gist.c
上传用户:blenddy
上传日期:2007-01-07
资源大小:6495k
文件大小:35k
- /*-------------------------------------------------------------------------
- *
- * gist.c
- * interface routines for the postgres GiST index access method.
- *
- *
- *
- * IDENTIFICATION
- * $Header: /usr/local/cvsroot/pgsql/src/backend/access/gist/gist.c,v 1.38.2.1 1999/08/02 05:24:28 scrappy Exp $
- *
- *-------------------------------------------------------------------------
- */
- #include "postgres.h"
- #include "access/genam.h"
- #include "access/gist.h"
- #include "access/gistscan.h"
- #include "access/heapam.h"
- #include "catalog/index.h"
- #include "catalog/pg_index.h"
- #include "executor/executor.h"
- #include "utils/syscache.h"
- /* non-export function prototypes */
- static InsertIndexResult gistdoinsert(Relation r, IndexTuple itup,
- GISTSTATE *GISTstate);
- static InsertIndexResult gistentryinsert(Relation r, GISTSTACK *stk,
- IndexTuple tup,
- GISTSTATE *giststate);
- static void gistentryinserttwo(Relation r, GISTSTACK *stk, IndexTuple ltup,
- IndexTuple rtup, GISTSTATE *giststate);
- static void gistAdjustKeys(Relation r, GISTSTACK *stk, BlockNumber blk,
- char *datum, int att_size, GISTSTATE *giststate);
- static void gistintinsert(Relation r, GISTSTACK *stk, IndexTuple ltup,
- IndexTuple rtup, GISTSTATE *giststate);
- static InsertIndexResult gistSplit(Relation r, Buffer buffer,
- GISTSTACK *stack, IndexTuple itup,
- GISTSTATE *giststate);
- static void gistnewroot(GISTSTATE *giststate, Relation r, IndexTuple lt,
- IndexTuple rt);
- static void GISTInitBuffer(Buffer b, uint32 f);
- static BlockNumber gistChooseSubtree(Relation r, IndexTuple itup, int level,
- GISTSTATE *giststate,
- GISTSTACK **retstack, Buffer *leafbuf);
- static OffsetNumber gistchoose(Relation r, Page p, IndexTuple it,
- GISTSTATE *giststate);
- static int gistnospace(Page p, IndexTuple it);
- void gistdelete(Relation r, ItemPointer tid);
- static IndexTuple gist_tuple_replacekey(Relation r, GISTENTRY entry, IndexTuple t);
- static void gistcentryinit(GISTSTATE *giststate, GISTENTRY *e, char *pr,
- Relation r, Page pg, OffsetNumber o, int b, bool l);
- #ifdef GISTDEBUG
- static char *int_range_out(INTRANGE *r);
- #endif
- /*
- ** routine to build an index. Basically calls insert over and over
- */
- void
- gistbuild(Relation heap,
- Relation index,
- int natts,
- AttrNumber *attnum,
- IndexStrategy istrat,
- uint16 pint,
- Datum *params,
- FuncIndexInfo *finfo,
- PredInfo *predInfo)
- {
- HeapScanDesc scan;
- AttrNumber i;
- HeapTuple htup;
- IndexTuple itup;
- TupleDesc hd,
- id;
- InsertIndexResult res;
- Datum *d;
- bool *nulls;
- int nb,
- nh,
- ni;
- #ifndef OMIT_PARTIAL_INDEX
- ExprContext *econtext;
- TupleTable tupleTable;
- TupleTableSlot *slot;
- #endif
- Oid hrelid,
- irelid;
- Node *pred,
- *oldPred;
- GISTSTATE giststate;
- GISTENTRY tmpcentry;
- Buffer buffer = InvalidBuffer;
- bool *compvec;
- /* no locking is needed */
- setheapoverride(true); /* so we can see the new pg_index tuple */
- initGISTstate(&giststate, index);
- setheapoverride(false);
- pred = predInfo->pred;
- oldPred = predInfo->oldPred;
- /*
- * We expect to be called exactly once for any index relation. If
- * that's not the case, big trouble's what we have.
- */
- if (oldPred == NULL && (nb = RelationGetNumberOfBlocks(index)) != 0)
- elog(ERROR, "%s already contains data", index->rd_rel->relname.data);
- /* initialize the root page (if this is a new index) */
- if (oldPred == NULL)
- {
- buffer = ReadBuffer(index, P_NEW);
- GISTInitBuffer(buffer, F_LEAF);
- WriteBuffer(buffer);
- }
- /* init the tuple descriptors and get set for a heap scan */
- hd = RelationGetDescr(heap);
- id = RelationGetDescr(index);
- d = (Datum *) palloc(natts * sizeof(*d));
- nulls = (bool *) palloc(natts * sizeof(*nulls));
- /*
- * If this is a predicate (partial) index, we will need to evaluate
- * the predicate using ExecQual, which requires the current tuple to
- * be in a slot of a TupleTable. In addition, ExecQual must have an
- * ExprContext referring to that slot. Here, we initialize dummy
- * TupleTable and ExprContext objects for this purpose. --Nels, Feb
- * '92
- */
- #ifndef OMIT_PARTIAL_INDEX
- if (pred != NULL || oldPred != NULL)
- {
- tupleTable = ExecCreateTupleTable(1);
- slot = ExecAllocTableSlot(tupleTable);
- econtext = makeNode(ExprContext);
- FillDummyExprContext(econtext, slot, hd, buffer);
- }
- else
- /* shut the compiler up */
- {
- tupleTable = NULL;
- slot = NULL;
- econtext = NULL;
- }
- #endif /* OMIT_PARTIAL_INDEX */
- /* int the tuples as we insert them */
- nh = ni = 0;
- scan = heap_beginscan(heap, 0, SnapshotNow, 0, (ScanKey) NULL);
- while (HeapTupleIsValid(htup = heap_getnext(scan, 0)))
- {
- nh++;
- /*
- * If oldPred != NULL, this is an EXTEND INDEX command, so skip
- * this tuple if it was already in the existing partial index
- */
- if (oldPred != NULL)
- {
- #ifndef OMIT_PARTIAL_INDEX
- /* SetSlotContents(slot, htup); */
- slot->val = htup;
- if (ExecQual((List *) oldPred, econtext) == true)
- {
- ni++;
- continue;
- }
- #endif /* OMIT_PARTIAL_INDEX */
- }
- /*
- * Skip this tuple if it doesn't satisfy the partial-index
- * predicate
- */
- if (pred != NULL)
- {
- #ifndef OMIT_PARTIAL_INDEX
- /* SetSlotContents(slot, htup); */
- slot->val = htup;
- if (ExecQual((List *) pred, econtext) == false)
- continue;
- #endif /* OMIT_PARTIAL_INDEX */
- }
- ni++;
- /*
- * For the current heap tuple, extract all the attributes we use
- * in this index, and note which are null.
