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Diffstat (limited to 'src/backend/access/rtree/rtscan.c')
| -rw-r--r-- | src/backend/access/rtree/rtscan.c | 422 |
1 files changed, 0 insertions, 422 deletions
diff --git a/src/backend/access/rtree/rtscan.c b/src/backend/access/rtree/rtscan.c deleted file mode 100644 index 52aedeae2b8..00000000000 --- a/src/backend/access/rtree/rtscan.c +++ /dev/null @@ -1,422 +0,0 @@ -/*------------------------------------------------------------------------- - * - * rtscan.c - * routines to manage scans on index relations - * - * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group - * Portions Copyright (c) 1994, Regents of the University of California - * - * - * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtscan.c,v 1.42 2002/06/20 20:29:25 momjian Exp $ - * - *------------------------------------------------------------------------- - */ - -#include "postgres.h" - -#include "access/genam.h" -#include "access/rtree.h" - - - -/* routines defined and used here */ -static void rtregscan(IndexScanDesc s); -static void rtdropscan(IndexScanDesc s); -static void rtadjone(IndexScanDesc s, int op, BlockNumber blkno, - OffsetNumber offnum); -static void adjuststack(RTSTACK *stk, BlockNumber blkno); -static void adjustiptr(IndexScanDesc s, ItemPointer iptr, - int op, BlockNumber blkno, OffsetNumber offnum); - -/* - * Whenever we start an rtree scan in a backend, we register it in private - * space. Then if the rtree index gets updated, we check all registered - * scans and adjust them if the tuple they point at got moved by the - * update. We only need to do this in private space, because when we update - * an rtree we have a write lock on the tree, so no other process can have - * any locks at all on it. A single transaction can have write and read - * locks on the same object, so that's why we need to handle this case. - */ - -typedef struct RTScanListData -{ - IndexScanDesc rtsl_scan; - struct RTScanListData *rtsl_next; -} RTScanListData; - -typedef RTScanListData *RTScanList; - -/* pointer to list of local scans on rtrees */ -static RTScanList RTScans = (RTScanList) NULL; - -Datum -rtbeginscan(PG_FUNCTION_ARGS) -{ - Relation r = (Relation) PG_GETARG_POINTER(0); - int nkeys = PG_GETARG_INT32(1); - ScanKey key = (ScanKey) PG_GETARG_POINTER(2); - IndexScanDesc s; - - s = RelationGetIndexScan(r, nkeys, key); - - rtregscan(s); - - PG_RETURN_POINTER(s); -} - -Datum -rtrescan(PG_FUNCTION_ARGS) -{ - IndexScanDesc s = (IndexScanDesc) PG_GETARG_POINTER(0); - ScanKey key = (ScanKey) PG_GETARG_POINTER(1); - RTreeScanOpaque p; - RegProcedure internal_proc; - int i; - - /* - * Clear all the pointers. - */ - ItemPointerSetInvalid(&s->currentItemData); - ItemPointerSetInvalid(&s->currentMarkData); - - if (s->numberOfKeys > 0) - { - memmove(s->keyData, - key, - s->numberOfKeys * sizeof(ScanKeyData)); - } - - p = (RTreeScanOpaque) s->opaque; - if (p != (RTreeScanOpaque) NULL) - { - freestack(p->s_stack); - freestack(p->s_markstk); - p->s_stack = p->s_markstk = (RTSTACK *) NULL; - p->s_flags = 0x0; - for (i = 0; i < s->numberOfKeys; i++) - p->s_internalKey[i].sk_argument = s->keyData[i].sk_argument; - } - else - { - /* initialize opaque data */ - p = (RTreeScanOpaque) palloc(sizeof(RTreeScanOpaqueData)); - p->s_stack = p->s_markstk = (RTSTACK *) NULL; - p->s_internalNKey = s->numberOfKeys; - p->s_flags = 0x0; - s->opaque = p; - if (s->numberOfKeys > 0) - { - p->s_internalKey = (ScanKey) palloc(sizeof(ScanKeyData) * s->numberOfKeys); - - /* - * Scans on internal pages use different operators than they - * do on leaf pages. For example, if the user wants all boxes - * that exactly match (x1,y1,x2,y2), then on internal pages we - * need to find all boxes that contain (x1,y1,x2,y2). - */ - - for (i = 0; i < s->numberOfKeys; i++) - { - p->s_internalKey[i].sk_argument = s->keyData[i].sk_argument; - internal_proc = RTMapOperator(s->indexRelation, - s->keyData[i].sk_attno, - s->keyData[i].sk_procedure); - ScanKeyEntryInitialize(&(p->s_internalKey[i]), - s->keyData[i].sk_flags, - s->keyData[i].sk_attno, - internal_proc, - s->keyData[i].sk_argument); - } - } - } - - PG_RETURN_VOID(); -} - -Datum -rtmarkpos(PG_FUNCTION_ARGS) -{ - IndexScanDesc s = (IndexScanDesc) PG_GETARG_POINTER(0); - RTreeScanOpaque p; - RTSTACK *o, - *n, - *tmp; - - s->currentMarkData = s->currentItemData; - p = (RTreeScanOpaque) s->opaque; - if (p->s_flags & RTS_CURBEFORE) - p->s_flags |= RTS_MRKBEFORE; - else - p->s_flags &= ~RTS_MRKBEFORE; - - o = (RTSTACK *) NULL; - n = p->s_stack; - - /* copy the parent stack from the current item data */ - while (n != (RTSTACK *) NULL) - { - tmp = (RTSTACK *) palloc(sizeof(RTSTACK)); - tmp->rts_child = n->rts_child; - tmp->rts_blk = n->rts_blk; - tmp->rts_parent = o; - o = tmp; - n = n->rts_parent; - } - - freestack(p->s_markstk); - p->s_markstk = o; - - PG_RETURN_VOID(); -} - -Datum -rtrestrpos(PG_FUNCTION_ARGS) -{ - IndexScanDesc s = (IndexScanDesc) PG_GETARG_POINTER(0); - RTreeScanOpaque p; - RTSTACK *o, - *n, - *tmp; - - s->currentItemData = s->currentMarkData; - p = (RTreeScanOpaque) s->opaque; - if (p->s_flags & RTS_MRKBEFORE) - p->s_flags |= RTS_CURBEFORE; - else - p->s_flags &= ~RTS_CURBEFORE; - - o = (RTSTACK *) NULL; - n = p->s_markstk; - - /* copy the parent stack from the current item data */ - while (n != (RTSTACK *) NULL) - { - tmp = (RTSTACK *) palloc(sizeof(RTSTACK)); - tmp->rts_child = n->rts_child; - tmp->rts_blk = n->rts_blk; - tmp->rts_parent = o; - o = tmp; - n = n->rts_parent; - } - - freestack(p->s_stack); - p->s_stack = o; - - PG_RETURN_VOID(); -} - -Datum -rtendscan(PG_FUNCTION_ARGS) -{ - IndexScanDesc s = (IndexScanDesc) PG_GETARG_POINTER(0); - RTreeScanOpaque p; - - p = (RTreeScanOpaque) s->opaque; - - if (p != (RTreeScanOpaque) NULL) - { - freestack(p->s_stack); - freestack(p->s_markstk); - pfree(s->opaque); - } - - rtdropscan(s); - /* XXX don't unset read lock -- two-phase locking */ - - PG_RETURN_VOID(); -} - -static void -rtregscan(IndexScanDesc s) -{ - RTScanList l; - - l = (RTScanList) palloc(sizeof(RTScanListData)); - l->rtsl_scan = s; - l->rtsl_next = RTScans; - RTScans = l; -} - -static void -rtdropscan(IndexScanDesc s) -{ - RTScanList l; - RTScanList prev; - - prev = (RTScanList) NULL; - - for (l = RTScans; - l != (RTScanList) NULL && l->rtsl_scan != s; - l = l->rtsl_next) - prev = l; - - if (l == (RTScanList) NULL) - elog(ERROR, "rtree scan list corrupted -- cannot find 0x%p", (void *) s); - - if (prev == (RTScanList) NULL) - RTScans = l->rtsl_next; - else - prev->rtsl_next = l->rtsl_next; - - pfree(l); -} - -/* - * AtEOXact_rtree() --- clean up rtree subsystem at xact abort or commit. - * - * This is here because it needs to touch this module's static var RTScans. - */ -void -AtEOXact_rtree(void) -{ - /* - * Note: these actions should only be necessary during xact abort; but - * they can't hurt during a commit. - */ - - /* - * Reset the active-scans list to empty. We do not need to free the - * list