#include "postgres.h"
#include "access/genam.h"
+#include "access/gin.h"
#include "access/gist.h"
#include "access/gist_private.h"
#include "access/gistscan.h"
#include "storage/lmgr.h"
#include "catalog/namespace.h"
#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/datum.h"
#include <fmgr.h>
#include <funcapi.h>
#include <access/heapam.h>
int len;
} IdxInfo;
+static Relation checkOpenedRelation(Relation r, Oid PgAmOid);
#ifdef PG_MODULE_MAGIC
/* >= 8.2 */
static Relation
gist_index_open(RangeVar *relvar) {
Oid relOid = RangeVarGetRelid(relvar, false);
- return index_open(relOid, AccessExclusiveLock);
+ return checkOpenedRelation(
+ index_open(relOid, AccessExclusiveLock), GIST_AM_OID);
}
#define gist_index_close(r) index_close((r), AccessExclusiveLock)
+static Relation
+gin_index_open(RangeVar *relvar) {
+ Oid relOid = RangeVarGetRelid(relvar, false);
+ return checkOpenedRelation(
+ index_open(relOid, AccessShareLock), GIN_AM_OID);
+}
+
+#define gin_index_close(r) index_close((r), AccessShareLock)
+
#else /* <8.2 */
static Relation
Relation rel = index_openrv(relvar);
LockRelation(rel, AccessExclusiveLock);
- return rel;
+ return checkOpenedRelation(rel, GIST_AM_OID);
}
static void
index_close(rel);
}
+static Relation
+gin_index_open(RangeVar *relvar) {
+ Relation rel = index_openrv(relvar);
+
+ LockRelation(rel, AccessShareLock);
+ return checkOpenedRelation(rel, GIN_AM_OID);
+}
+
+static void
+gin_index_close(Relation rel) {
+ UnlockRelation(rel, AccessShareLock);
+ index_close(rel);
+}
+
#endif
#if PG_VERSION_NUM >= 80300
#define SET_VARSIZE(p,l) VARATT_SIZEP(p)=(l)
#endif
+static Relation
+checkOpenedRelation(Relation r, Oid PgAmOid) {
+ if ( r->rd_am == NULL )
+ elog(ERROR, "Relation %s.%s is not an index",
+ get_namespace_name(RelationGetNamespace(r)),
+ RelationGetRelationName(r)
+ );
+
+ if ( r->rd_rel->relam != PgAmOid )
+ elog(ERROR, "Index %s.%s has wrong type",
+ get_namespace_name(RelationGetNamespace(r)),
+ RelationGetRelationName(r)
+ );
+
+ return r;
+}
+
static void
gist_dumptree(Relation r, int level, BlockNumber blk, OffsetNumber coff, IdxInfo *info) {
Buffer buffer;
SRF_RETURN_NEXT(funcctx, result);
}
+typedef struct GinStatState {
+ Relation index;
+ GinState ginstate;
+
+ Buffer buffer;
+ OffsetNumber offset;
+ Datum curval;
+ Datum dvalues[2];
+ char nulls[2];
+} GinStatState;
+
+static bool
+moveRightIfItNeeded( GinStatState *st )
+{
+ Page page = BufferGetPage(st->buffer);
+
+ if ( st->offset > PageGetMaxOffsetNumber(page) ) {
+ /*
+ * We scaned the whole page, so we should take right page
+ */
+ BlockNumber blkno = GinPageGetOpaque(page)->rightlink;
+
+ if ( GinPageRightMost(page) )
+ return false; /* no more page */
+
+ LockBuffer(st->buffer, GIN_UNLOCK);
+ st->buffer = ReleaseAndReadBuffer(st->buffer, st->index, blkno);
+ LockBuffer(st->buffer, GIN_SHARE);
+ st->offset = FirstOffsetNumber;
+ }
+
+ return true;
+}
+
+/*
+ * Refinds a previois position, at returns it has correctly
+ * set offset and buffer is locked
+ */
+static bool
+refindPosition(GinStatState *st)
+{
+ Page page;
+
+ /* find left if needed (it causes only for first search) */
+ for (;;) {
+ IndexTuple itup;
+ BlockNumber blkno;
+
+ LockBuffer(st->buffer, GIN_SHARE);
+
+ page = BufferGetPage(st->buffer);
+ if (GinPageIsLeaf(page))
+ break;
+
+ itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, FirstOffsetNumber));
+ blkno = GinItemPointerGetBlockNumber(&(itup)->t_tid);
+
+ LockBuffer(st->buffer,GIN_UNLOCK);
+ st->buffer = ReleaseAndReadBuffer(st->buffer, st->index, blkno);
+ }
+
+ if (st->offset == InvalidOffsetNumber) {
+ return (PageGetMaxOffsetNumber(page) >= FirstOffsetNumber ) ? true : false; /* first one */
+ }
+
+ for(;;) {
+ int cmp;
+ bool isnull;
+ Datum datum;
+ IndexTuple itup;
+
+ if (moveRightIfItNeeded(st)==false)
