gistutil.c File Reference

#include "postgres.h"
#include <math.h>
#include "access/gist_private.h"
#include "access/htup_details.h"
#include "access/reloptions.h"
#include "catalog/pg_opclass.h"
#include "storage/indexfsm.h"
#include "storage/lmgr.h"
#include "utils/float.h"
#include "utils/lsyscache.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"

Include dependency graph for gistutil.c:

Go to the source code of this file.

Functions
void	gistfillbuffer (Page page, IndexTuple *itup, int len, OffsetNumber off)
bool	gistnospace (Page page, IndexTuple *itvec, int len, OffsetNumber todelete, Size freespace)
bool	gistfitpage (IndexTuple *itvec, int len)
IndexTuple *	gistextractpage (Page page, int *len)
IndexTuple *	gistjoinvector (IndexTuple *itvec, int *len, IndexTuple *additvec, int addlen)
IndexTupleData *	gistfillitupvec (IndexTuple *vec, int veclen, int *memlen)
void	gistMakeUnionItVec (GISTSTATE *giststate, IndexTuple *itvec, int len, Datum *attr, bool *isnull)
IndexTuple	gistunion (Relation r, IndexTuple *itvec, int len, GISTSTATE *giststate)
void	gistMakeUnionKey (GISTSTATE *giststate, int attno, GISTENTRY *entry1, bool isnull1, GISTENTRY *entry2, bool isnull2, Datum *dst, bool *dstisnull)
bool	gistKeyIsEQ (GISTSTATE *giststate, int attno, Datum a, Datum b)
void	gistDeCompressAtt (GISTSTATE *giststate, Relation r, IndexTuple tuple, Page p, OffsetNumber o, GISTENTRY *attdata, bool *isnull)
IndexTuple	gistgetadjusted (Relation r, IndexTuple oldtup, IndexTuple addtup, GISTSTATE *giststate)
OffsetNumber	gistchoose (Relation r, Page p, IndexTuple it, GISTSTATE *giststate)
void	gistdentryinit (GISTSTATE *giststate, int nkey, GISTENTRY *e, Datum k, Relation r, Page pg, OffsetNumber o, bool l, bool isNull)
IndexTuple	gistFormTuple (GISTSTATE *giststate, Relation r, Datum attdata[], bool isnull[], bool isleaf)
static Datum	gistFetchAtt (GISTSTATE *giststate, int nkey, Datum k, Relation r)
HeapTuple	gistFetchTuple (GISTSTATE *giststate, Relation r, IndexTuple tuple)
float	gistpenalty (GISTSTATE *giststate, int attno, GISTENTRY *orig, bool isNullOrig, GISTENTRY *add, bool isNullAdd)
void	GISTInitBuffer (Buffer b, uint32 f)
void	gistcheckpage (Relation rel, Buffer buf)
Buffer	gistNewBuffer (Relation r)
bool	gistPageRecyclable (Page page)
bytea *	gistoptions (Datum reloptions, bool validate)
bool	gistproperty (Oid index_oid, int attno, IndexAMProperty prop, const char *propname, bool *res, bool *isnull)
XLogRecPtr	gistGetFakeLSN (Relation rel)

Function Documentation

gistcheckpage()

void gistcheckpage	(	Relation	rel,
		Buffer	buf
	)

Definition at line 770 of file gistutil.c.

References BufferGetBlockNumber(), BufferGetPage, ereport, errcode(), errhint(), errmsg(), ERROR, MAXALIGN, PageGetSpecialSize, PageIsNew, and RelationGetRelationName.

Referenced by gistBufferingFindCorrectParent(), gistdoinsert(), gistFindCorrectParent(), gistFindPath(), gistkillitems(), gistNewBuffer(), gistScanPage(), gistvacuum_delete_empty_pages(), and pgstat_gist_page().

{
    Page        page = BufferGetPage(buf);

    /*
     * ReadBuffer verifies that every newly-read page passes
     * PageHeaderIsValid, which means it either contains a reasonably sane
     * page header or is all-zero.  We have to defend against the all-zero
     * case, however.
     */
    if (PageIsNew(page))
        ereport(ERROR,
                (errcode(ERRCODE_INDEX_CORRUPTED),
                 errmsg("index \"%s\" contains unexpected zero page at block %u",
                        RelationGetRelationName(rel),
                        BufferGetBlockNumber(buf)),
                 errhint("Please REINDEX it.")));

    /*
     * Additionally check that the special area looks sane.
     */
    if (PageGetSpecialSize(page) != MAXALIGN(sizeof(GISTPageOpaqueData)))
        ereport(ERROR,
                (errcode(ERRCODE_INDEX_CORRUPTED),
                 errmsg("index \"%s\" contains corrupted page at block %u",
                        RelationGetRelationName(rel),
                        BufferGetBlockNumber(buf)),
                 errhint("Please REINDEX it.")));
}

gistchoose()

OffsetNumber gistchoose	(	Relation	r,
		Page	p,
		IndexTuple	it,
		GISTSTATE *	giststate
	)

Definition at line 373 of file gistutil.c.

