1 /*-------------------------------------------------------------------------
4 * utilities routines for the postgres inverted index access method.
7 * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
8 * Portions Copyright (c) 1994, Regents of the University of California
11 * $PostgreSQL: pgsql/src/backend/access/gin/ginutil.c,v 1.21 2009/03/24 20:17:11 tgl Exp $
12 *-------------------------------------------------------------------------
16 #include "access/genam.h"
17 #include "access/gin.h"
18 #include "access/reloptions.h"
19 #include "catalog/pg_type.h"
20 #include "storage/bufmgr.h"
21 #include "storage/freespace.h"
22 #include "storage/indexfsm.h"
23 #include "storage/lmgr.h"
26 initGinState(GinState *state, Relation index)
30 state->origTupdesc = index->rd_att;
32 state->oneCol = (index->rd_att->natts == 1) ? true : false;
34 for(i=0;i<index->rd_att->natts;i++)
36 state->tupdesc[i] = CreateTemplateTupleDesc(2,false);
38 TupleDescInitEntry( state->tupdesc[i], (AttrNumber) 1, NULL,
40 TupleDescInitEntry( state->tupdesc[i], (AttrNumber) 2, NULL,
41 index->rd_att->attrs[i]->atttypid,
42 index->rd_att->attrs[i]->atttypmod,
43 index->rd_att->attrs[i]->attndims
46 fmgr_info_copy(&(state->compareFn[i]),
47 index_getprocinfo(index, i+1, GIN_COMPARE_PROC),
48 CurrentMemoryContext);
49 fmgr_info_copy(&(state->extractValueFn[i]),
50 index_getprocinfo(index, i+1, GIN_EXTRACTVALUE_PROC),
51 CurrentMemoryContext);
52 fmgr_info_copy(&(state->extractQueryFn[i]),
53 index_getprocinfo(index, i+1, GIN_EXTRACTQUERY_PROC),
54 CurrentMemoryContext);
55 fmgr_info_copy(&(state->consistentFn[i]),
56 index_getprocinfo(index, i+1, GIN_CONSISTENT_PROC),
57 CurrentMemoryContext);
60 * Check opclass capability to do partial match.
62 if ( index_getprocid(index, i+1, GIN_COMPARE_PARTIAL_PROC) != InvalidOid )
64 fmgr_info_copy(&(state->comparePartialFn[i]),
65 index_getprocinfo(index, i+1, GIN_COMPARE_PARTIAL_PROC),
66 CurrentMemoryContext);
68 state->canPartialMatch[i] = true;
72 state->canPartialMatch[i] = false;
78 * Extract attribute (column) number of stored entry from GIN tuple
81 gintuple_get_attrnum(GinState *ginstate, IndexTuple tuple)
83 OffsetNumber colN = FirstOffsetNumber;
85 if ( !ginstate->oneCol )
91 * First attribute is always int16, so we can safely use any
92 * tuple descriptor to obtain first attribute of tuple
94 res = index_getattr(tuple, FirstOffsetNumber, ginstate->tupdesc[0],
98 colN = DatumGetUInt16(res);
99 Assert( colN >= FirstOffsetNumber && colN <= ginstate->origTupdesc->natts );
106 * Extract stored datum from GIN tuple
109 gin_index_getattr(GinState *ginstate, IndexTuple tuple)
114 if ( ginstate->oneCol )
117 * Single column index doesn't store attribute numbers in tuples
119 res = index_getattr(tuple, FirstOffsetNumber, ginstate->origTupdesc,
125 * Since the datum type depends on which index column it's from,
126 * we must be careful to use the right tuple descriptor here.
128 OffsetNumber colN = gintuple_get_attrnum(ginstate, tuple);
130 res = index_getattr(tuple, OffsetNumberNext(FirstOffsetNumber),
131 ginstate->tupdesc[colN - 1],
141 * Allocate a new page (either by recycling, or by extending the index file)
142 * The returned buffer is already pinned and exclusive-locked
143 * Caller is responsible for initializing the page by calling GinInitBuffer
147 GinNewBuffer(Relation index)
152 /* First, try to get a page from FSM */
155 BlockNumber blkno = GetFreeIndexPage(index);
157 if (blkno == InvalidBlockNumber)
160 buffer = ReadBuffer(index, blkno);
163 * We have to guard against the possibility that someone else already
164 * recycled this page; the buffer may be locked if so.