- */
- for (i = 1; i <= natts; i++)
- {
- int attoff;
- bool attnull;
- /*
- * Offsets are from the start of the tuple, and are
- * zero-based; indices are one-based. The next call returns i
- * - 1. That's data hiding for you.
- */
- attoff = AttrNumberGetAttrOffset(i);
- /*
- * d[attoff] = HeapTupleGetAttributeValue(htup, buffer,
- */
- d[attoff] = GetIndexValue(htup,
- hd,
- attoff,
- attnum,
- finfo,
- &attnull);
- nulls[attoff] = (attnull ? 'n' : ' ');
- }
- /* immediately compress keys to normalize */
- compvec = (bool *) palloc(sizeof(bool) * natts);
- for (i = 0; i < natts; i++)
- {
- gistcentryinit(&giststate, &tmpcentry, (char *) d[i],
- (Relation) NULL, (Page) NULL, (OffsetNumber) 0,
- -1 /* size is currently bogus */ , TRUE);
- if (d[i] != (Datum) tmpcentry.pred && !(giststate.keytypbyval))
- compvec[i] = TRUE;
- else
- compvec[i] = FALSE;
- d[i] = (Datum) tmpcentry.pred;
- }
- /* form an index tuple and point it at the heap tuple */
- itup = index_formtuple(id, &d[0], nulls);
- itup->t_tid = htup->t_self;
- /*
- * Since we already have the index relation locked, we call
- * gistdoinsert directly. Normal access method calls dispatch
- * through gistinsert, which locks the relation for write. This
- * is the right thing to do if you're inserting single tups, but
- * not when you're initializing the whole index at once.
- */
- res = gistdoinsert(index, itup, &giststate);
- for (i = 0; i < natts; i++)
- if (compvec[i] == TRUE)
- pfree((char *) d[i]);
- pfree(itup);
- pfree(res);
- pfree(compvec);
- }
- /* okay, all heap tuples are indexed */
- heap_endscan(scan);
- if (pred != NULL || oldPred != NULL)
- {
- #ifndef OMIT_PARTIAL_INDEX
- ExecDestroyTupleTable(tupleTable, true);
- pfree(econtext);
- #endif /* OMIT_PARTIAL_INDEX */
- }
- /*
- * Since we just inted the tuples in the heap, we update its stats in
- * pg_relation to guarantee that the planner takes advantage of the
- * index we just created. UpdateStats() does a
- * CommandinterIncrement(), which flushes changed entries from the
- * system relcache. The act of constructing an index changes these
- * heap and index tuples in the system catalogs, so they need to be
- * flushed. We close them to guarantee that they will be.
- */
- hrelid = RelationGetRelid(heap);
- irelid = RelationGetRelid(index);
- heap_close(heap);
- index_close(index);
- UpdateStats(hrelid, nh, true);
- UpdateStats(irelid, ni, false);
- if (oldPred != NULL)
- {
- if (ni == nh)
- pred = NULL;
- UpdateIndexPredicate(irelid, oldPred, pred);
- }
- /* be tidy */
- pfree(nulls);
- pfree(d);
- }
- /*
- * gistinsert -- wrapper for GiST tuple insertion.
- *
- * This is the public interface routine for tuple insertion in GiSTs.
- * It doesn't do any work; just locks the relation and passes the buck.
- */
- InsertIndexResult
- gistinsert(Relation r, Datum *datum, char *nulls, ItemPointer ht_ctid, Relation heapRel)
- {
- InsertIndexResult res;
- IndexTuple itup;
- GISTSTATE giststate;
- GISTENTRY tmpentry;
- int i;
- bool *compvec;
- initGISTstate(&giststate, r);
- /* immediately compress keys to normalize */
- compvec = (bool *) palloc(sizeof(bool) * r->rd_att->natts);
- for (i = 0; i < r->rd_att->natts; i++)
- {
- gistcentryinit(&giststate, &tmpentry, (char *) datum[i],
- (Relation) NULL, (Page) NULL, (OffsetNumber) 0,
- -1 /* size is currently bogus */ , TRUE);
- if (datum[i] != (Datum) tmpentry.pred && !(giststate.keytypbyval))
- compvec[i] = TRUE;
- else
- compvec[i] = FALSE;
- datum[i] = (Datum) tmpentry.pred;
- }
- itup = index_formtuple(RelationGetDescr(r), datum, nulls);
- itup->t_tid = *ht_ctid;
- /*
- * Notes in ExecUtils:ExecOpenIndices()
- *
- * RelationSetLockForWrite(r);
- */
- res = gistdoinsert(r, itup, &giststate);
- for (i = 0; i < r->rd_att->natts; i++)
- if (compvec[i] == TRUE)
- pfree((char *) datum[i]);
- pfree(itup);
- pfree(compvec);
- return res;
- }
- /*
- ** Take a compressed entry, and install it on a page. Since we now know
- ** where the entry will live, we decompress it and recompress it using
- ** that knowledge (some compression routines may want to fish around
- ** on the page, for example, or do something special for leaf nodes.)