References Assert, FirstOffsetNumber, gistDeCompressAtt(), gistdentryinit(), GistPageIsLeaf, gistpenalty(), i, index_getattr, INDEX_MAX_KEYS, IndexRelationGetNumberOfKeyAttributes, GISTSTATE::leafTupdesc, MAX_RANDOM_VALUE, OffsetNumberNext, PageGetItem, PageGetItemId, PageGetMaxOffsetNumber, and random().

Referenced by gistdoinsert(), and gistProcessItup().

{
    OffsetNumber result;
    OffsetNumber maxoff;
    OffsetNumber i;
    float       best_penalty[INDEX_MAX_KEYS];
    GISTENTRY   entry,
                identry[INDEX_MAX_KEYS];
    bool        isnull[INDEX_MAX_KEYS];
    int         keep_current_best;

    Assert(!GistPageIsLeaf(p));

    gistDeCompressAtt(giststate, r,
                      it, NULL, (OffsetNumber) 0,
                      identry, isnull);

    /* we'll return FirstOffsetNumber if page is empty (shouldn't happen) */
    result = FirstOffsetNumber;

    /*
     * The index may have multiple columns, and there's a penalty value for
     * each column.  The penalty associated with a column that appears earlier
     * in the index definition is strictly more important than the penalty of
     * a column that appears later in the index definition.
     *
     * best_penalty[j] is the best penalty we have seen so far for column j,
     * or -1 when we haven't yet examined column j.  Array entries to the
     * right of the first -1 are undefined.
     */
    best_penalty[0] = -1;

    /*
     * If we find a tuple that's exactly as good as the currently best one, we
     * could use either one.  When inserting a lot of tuples with the same or
     * similar keys, it's preferable to descend down the same path when
     * possible, as that's more cache-friendly.  On the other hand, if all
     * inserts land on the same leaf page after a split, we're never going to
     * insert anything to the other half of the split, and will end up using
     * only 50% of the available space.  Distributing the inserts evenly would
     * lead to better space usage, but that hurts cache-locality during
     * insertion.  To get the best of both worlds, when we find a tuple that's
     * exactly as good as the previous best, choose randomly whether to stick
     * to the old best, or use the new one.  Once we decide to stick to the
     * old best, we keep sticking to it for any subsequent equally good tuples
     * we might find.  This favors tuples with low offsets, but still allows
     * some inserts to go to other equally-good subtrees.
     *
     * keep_current_best is -1 if we haven't yet had to make a random choice
     * whether to keep the current best tuple.  If we have done so, and
     * decided to keep it, keep_current_best is 1; if we've decided to
     * replace, keep_current_best is 0.  (This state will be reset to -1 as
     * soon as we've made the replacement, but sometimes we make the choice in
     * advance of actually finding a replacement best tuple.)
     */
    keep_current_best = -1;

    /*
     * Loop over tuples on page.
     */
    maxoff = PageGetMaxOffsetNumber(p);
    Assert(maxoff >= FirstOffsetNumber);

    for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
    {
        IndexTuple  itup = (IndexTuple) PageGetItem(p, PageGetItemId(p, i));
        bool        zero_penalty;
        int         j;

        zero_penalty = true;

        /* Loop over index attributes. */
        for (j = 0; j < IndexRelationGetNumberOfKeyAttributes(r); j++)
        {
            Datum       datum;
            float       usize;
            bool        IsNull;

            /* Compute penalty for this column. */
            datum = index_getattr(itup, j + 1, giststate->leafTupdesc,
                                  &IsNull);
            gistdentryinit(giststate, j, &entry, datum, r, p, i,
                           false, IsNull);
            usize = gistpenalty(giststate, j, &entry, IsNull,
                                &identry[j], isnull[j]);
            if (usize > 0)
                zero_penalty = false;

            if (best_penalty[j] < 0 || usize < best_penalty[j])
            {
                /*
                 * New best penalty for column.  Tentatively select this tuple
                 * as the target, and record the best penalty.  Then reset the
                 * next column's penalty to "unknown" (and indirectly, the
                 * same for all the ones to its right).  This will force us to
                 * adopt this tuple's penalty values as the best for all the
                 * remaining columns during subsequent loop iterations.
                 */
                result = i;
                best_penalty[j] = usize;

                if (j < IndexRelationGetNumberOfKeyAttributes(r) - 1)
                    best_penalty[j + 1] = -1;

                /* we have new best, so reset keep-it decision */
                keep_current_best = -1;
            }
            else if (best_penalty[j] == usize)
            {
                /*
                 * The current tuple is exactly as good for this column as the
                 * best tuple seen so far.  The next iteration of this loop
                 * will compare the next column.
                 */
            }
            else
            {
                /*
                 * The current tuple is worse for this column than the best
                 * tuple seen so far.  Skip the remaining columns and move on
                 * to the next tuple, if any.
                 */
                zero_penalty = false;   /* so outer loop won't exit */
                break;
            }
        }

        /*
         * If we looped past the last column, and did not update "result",
         * then this tuple is exactly as good as the prior best tuple.
         */
        if (j == IndexRelationGetNumberOfKeyAttributes(r) && result != i)
        {
            if (keep_current_best == -1)
            {
                /* we didn't make the random choice yet for this old best */
                keep_current_best = (random() <= (MAX_RANDOM_VALUE / 2)) ? 1 : 0;
            }
            if (keep_current_best == 0)
            {
                /* we choose to use the new tuple */
                result = i;
                /* choose again if there are even more exactly-as-good ones */
                keep_current_best = -1;
            }
        }

