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Diffstat (limited to 'src/backend/access/rtree/rtget.c')
-rw-r--r--src/backend/access/rtree/rtget.c544
1 files changed, 291 insertions, 253 deletions
diff --git a/src/backend/access/rtree/rtget.c b/src/backend/access/rtree/rtget.c
index 09f10f1aa98..eaf16c1ae9d 100644
--- a/src/backend/access/rtree/rtget.c
+++ b/src/backend/access/rtree/rtget.c
@@ -1,19 +1,19 @@
/*-------------------------------------------------------------------------
*
* rtget.c--
- * fetch tuples from an rtree scan.
+ * fetch tuples from an rtree scan.
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtget.c,v 1.7 1996/11/21 06:13:43 vadim Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtget.c,v 1.8 1997/09/07 04:39:11 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include <postgres.h>
-
+
#include <storage/bufmgr.h>
#include <access/sdir.h>
#include <access/relscan.h>
@@ -21,14 +21,15 @@
#include <access/rtree.h>
#include <storage/bufpage.h>
#ifndef HAVE_MEMMOVE
-# include <regex/utils.h>
+#include <regex/utils.h>
#else
-# include <string.h>
+#include <string.h>
#endif
-static OffsetNumber findnext(IndexScanDesc s, Page p, OffsetNumber n,
- ScanDirection dir);
+static OffsetNumber
+findnext(IndexScanDesc s, Page p, OffsetNumber n,
+ ScanDirection dir);
static RetrieveIndexResult rtscancache(IndexScanDesc s, ScanDirection dir);
static RetrieveIndexResult rtfirst(IndexScanDesc s, ScanDirection dir);
static RetrieveIndexResult rtnext(IndexScanDesc s, ScanDirection dir);
@@ -38,278 +39,315 @@ static ItemPointer rtheapptr(Relation r, ItemPointer itemp);
RetrieveIndexResult
rtgettuple(IndexScanDesc s, ScanDirection dir)
{
- RetrieveIndexResult res;
-
- /* if we have it cached in the scan desc, just return the value */
- if ((res = rtscancache(s, dir)) != (RetrieveIndexResult) NULL)
+ RetrieveIndexResult res;
+
+ /* if we have it cached in the scan desc, just return the value */
+ if ((res = rtscancache(s, dir)) != (RetrieveIndexResult) NULL)
+ return (res);
+
+ /* not cached, so we'll have to do some work */
+ if (ItemPointerIsValid(&(s->currentItemData)))
+ {
+ res = rtnext(s, dir);
+ }
+ else
+ {
+ res = rtfirst(s, dir);
+ }
return (res);
-
- /* not cached, so we'll have to do some work */
- if (ItemPointerIsValid(&(s->currentItemData))) {
- res = rtnext(s, dir);
- } else {
- res = rtfirst(s, dir);
- }
- return (res);
}
-static RetrieveIndexResult
+static RetrieveIndexResult
rtfirst(IndexScanDesc s, ScanDirection dir)
{
- Buffer b;
- Page p;
- OffsetNumber n;
- OffsetNumber maxoff;
- RetrieveIndexResult res;
- RTreePageOpaque po;
- RTreeScanOpaque so;
- RTSTACK *stk;
- BlockNumber blk;
- IndexTuple it;
-
- b = ReadBuffer(s->relation, P_ROOT);
- p = BufferGetPage(b);
- po = (RTreePageOpaque) PageGetSpecialPointer(p);
- so = (RTreeScanOpaque) s->opaque;
-
- for (;;) {