- */
- static OffsetNumber
- gistPageAddItem(GISTSTATE *giststate,
- Relation r,
- Page page,
- Item item,
- Size size,
- OffsetNumber offsetNumber,
- ItemIdFlags flags,
- GISTENTRY *dentry,
- IndexTuple *newtup)
- {
- GISTENTRY tmpcentry;
- IndexTuple itup = (IndexTuple) item;
- /*
- * recompress the item given that we now know the exact page and
- * offset for insertion
- */
- gistdentryinit(giststate, dentry,
- (((char *) itup) + sizeof(IndexTupleData)),
- (Relation) 0, (Page) 0, (OffsetNumber) InvalidOffsetNumber,
- IndexTupleSize(itup) - sizeof(IndexTupleData), FALSE);
- gistcentryinit(giststate, &tmpcentry, dentry->pred, r, page,
- offsetNumber, dentry->bytes, FALSE);
- *newtup = gist_tuple_replacekey(r, *dentry, itup);
- /* be tidy */
- if (tmpcentry.pred != dentry->pred
- && tmpcentry.pred != (((char *) itup) + sizeof(IndexTupleData)))
- pfree(tmpcentry.pred);
- return (PageAddItem(page, (Item) *newtup, IndexTupleSize(*newtup),
- offsetNumber, flags));
- }
- static InsertIndexResult
- gistdoinsert(Relation r,
- IndexTuple itup, /* itup contains compressed entry */
- GISTSTATE *giststate)
- {
- GISTENTRY tmpdentry;
- InsertIndexResult res;
- OffsetNumber l;
- GISTSTACK *stack;
- Buffer buffer;
- BlockNumber blk;
- Page page;
- OffsetNumber off;
- IndexTuple newtup;
- /* 3rd arg is ignored for now */
- blk = gistChooseSubtree(r, itup, 0, giststate, &stack, &buffer);
- page = (Page) BufferGetPage(buffer);
- if (gistnospace(page, itup))
- {
- /* need to do a split */
- res = gistSplit(r, buffer, stack, itup, giststate);
- gistfreestack(stack);
- WriteBuffer(buffer); /* don't forget to release buffer! */
- return res;
- }
- if (PageIsEmpty(page))
- off = FirstOffsetNumber;
- else
- off = OffsetNumberNext(PageGetMaxOffsetNumber(page));
- /* add the item and write the buffer */
- l = gistPageAddItem(giststate, r, page, (Item) itup, IndexTupleSize(itup),
- off, LP_USED, &tmpdentry, &newtup);
- WriteBuffer(buffer);
- /* now expand the page boundary in the parent to include the new child */
- gistAdjustKeys(r, stack, blk, tmpdentry.pred, tmpdentry.bytes, giststate);
- gistfreestack(stack);
- /* be tidy */
- if (itup != newtup)
- pfree(newtup);
- if (tmpdentry.pred != (((char *) itup) + sizeof(IndexTupleData)))
- pfree(tmpdentry.pred);
- /* build and return an InsertIndexResult for this insertion */
- res = (InsertIndexResult) palloc(sizeof(InsertIndexResultData));
- ItemPointerSet(&(res->pointerData), blk, l);
- return res;
- }
- static BlockNumber
- gistChooseSubtree(Relation r, IndexTuple itup, /* itup has compressed
- * entry */
- int level,
- GISTSTATE *giststate,
- GISTSTACK **retstack /* out */ ,
- Buffer *leafbuf /* out */ )
- {
- Buffer buffer;
- BlockNumber blk;
- GISTSTACK *stack;
- Page page;
- GISTPageOpaque opaque;
- IndexTuple which;
- blk = GISTP_ROOT;
- buffer = InvalidBuffer;
- stack = (GISTSTACK *) NULL;
- do
- {
- /* let go of current buffer before getting next */
- if (buffer != InvalidBuffer)
- ReleaseBuffer(buffer);
- /* get next buffer */
- buffer = ReadBuffer(r, blk);
- page = (Page) BufferGetPage(buffer);
- opaque = (GISTPageOpaque) PageGetSpecialPointer(page);
- if (!(opaque->flags & F_LEAF))
- {
- GISTSTACK *n;
- ItemId iid;
- n = (GISTSTACK *) palloc(sizeof(GISTSTACK));
- n->gs_parent = stack;
- n->gs_blk = blk;
- n->gs_child = gistchoose(r, page, itup, giststate);
- stack = n;
- iid = PageGetItemId(page, n->gs_child);
- which = (IndexTuple) PageGetItem(page, iid);
- blk = ItemPointerGetBlockNumber(&(which->t_tid));
- }
- } while (!(opaque->flags & F_LEAF));
- *retstack = stack;
- *leafbuf = buffer;
- return blk;
- }
- static void
- gistAdjustKeys(Relation r,
- GISTSTACK *stk,
- BlockNumber blk,
- char *datum, /* datum is uncompressed */
- int att_size,
- GISTSTATE *giststate)
- {
- char *oldud;
- Page p;
- Buffer b;
- bool result;
- bytea *evec;
- GISTENTRY centry,
- *ev0p,
- *ev1p;
- int size,
- datumsize;
- IndexTuple tid;
