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-rw-r--r--src/backend/access/index/genam.c328
1 files changed, 171 insertions, 157 deletions
diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c
index 52b7b1473bf..da7fc0dc09f 100644
--- a/src/backend/access/index/genam.c
+++ b/src/backend/access/index/genam.c
@@ -1,17 +1,17 @@
/*-------------------------------------------------------------------------
*
* genam.c--
- * general index access method routines
+ * general index access method routines
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/access/index/genam.c,v 1.7 1997/08/19 21:29:26 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/index/genam.c,v 1.8 1997/09/07 04:38:17 momjian Exp $
*
* NOTES
- * many of the old access method routines have been turned into
- * macros and moved to genam.h -cim 4/30/91
+ * many of the old access method routines have been turned into
+ * macros and moved to genam.h -cim 4/30/91
*
*-------------------------------------------------------------------------
*/
@@ -29,18 +29,18 @@
* previous, current, next. Note that the case of reverse scans works
* identically.
*
- * State Result
- * (1) + + - + 0 0 (if the next item pointer is invalid)
- * (2) + X - (otherwise)
- * (3) * 0 0 * 0 0 (no change)
- * (4) + X 0 X 0 0 (shift)
- * (5) * + X + X - (shift, add unknown)
+ * State Result
+ * (1) + + - + 0 0 (if the next item pointer is invalid)
+ * (2) + X - (otherwise)
+ * (3) * 0 0 * 0 0 (no change)
+ * (4) + X 0 X 0 0 (shift)
+ * (5) * + X + X - (shift, add unknown)
*
* All other states cannot occur.
*
* Note:
*It would be possible to cache the status of the previous and
- * next item pointer using the flags.
+ * next item pointer using the flags.
* ----------------------------------------------------------------
*/
@@ -51,220 +51,234 @@
#include <storage/bufmgr.h>
#ifndef HAVE_MEMMOVE
-# include <regex/utils.h>
+#include <regex/utils.h>
#else
-# include <string.h>
+#include <string.h>
#endif
/* ----------------------------------------------------------------
- * general access method routines
+ * general access method routines
*
- * All indexed access methods use an identical scan structure.
- * We don't know how the various AMs do locking, however, so we don't
- * do anything about that here.
+ * All indexed access methods use an identical scan structure.
+ * We don't know how the various AMs do locking, however, so we don't
+ * do anything about that here.
*
- * The intent is that an AM implementor will define a front-end routine
- * that calls this one, to fill in the scan, and then does whatever kind
- * of locking he wants.
+ * The intent is that an AM implementor will define a front-end routine
+ * that calls this one, to fill in the scan, and then does whatever kind
+ * of locking he wants.
* ----------------------------------------------------------------
*/
/* ----------------
- * RelationGetIndexScan -- Create and fill an IndexScanDesc.
+ * RelationGetIndexScan -- Create and fill an IndexScanDesc.
*
- * This routine creates an index scan structure and sets its contents
- * up correctly. This routine calls AMrescan to set up the scan with
- * the passed key.
+ * This routine creates an index scan structure and sets its contents
+ * up correctly. This routine calls AMrescan to set up the scan with
+ * the passed key.
*
- * Parameters:
- * relation -- index relation for scan.
- * scanFromEnd -- if true, begin scan at one of the index's
- * endpoints.
- * numberOfKeys -- count of scan keys (more than one won't
- * necessarily do anything useful, yet).
- * key -- the ScanKey for the starting position of the scan.
+ * Parameters:
+ * relation -- index relation for scan.
+ * scanFromEnd -- if true, begin scan at one of the index's
+ * endpoints.
+ * numberOfKeys -- count of scan keys (more than one won't
+ * necessarily do anything useful, yet).
+ * key -- the ScanKey for the starting position of the scan.
*
- * Returns:
- * An initialized IndexScanDesc.
+ * Returns:
+ * An initialized IndexScanDesc.
+ *
+ * Side Effects:
+ * Bumps the ref count on the relation to keep it in the cache.
*
- * Side Effects:
- * Bumps the ref count on the relation to keep it in the cache.