- maxoff = PageGetMaxOffsetNumber(p);
- if (ScanDirectionIsBackward(dir))
- n = findnext(s, p, maxoff, dir);
- else
- n = findnext(s, p, FirstOffsetNumber, dir);
-
- while (n < FirstOffsetNumber || n > maxoff) {
-
- ReleaseBuffer(b);
- if (so->s_stack == (RTSTACK *) NULL)
- return ((RetrieveIndexResult) NULL);
-
- stk = so->s_stack;
- b = ReadBuffer(s->relation, stk->rts_blk);
- p = BufferGetPage(b);
- po = (RTreePageOpaque) PageGetSpecialPointer(p);
- maxoff = PageGetMaxOffsetNumber(p);
-
- if (ScanDirectionIsBackward(dir)) {
- n = OffsetNumberPrev(stk->rts_child);
- } else {
- n = OffsetNumberNext(stk->rts_child);
- }
- so->s_stack = stk->rts_parent;
- pfree(stk);
-
- n = findnext(s, p, n, dir);
- }
- if (po->flags & F_LEAF) {
- ItemPointerSet(&(s->currentItemData), BufferGetBlockNumber(b), n);
-
- it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
-
- res = FormRetrieveIndexResult(&(s->currentItemData), &(it->t_tid));
-
- ReleaseBuffer(b);
- return (res);
- } else {
- stk = (RTSTACK *) palloc(sizeof(RTSTACK));
- stk->rts_child = n;
- stk->rts_blk = BufferGetBlockNumber(b);
- stk->rts_parent = so->s_stack;
- so->s_stack = stk;
-
- it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
- blk = ItemPointerGetBlockNumber(&(it->t_tid));
-
- ReleaseBuffer(b);
- b = ReadBuffer(s->relation, blk);
- p = BufferGetPage(b);
- po = (RTreePageOpaque) PageGetSpecialPointer(p);
+ Buffer b;
+ Page p;
+ OffsetNumber n;
+ OffsetNumber maxoff;
+ RetrieveIndexResult res;
+ RTreePageOpaque po;
+ RTreeScanOpaque so;
+ RTSTACK *stk;
+ BlockNumber blk;
+ IndexTuple it;
+
+ b = ReadBuffer(s->relation, P_ROOT);
+ p = BufferGetPage(b);
+ po = (RTreePageOpaque) PageGetSpecialPointer(p);
+ so = (RTreeScanOpaque) s->opaque;
+
+ for (;;)
+ {
+ maxoff = PageGetMaxOffsetNumber(p);
+ if (ScanDirectionIsBackward(dir))
+ n = findnext(s, p, maxoff, dir);
+ else
+ n = findnext(s, p, FirstOffsetNumber, dir);
+
+ while (n < FirstOffsetNumber || n > maxoff)
+ {
+
+ ReleaseBuffer(b);
+ if (so->s_stack == (RTSTACK *) NULL)
+ return ((RetrieveIndexResult) NULL);
+
+ stk = so->s_stack;
+ b = ReadBuffer(s->relation, stk->rts_blk);
+ p = BufferGetPage(b);
+ po = (RTreePageOpaque) PageGetSpecialPointer(p);
+ maxoff = PageGetMaxOffsetNumber(p);
+
+ if (ScanDirectionIsBackward(dir))
+ {
+ n = OffsetNumberPrev(stk->rts_child);
+ }
+ else
+ {
+ n = OffsetNumberNext(stk->rts_child);
+ }
+ so->s_stack = stk->rts_parent;
+ pfree(stk);
+
+ n = findnext(s, p, n, dir);
+ }
+ if (po->flags & F_LEAF)
+ {
+ ItemPointerSet(&(s->currentItemData), BufferGetBlockNumber(b), n);
+
+ it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
+
+ res = FormRetrieveIndexResult(&(s->currentItemData), &(it->t_tid));
+
+ ReleaseBuffer(b);
+ return (res);
+ }
+ else
+ {
+ stk = (RTSTACK *) palloc(sizeof(RTSTACK));
+ stk->rts_child = n;
+ stk->rts_blk = BufferGetBlockNumber(b);
