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Diffstat (limited to 'src/backend/access/gist/gistscan.c')
| -rw-r--r-- | src/backend/access/gist/gistscan.c | 421 |
1 files changed, 0 insertions, 421 deletions
diff --git a/src/backend/access/gist/gistscan.c b/src/backend/access/gist/gistscan.c deleted file mode 100644 index 9c1c92a880a..00000000000 --- a/src/backend/access/gist/gistscan.c +++ /dev/null @@ -1,421 +0,0 @@ -/*------------------------------------------------------------------------- - * - * gistscan.c - * routines to manage scans on GiST 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/gist/gistscan.c,v 1.43 2002/06/20 20:29:24 momjian Exp $ - * - *------------------------------------------------------------------------- - */ -#include "postgres.h" - -#include "access/genam.h" -#include "access/gist.h" -#include "access/gistscan.h" - - -/* routines defined and used here */ -static void gistregscan(IndexScanDesc s); -static void gistdropscan(IndexScanDesc s); -static void gistadjone(IndexScanDesc s, int op, BlockNumber blkno, - OffsetNumber offnum); -static void adjuststack(GISTSTACK *stk, BlockNumber blkno); -static void adjustiptr(IndexScanDesc s, ItemPointer iptr, - int op, BlockNumber blkno, OffsetNumber offnum); - -/* - * Whenever we start a GiST scan in a backend, we register it in private - * space. Then if the GiST 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 GiST 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 GISTScanListData -{ - IndexScanDesc gsl_scan; - struct GISTScanListData *gsl_next; -} GISTScanListData; - -typedef GISTScanListData *GISTScanList; - -/* pointer to list of local scans on GiSTs */ -static GISTScanList GISTScans = (GISTScanList) NULL; - -Datum -gistbeginscan(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); - - gistregscan(s); - - PG_RETURN_POINTER(s); -} - -Datum -gistrescan(PG_FUNCTION_ARGS) -{ - IndexScanDesc s = (IndexScanDesc) PG_GETARG_POINTER(0); - ScanKey key = (ScanKey) PG_GETARG_POINTER(1); - GISTScanOpaque p; - 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 = (GISTScanOpaque) s->opaque; - if (p != (GISTScanOpaque) NULL) - { - gistfreestack(p->s_stack); - gistfreestack(p->s_markstk); - p->s_stack = p->s_markstk = (GISTSTACK *) NULL; - p->s_flags = 0x0; - for (i = 0; i < s->numberOfKeys; i++) - { - s->keyData[i].sk_procedure - = RelationGetGISTStrategy(s->indexRelation, - s->keyData[i].sk_attno, - s->keyData[i].sk_procedure); - s->keyData[i].sk_func = p->giststate->consistentFn[s->keyData[i].sk_attno - 1]; - } - } - else - { - /* initialize opaque data */ - p = (GISTScanOpaque) palloc(sizeof(GISTScanOpaqueData)); - p->s_stack = p->s_markstk = (GISTSTACK *) NULL; - p->s_flags = 0x0; - s->opaque = p; - p->giststate = (GISTSTATE *) palloc(sizeof(GISTSTATE)); - initGISTstate(p->giststate, s->indexRelation); - if (s->numberOfKeys > 0) - - /* - * * Play games here with the scan key to use the Consistent * - * function for all comparisons: * 1) the sk_procedure field - * will now be used to hold the * strategy number * 2) the - * sk_func field will point to the Consistent function - */ - for (i = 0; i < s->numberOfKeys; i++) - { - s->keyData[i].sk_procedure = - RelationGetGISTStrategy(s->indexRelation, - s->keyData[i].sk_attno, - s->keyData[i].sk_procedure); - s->keyData[i].sk_func = p->giststate->consistentFn[s->keyData[i].sk_attno - 1]; - } - } - - PG_RETURN_VOID(); -} - -Datum -gistmarkpos(PG_FUNCTION_ARGS) -{ - IndexScanDesc s = (IndexScanDesc) PG_GETARG_POINTER(0); - GISTScanOpaque p; - GISTSTACK *o, - *n, - *tmp; - - s->currentMarkData = s->currentItemData; - p = (GISTScanOpaque) s->opaque; - if (p->s_flags & GS_CURBEFORE) - p->s_flags |= GS_MRKBEFORE; - else - p->s_flags &= ~GS_MRKBEFORE; - - o = (GISTSTACK *) NULL; - n = p->s_stack; - - /* copy the parent stack from the current item data */ - while (n != (GISTSTACK *) NULL) - { - tmp = (GISTSTACK *) palloc(sizeof(GISTSTACK)); - tmp->gs_child = n->gs_child; - tmp->gs_blk = n->gs_blk; - tmp->gs_parent = o; - o = tmp; - n = n->gs_parent; - } - - gistfreestack(p->s_markstk); - p->s_markstk = o; - - PG_RETURN_VOID(); -} - -Datum -gistrestrpos(PG_FUNCTION_ARGS) -{ - IndexScanDesc s = (IndexScanDesc) PG_GETARG_POINTER(0); - GISTScanOpaque p; - GISTSTACK *o, - *n, - *tmp; - - s->currentItemData = s->currentMarkData; - p = (GISTScanOpaque) s->opaque; - if (p->s_flags & GS_MRKBEFORE) - p->s_flags |= GS_CURBEFORE; - else - p->s_flags &= ~GS_CURBEFORE; - - o = (GISTSTACK *) NULL; - n = p->s_markstk; - - /* copy the parent stack from the current item data */ - while (n != (GISTSTACK *) NULL) - { - tmp = (GISTSTACK *) palloc(sizeof(GISTSTACK)); - tmp->gs_child = n->gs_child; - tmp->gs_blk = n->gs_blk; - tmp->gs_parent = o; - o = tmp; - n = n->gs_parent; - } - - gistfreestack(p->s_stack); - p->s_stack = o; - - PG_RETURN_VOID(); -} - -Datum -gistendscan(PG_FUNCTION_ARGS) -{ - IndexScanDesc s = (IndexScanDesc) PG_GETARG_POINTER(0); - GISTScanOpaque p; - - p = (GISTScanOpaque) s->opaque; - - if (p != (GISTScanOpaque) NULL) - { - gistfreestack(p->s_stack); - gistfreestack(p->s_markstk); - if (p->giststate != NULL) - freeGISTstate(p->giststate); - pfree(s->opaque); - } - - gistdropscan(s); - /* XXX don't unset read lock -- two-phase locking */ - - PG_RETURN_VOID(); -} - -static void -gistregscan(IndexScanDesc s) -{ - GISTScanList l; - - l = (GISTScanList) palloc(sizeof(GISTScanListData)); - l->gsl_scan = s; - l->gsl_next = GISTScans; - GISTScans = l; -} - -static void -gistdropscan(IndexScanDesc s) -{ - GISTScanList l; - GISTScanList prev; - - prev = (GISTScanList) NULL; - - for (l = GISTScans; - l != (GISTScanList) NULL && l->gsl_scan != s; - l = l->gsl_next) - prev = l; - - if (l == (GISTScanList) NULL) - elog(ERROR, "GiST scan list corrupted -- cannot find 0x%p", (void *) s); - - if (prev == (GISTScanList) NULL) - GISTScans = l->gsl_next; - else - prev->gsl_next = l->gsl_next; - - pfree(l); -} - -/* - * AtEOXact_gist() --- clean up gist subsystem at xact abort or commit. - * - * This is here because it needs to touch this module's static var GISTScans. - */ -void -AtEOXact_gist(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. - */ - GISTScans = NULL; -} - -void -gistadjscans(Relation rel, int op, BlockNumber blkno, OffsetNumber offnum) -{ - GISTScanList l; - Oid relid; - - relid = RelationGetRelid(rel); - for (l = GISTScans; l != (GISTScanList) NULL; l = l->gsl_next) - { - if (l->gsl_scan->indexRelation->rd_id == relid) - gistadjone(l->gsl_scan, op, blkno, offnum); - } -} - -/* - * gistadjone() -- 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 -gistadjone(IndexScanDesc s, - int op, - BlockNumber blkno, - OffsetNumber offnum) -{ - GISTScanOpaque so; - - adjustiptr(s, &(s->currentItemData), op, blkno, offnum); - adjustiptr(s, &(s->currentMarkData), op, blkno, offnum); - - so = (GISTScanOpaque) s->opaque; - - if (op == GISTOP_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; - GISTScanOpaque so; - - if (ItemPointerIsValid(iptr)) - { - if (ItemPointerGetBlockNumber(iptr) == blkno) - { - curoff = ItemPointerGetOffsetNumber(iptr); - so = (GISTScanOpaque) s->opaque; - - switch (op) - { - case GISTOP_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 |= GS_CURBEFORE; - else - so->s_flags |= GS_MRKBEFORE; - } - } - break; - - case GISTOP_SPLIT: - /* back to start of page on split */ - ItemPointerSet(iptr, blkno, FirstOffsetNumber); - if (iptr == &(s->currentItemData)) - so->s_flags &= ~GS_CURBEFORE; - else - so->s_flags &= ~GS_MRKBEFORE; - break; - - default: - elog(ERROR, "Bad operation in GiST 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 GiSTs 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(GISTSTACK *stk, - BlockNumber blkno) -{ - while (stk != (GISTSTACK *) NULL) - { - if (stk->gs_blk == blkno) - stk->gs_child = FirstOffsetNumber; - - stk = stk->gs_parent; - } -} |