        /*
         * If we find a tuple with zero penalty for all columns, and we've
         * decided we don't want to search for another tuple with equal
         * penalty, there's no need to examine remaining tuples; just break
         * out of the loop and return it.
         */
        if (zero_penalty)
        {
            if (keep_current_best == -1)
            {
                /* we didn't make the random choice yet for this old best */
                keep_current_best = (random() <= (MAX_RANDOM_VALUE / 2)) ? 1 : 0;
            }
            if (keep_current_best == 1)
                break;
        }
    }

    return result;
}

gistDeCompressAtt()

void gistDeCompressAtt	(	GISTSTATE *	giststate,
		Relation	r,
		IndexTuple	tuple,
		Page	p,
		OffsetNumber	o,
		GISTENTRY *	attdata,
		bool *	isnull
	)

Definition at line 295 of file gistutil.c.

References gistdentryinit(), i, index_getattr, IndexRelationGetNumberOfKeyAttributes, and GISTSTATE::leafTupdesc.

Referenced by gistchoose(), gistgetadjusted(), gistRelocateBuildBuffersOnSplit(), and placeOne().

{
    int         i;

    for (i = 0; i < IndexRelationGetNumberOfKeyAttributes(r); i++)
    {
        Datum       datum;

        datum = index_getattr(tuple, i + 1, giststate->leafTupdesc, &isnull[i]);
        gistdentryinit(giststate, i, &attdata[i],
                       datum, r, p, o,
                       false, isnull[i]);
    }
}

gistdentryinit()

void gistdentryinit	(	GISTSTATE *	giststate,
		int	nkey,
		GISTENTRY *	e,
		Datum	k,
		Relation	r,
		Page	pg,
		OffsetNumber	o,
		bool	l,
		bool	isNull
	)

Definition at line 546 of file gistutil.c.

References DatumGetPointer, GISTSTATE::decompressFn, FmgrInfo::fn_oid, FunctionCall1Coll(), gistentryinit, GISTENTRY::key, GISTENTRY::leafkey, GISTENTRY::offset, OidIsValid, GISTENTRY::page, PointerGetDatum, GISTENTRY::rel, and GISTSTATE::supportCollation.

Referenced by gistchoose(), gistDeCompressAtt(), gistindex_keytest(), gistMakeUnionItVec(), and gistSplitByKey().

{
    if (!isNull)
    {
        GISTENTRY  *dep;

        gistentryinit(*e, k, r, pg, o, l);

        /* there may not be a decompress function in opclass */
        if (!OidIsValid(giststate->decompressFn[nkey].fn_oid))
            return;

        dep = (GISTENTRY *)
            DatumGetPointer(FunctionCall1Coll(&giststate->decompressFn[nkey],
                                              giststate->supportCollation[nkey],
                                              PointerGetDatum(e)));
        /* decompressFn may just return the given pointer */
        if (dep != e)
            gistentryinit(*e, dep->key, dep->rel, dep->page, dep->offset,
                          dep->leafkey);
    }
    else
        gistentryinit(*e, (Datum) 0, r, pg, o, l);
}

gistextractpage()

IndexTuple* gistextractpage	(	Page	page,
		int *	len
	)

Definition at line 94 of file gistutil.c.

References FirstOffsetNumber, i, OffsetNumberNext, PageGetItem, PageGetItemId, PageGetMaxOffsetNumber, and palloc().

Referenced by gistplacetopage().

{
    OffsetNumber i,
                maxoff;
    IndexTuple *itvec;

    maxoff = PageGetMaxOffsetNumber(page);
    *len = maxoff;
    itvec = palloc(sizeof(IndexTuple) * maxoff);
    for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
        itvec[i - FirstOffsetNumber] = (IndexTuple) PageGetItem(page, PageGetItemId(page, i));

    return itvec;
}

gistFetchAtt()

static Datum gistFetchAtt ( GISTSTATE *  giststate, int  nkey, Datum  k, Relation  r  )

static

Definition at line 637 of file gistutil.c.

References DatumGetPointer, GISTSTATE::fetchFn, FunctionCall1Coll(), gistentryinit, GISTENTRY::key, PointerGetDatum, and GISTSTATE::supportCollation.

Referenced by gistFetchTuple().

{
    GISTENTRY   fentry;
    GISTENTRY  *fep;

    gistentryinit(fentry, k, r, NULL, (OffsetNumber) 0, false);

    fep = (GISTENTRY *)
        DatumGetPointer(FunctionCall1Coll(&giststate->fetchFn[nkey],
                                          giststate->supportCollation[nkey],
                                          PointerGetDatum(&fentry)));

    /* fetchFn set 'key', return it to the caller */
    return fep->key;
}

gistFetchTuple()

HeapTuple gistFetchTuple	(	GISTSTATE *	giststate,
		Relation	r,
		IndexTuple	tuple
	)

Definition at line 658 of file gistutil.c.