- if (stk == (GISTSTACK *) NULL)
- return;
- b = ReadBuffer(r, stk->gs_blk);
- p = BufferGetPage(b);
- oldud = (char *) PageGetItem(p, PageGetItemId(p, stk->gs_child));
- tid = (IndexTuple) oldud;
- size = IndexTupleSize((IndexTuple) oldud) - sizeof(IndexTupleData);
- oldud += sizeof(IndexTupleData);
- evec = (bytea *) palloc(2 * sizeof(GISTENTRY) + VARHDRSZ);
- VARSIZE(evec) = 2 * sizeof(GISTENTRY) + VARHDRSZ;
- /* insert decompressed oldud into entry vector */
- gistdentryinit(giststate, &((GISTENTRY *) VARDATA(evec))[0],
- oldud, r, p, stk->gs_child,
- size, FALSE);
- ev0p = &((GISTENTRY *) VARDATA(evec))[0];
- /* insert datum entry into entry vector */
- gistentryinit(((GISTENTRY *) VARDATA(evec))[1], datum,
- (Relation) NULL, (Page) NULL, (OffsetNumber) 0, att_size, FALSE);
- ev1p = &((GISTENTRY *) VARDATA(evec))[1];
- /* form union of decompressed entries */
- datum = (*fmgr_faddr(&giststate->unionFn)) (evec, &datumsize);
- /* did union leave decompressed version of oldud unchanged? */
- (*fmgr_faddr(&giststate->equalFn)) (ev0p->pred, datum, &result);
- if (!result)
- {
- TupleDesc td = RelationGetDescr(r);
- /* compress datum for storage on page */
- gistcentryinit(giststate, ¢ry, datum, ev0p->rel, ev0p->page,
- ev0p->offset, datumsize, FALSE);
- if (td->attrs[0]->attlen >= 0)
- {
- memmove(oldud, centry.pred, att_size);
- gistAdjustKeys(r, stk->gs_parent, stk->gs_blk, datum, att_size,
- giststate);
- }
- else if (VARSIZE(centry.pred) == VARSIZE(oldud))
- {
- memmove(oldud, centry.pred, VARSIZE(centry.pred));
- gistAdjustKeys(r, stk->gs_parent, stk->gs_blk, datum, att_size,
- giststate);
- }
- else
- {
- /*
- * * new datum is not the same size as the old. * We have to
- * delete the old entry and insert the new * one. Note that
- * this may cause a split here!
- */
- IndexTuple newtup;
- ItemPointerData oldtid;
- char *isnull;
- TupleDesc tupDesc;
- InsertIndexResult res;
- /* delete old tuple */
- ItemPointerSet(&oldtid, stk->gs_blk, stk->gs_child);
- gistdelete(r, (ItemPointer) &oldtid);
- /* generate and insert new tuple */
- tupDesc = r->rd_att;
- isnull = (char *) palloc(r->rd_rel->relnatts);
- MemSet(isnull, ' ', r->rd_rel->relnatts);
- newtup = (IndexTuple) index_formtuple(tupDesc,
- (Datum *) ¢ry.pred, isnull);
- pfree(isnull);
- /* set pointer in new tuple to point to current child */
- ItemPointerSet(&oldtid, blk, 1);
- newtup->t_tid = oldtid;
- /* inserting the new entry also adjust keys above */
- res = gistentryinsert(r, stk, newtup, giststate);
- /* in stack, set info to point to new tuple */
- stk->gs_blk = ItemPointerGetBlockNumber(&(res->pointerData));
- stk->gs_child = ItemPointerGetOffsetNumber(&(res->pointerData));
- pfree(res);
- }
- WriteBuffer(b);
- if (centry.pred != datum)
- pfree(datum);
- }
- else
- ReleaseBuffer(b);
- pfree(evec);
- }
- /*
- * gistSplit -- split a page in the tree.
- *
- */
- static InsertIndexResult
- gistSplit(Relation r,
- Buffer buffer,
- GISTSTACK *stack,
- IndexTuple itup, /* contains compressed entry */
- GISTSTATE *giststate)
- {
- Page p;
- Buffer leftbuf,
- rightbuf;
- Page left,
- right;
- ItemId itemid;
- IndexTuple item;
- IndexTuple ltup,
- rtup,
- newtup;
- OffsetNumber maxoff;
- OffsetNumber i;
- OffsetNumber leftoff,
- rightoff;
- BlockNumber lbknum,
- rbknum;
- BlockNumber bufblock;
- GISTPageOpaque opaque;
- int blank;
- InsertIndexResult res;
- char *isnull;
- GIST_SPLITVEC v;
- TupleDesc tupDesc;
- bytea *entryvec;
- bool *decompvec;
- IndexTuple item_1;
- GISTENTRY tmpdentry,
- tmpentry;
- isnull = (char *) palloc(r->rd_rel->relnatts);
- for (blank = 0; blank < r->rd_rel->relnatts; blank++)
- isnull[blank] = ' ';
- p = (Page) BufferGetPage(buffer);
- opaque = (GISTPageOpaque) PageGetSpecialPointer(p);
- /*
- * The root of the tree is the first block in the relation. If we're
- * about to split the root, we need to do some hocus-pocus to enforce
- * this guarantee.