elements, because they're all palloc()'d, so they'll go away - * at end of transaction anyway. - */ - RTScans = NULL; -} - -void -rtadjscans(Relation r, int op, BlockNumber blkno, OffsetNumber offnum) -{ - RTScanList l; - Oid relid; - - relid = RelationGetRelid(r); - for (l = RTScans; l != (RTScanList) NULL; l = l->rtsl_next) - { - if (RelationGetRelid(l->rtsl_scan->indexRelation) == relid) - rtadjone(l->rtsl_scan, op, blkno, offnum); - } -} - -/* - * rtadjone() -- adjust one scan for update. - * - * By here, the scan passed in is on a modified relation. Op tells - * us what the modification is, and blkno and offind tell us what - * block and offset index were affected. This routine checks the - * current and marked positions, and the current and marked stacks, - * to see if any stored location needs to be changed because of the - * update. If so, we make the change here. - */ -static void -rtadjone(IndexScanDesc s, - int op, - BlockNumber blkno, - OffsetNumber offnum) -{ - RTreeScanOpaque so; - - adjustiptr(s, &(s->currentItemData), op, blkno, offnum); - adjustiptr(s, &(s->currentMarkData), op, blkno, offnum); - - so = (RTreeScanOpaque) s->opaque; - - if (op == RTOP_SPLIT) - { - adjuststack(so->s_stack, blkno); - adjuststack(so->s_markstk, blkno); - } -} - -/* - * adjustiptr() -- adjust current and marked item pointers in the scan - * - * Depending on the type of update and the place it happened, we - * need to do nothing, to back up one record, or to start over on - * the same page. - */ -static void -adjustiptr(IndexScanDesc s, - ItemPointer iptr, - int op, - BlockNumber blkno, - OffsetNumber offnum) -{ - OffsetNumber curoff; - RTreeScanOpaque so; - - if (ItemPointerIsValid(iptr)) - { - if (ItemPointerGetBlockNumber(iptr) == blkno) - { - curoff = ItemPointerGetOffsetNumber(iptr); - so = (RTreeScanOpaque) s->opaque; - - switch (op) - { - case RTOP_DEL: - /* back up one if we need to */ - if (curoff >= offnum) - { - - if (curoff > FirstOffsetNumber) - { - /* just adjust the item pointer */ - ItemPointerSet(iptr, blkno, OffsetNumberPrev(curoff)); - } - else - { - /* - * remember that we're before the current - * tuple - */ - ItemPointerSet(iptr, blkno, FirstOffsetNumber); - if (iptr == &(s->currentItemData)) - so->s_flags |= RTS_CURBEFORE; - else - so->s_flags |= RTS_MRKBEFORE; - } - } - break; - - case RTOP_SPLIT: - /* back to start of page on split */ - ItemPointerSet(iptr, blkno, FirstOffsetNumber); - if (iptr == &(s->currentItemData)) - so->s_flags &= ~RTS_CURBEFORE; - else - so->s_flags &= ~RTS_MRKBEFORE; - break; - - default: - elog(ERROR, "Bad operation in rtree scan adjust: %d", op); - } - } - } -} - -/* - * adjuststack() -- adjust the supplied stack for a split on a page in - * the index we're scanning. - * - * If a page on our parent stack has split, we need to back up to the - * beginning of the page and rescan it. The reason for this is that - * the split algorithm for rtrees doesn't order tuples in any useful - * way on a single page. This means on that a split, we may wind up - * looking at some heap tuples more than once. This is handled in the - * access method update code for heaps; if we've modified the tuple we - * are looking at already in this transaction, we ignore the update - * request. - */ -/*ARGSUSED*/ -static void -adjuststack(RTSTACK *stk, - BlockNumber blkno) -{ - while (stk != (RTSTACK *) NULL) - { - if (stk->rts_blk == blkno) - stk->rts_child = FirstOffsetNumber; - - stk = stk->rts_parent; - } -} |