+ stk->rts_parent = so->s_stack;
+ so->s_stack = stk;
+
+ it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
+ blk = ItemPointerGetBlockNumber(&(it->t_tid));
+
+ ReleaseBuffer(b);
+ b = ReadBuffer(s->relation, blk);
+ p = BufferGetPage(b);
+ po = (RTreePageOpaque) PageGetSpecialPointer(p);
+ }
}
- }
}
-static RetrieveIndexResult
+static RetrieveIndexResult
rtnext(IndexScanDesc s, ScanDirection dir)
{
- Buffer b;
- Page p;
- OffsetNumber n;
- OffsetNumber maxoff;
- RetrieveIndexResult res;
- RTreePageOpaque po;
- RTreeScanOpaque so;
- RTSTACK *stk;
- BlockNumber blk;
- IndexTuple it;
-
- blk = ItemPointerGetBlockNumber(&(s->currentItemData));
- n = ItemPointerGetOffsetNumber(&(s->currentItemData));
-
- if (ScanDirectionIsForward(dir)) {
- n = OffsetNumberNext(n);
- } else {
- n = OffsetNumberPrev(n);
- }
-
- b = ReadBuffer(s->relation, blk);
- p = BufferGetPage(b);
- po = (RTreePageOpaque) PageGetSpecialPointer(p);
- so = (RTreeScanOpaque) s->opaque;
-
- for (;;) {
- maxoff = PageGetMaxOffsetNumber(p);
- n = findnext(s, p, n, dir);
-
- while (n < FirstOffsetNumber || n > maxoff) {
-
- ReleaseBuffer(b);
- if (so->s_stack == (RTSTACK *) NULL)
- return ((RetrieveIndexResult) NULL);
-
- stk = so->s_stack;
- b = ReadBuffer(s->relation, stk->rts_blk);
- p = BufferGetPage(b);
- maxoff = PageGetMaxOffsetNumber(p);
- po = (RTreePageOpaque) PageGetSpecialPointer(p);
-
- if (ScanDirectionIsBackward(dir)) {
- n = OffsetNumberPrev(stk->rts_child);
- } else {
- n = OffsetNumberNext(stk->rts_child);
- }
- so->s_stack = stk->rts_parent;
- pfree(stk);
-
- n = findnext(s, p, n, dir);
+ Buffer b;
+ Page p;
+ OffsetNumber n;
+ OffsetNumber maxoff;
+ RetrieveIndexResult res;
+ RTreePageOpaque po;
+ RTreeScanOpaque so;
+ RTSTACK *stk;
+ BlockNumber blk;
+ IndexTuple it;
+
+ blk = ItemPointerGetBlockNumber(&(s->currentItemData));
+ n = ItemPointerGetOffsetNumber(&(s->currentItemData));
+
+ if (ScanDirectionIsForward(dir))
+ {
+ n = OffsetNumberNext(n);
+ }
+ else
+ {
+ n = OffsetNumberPrev(n);
}
- if (po->flags & F_LEAF) {
- ItemPointerSet(&(s->currentItemData), BufferGetBlockNumber(b), n);
-
- it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
-
- res = FormRetrieveIndexResult(&(s->currentItemData), &(it->t_tid));
-
- ReleaseBuffer(b);
- return (res);
- } else {
- stk = (RTSTACK *) palloc(sizeof(RTSTACK));
- stk->rts_child = n;
- stk->rts_blk = BufferGetBlockNumber(b);
- stk->rts_parent = so->s_stack;
- so->s_stack = stk;
-
- it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
- blk = ItemPointerGetBlockNumber(&(it->t_tid));
-
- ReleaseBuffer(b);
- b = ReadBuffer(s->relation, blk);
- p = BufferGetPage(b);
- po = (RTreePageOpaque) PageGetSpecialPointer(p);
-
- if (ScanDirectionIsBackward(dir)) {
- n = PageGetMaxOffsetNumber(p);
- } else {
- n = FirstOffsetNumber;
- }
+
+ b = ReadBuffer(s->relation, blk);
+ p = BufferGetPage(b);
