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postgres/src/backend/access/gist/gist.c
Vadim B. Mikheev 737ab85cc0 1. Pass GISTENTRYs to giststate->penaltyFn by pointers, not by vals. 
2. Re-initialize keys in gistrescan (if gist used in inner scan).
1997-05-22 16:01:33 +00:00

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/*-------------------------------------------------------------------------
*
* gist.c--
* interface routines for the postgres GiST index access method.
*
*
*
* IDENTIFICATION
*
*
*-------------------------------------------------------------------------
*/
#include <postgres.h>
#include <fmgr.h>
#include <access/genam.h>
#include <access/gist.h>
#include <access/gistscan.h>
#include <access/heapam.h>
#include <catalog/index.h>
#include <executor/executor.h>
#include <storage/bufmgr.h>
#include <storage/bufpage.h>
#include <storage/lmgr.h>
#include <utils/syscache.h>
#ifndef HAVE_MEMMOVE
# include <regex/utils.h>
#else
# include <string.h>
#endif
/* 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);
/*
** 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;
Buffer buffer;
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;
bool *compvec;
/* GiSTs only know how to do stupid locking now */
RelationSetLockForWrite(index);
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(WARN, "%.16s already contains data", &(index->rd_rel->relname.data[0]));
/* 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 = RelationGetTupleDescriptor(heap);
id = RelationGetTupleDescriptor(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 */
scan = heap_beginscan(heap, 0, NowTimeQual, 0, (ScanKey) NULL);
htup = heap_getnext(scan, 0, &buffer);
/* int the tuples as we insert them */
nh = ni = 0;
for (; HeapTupleIsValid(htup); htup = heap_getnext(scan, 0, &buffer)) {
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,
buffer);
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_ctid;
/*
* 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);
RelationUnsetLockForWrite(index);
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 = heap->rd_id;
irelid = index->rd_id;
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(RelationGetTupleDescriptor(r), datum, nulls);
itup->t_tid = *ht_ctid;
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);
/* XXX two-phase locking -- don't unlock the relation until EOT */
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 = (char *) (giststate->unionFn)(evec, &datumsize);
/* did union leave decompressed version of oldud unchanged? */
(giststate->equalFn)(ev0p->pred, datum, &result);
if (!result) {
TupleDesc td = RelationGetTupleDescriptor(r);
/* compress datum for storage on page */
gistcentryinit(giststate, &centry, 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 *) &centry.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 */
(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)) {
(void) 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 {
(void) 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) {
(void) 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 {
(void) 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(&ltid, stk->gs_blk, stk->gs_child);
gistdelete(r, (ItemPointer)&ltid);
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 {
(void) 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);
(void)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);
(void) 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);
(void) 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);
(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;
/* must write-lock on delete */
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);
/* XXX -- two-phase locking, don't release the write lock */
}
void
initGISTstate(GISTSTATE *giststate, Relation index)
{
RegProcedure consistent_proc, union_proc, compress_proc, decompress_proc;
RegProcedure penalty_proc, picksplit_proc, equal_proc;
func_ptr user_fn;
int pronargs;
HeapTuple htup;
IndexTupleForm 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, &user_fn, &pronargs);
giststate->consistentFn = user_fn;
fmgr_info(union_proc, &user_fn, &pronargs);
giststate->unionFn = user_fn;
fmgr_info(compress_proc, &user_fn, &pronargs);
giststate->compressFn = user_fn;
fmgr_info(decompress_proc, &user_fn, &pronargs);
giststate->decompressFn = user_fn;
fmgr_info(penalty_proc, &user_fn, &pronargs);
giststate->penaltyFn = user_fn;
fmgr_info(picksplit_proc, &user_fn, &pronargs);
giststate->picksplitFn = user_fn;
fmgr_info(equal_proc, &user_fn, &pronargs);
giststate->equalFn = user_fn;
/* see if key type is different from type of attribute being indexed */
htup = SearchSysCacheTuple(INDEXRELID, ObjectIdGetDatum(index->rd_id),
0,0,0);
itupform = (IndexTupleForm)GETSTRUCT(htup);
if (!HeapTupleIsValid(htup))
elog(WARN, "initGISTstate: index %d not found", index->rd_id);
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(WARN, "initGISTstate: no attribute tuple %d %d",
itupform->indexrelid, FirstOffsetNumber);
return;
}
giststate->keytypbyval = (((AttributeTupleForm)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 *)((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
*/
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 *)((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:%s\n",
offnum, IndexTupleSize(itup), itblkno, itoffno, itkey);
pfree(itkey);
}
ReleaseBuffer(buf);
}
}
char *text_range_out(TXTRANGE *r)
{
char *result;
char *lower, *upper;
if (r == NULL)
return(NULL);
result = (char *)palloc(16 + VARSIZE(TRLOWER(r)) + VARSIZE(TRUPPER(r))
- 2*VARHDRSZ);
lower = (char *)palloc(VARSIZE(TRLOWER(r)) + 1 - VARHDRSZ);
memcpy(lower, VARDATA(TRLOWER(r)), VARSIZE(TRLOWER(r)) - VARHDRSZ);
lower[VARSIZE(TRLOWER(r)) - VARHDRSZ] = '\0';
upper = (char *)palloc(VARSIZE(TRUPPER(r)) + 1 - VARHDRSZ);
memcpy(upper, VARDATA(TRUPPER(r)), VARSIZE(TRUPPER(r)) - VARHDRSZ);
upper[VARSIZE(TRUPPER(r)) - VARHDRSZ] = '\0';
(void) sprintf(result, "[%s,%s): %d", lower, upper, r->flag);
pfree(lower);
pfree(upper);
return(result);
}
char *
int_range_out(INTRANGE *r)
{
char *result;
if (r == NULL)
return(NULL);
result = (char *)palloc(80);
(void) sprintf(result, "[%d,%d): %d",r->lower, r->upper, r->flag);
return(result);
}
#endif /* defined GISTDEBUG */
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