References GISTSTATE::compressFn, fetchatt, GISTSTATE::fetchFn, GISTSTATE::fetchTupdesc, FmgrInfo::fn_oid, gistFetchAtt(), heap_form_tuple(), i, index_getattr, INDEX_MAX_KEYS, IndexRelationGetNumberOfKeyAttributes, InvalidOid, GISTSTATE::leafTupdesc, MemoryContextSwitchTo(), TupleDescData::natts, RelationData::rd_att, and GISTSTATE::tempCxt.

Referenced by gistScanPage().

{
    MemoryContext oldcxt = MemoryContextSwitchTo(giststate->tempCxt);
    Datum       fetchatt[INDEX_MAX_KEYS];
    bool        isnull[INDEX_MAX_KEYS];
    int         i;

    for (i = 0; i < IndexRelationGetNumberOfKeyAttributes(r); i++)
    {
        Datum       datum;

        datum = index_getattr(tuple, i + 1, giststate->leafTupdesc, &isnull[i]);

        if (giststate->fetchFn[i].fn_oid != InvalidOid)
        {
            if (!isnull[i])
                fetchatt[i] = gistFetchAtt(giststate, i, datum, r);
            else
                fetchatt[i] = (Datum) 0;
        }
        else if (giststate->compressFn[i].fn_oid == InvalidOid)
        {
            /*
             * If opclass does not provide compress method that could change
             * original value, att is necessarily stored in original form.
             */
            if (!isnull[i])
                fetchatt[i] = datum;
            else
                fetchatt[i] = (Datum) 0;
        }
        else
        {
            /*
             * Index-only scans not supported for this column. Since the
             * planner chose an index-only scan anyway, it is not interested
             * in this column, and we can replace it with a NULL.
             */
            isnull[i] = true;
            fetchatt[i] = (Datum) 0;
        }
    }

    /*
     * Get each included attribute.
     */
    for (; i < r->rd_att->natts; i++)
    {
        fetchatt[i] = index_getattr(tuple, i + 1, giststate->leafTupdesc,
                                    &isnull[i]);
    }
    MemoryContextSwitchTo(oldcxt);

    return heap_form_tuple(giststate->fetchTupdesc, fetchatt, isnull);
}

gistfillbuffer()

void gistfillbuffer	(	Page	page,
		IndexTuple *	itup,
		int	len,
		OffsetNumber	off
	)

Definition at line 33 of file gistutil.c.

References elog, ERROR, FirstOffsetNumber, i, IndexTupleSize, InvalidOffsetNumber, OffsetNumberNext, PageAddItem, PageGetMaxOffsetNumber, and PageIsEmpty.

Referenced by gistplacetopage(), and gistRedoPageSplitRecord().

{
    OffsetNumber l = InvalidOffsetNumber;
    int         i;

    if (off == InvalidOffsetNumber)
        off = (PageIsEmpty(page)) ? FirstOffsetNumber :
            OffsetNumberNext(PageGetMaxOffsetNumber(page));

    for (i = 0; i < len; i++)
    {
        Size        sz = IndexTupleSize(itup[i]);

        l = PageAddItem(page, (Item) itup[i], sz, off, false, false);
        if (l == InvalidOffsetNumber)
            elog(ERROR, "failed to add item to GiST index page, item %d out of %d, size %d bytes",
                 i, len, (int) sz);
        off++;
    }
}

gistfillitupvec()

IndexTupleData* gistfillitupvec	(	IndexTuple *	vec,
		int	veclen,
		int *	memlen
	)

Definition at line 126 of file gistutil.c.

References i, IndexTupleSize, and palloc().

Referenced by gistplacetopage(), and gistSplit().

{
    char       *ptr,
               *ret;
    int         i;

    *memlen = 0;

    for (i = 0; i < veclen; i++)
        *memlen += IndexTupleSize(vec[i]);

    ptr = ret = palloc(*memlen);

    for (i = 0; i < veclen; i++)
    {
        memcpy(ptr, vec[i], IndexTupleSize(vec[i]));
        ptr += IndexTupleSize(vec[i]);
    }

    return (IndexTupleData *) ret;
}

gistfitpage()

bool gistfitpage	(	IndexTuple *	itvec,
		int	len
	)

Definition at line 78 of file gistutil.c.

References GiSTPageSize, i, and IndexTupleSize.

Referenced by gistSplit().

{
    int         i;
    Size        size = 0;

    for (i = 0; i < len; i++)
        size += IndexTupleSize(itvec[i]) + sizeof(ItemIdData);

    /* TODO: Consider fillfactor */
    return (size <= GiSTPageSize);
}

gistFormTuple()

IndexTuple gistFormTuple	(	GISTSTATE *	giststate,
		Relation	r,
		Datum	attdata[],
		bool	isnull[],
		bool	isleaf
	)

Definition at line 574 of file gistutil.c.

References GISTSTATE::compressFn, DatumGetPointer, FmgrInfo::fn_oid, FunctionCall1Coll(), gistentryinit, i, index_form_tuple(), INDEX_MAX_KEYS, IndexRelationGetNumberOfKeyAttributes, ItemPointerSetOffsetNumber, GISTENTRY::key, GISTSTATE::leafTupdesc, TupleDescData::natts, GISTSTATE::nonLeafTupdesc, OidIsValid, PointerGetDatum, RelationData::rd_att, GISTSTATE::supportCollation, and IndexTupleData::t_tid.