+ po = (RTreePageOpaque) PageGetSpecialPointer(p);
+ so = (RTreeScanOpaque) s->opaque;
+
+ for (;;)
+ {
+ maxoff = PageGetMaxOffsetNumber(p);
+ n = findnext(s, p, n, dir);
+
+ while (n < FirstOffsetNumber || n > maxoff)
+ {
+
+ ReleaseBuffer(b);
+ if (so->s_stack == (RTSTACK *) NULL)
+ return ((RetrieveIndexResult) NULL);
+
+ stk = so->s_stack;
+ b = ReadBuffer(s->relation, stk->rts_blk);
+ p = BufferGetPage(b);
+ maxoff = PageGetMaxOffsetNumber(p);
+ po = (RTreePageOpaque) PageGetSpecialPointer(p);
+
+ if (ScanDirectionIsBackward(dir))
+ {
+ n = OffsetNumberPrev(stk->rts_child);
+ }
+ else
+ {
+ n = OffsetNumberNext(stk->rts_child);
+ }
+ so->s_stack = stk->rts_parent;
+ pfree(stk);
+
+ n = findnext(s, p, n, dir);
+ }
+ if (po->flags & F_LEAF)
+ {
+ ItemPointerSet(&(s->currentItemData), BufferGetBlockNumber(b), n);
+
+ it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
+
+ res = FormRetrieveIndexResult(&(s->currentItemData), &(it->t_tid));
+
+ ReleaseBuffer(b);
+ return (res);
+ }
+ else
+ {
+ stk = (RTSTACK *) palloc(sizeof(RTSTACK));
+ stk->rts_child = n;
+ stk->rts_blk = BufferGetBlockNumber(b);
+ stk->rts_parent = so->s_stack;
+ so->s_stack = stk;
+
+ it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
+ blk = ItemPointerGetBlockNumber(&(it->t_tid));
+
+ ReleaseBuffer(b);
+ b = ReadBuffer(s->relation, blk);
+ p = BufferGetPage(b);
+ po = (RTreePageOpaque) PageGetSpecialPointer(p);
+
+ if (ScanDirectionIsBackward(dir))
+ {
+ n = PageGetMaxOffsetNumber(p);
+ }
+ else
+ {
+ n = FirstOffsetNumber;
+ }
+ }
}
- }
}
-static OffsetNumber
+static OffsetNumber
findnext(IndexScanDesc s, Page p, OffsetNumber n, ScanDirection dir)
{
- OffsetNumber maxoff;
- IndexTuple it;
- RTreePageOpaque po;
- RTreeScanOpaque so;
-
- maxoff = PageGetMaxOffsetNumber(p);
- po = (RTreePageOpaque) PageGetSpecialPointer(p);
- so = (RTreeScanOpaque) s->opaque;
-
- /*
- * If we modified the index during the scan, we may have a pointer to
- * a ghost tuple, before the scan. If this is the case, back up one.
- */
-
- if (so->s_flags & RTS_CURBEFORE) {
- so->s_flags &= ~RTS_CURBEFORE;
- n = OffsetNumberPrev(n);
- }
-
- while (n >= FirstOffsetNumber && n <= maxoff) {
- it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
- if (po->flags & F_LEAF) {
- if (index_keytest(it,
- RelationGetTupleDescriptor(s->relation),
- s->numberOfKeys, s->keyData))
- break;
- } else {
- if (index_keytest(it,
- RelationGetTupleDescriptor(s->relation),
- so->s_internalNKey, so->s_internalKey))
- break;
+ OffsetNumber maxoff;
+ IndexTuple it;
+ RTreePageOpaque po;
+ RTreeScanOpaque so;
+
+ maxoff = PageGetMaxOffsetNumber(p);
+ po = (RTreePageOpaque) PageGetSpecialPointer(p);
+ so = (RTreeScanOpaque) s->opaque;
+
+ /*
+ * If we modified the index during the scan, we may have a pointer to
+ * a ghost tuple, before the scan. If this is the case, back up one.