- */
- if (BufferGetBlockNumber(buffer) == GISTP_ROOT)
- {
- leftbuf = ReadBuffer(r, P_NEW);
- GISTInitBuffer(leftbuf, opaque->flags);
- lbknum = BufferGetBlockNumber(leftbuf);
- left = (Page) BufferGetPage(leftbuf);
- }
- else
- {
- leftbuf = buffer;
- IncrBufferRefCount(buffer);
- lbknum = BufferGetBlockNumber(buffer);
- left = (Page) PageGetTempPage(p, sizeof(GISTPageOpaqueData));
- }
- rightbuf = ReadBuffer(r, P_NEW);
- GISTInitBuffer(rightbuf, opaque->flags);
- rbknum = BufferGetBlockNumber(rightbuf);
- right = (Page) BufferGetPage(rightbuf);
- /* generate the item array */
- maxoff = PageGetMaxOffsetNumber(p);
- entryvec = (bytea *) palloc(VARHDRSZ + (maxoff + 2) * sizeof(GISTENTRY));
- decompvec = (bool *) palloc(VARHDRSZ + (maxoff + 2) * sizeof(bool));
- for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
- {
- item_1 = (IndexTuple) PageGetItem(p, PageGetItemId(p, i));
- gistdentryinit(giststate, &((GISTENTRY *) VARDATA(entryvec))[i],
- (((char *) item_1) + sizeof(IndexTupleData)),
- r, p, i,
- IndexTupleSize(item_1) - sizeof(IndexTupleData), FALSE);
- if ((char *) (((GISTENTRY *) VARDATA(entryvec))[i].pred)
- == (((char *) item_1) + sizeof(IndexTupleData)))
- decompvec[i] = FALSE;
- else
- decompvec[i] = TRUE;
- }
- /* add the new datum as the last entry */
- gistdentryinit(giststate, &(((GISTENTRY *) VARDATA(entryvec))[maxoff + 1]),
- (((char *) itup) + sizeof(IndexTupleData)),
- (Relation) NULL, (Page) NULL,
- (OffsetNumber) 0, tmpentry.bytes, FALSE);
- if ((char *) (((GISTENTRY *) VARDATA(entryvec))[maxoff + 1]).pred !=
- (((char *) itup) + sizeof(IndexTupleData)))
- decompvec[maxoff + 1] = TRUE;
- else
- decompvec[maxoff + 1] = FALSE;
- VARSIZE(entryvec) = (maxoff + 2) * sizeof(GISTENTRY) + VARHDRSZ;
- /* now let the user-defined picksplit function set up the split vector */
- (*fmgr_faddr(&giststate->picksplitFn)) (entryvec, &v);
- /* compress ldatum and rdatum */
- gistcentryinit(giststate, &tmpentry, v.spl_ldatum, (Relation) NULL,
- (Page) NULL, (OffsetNumber) 0,
- ((GISTENTRY *) VARDATA(entryvec))[i].bytes, FALSE);
- if (v.spl_ldatum != tmpentry.pred)
- pfree(v.spl_ldatum);
- v.spl_ldatum = tmpentry.pred;
- gistcentryinit(giststate, &tmpentry, v.spl_rdatum, (Relation) NULL,
- (Page) NULL, (OffsetNumber) 0,
- ((GISTENTRY *) VARDATA(entryvec))[i].bytes, FALSE);
- if (v.spl_rdatum != tmpentry.pred)
- pfree(v.spl_rdatum);
- v.spl_rdatum = tmpentry.pred;
- /* clean up the entry vector: its preds need to be deleted, too */
- for (i = FirstOffsetNumber; i <= maxoff + 1; i = OffsetNumberNext(i))
- if (decompvec[i])
- pfree(((GISTENTRY *) VARDATA(entryvec))[i].pred);
- pfree(entryvec);
- pfree(decompvec);
- leftoff = rightoff = FirstOffsetNumber;
- maxoff = PageGetMaxOffsetNumber(p);
- for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
- {
- itemid = PageGetItemId(p, i);
- item = (IndexTuple) PageGetItem(p, itemid);
- if (i == *(v.spl_left))
- {
- gistPageAddItem(giststate, r, left, (Item) item,
- IndexTupleSize(item),
- leftoff, LP_USED, &tmpdentry, &newtup);
- leftoff = OffsetNumberNext(leftoff);
- v.spl_left++; /* advance in left split vector */
- /* be tidy */
- if (tmpdentry.pred != (((char *) item) + sizeof(IndexTupleData)))
- pfree(tmpdentry.pred);
- if ((IndexTuple) item != newtup)
- pfree(newtup);
- }
- else
- {
- gistPageAddItem(giststate, r, right, (Item) item,
- IndexTupleSize(item),
- rightoff, LP_USED, &tmpdentry, &newtup);
- rightoff = OffsetNumberNext(rightoff);
- v.spl_right++; /* advance in right split vector */
- /* be tidy */
- if (tmpdentry.pred != (((char *) item) + sizeof(IndexTupleData)))
- pfree(tmpdentry.pred);
- if (item != newtup)
- pfree(newtup);
- }
- }
- /* build an InsertIndexResult for this insertion */
- res = (InsertIndexResult) palloc(sizeof(InsertIndexResultData));
- /* now insert the new index tuple */
- if (*(v.spl_left) != FirstOffsetNumber)
- {
- gistPageAddItem(giststate, r, left, (Item) itup,
- IndexTupleSize(itup),
- leftoff, LP_USED, &tmpdentry, &newtup);
- leftoff = OffsetNumberNext(leftoff);
- ItemPointerSet(&(res->pointerData), lbknum, leftoff);
- /* be tidy */
- if (tmpdentry.pred != (((char *) itup) + sizeof(IndexTupleData)))
- pfree(tmpdentry.pred);
- if (itup != newtup)
- pfree(newtup);
- }
- else
- {
- gistPageAddItem(giststate, r, right, (Item) itup,
- IndexTupleSize(itup),
- rightoff, LP_USED, &tmpdentry, &newtup);
- rightoff = OffsetNumberNext(rightoff);
- ItemPointerSet(&(res->pointerData), rbknum, rightoff);
- /* be tidy */
- if (tmpdentry.pred != (((char *) itup) + sizeof(IndexTupleData)))
- pfree(tmpdentry.pred);
- if (itup != newtup)
- pfree(newtup);
- }
- if ((bufblock = BufferGetBlockNumber(buffer)) != GISTP_ROOT)
- PageRestoreTempPage(left, p);
- WriteBuffer(leftbuf);
- WriteBuffer(rightbuf);
- /*
- * Okay, the page is split. We have three things left to do:
- *
- * 1) Adjust any active scans on this index to cope with changes we
- * introduced in its structure by splitting this page.