Referenced by gistBuildCallback(), gistgetadjusted(), gistinsert(), gistSplit(), and gistunion().

{
    Datum       compatt[INDEX_MAX_KEYS];
    int         i;
    IndexTuple  res;

    /*
     * Call the compress method on each attribute.
     */
    for (i = 0; i < IndexRelationGetNumberOfKeyAttributes(r); i++)
    {
        if (isnull[i])
            compatt[i] = (Datum) 0;
        else
        {
            GISTENTRY   centry;
            GISTENTRY  *cep;

            gistentryinit(centry, attdata[i], r, NULL, (OffsetNumber) 0,
                          isleaf);
            /* there may not be a compress function in opclass */
            if (OidIsValid(giststate->compressFn[i].fn_oid))
                cep = (GISTENTRY *)
                    DatumGetPointer(FunctionCall1Coll(&giststate->compressFn[i],
                                                      giststate->supportCollation[i],
                                                      PointerGetDatum(&centry)));
            else
                cep = &centry;
            compatt[i] = cep->key;
        }
    }

    if (isleaf)
    {
        /*
         * Emplace each included attribute if any.
         */
        for (; i < r->rd_att->natts; i++)
        {
            if (isnull[i])
                compatt[i] = (Datum) 0;
            else
                compatt[i] = attdata[i];
        }
    }

    res = index_form_tuple(isleaf ? giststate->leafTupdesc :
                           giststate->nonLeafTupdesc,
                           compatt, isnull);

    /*
     * The offset number on tuples on internal pages is unused. For historical
     * reasons, it is set to 0xffff.
     */
    ItemPointerSetOffsetNumber(&(res->t_tid), 0xffff);
    return res;
}

gistgetadjusted()

IndexTuple gistgetadjusted	(	Relation	r,
		IndexTuple	oldtup,
		IndexTuple	addtup,
		GISTSTATE *	giststate
	)

Definition at line 315 of file gistutil.c.

References gistDeCompressAtt(), gistFormTuple(), gistKeyIsEQ(), gistMakeUnionKey(), i, INDEX_MAX_KEYS, IndexRelationGetNumberOfKeyAttributes, sort-test::key, and IndexTupleData::t_tid.

Referenced by gistdoinsert(), gistformdownlink(), gistProcessItup(), and gistRelocateBuildBuffersOnSplit().

{
    bool        neednew = false;
    GISTENTRY   oldentries[INDEX_MAX_KEYS],
                addentries[INDEX_MAX_KEYS];
    bool        oldisnull[INDEX_MAX_KEYS],
                addisnull[INDEX_MAX_KEYS];
    Datum       attr[INDEX_MAX_KEYS];
    bool        isnull[INDEX_MAX_KEYS];
    IndexTuple  newtup = NULL;
    int         i;

    gistDeCompressAtt(giststate, r, oldtup, NULL,
                      (OffsetNumber) 0, oldentries, oldisnull);

    gistDeCompressAtt(giststate, r, addtup, NULL,
                      (OffsetNumber) 0, addentries, addisnull);

    for (i = 0; i < IndexRelationGetNumberOfKeyAttributes(r); i++)
    {
        gistMakeUnionKey(giststate, i,
                         oldentries + i, oldisnull[i],
                         addentries + i, addisnull[i],
                         attr + i, isnull + i);

        if (neednew)
            /* we already need new key, so we can skip check */
            continue;

        if (isnull[i])
            /* union of key may be NULL if and only if both keys are NULL */
            continue;

        if (!addisnull[i])
        {
            if (oldisnull[i] ||
                !gistKeyIsEQ(giststate, i, oldentries[i].key, attr[i]))
                neednew = true;
        }
    }

    if (neednew)
    {
        /* need to update key */
        newtup = gistFormTuple(giststate, r, attr, isnull, false);
        newtup->t_tid = oldtup->t_tid;
    }

    return newtup;
}

gistGetFakeLSN()

XLogRecPtr gistGetFakeLSN

(

Relation

rel

)

Definition at line 1012 of file gistutil.c.

References Assert, FirstNormalUnloggedLSN, GetFakeLSNForUnloggedRel(), and RelationData::rd_rel.

Referenced by gistdeletepage(), gistplacetopage(), gistprunepage(), gistvacuumpage(), and gistvacuumscan().

{
    static XLogRecPtr counter = FirstNormalUnloggedLSN;

    if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
    {
        /*
         * Temporary relations are only accessible in our session, so a simple
         * backend-local counter will do.
         */
        return counter++;
    }
    else
    {
        /*
         * Unlogged relations are accessible from other backends, and survive
         * (clean) restarts. GetFakeLSNForUnloggedRel() handles that for us.
         */
        Assert(rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED);
        return GetFakeLSNForUnloggedRel();
    }
}

GISTInitBuffer()

void GISTInitBuffer	(	Buffer	b,
		uint32	f
	)

Definition at line 748 of file gistutil.c.

References BufferGetPage, BufferGetPageSize, GISTPageOpaqueData::flags, GISTPageOpaqueData::gist_page_id, GIST_PAGE_ID, GistPageGetOpaque, InvalidBlockNumber, PageInit(), and GISTPageOpaqueData::rightlink.