- *
* ----------------
*/
IndexScanDesc
RelationGetIndexScan(Relation relation,
- bool scanFromEnd,
- uint16 numberOfKeys,
- ScanKey key)
+ bool scanFromEnd,
+ uint16 numberOfKeys,
+ ScanKey key)
{
- IndexScanDesc scan;
-
- if (! RelationIsValid(relation))
- elog(WARN, "RelationGetIndexScan: relation invalid");
-
- scan = (IndexScanDesc) palloc(sizeof(IndexScanDescData));
-
- scan->relation = relation;
- scan->opaque = NULL;
- scan->numberOfKeys = numberOfKeys;
-
- ItemPointerSetInvalid(&scan->previousItemData);
- ItemPointerSetInvalid(&scan->currentItemData);
- ItemPointerSetInvalid(&scan->nextItemData);
- ItemPointerSetInvalid(&scan->previousMarkData);
- ItemPointerSetInvalid(&scan->currentMarkData);
- ItemPointerSetInvalid(&scan->nextMarkData);
+ IndexScanDesc scan;
+
+ if (!RelationIsValid(relation))
+ elog(WARN, "RelationGetIndexScan: relation invalid");
+
+ scan = (IndexScanDesc) palloc(sizeof(IndexScanDescData));
- if (numberOfKeys > 0) {
- scan->keyData = (ScanKey) palloc(sizeof(ScanKeyData) * numberOfKeys);
- } else {
- scan->keyData = NULL;
- }
+ scan->relation = relation;
+ scan->opaque = NULL;
+ scan->numberOfKeys = numberOfKeys;
+
+ ItemPointerSetInvalid(&scan->previousItemData);
+ ItemPointerSetInvalid(&scan->currentItemData);
+ ItemPointerSetInvalid(&scan->nextItemData);
+ ItemPointerSetInvalid(&scan->previousMarkData);
+ ItemPointerSetInvalid(&scan->currentMarkData);
+ ItemPointerSetInvalid(&scan->nextMarkData);
+
+ if (numberOfKeys > 0)
+ {
+ scan->keyData = (ScanKey) palloc(sizeof(ScanKeyData) * numberOfKeys);
+ }
+ else
+ {
+ scan->keyData = NULL;
+ }
- index_rescan(scan, scanFromEnd, key);
-
- return (scan);
+ index_rescan(scan, scanFromEnd, key);
+
+ return (scan);
}
#ifdef NOT_USED
/* ----------------
- * IndexScanRestart -- Restart an index scan.
+ * IndexScanRestart -- Restart an index scan.
*
- * This routine isn't used by any existing access method. It's
- * appropriate if relation level locks are what you want.
+ * This routine isn't used by any existing access method. It's
+ * appropriate if relation level locks are what you want.
*
- * Returns:
- * None.
+ * Returns:
+ * None.
*
- * Side Effects:
- * None.
+ * Side Effects:
+ * None.
* ----------------
*/
void
IndexScanRestart(IndexScanDesc scan,
- bool scanFromEnd,
- ScanKey key)
+ bool scanFromEnd,
+ ScanKey key)
{
- if (! IndexScanIsValid(scan))
- elog(WARN, "IndexScanRestart: invalid scan");
-
- ItemPointerSetInvalid(&scan->previousItemData);
- ItemPointerSetInvalid(&scan->currentItemData);
- ItemPointerSetInvalid(&scan->nextItemData);
-
- if (RelationGetNumberOfBlocks(scan->relation) == 0)
- scan->flags = ScanUnmarked;
- else if (scanFromEnd)
- scan->flags = ScanUnmarked | ScanUncheckedPrevious;
- else
- scan->flags = ScanUnmarked | ScanUncheckedNext;
-
- scan->scanFromEnd = (bool) scanFromEnd;
-
- if (scan->numberOfKeys > 0)
- memmove(scan->keyData,
- key,
- scan->numberOfKeys * sizeof(ScanKeyData));
+ if (!IndexScanIsValid(scan))
+ elog(WARN, "IndexScanRestart: invalid scan");
+
+ ItemPointerSetInvalid(&scan->previousItemData);
+ ItemPointerSetInvalid(&scan->currentItemData);
+ ItemPointerSetInvalid(&scan->nextItemData);
+
+ if (RelationGetNumberOfBlocks(scan->relation) == 0)
+ scan->flags = ScanUnmarked;
+ else if (scanFromEnd)
+ scan->flags = ScanUnmarked | ScanUncheckedPrevious;
+ else
+ scan->flags = ScanUnmarked | ScanUncheckedNext;
+
+ scan->scanFromEnd = (bool) scanFromEnd;
+
+ if (scan->numberOfKeys > 0)
+ memmove(scan->keyData,
+ key,
+ scan->numberOfKeys * sizeof(ScanKeyData));
}
+
#endif
#ifdef NOT_USED
/* ----------------
- * IndexScanEnd -- End and index scan.
+ * IndexScanEnd -- End and index scan.
*
- * This routine is not used by any existing access method, but is
- * suitable for use if you don't want to do sophisticated locking.
+ * This routine is not used by any existing access method, but is
+ * suitable for use if you don't want to do sophisticated locking.
*
- * Returns:
- * None.
+ * Returns:
+ * None.