- *
- * 2) "Tighten" the bounding box of the pointer to the left page in the
- * parent node in the tree, if any. Since we moved a bunch of stuff
- * off the left page, we expect it to get smaller. This happens in
- * the internal insertion routine.
- *
- * 3) Insert a pointer to the right page in the parent. This may cause
- * the parent to split. If it does, we need to repeat steps one and
- * two for each split node in the tree.
- */
- /* adjust active scans */
- gistadjscans(r, GISTOP_SPLIT, bufblock, FirstOffsetNumber);
- tupDesc = r->rd_att;
- ltup = (IndexTuple) index_formtuple(tupDesc,
- (Datum *) &(v.spl_ldatum), isnull);
- rtup = (IndexTuple) index_formtuple(tupDesc,
- (Datum *) &(v.spl_rdatum), isnull);
- pfree(isnull);
- /* set pointers to new child pages in the internal index tuples */
- ItemPointerSet(&(ltup->t_tid), lbknum, 1);
- ItemPointerSet(&(rtup->t_tid), rbknum, 1);
- gistintinsert(r, stack, ltup, rtup, giststate);
- pfree(ltup);
- pfree(rtup);
- return res;
- }
- /*
- ** After a split, we need to overwrite the old entry's key in the parent,
- ** and install install an entry for the new key into the parent.
- */
- static void
- gistintinsert(Relation r,
- GISTSTACK *stk,
- IndexTuple ltup, /* new version of entry for old page */
- IndexTuple rtup, /* entry for new page */
- GISTSTATE *giststate)
- {
- ItemPointerData ltid;
- if (stk == (GISTSTACK *) NULL)
- {
- gistnewroot(giststate, r, ltup, rtup);
- return;
- }
- /* remove old left pointer, insert the 2 new entries */
- ItemPointerSet(<id, stk->gs_blk, stk->gs_child);
- gistdelete(r, (ItemPointer) <id);
- gistentryinserttwo(r, stk, ltup, rtup, giststate);
- }
- /*
- ** Insert two entries onto one page, handling a split for either one!
- */
- static void
- gistentryinserttwo(Relation r, GISTSTACK *stk, IndexTuple ltup,
- IndexTuple rtup, GISTSTATE *giststate)
- {
- Buffer b;
- Page p;
- InsertIndexResult res;
- GISTENTRY tmpentry;
- IndexTuple newtup;
- b = ReadBuffer(r, stk->gs_blk);
- p = BufferGetPage(b);
- if (gistnospace(p, ltup))
- {
- res = gistSplit(r, b, stk->gs_parent, ltup, giststate);
- WriteBuffer(b); /* don't forget to release buffer! -
- * 01/31/94 */
- pfree(res);
- gistdoinsert(r, rtup, giststate);
- }
- else
- {
- gistPageAddItem(giststate, r, p, (Item) ltup,
- IndexTupleSize(ltup), InvalidOffsetNumber,
- LP_USED, &tmpentry, &newtup);
- WriteBuffer(b);
- gistAdjustKeys(r, stk->gs_parent, stk->gs_blk, tmpentry.pred,
- tmpentry.bytes, giststate);
- /* be tidy */
- if (tmpentry.pred != (((char *) ltup) + sizeof(IndexTupleData)))
- pfree(tmpentry.pred);
- if (ltup != newtup)
- pfree(newtup);
- gistentryinsert(r, stk, rtup, giststate);
- }
- }
- /*
- ** Insert an entry onto a page
- */
- static InsertIndexResult
- gistentryinsert(Relation r, GISTSTACK *stk, IndexTuple tup,
- GISTSTATE *giststate)
- {
- Buffer b;
- Page p;
- InsertIndexResult res;
- OffsetNumber off;
- GISTENTRY tmpentry;
- IndexTuple newtup;
- b = ReadBuffer(r, stk->gs_blk);
- p = BufferGetPage(b);
- if (gistnospace(p, tup))
- {
- res = gistSplit(r, b, stk->gs_parent, tup, giststate);
- WriteBuffer(b); /* don't forget to release buffer! -
- * 01/31/94 */
- return res;
- }
- else
- {
- res = (InsertIndexResult) palloc(sizeof(InsertIndexResultData));
- off = gistPageAddItem(giststate, r, p, (Item) tup, IndexTupleSize(tup),
- InvalidOffsetNumber, LP_USED, &tmpentry, &newtup);
- WriteBuffer(b);
- ItemPointerSet(&(res->pointerData), stk->gs_blk, off);
- gistAdjustKeys(r, stk->gs_parent, stk->gs_blk, tmpentry.pred,
- tmpentry.bytes, giststate);
- /* be tidy */
- if (tmpentry.pred != (((char *) tup) + sizeof(IndexTupleData)))
- pfree(tmpentry.pred);
- if (tup != newtup)
- pfree(newtup);
- return res;
- }
- }
- static void
- gistnewroot(GISTSTATE *giststate, Relation r, IndexTuple lt, IndexTuple rt)
- {
- Buffer b;
- Page p;
- GISTENTRY tmpentry;
- IndexTuple newtup;
- b = ReadBuffer(r, GISTP_ROOT);
- GISTInitBuffer(b, 0);
- p = BufferGetPage(b);
- gistPageAddItem(giststate, r, p, (Item) lt, IndexTupleSize(lt),
- FirstOffsetNumber,
- LP_USED, &tmpentry, &newtup);
- /* be tidy */
- if (tmpentry.pred != (((char *) lt) + sizeof(IndexTupleData)))
- pfree(tmpentry.pred);
- if (lt != newtup)
- pfree(newtup);
