloom signature length in bits.
  90  */
  91 #define DEFAULT_BLOOM_LENGTH    (5 * SIGNWORDBITS)
  92 #define MAX_BLOOM_LENGTH                (256 * SIGNWORDBITS)
  93
  94 /*
  95  * Default and maximum signature bits generated per index key.
  96  */
  97 #define DEFAULT_BLOOM_BITS              2
  98 #define MAX_BLOOM_BITS                  (MAX_BLOOM_LENGTH - 1)
  99
 100 /* Bloom index options */
 101 typedef struct BloomOptions
 102 {
 103         int32           vl_len_;                /* varlena header (do not touch directly!) */
 104         int                     bloomLength;    /* length of signature in words (not bits!) */
 105         int                     bitSize[INDEX_MAX_KEYS];        /* # of bits generated for each
 106                                                                                          * index key */
 107 } BloomOptions;
 108
 109 /*
 110  * FreeBlockNumberArray - array of block numbers sized so that metadata fill
 111  * all space in metapage.
 112  */
 113 typedef BlockNumber FreeBlockNumberArray[
 114                                                                                  MAXALIGN_DOWN(
 115                                                                                                            BLCKSZ - SizeOfPageHeaderData - MAXALIGN(sizeof(BloomPageOpaqueData))
 116                                                                                                            - MAXALIGN(sizeof(uint16) * 2 + sizeof(uint32) + sizeof(BloomOptions))
 117                                                                                                            ) / sizeof(BlockNumber)
 118 ];
 119
 120 /* Metadata of bloom index */
 121 typedef struct BloomMetaPageData
 122 {
 123         uint32          magickNumber;
 124         uint16          nStart;
 125         uint16          nEnd;
 126         BloomOptions opts;
 127         FreeBlockNumberArray notFullPage;
 128 } BloomMetaPageData;
 129
 130 /* Magic number to distinguish bloom pages among anothers */
 131 #define BLOOM_MAGICK_NUMBER (0xDBAC0DED)
 132
 133 /* Number of blocks numbers fit in BloomMetaPageData */
 134 #define BloomMetaBlockN         (sizeof(FreeBlockNumberArray) / sizeof(BlockNumber))
 135
 136 #define BloomPageGetMeta(page)  ((BloomMetaPageData *) PageGetContents(page))
 137
 138 typedef struct BloomState
 139 {
 140         FmgrInfo        hashFn[INDEX_MAX_KEYS];
 141         Oid                     collations[INDEX_MAX_KEYS];
 142         BloomOptions opts;                      /* copy of options on index's metapage */
 143         int32           nColumns;
 144
 145         /*
 146          * sizeOfBloomTuple is index-specific, and it depends on reloptions, so
 147          * precompute it
 148          */
 149         Size            sizeOfBloomTuple;
 150 } BloomState;
 151
 152 #define BloomPageGetFreeSpace(state, page) \
 153         (BLCKSZ - MAXALIGN(SizeOfPageHeaderData) \
 154                 - BloomPageGetMaxOffset(page) * (state)->sizeOfBloomTuple \
 155                 - MAXALIGN(sizeof(BloomPageOpaqueData)))
 156
 157 /*
 158  * Tuples are very different from all other relations
 159  */
 160 typedef struct BloomTuple
 161 {
 162         ItemPointerData heapPtr;
 163         BloomSignatureWord sign[FLEXIBLE_ARRAY_MEMBER];
 164 } BloomTuple;
 165
 166 #define BLOOMTUPLEHDRSZ offsetof(BloomTuple, sign)
 167
 168 /* Opaque data structure for bloom index scan */
 169 typedef struct BloomScanOpaqueData
 170 {
 171         BloomSignatureWord *sign;       /* Scan signature */
 172         BloomState      state;
 173 } BloomScanOpaqueData;
 174
 175 typedef BloomScanOpaqueData *BloomScanOpaque;
 176
 177 /* blutils.c */
 178 extern void _PG_init(void);
 179 extern void initBloomState(BloomState *state, Relation index);
 180 extern void BloomFillMetapage(Relation index, Page metaPage);
 181 extern void BloomInitMetapage(Relation index);
 182 extern void BloomInitPage(Page page, uint16 flags);
 183 extern Buffer BloomNewBuffer(Relation index);
 184 extern void signValue(BloomState *state, BloomSignatureWord *sign, Datum value, int attno);
 185 extern BloomTuple *BloomFormTuple(BloomState *state, ItemPointer iptr, Datum *values, bool *isnull);
 186 extern bool BloomPageAddItem(BloomState *state, Page page, BloomTuple *tuple);
 187
 188 /* blvalidate.c */
 189 extern bool blvalidate(Oid opclassoid);
 190
 191 /* index access method interface functions */
 192 extern bool blinsert(Relation index, Datum *values, bool *isnull,
 193                                          ItemPointer ht_ctid, Relation heapRel,
 194                                          IndexUniqueCheck checkUnique,
 195                                          struct IndexInfo *indexInfo);
 196 extern IndexScanDesc blbeginscan(Relation r, int nkeys, int norderbys);
 197 extern int64 blgetbitmap(IndexScanDesc scan, TIDBitmap *tbm);
 198 extern void blrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
 199                                          ScanKey orderbys, int norderbys);
 200 extern void blendscan(IndexScanDesc scan);
 201 extern IndexBuildResult *blbuild(Relation heap, Relation index,
 202                                                                  struct IndexInfo *indexInfo);
 203 extern void blbuildempty(Relation index);
 204 extern IndexBulkDeleteResult *blbulkdelete(IndexVacuumInfo *info,
 205                                                                                    IndexBulkDeleteResult *stats, IndexBulkDeleteCallback callback,
 206                                                                                    void *callback_state);
 207 extern IndexBulkDeleteResult *blvacuumcleanup(IndexVacuumInfo *info,
 208                                                                                           IndexBulkDeleteResult *stats);
 209 extern bytea *bloptions(Datum reloptions, bool validate);
 210 extern void blcostestimate(PlannerInfo *root, IndexPath *path,
 211                                                    double loop_count, Cost *indexStartupCost,
 212                                                    Cost *indexTotalCost, Selectivity *indexSelectivity,
 213                                                    double *indexCorrelation, double *indexPages);
 214
 215 #endif