*
- * Side Effects:
- * None.
+ * Side Effects:
+ * None.
* ----------------
*/
void
IndexScanEnd(IndexScanDesc scan)
{
- if (! IndexScanIsValid(scan))
- elog(WARN, "IndexScanEnd: invalid scan");
-
- pfree(scan);
+ if (!IndexScanIsValid(scan))
+ elog(WARN, "IndexScanEnd: invalid scan");
+
+ pfree(scan);
}
+
#endif
/* ----------------
- * IndexScanMarkPosition -- Mark current position in a scan.
+ * IndexScanMarkPosition -- Mark current position in a scan.
*
- * This routine isn't used by any existing access method, but is the
- * one that AM implementors should use, if they don't want to do any
- * special locking. If relation-level locking is sufficient, this is
- * the routine for you.
+ * This routine isn't used by any existing access method, but is the
+ * one that AM implementors should use, if they don't want to do any
+ * special locking. If relation-level locking is sufficient, this is
+ * the routine for you.
*
- * Returns:
- * None.
+ * Returns:
+ * None.
*
- * Side Effects:
- * None.
+ * Side Effects:
+ * None.
* ----------------
*/
void
IndexScanMarkPosition(IndexScanDesc scan)
{
- RetrieveIndexResult result;
-
- if (scan->flags & ScanUncheckedPrevious) {
- result =
- index_getnext(scan, BackwardScanDirection);
-
- if (result != NULL) {
- scan->previousItemData = result->index_iptr;
- } else {
- ItemPointerSetInvalid(&scan->previousItemData);
+ RetrieveIndexResult result;
+
+ if (scan->flags & ScanUncheckedPrevious)
+ {
+ result =
+ index_getnext(scan, BackwardScanDirection);
+
+ if (result != NULL)
+ {
+ scan->previousItemData = result->index_iptr;
+ }
+ else
+ {
+ ItemPointerSetInvalid(&scan->previousItemData);
+ }
+
}
-
- } else if (scan->flags & ScanUncheckedNext) {
- result = (RetrieveIndexResult)
- index_getnext(scan, ForwardScanDirection);
-
- if (result != NULL) {
- scan->nextItemData = result->index_iptr;
- } else {
- ItemPointerSetInvalid(&scan->nextItemData);
+ else if (scan->flags & ScanUncheckedNext)
+ {
+ result = (RetrieveIndexResult)
+ index_getnext(scan, ForwardScanDirection);
+
+ if (result != NULL)
+ {
+ scan->nextItemData = result->index_iptr;
+ }
+ else
+ {
+ ItemPointerSetInvalid(&scan->nextItemData);
+ }
}
- }
-
- scan->previousMarkData = scan->previousItemData;
- scan->currentMarkData = scan->currentItemData;
- scan->nextMarkData = scan->nextItemData;
-
- scan->flags = 0x0; /* XXX should have a symbolic name */
+
+ scan->previousMarkData = scan->previousItemData;
+ scan->currentMarkData = scan->currentItemData;
+ scan->nextMarkData = scan->nextItemData;
+
+ scan->flags = 0x0; /* XXX should have a symbolic name */
}
/* ----------------
- * IndexScanRestorePosition -- Restore position on a marked scan.
+ * IndexScanRestorePosition -- Restore position on a marked scan.
*
- * This routine isn't used by any existing access method, but is the
- * one that AM implementors should use if they don't want to do any
- * special locking. If relation-level locking is sufficient, then
- * this is the one you want.
+ * This routine isn't used by any existing access method, but is the
+ * one that AM implementors should use if they don't want to do any
+ * special locking. If relation-level locking is sufficient, then
+ * this is the one you want.
*
- * Returns:
- * None.
+ * Returns:
+ * None.
*
- * Side Effects:
- * None.
+ * Side Effects:
+ * None.
* ----------------
*/
void
IndexScanRestorePosition(IndexScanDesc scan)
-{
- if (scan->flags & ScanUnmarked)
- elog(WARN, "IndexScanRestorePosition: no mark to restore");
-
- scan->previousItemData = scan->previousMarkData;
- scan->currentItemData = scan->currentMarkData;
- scan->nextItemData = scan->nextMarkData;
-
- scan->flags = 0x0; /* XXX should have a symbolic name */
+{
+ if (scan->flags & ScanUnmarked)
+ elog(WARN, "IndexScanRestorePosition: no mark to restore");
+
+ scan->previousItemData = scan->previousMarkData;
+ scan->currentItemData = scan->currentMarkData;
+ scan->nextItemData = scan->nextMarkData;
+
+ scan->flags = 0x0; /* XXX should have a symbolic name */
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-03 06:46:19 +0000