- gistPageAddItem(giststate, r, p, (Item) rt, IndexTupleSize(rt),
- OffsetNumberNext(FirstOffsetNumber), LP_USED,
- &tmpentry, &newtup);
- /* be tidy */
- if (tmpentry.pred != (((char *) rt) + sizeof(IndexTupleData)))
- pfree(tmpentry.pred);
- if (rt != newtup)
- pfree(newtup);
- WriteBuffer(b);
- }
- static void
- GISTInitBuffer(Buffer b, uint32 f)
- {
- GISTPageOpaque opaque;
- Page page;
- Size pageSize;
- pageSize = BufferGetPageSize(b);
- page = BufferGetPage(b);
- MemSet(page, 0, (int) pageSize);
- PageInit(page, pageSize, sizeof(GISTPageOpaqueData));
- opaque = (GISTPageOpaque) PageGetSpecialPointer(page);
- opaque->flags = f;
- }
- /*
- ** find entry with lowest penalty
- */
- static OffsetNumber
- gistchoose(Relation r, Page p, IndexTuple it, /* it has compressed entry */
- GISTSTATE *giststate)
- {
- OffsetNumber maxoff;
- OffsetNumber i;
- char *id;
- char *datum;
- float usize;
- OffsetNumber which;
- float which_grow;
- GISTENTRY entry,
- identry;
- int size,
- idsize;
- idsize = IndexTupleSize(it) - sizeof(IndexTupleData);
- id = ((char *) it) + sizeof(IndexTupleData);
- maxoff = PageGetMaxOffsetNumber(p);
- which_grow = -1.0;
- which = -1;
- gistdentryinit(giststate, &identry, id, (Relation) NULL, (Page) NULL,
- (OffsetNumber) 0, idsize, FALSE);
- for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
- {
- datum = (char *) PageGetItem(p, PageGetItemId(p, i));
- size = IndexTupleSize(datum) - sizeof(IndexTupleData);
- datum += sizeof(IndexTupleData);
- gistdentryinit(giststate, &entry, datum, r, p, i, size, FALSE);
- (*fmgr_faddr(&giststate->penaltyFn)) (&entry, &identry, &usize);
- if (which_grow < 0 || usize < which_grow)
- {
- which = i;
- which_grow = usize;
- if (which_grow == 0)
- break;
- }
- if (entry.pred != datum)
- pfree(entry.pred);
- }
- if (identry.pred != id)
- pfree(identry.pred);
- return which;
- }
- static int
- gistnospace(Page p, IndexTuple it)
- {
- return PageGetFreeSpace(p) < IndexTupleSize(it);
- }
- void
- gistfreestack(GISTSTACK *s)
- {
- GISTSTACK *p;
- while (s != (GISTSTACK *) NULL)
- {
- p = s->gs_parent;
- pfree(s);
- s = p;
- }
- }
- /*
- ** remove an entry from a page
- */
- void
- gistdelete(Relation r, ItemPointer tid)
- {
- BlockNumber blkno;
- OffsetNumber offnum;
- Buffer buf;
- Page page;
- /*
- * Notes in ExecUtils:ExecOpenIndices() Also note that only vacuum
- * deletes index tuples now...
- *
- * RelationSetLockForWrite(r);
- */
- blkno = ItemPointerGetBlockNumber(tid);
- offnum = ItemPointerGetOffsetNumber(tid);
- /* adjust any scans that will be affected by this deletion */
- gistadjscans(r, GISTOP_DEL, blkno, offnum);
- /* delete the index tuple */
- buf = ReadBuffer(r, blkno);
- page = BufferGetPage(buf);
- PageIndexTupleDelete(page, offnum);
- WriteBuffer(buf);
- }
- void
- initGISTstate(GISTSTATE *giststate, Relation index)
- {
- RegProcedure consistent_proc,
- union_proc,
- compress_proc,
- decompress_proc;
- RegProcedure penalty_proc,
- picksplit_proc,
- equal_proc;
- HeapTuple htup;
- Form_pg_index itupform;
- consistent_proc = index_getprocid(index, 1, GIST_CONSISTENT_PROC);
- union_proc = index_getprocid(index, 1, GIST_UNION_PROC);
- compress_proc = index_getprocid(index, 1, GIST_COMPRESS_PROC);
- decompress_proc = index_getprocid(index, 1, GIST_DECOMPRESS_PROC);
- penalty_proc = index_getprocid(index, 1, GIST_PENALTY_PROC);
- picksplit_proc = index_getprocid(index, 1, GIST_PICKSPLIT_PROC);
- equal_proc = index_getprocid(index, 1, GIST_EQUAL_PROC);
- fmgr_info(consistent_proc, &giststate->consistentFn);
- fmgr_info(union_proc, &giststate->unionFn);
- fmgr_info(compress_proc, &giststate->compressFn);
- fmgr_info(decompress_proc, &giststate->decompressFn);
- fmgr_info(penalty_proc, &giststate->penaltyFn);
- fmgr_info(picksplit_proc, &giststate->picksplitFn);
- fmgr_info(equal_proc, &giststate->equalFn);
- /* see if key type is different from type of attribute being indexed */
- htup = SearchSysCacheTuple(INDEXRELID,
- ObjectIdGetDatum(RelationGetRelid(index)),
- 0, 0, 0);
- itupform = (Form_pg_index) GETSTRUCT(htup);
- if (!HeapTupleIsValid(htup))
- elog(ERROR, "initGISTstate: index %u not found",
- RelationGetRelid(index));
- giststate->haskeytype = itupform->indhaskeytype;
- if (giststate->haskeytype)
- {
- /* key type is different -- is it byval? */