+ */
+
+ if (so->s_flags & RTS_CURBEFORE)
+ {
+ so->s_flags &= ~RTS_CURBEFORE;
+ n = OffsetNumberPrev(n);
}
-
- if (ScanDirectionIsBackward(dir)) {
- n = OffsetNumberPrev(n);
- } else {
- n = OffsetNumberNext(n);
+
+ while (n >= FirstOffsetNumber && n <= maxoff)
+ {
+ it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
+ if (po->flags & F_LEAF)
+ {
+ if (index_keytest(it,
+ RelationGetTupleDescriptor(s->relation),
+ s->numberOfKeys, s->keyData))
+ break;
+ }
+ else
+ {
+ if (index_keytest(it,
+ RelationGetTupleDescriptor(s->relation),
+ so->s_internalNKey, so->s_internalKey))
+ break;
+ }
+
+ if (ScanDirectionIsBackward(dir))
+ {
+ n = OffsetNumberPrev(n);
+ }
+ else
+ {
+ n = OffsetNumberNext(n);
+ }
}
- }
-
- return (n);
+
+ return (n);
}
-static RetrieveIndexResult
+static RetrieveIndexResult
rtscancache(IndexScanDesc s, ScanDirection dir)
{
- RetrieveIndexResult res;
- ItemPointer ip;
-
- if (!(ScanDirectionIsNoMovement(dir)
- && ItemPointerIsValid(&(s->currentItemData)))) {
-
- return ((RetrieveIndexResult) NULL);
- }
-
- ip = rtheapptr(s->relation, &(s->currentItemData));
-
- if (ItemPointerIsValid(ip))
- res = FormRetrieveIndexResult(&(s->currentItemData), ip);
- else
- res = (RetrieveIndexResult) NULL;
-
- pfree (ip);
-
- return (res);
+ RetrieveIndexResult res;
+ ItemPointer ip;
+
+ if (!(ScanDirectionIsNoMovement(dir)
+ && ItemPointerIsValid(&(s->currentItemData))))
+ {
+
+ return ((RetrieveIndexResult) NULL);
+ }
+
+ ip = rtheapptr(s->relation, &(s->currentItemData));
+
+ if (ItemPointerIsValid(ip))
+ res = FormRetrieveIndexResult(&(s->currentItemData), ip);
+ else
+ res = (RetrieveIndexResult) NULL;
+
+ pfree(ip);
+
+ return (res);
}
/*
- * rtheapptr returns the item pointer to the tuple in the heap relation
- * for which itemp is the index relation item pointer.
+ * rtheapptr returns the item pointer to the tuple in the heap relation
+ * for which itemp is the index relation item pointer.
*/
-static ItemPointer
+static ItemPointer
rtheapptr(Relation r, ItemPointer itemp)
{
- Buffer b;
- Page p;
- IndexTuple it;
- ItemPointer ip;
- OffsetNumber n;
-
- ip = (ItemPointer) palloc(sizeof(ItemPointerData));
- if (ItemPointerIsValid(itemp)) {
- b = ReadBuffer(r, ItemPointerGetBlockNumber(itemp));
- p = BufferGetPage(b);
- n = ItemPointerGetOffsetNumber(itemp);
- it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
- memmove((char *) ip, (char *) &(it->t_tid),
- sizeof(ItemPointerData));
- ReleaseBuffer(b);
- } else {
- ItemPointerSetInvalid(ip);
- }
-
- return (ip);
+ Buffer b;
+ Page p;
+ IndexTuple it;
+ ItemPointer ip;
+ OffsetNumber n;
+
+ ip = (ItemPointer) palloc(sizeof(ItemPointerData));
+ if (ItemPointerIsValid(itemp))
+ {
+ b = ReadBuffer(r, ItemPointerGetBlockNumber(itemp));
+ p = BufferGetPage(b);
+ n = ItemPointerGetOffsetNumber(itemp);
+ it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
+ memmove((char *) ip, (char *) &(it->t_tid),
+ sizeof(ItemPointerData));
+ ReleaseBuffer(b);
+ }
+ else
+ {
+ ItemPointerSetInvalid(ip);
+ }
+
+ return (ip);
}
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