Referenced by gistbuild(), gistbuildempty(), gistplacetopage(), and gistRedoPageSplitRecord().

{
    GISTPageOpaque opaque;
    Page        page;
    Size        pageSize;

    pageSize = BufferGetPageSize(b);
    page = BufferGetPage(b);
    PageInit(page, pageSize, sizeof(GISTPageOpaqueData));

    opaque = GistPageGetOpaque(page);
    /* page was already zeroed by PageInit, so this is not needed: */
    /* memset(&(opaque->nsn), 0, sizeof(GistNSN)); */
    opaque->rightlink = InvalidBlockNumber;
    opaque->flags = f;
    opaque->gist_page_id = GIST_PAGE_ID;
}

gistjoinvector()

IndexTuple* gistjoinvector	(	IndexTuple *	itvec,
		int *	len,
		IndexTuple *	additvec,
		int	addlen
	)

Definition at line 113 of file gistutil.c.

References repalloc().

Referenced by gistplacetopage().

{
    itvec = (IndexTuple *) repalloc((void *) itvec, sizeof(IndexTuple) * ((*len) + addlen));
    memmove(&itvec[*len], additvec, sizeof(IndexTuple) * addlen);
    *len += addlen;
    return itvec;
}

gistKeyIsEQ()

bool gistKeyIsEQ	(	GISTSTATE *	giststate,
		int	attno,
		Datum	a,
		Datum	b
	)

Definition at line 280 of file gistutil.c.

References GISTSTATE::equalFn, FunctionCall3Coll(), PointerGetDatum, and GISTSTATE::supportCollation.

Referenced by gistgetadjusted(), and gistUserPicksplit().

{
    bool        result;

    FunctionCall3Coll(&giststate->equalFn[attno],
                      giststate->supportCollation[attno],
                      a, b,
                      PointerGetDatum(&result));
    return result;
}

gistMakeUnionItVec()

void gistMakeUnionItVec	(	GISTSTATE *	giststate,
		IndexTuple *	itvec,
		int	len,
		Datum *	attr,
		bool *	isnull
	)

Definition at line 154 of file gistutil.c.

References FunctionCall2Coll(), GEVHDRSZ, gistdentryinit(), i, index_getattr, GISTSTATE::leafTupdesc, GistEntryVector::n, TupleDescData::natts, GISTSTATE::nonLeafTupdesc, palloc(), PointerGetDatum, GISTSTATE::supportCollation, GISTSTATE::unionFn, and GistEntryVector::vector.

Referenced by gistunion(), and gistunionsubkeyvec().

{
    int         i;
    GistEntryVector *evec;
    int         attrsize;

    evec = (GistEntryVector *) palloc((len + 2) * sizeof(GISTENTRY) + GEVHDRSZ);

    for (i = 0; i < giststate->nonLeafTupdesc->natts; i++)
    {
        int         j;

        /* Collect non-null datums for this column */
        evec->n = 0;
        for (j = 0; j < len; j++)
        {
            Datum       datum;
            bool        IsNull;

            datum = index_getattr(itvec[j], i + 1, giststate->leafTupdesc,
                                  &IsNull);
            if (IsNull)
                continue;

            gistdentryinit(giststate, i,
                           evec->vector + evec->n,
                           datum,
                           NULL, NULL, (OffsetNumber) 0,
                           false, IsNull);
            evec->n++;
        }

        /* If this column was all NULLs, the union is NULL */
        if (evec->n == 0)
        {
            attr[i] = (Datum) 0;
            isnull[i] = true;
        }
        else
        {
            if (evec->n == 1)
            {
                /* unionFn may expect at least two inputs */
                evec->n = 2;
                evec->vector[1] = evec->vector[0];
            }

            /* Make union and store in attr array */
            attr[i] = FunctionCall2Coll(&giststate->unionFn[i],
                                        giststate->supportCollation[i],
                                        PointerGetDatum(evec),
                                        PointerGetDatum(&attrsize));

            isnull[i] = false;
        }
    }
}

gistMakeUnionKey()

void gistMakeUnionKey	(	GISTSTATE *	giststate,
		int	attno,
		GISTENTRY *	entry1,
		bool	isnull1,
		GISTENTRY *	entry2,
		bool	isnull2,
		Datum *	dst,
		bool *	dstisnull
	)

Definition at line 232 of file gistutil.c.

References FunctionCall2Coll(), GEVHDRSZ, GistEntryVector::n, PointerGetDatum, GISTSTATE::supportCollation, GISTSTATE::unionFn, and GistEntryVector::vector.

Referenced by gistgetadjusted(), and supportSecondarySplit().

{
    /* we need a GistEntryVector with room for exactly 2 elements */
    union
    {
        GistEntryVector gev;
        char        padding[2 * sizeof(GISTENTRY) + GEVHDRSZ];
    }           storage;
    GistEntryVector *evec = &storage.gev;
    int         dstsize;

    evec->n = 2;

    if (isnull1 && isnull2)
    {
        *dstisnull = true;
        *dst = (Datum) 0;
    }
    else
    {
        if (isnull1 == false && isnull2 == false)
        {
            evec->vector[0] = *entry1;
            evec->vector[1] = *entry2;
        }
        else if (isnull1 == false)
        {
            evec->vector[0] = *entry1;
            evec->vector[1] = *entry1;
        }
        else
        {
            evec->vector[0] = *entry2;
            evec->vector[1] = *entry2;
        }

        *dstisnull = false;
        *dst = FunctionCall2Coll(&giststate->unionFn[attno],
                                 giststate->supportCollation[attno],
                                 PointerGetDatum(evec),
                                 PointerGetDatum(&dstsize));
    }
}

gistNewBuffer()

Buffer gistNewBuffer

(

Relation

r

)

Definition at line 809 of file gistutil.c.