- htup = SearchSysCacheTuple(ATTNUM,
- ObjectIdGetDatum(itupform->indexrelid),
- UInt16GetDatum(FirstOffsetNumber),
- 0, 0);
- if (!HeapTupleIsValid(htup))
- {
- elog(ERROR, "initGISTstate: no attribute tuple %u %d",
- itupform->indexrelid, FirstOffsetNumber);
- return;
- }
- giststate->keytypbyval = (((Form_pg_attribute) htup)->attbyval);
- }
- else
- giststate->keytypbyval = FALSE;
- return;
- }
- /*
- ** Given an IndexTuple to be inserted on a page, this routine replaces
- ** the key with another key, which may involve generating a new IndexTuple
- ** if the sizes don't match
- */
- static IndexTuple
- gist_tuple_replacekey(Relation r, GISTENTRY entry, IndexTuple t)
- {
- char *datum = (((char *) t) + sizeof(IndexTupleData));
- /* if new entry fits in index tuple, copy it in */
- if (entry.bytes < IndexTupleSize(t) - sizeof(IndexTupleData))
- {
- memcpy(datum, entry.pred, entry.bytes);
- /* clear out old size */
- t->t_info &= 0xe000;
- /* or in new size */
- t->t_info |= MAXALIGN(entry.bytes + sizeof(IndexTupleData));
- return t;
- }
- else
- {
- /* generate a new index tuple for the compressed entry */
- TupleDesc tupDesc = r->rd_att;
- IndexTuple newtup;
- char *isnull;
- int blank;
- isnull = (char *) palloc(r->rd_rel->relnatts);
- for (blank = 0; blank < r->rd_rel->relnatts; blank++)
- isnull[blank] = ' ';
- newtup = (IndexTuple) index_formtuple(tupDesc,
- (Datum *) &(entry.pred),
- isnull);
- newtup->t_tid = t->t_tid;
- pfree(isnull);
- return newtup;
- }
- }
- /*
- ** initialize a GiST entry with a decompressed version of pred
- */
- void
- gistdentryinit(GISTSTATE *giststate, GISTENTRY *e, char *pr, Relation r,
- Page pg, OffsetNumber o, int b, bool l)
- {
- GISTENTRY *dep;
- gistentryinit(*e, pr, r, pg, o, b, l);
- if (giststate->haskeytype)
- {
- dep = (GISTENTRY *) ((*fmgr_faddr(&giststate->decompressFn)) (e));
- gistentryinit(*e, dep->pred, dep->rel, dep->page, dep->offset, dep->bytes,
- dep->leafkey);
- if (dep != e)
- pfree(dep);
- }
- }
- /*
- ** initialize a GiST entry with a compressed version of pred
- */
- static void
- gistcentryinit(GISTSTATE *giststate, GISTENTRY *e, char *pr, Relation r,
- Page pg, OffsetNumber o, int b, bool l)
- {
- GISTENTRY *cep;
- gistentryinit(*e, pr, r, pg, o, b, l);
- if (giststate->haskeytype)
- {
- cep = (GISTENTRY *) ((*fmgr_faddr(&giststate->compressFn)) (e));
- gistentryinit(*e, cep->pred, cep->rel, cep->page, cep->offset, cep->bytes,
- cep->leafkey);
- if (cep != e)
- pfree(cep);
- }
- }
- #ifdef GISTDEBUG
- /*
- ** sloppy debugging support routine, requires recompilation with appropriate
- ** "out" method for the index keys. Could be fixed to find that info
- ** in the catalogs...
- */
- void
- _gistdump(Relation r)
- {
- Buffer buf;
- Page page;
- OffsetNumber offnum,
- maxoff;
- BlockNumber blkno;
- BlockNumber nblocks;
- GISTPageOpaque po;
- IndexTuple itup;
- BlockNumber itblkno;
- OffsetNumber itoffno;
- char *datum;
- char *itkey;
- nblocks = RelationGetNumberOfBlocks(r);
- for (blkno = 0; blkno < nblocks; blkno++)
- {
- buf = ReadBuffer(r, blkno);
- page = BufferGetPage(buf);
- po = (GISTPageOpaque) PageGetSpecialPointer(page);
- maxoff = PageGetMaxOffsetNumber(page);
- printf("Page %d maxoff %d <%s>n", blkno, maxoff,
- (po->flags & F_LEAF ? "LEAF" : "INTERNAL"));
- if (PageIsEmpty(page))
- {
- ReleaseBuffer(buf);
- continue;
- }
- for (offnum = FirstOffsetNumber;
- offnum <= maxoff;
- offnum = OffsetNumberNext(offnum))
- {
- itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, offnum));
- itblkno = ItemPointerGetBlockNumber(&(itup->t_tid));
- itoffno = ItemPointerGetOffsetNumber(&(itup->t_tid));
- datum = ((char *) itup);
- datum += sizeof(IndexTupleData);
- /* get out function for type of key, and out it! */
- itkey = (char *) int_range_out((INTRANGE *) datum);
- /* itkey = " unable to print"; */
- printf("t[%d] size %d heap <%d,%d> key:%sn",
- offnum, IndexTupleSize(itup), itblkno, itoffno, itkey);
- pfree(itkey);
- }
- ReleaseBuffer(buf);
- }
- }
- static char *
- int_range_out(INTRANGE *r)
- {
- char *result;
- if (r == NULL)
- return NULL;
- result = (char *) palloc(80);
- snprintf(result, 80, "[%d,%d): %d", r->lower, r->upper, r->flag);
- return result;
- }
- #endif /* defined GISTDEBUG */