+ return false;
+
+ itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, st->offset));
+ datum = index_getattr(itup, FirstOffsetNumber, st->ginstate.tupdesc, &isnull);
+ cmp = DatumGetInt32(
+ FunctionCall2(
+ &st->ginstate.compareFn,
+ st->curval,
+ datum
+ ));
+ if ( cmp == 0 )
+ return true;
+
+ st->offset++;
+ }
+
+ return false;
+}
+
+static void
+gin_setup_firstcall(FuncCallContext *funcctx, text *name) {
+ MemoryContext oldcontext;
+ GinStatState *st;
+ char *relname=t2c(name);
+ TupleDesc tupdesc;
+
+ oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+ st=(GinStatState*)palloc( sizeof(GinStatState) );
+ memset(st,0,sizeof(GinStatState));
+ st->index = gin_index_open(
+ makeRangeVarFromNameList(stringToQualifiedNameList(relname, "gist_tree")));
+ initGinState( &st->ginstate, st->index );
+
+ funcctx->user_fctx = (void*)st;
+
+ tupdesc = CreateTemplateTupleDesc(2, false);
+ TupleDescInitEntry(tupdesc, 1, "value",
+ st->index->rd_att->attrs[0]->atttypid,
+ st->index->rd_att->attrs[0]->atttypmod,
+ st->index->rd_att->attrs[0]->attndims);
+ TupleDescInitEntry(tupdesc, 2, "nrow", INT4OID, -1, 0);
+
+ memset( st->nulls, ' ', 2*sizeof(char) );
+
+ funcctx->slot = TupleDescGetSlot(tupdesc);
+ funcctx->attinmeta = TupleDescGetAttInMetadata(tupdesc);
+
+ MemoryContextSwitchTo(oldcontext);
+ pfree(relname);
+
+ st->offset = InvalidOffsetNumber;
+ st->buffer = ReadBuffer( st->index, GIN_ROOT_BLKNO );
+}
+
+static void
+processTuple( FuncCallContext *funcctx, GinStatState *st, IndexTuple itup ) {
+ MemoryContext oldcontext;
+ Datum datum;
+ bool isnull;
+
+ datum = index_getattr(itup, FirstOffsetNumber, st->ginstate.tupdesc, &isnull);
+ oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+ st->curval = datumCopy(
+ index_getattr(itup, FirstOffsetNumber, st->ginstate.tupdesc, &isnull),
+ st->ginstate.tupdesc->attrs[0]->attbyval,
+ st->ginstate.tupdesc->attrs[0]->attlen );
+ MemoryContextSwitchTo(oldcontext);
+
+ st->dvalues[0] = st->curval;
+
+ if ( GinIsPostingTree(itup) ) {
+ BlockNumber rootblkno = GinGetPostingTree(itup);
+ GinPostingTreeScan *gdi;
+ Buffer entrybuffer;
+ Page page;
+
+ LockBuffer(st->buffer, GIN_UNLOCK);
+ gdi = prepareScanPostingTree(st->index, rootblkno, TRUE);
+ entrybuffer = scanBeginPostingTree(gdi);
+
+ page = BufferGetPage(entrybuffer);
+ st->dvalues[1] = Int32GetDatum( gdi->stack->predictNumber * GinPageGetOpaque(page)->maxoff );
+
+ LockBuffer(entrybuffer, GIN_UNLOCK);
+ freeGinBtreeStack(gdi->stack);
+ pfree(gdi);
+ } else {
+ st->dvalues[1] = Int32GetDatum( GinGetNPosting(itup) );
+ LockBuffer(st->buffer, GIN_UNLOCK);
+ }
+}
+
+PG_FUNCTION_INFO_V1(gin_stat);
+Datum gin_stat(PG_FUNCTION_ARGS);
+Datum
+gin_stat(PG_FUNCTION_ARGS) {
+ FuncCallContext *funcctx;
+ GinStatState *st;
+ Datum result=(Datum)0;
+ IndexTuple ituple;
+ HeapTuple htuple;
+ Page page;
+
+ if (SRF_IS_FIRSTCALL()) {
+ text *name=PG_GETARG_TEXT_P(0);
+ funcctx = SRF_FIRSTCALL_INIT();
+ gin_setup_firstcall(funcctx, name);
+ PG_FREE_IF_COPY(name,0);
+ }
+
+ funcctx = SRF_PERCALL_SETUP();
+ st = (GinStatState*)(funcctx->user_fctx);
+
+ if ( refindPosition(st) == false ) {
+ UnlockReleaseBuffer( st->buffer );
+ gin_index_close(st->index);
+
+ SRF_RETURN_DONE(funcctx);
+ }
+
+ st->offset++;
+
+ if (moveRightIfItNeeded(st)==false) {
+ UnlockReleaseBuffer( st->buffer );
+ gin_index_close(st->index);
+
+ SRF_RETURN_DONE(funcctx);
+ }
+
+ page = BufferGetPage(st->buffer);
+ ituple = (IndexTuple) PageGetItem(page, PageGetItemId(page, st->offset));
+
+ processTuple( funcctx, st, ituple );
+
+ htuple = heap_formtuple(funcctx->attinmeta->tupdesc, st->dvalues, st->nulls);
+ result = TupleGetDatum(funcctx->slot, htuple);
+
+ SRF_RETURN_NEXT(funcctx, result);
+}
+
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