166 if (ConditionalLockBuffer(buffer))
168 Page page = BufferGetPage(buffer);
171 return buffer; /* OK to use, if never initialized */
173 if (GinPageIsDeleted(page))
174 return buffer; /* OK to use */
176 LockBuffer(buffer, GIN_UNLOCK);
179 /* Can't use it, so release buffer and try again */
180 ReleaseBuffer(buffer);
183 /* Must extend the file */
184 needLock = !RELATION_IS_LOCAL(index);
186 LockRelationForExtension(index, ExclusiveLock);
188 buffer = ReadBuffer(index, P_NEW);
189 LockBuffer(buffer, GIN_EXCLUSIVE);
192 UnlockRelationForExtension(index, ExclusiveLock);
198 GinInitPage(Page page, uint32 f, Size pageSize)
200 GinPageOpaque opaque;
202 PageInit(page, pageSize, sizeof(GinPageOpaqueData));
204 opaque = GinPageGetOpaque(page);
205 memset(opaque, 0, sizeof(GinPageOpaqueData));
207 opaque->rightlink = InvalidBlockNumber;
211 GinInitBuffer(Buffer b, uint32 f)
213 GinInitPage(BufferGetPage(b), f, BufferGetPageSize(b));
217 GinInitMetabuffer(Buffer b)
219 GinMetaPageData *metadata;
220 Page page = BufferGetPage(b);
222 GinInitPage(page, GIN_META, BufferGetPageSize(b));
224 metadata = GinPageGetMeta(page);
226 metadata->head = metadata->tail = InvalidBlockNumber;
227 metadata->tailFreeSize = 0;
228 metadata->nPendingPages = 0;
229 metadata->nPendingHeapTuples = 0;
233 compareEntries(GinState *ginstate, OffsetNumber attnum, Datum a, Datum b)
235 return DatumGetInt32(
237 &ginstate->compareFn[attnum-1],
244 compareAttEntries(GinState *ginstate, OffsetNumber attnum_a, Datum a,
245 OffsetNumber attnum_b, Datum b)
247 if ( attnum_a == attnum_b )
248 return compareEntries( ginstate, attnum_a, a, b);
250 return ( attnum_a < attnum_b ) ? -1 : 1;
255 FmgrInfo *cmpDatumFunc;
260 cmpEntries(const Datum *a, const Datum *b, cmpEntriesData *arg)
262 int res = DatumGetInt32(FunctionCall2(arg->cmpDatumFunc,
266 *(arg->needUnique) = TRUE;
272 extractEntriesS(GinState *ginstate, OffsetNumber attnum, Datum value, int32 *nentries,
277 entries = (Datum *) DatumGetPointer(FunctionCall2(
278 &ginstate->extractValueFn[attnum-1],
280 PointerGetDatum(nentries)
291 arg.cmpDatumFunc = &ginstate->compareFn[attnum-1];
292 arg.needUnique = needUnique;
293 qsort_arg(entries, *nentries, sizeof(Datum),
294 (qsort_arg_comparator) cmpEntries, (void *) &arg);
302 extractEntriesSU(GinState *ginstate, OffsetNumber attnum, Datum value, int32 *nentries)
305 Datum *entries = extractEntriesS(ginstate, attnum, value, nentries,
315 while (ptr - entries < *nentries)
317 if (compareEntries(ginstate, attnum, *ptr, *res) != 0)
323 *nentries = res + 1 - entries;
330 ginoptions(PG_FUNCTION_ARGS)
332 Datum reloptions = PG_GETARG_DATUM(0);
333 bool validate = PG_GETARG_BOOL(1);
334 relopt_value *options;
337 static const relopt_parse_elt tab[] = {
338 {"fastupdate", RELOPT_TYPE_BOOL, offsetof(GinOptions, useFastUpdate)}
341 options = parseRelOptions(reloptions, validate, RELOPT_KIND_GIN,
344 /* if none set, we're done */
348 rdopts = allocateReloptStruct(sizeof(GinOptions), options, numoptions);
350 fillRelOptions((void *) rdopts, sizeof(GinOptions), options, numoptions,
351 validate, tab, lengthof(tab));
355 PG_RETURN_BYTEA_P(rdopts);