References DataPageDeleteStack::blkno, BufferGetPage, ConditionalLockBuffer(), ExclusiveLock, GetFreeIndexPage(), GIST_EXCLUSIVE, GIST_UNLOCK, gistcheckpage(), GistPageGetDeleteXid(), gistPageRecyclable(), gistXLogPageReuse(), InvalidBlockNumber, LockBuffer(), LockRelationForExtension(), P_NEW, PageIsNew, ReadBuffer(), RELATION_IS_LOCAL, RelationNeedsWAL, ReleaseBuffer(), UnlockRelationForExtension(), and XLogStandbyInfoActive.

Referenced by gistbuild(), and gistplacetopage().

{
    Buffer      buffer;
    bool        needLock;

    /* First, try to get a page from FSM */
    for (;;)
    {
        BlockNumber blkno = GetFreeIndexPage(r);

        if (blkno == InvalidBlockNumber)
            break;              /* nothing left in FSM */

        buffer = ReadBuffer(r, blkno);

        /*
         * We have to guard against the possibility that someone else already
         * recycled this page; the buffer may be locked if so.
         */
        if (ConditionalLockBuffer(buffer))
        {
            Page        page = BufferGetPage(buffer);

            /*
             * If the page was never initialized, it's OK to use.
             */
            if (PageIsNew(page))
                return buffer;

            gistcheckpage(r, buffer);

            /*
             * Otherwise, recycle it if deleted, and too old to have any
             * processes interested in it.
             */
            if (gistPageRecyclable(page))
            {
                /*
                 * If we are generating WAL for Hot Standby then create a WAL
                 * record that will allow us to conflict with queries running
                 * on standby, in case they have snapshots older than the
                 * page's deleteXid.
                 */
                if (XLogStandbyInfoActive() && RelationNeedsWAL(r))
                    gistXLogPageReuse(r, blkno, GistPageGetDeleteXid(page));

                return buffer;
            }

            LockBuffer(buffer, GIST_UNLOCK);
        }

        /* Can't use it, so release buffer and try again */
        ReleaseBuffer(buffer);
    }

    /* Must extend the file */
    needLock = !RELATION_IS_LOCAL(r);

    if (needLock)
        LockRelationForExtension(r, ExclusiveLock);

    buffer = ReadBuffer(r, P_NEW);
    LockBuffer(buffer, GIST_EXCLUSIVE);

    if (needLock)
        UnlockRelationForExtension(r, ExclusiveLock);

    return buffer;
}

gistnospace()

bool gistnospace	(	Page	page,
		IndexTuple *	itvec,
		int	len,
		OffsetNumber	todelete,
		Size	freespace
	)

Definition at line 58 of file gistutil.c.

References i, IndexTupleSize, InvalidOffsetNumber, PageGetFreeSpace(), PageGetItem, and PageGetItemId.

Referenced by gistplacetopage().

{
    unsigned int size = freespace,
                deleted = 0;
    int         i;

    for (i = 0; i < len; i++)
        size += IndexTupleSize(itvec[i]) + sizeof(ItemIdData);

    if (todelete != InvalidOffsetNumber)
    {
        IndexTuple  itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, todelete));

        deleted = IndexTupleSize(itup) + sizeof(ItemIdData);
    }

    return (PageGetFreeSpace(page) + deleted < size);
}

gistoptions()

bytea* gistoptions	(	Datum	reloptions,
		bool	validate
	)

Definition at line 908 of file gistutil.c.

References build_reloptions(), fillfactor, lengthof, offsetof, RELOPT_KIND_GIST, RELOPT_TYPE_ENUM, and RELOPT_TYPE_INT.

Referenced by gisthandler().

{
    static const relopt_parse_elt tab[] = {
        {"fillfactor", RELOPT_TYPE_INT, offsetof(GiSTOptions, fillfactor)},
        {"buffering", RELOPT_TYPE_ENUM, offsetof(GiSTOptions, buffering_mode)}
    };

    return (bytea *) build_reloptions(reloptions, validate,
                                      RELOPT_KIND_GIST,
                                      sizeof(GiSTOptions),
                                      tab, lengthof(tab));
}

gistPageRecyclable()

bool gistPageRecyclable

(

Page

page

)

Definition at line 882 of file gistutil.c.

References FullTransactionIdPrecedes, GetFullRecentGlobalXmin(), GistPageGetDeleteXid(), GistPageIsDeleted, and PageIsNew.

Referenced by gistNewBuffer(), and gistvacuumpage().

{
    if (PageIsNew(page))
        return true;
    if (GistPageIsDeleted(page))
    {
        /*
         * The page was deleted, but when? If it was just deleted, a scan
         * might have seen the downlink to it, and will read the page later.
         * As long as that can happen, we must keep the deleted page around as
         * a tombstone.
         *
         * Compare the deletion XID with RecentGlobalXmin. If deleteXid <
         * RecentGlobalXmin, then no scan that's still in progress could have
         * seen its downlink, and we can recycle it.
         */
        FullTransactionId deletexid_full = GistPageGetDeleteXid(page);
        FullTransactionId recentxmin_full = GetFullRecentGlobalXmin();

        if (FullTransactionIdPrecedes(deletexid_full, recentxmin_full))
            return true;
    }
    return false;
}

gistpenalty()

float gistpenalty	(	GISTSTATE *	giststate,
		int	attno,
		GISTENTRY *	orig,
		bool	isNullOrig,
		GISTENTRY *	add,
		bool	isNullAdd
	)

Definition at line 715 of file gistutil.c.

References FmgrInfo::fn_strict, FunctionCall3Coll(), get_float4_infinity(), GISTSTATE::penaltyFn, PointerGetDatum, and GISTSTATE::supportCollation.

Referenced by findDontCares(), gistchoose(), gistRelocateBuildBuffersOnSplit(), placeOne(), and supportSecondarySplit().

{
    float       penalty = 0.0;

    if (giststate->penaltyFn[attno].fn_strict == false ||
        (isNullOrig == false && isNullAdd == false))
    {
        FunctionCall3Coll(&giststate->penaltyFn[attno],
                          giststate->supportCollation[attno],
                          PointerGetDatum(orig),
                          PointerGetDatum(add),
                          PointerGetDatum(&penalty));
        /* disallow negative or NaN penalty */
        if (isnan(penalty) || penalty < 0.0)
            penalty = 0.0;
    }
    else if (isNullOrig && isNullAdd)
        penalty = 0.0;
    else
    {
        /* try to prevent mixing null and non-null values */
        penalty = get_float4_infinity();
    }

    return penalty;
}

gistproperty()

bool gistproperty	(	Oid	index_oid,
		int	attno,
		IndexAMProperty	prop,
		const char *	propname,
		bool *	res,
		bool *	isnull
	)

Definition at line 929 of file gistutil.c.

References AMPROCNUM, AMPROP_DISTANCE_ORDERABLE, AMPROP_RETURNABLE, get_index_column_opclass(), get_opclass_opfamily_and_input_type(), GIST_COMPRESS_PROC, GIST_DISTANCE_PROC, GIST_FETCH_PROC, Int16GetDatum, ObjectIdGetDatum, OidIsValid, and SearchSysCacheExists4.

Referenced by gisthandler().

{
    Oid         opclass,
                opfamily,
                opcintype;
    int16       procno;

    /* Only answer column-level inquiries */
    if (attno == 0)
        return false;

    /*
     * Currently, GiST distance-ordered scans require that there be a distance
     * function in the opclass with the default types (i.e. the one loaded
     * into the relcache entry, see initGISTstate).  So we assume that if such
     * a function exists, then there's a reason for it (rather than grubbing
     * through all the opfamily's operators to find an ordered one).
     *
     * Essentially the same code can test whether we support returning the
     * column data, since that's true if the opclass provides a fetch proc.
     */

    switch (prop)
    {
        case AMPROP_DISTANCE_ORDERABLE:
            procno = GIST_DISTANCE_PROC;
            break;
        case AMPROP_RETURNABLE:
            procno = GIST_FETCH_PROC;
            break;
        default:
            return false;
    }

    /* First we need to know the column's opclass. */
    opclass = get_index_column_opclass(index_oid, attno);
    if (!OidIsValid(opclass))
    {
        *isnull = true;
        return true;
    }

    /* Now look up the opclass family and input datatype. */
    if (!get_opclass_opfamily_and_input_type(opclass, &opfamily, &opcintype))
    {
        *isnull = true;
        return true;
    }

    /* And now we can check whether the function is provided. */

    *res = SearchSysCacheExists4(AMPROCNUM,
                                 ObjectIdGetDatum(opfamily),
                                 ObjectIdGetDatum(opcintype),
                                 ObjectIdGetDatum(opcintype),
                                 Int16GetDatum(procno));

    /*
     * Special case: even without a fetch function, AMPROP_RETURNABLE is true
     * if the opclass has no compress function.
     */
    if (prop == AMPROP_RETURNABLE && !*res)
    {
        *res = !SearchSysCacheExists4(AMPROCNUM,
                                      ObjectIdGetDatum(opfamily),
                                      ObjectIdGetDatum(opcintype),
                                      ObjectIdGetDatum(opcintype),
                                      Int16GetDatum(GIST_COMPRESS_PROC));
    }

    *isnull = false;

    return true;
}

gistunion()

IndexTuple gistunion	(	Relation	r,
		IndexTuple *	itvec,
		int	len,
		GISTSTATE *	giststate
	)

Definition at line 218 of file gistutil.c.

References gistFormTuple(), gistMakeUnionItVec(), and INDEX_MAX_KEYS.

{
    Datum       attr[INDEX_MAX_KEYS];
    bool        isnull[INDEX_MAX_KEYS];

    gistMakeUnionItVec(giststate, itvec, len, attr, isnull);

    return gistFormTuple(giststate, r, attr, isnull, false);
}