nbtutils.c File Reference

#include "postgres.h"
#include <time.h>
#include "access/nbtree.h"
#include "access/reloptions.h"
#include "access/relscan.h"
#include "miscadmin.h"
#include "utils/array.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rel.h"

Include dependency graph for nbtutils.c:

Go to the source code of this file.

Data Structures
struct	BTSortArrayContext
struct	BTOneVacInfo
struct	BTVacInfo

Typedefs
typedef struct BTSortArrayContext	BTSortArrayContext
typedef struct BTOneVacInfo	BTOneVacInfo
typedef struct BTVacInfo	BTVacInfo

Functions
static Datum	_bt_find_extreme_element (IndexScanDesc scan, ScanKey skey, StrategyNumber strat, Datum *elems, int nelems)
static int	_bt_sort_array_elements (IndexScanDesc scan, ScanKey skey, bool reverse, Datum *elems, int nelems)
static int	_bt_compare_array_elements (const void *a, const void *b, void *arg)
static bool	_bt_compare_scankey_args (IndexScanDesc scan, ScanKey op, ScanKey leftarg, ScanKey rightarg, bool *result)
static bool	_bt_fix_scankey_strategy (ScanKey skey, int16 *indoption)
static void	_bt_mark_scankey_required (ScanKey skey)
static bool	_bt_check_rowcompare (ScanKey skey, IndexTuple tuple, TupleDesc tupdesc, ScanDirection dir, bool *continuescan)
ScanKey	_bt_mkscankey (Relation rel, IndexTuple itup)
ScanKey	_bt_mkscankey_nodata (Relation rel)
void	_bt_freeskey (ScanKey skey)
void	_bt_freestack (BTStack stack)
void	_bt_preprocess_array_keys (IndexScanDesc scan)
void	_bt_start_array_keys (IndexScanDesc scan, ScanDirection dir)
bool	_bt_advance_array_keys (IndexScanDesc scan, ScanDirection dir)
void	_bt_mark_array_keys (IndexScanDesc scan)
void	_bt_restore_array_keys (IndexScanDesc scan)
void	_bt_preprocess_keys (IndexScanDesc scan)
IndexTuple	_bt_checkkeys (IndexScanDesc scan, Page page, OffsetNumber offnum, ScanDirection dir, bool *continuescan)
void	_bt_killitems (IndexScanDesc scan)
BTCycleId	_bt_vacuum_cycleid (Relation rel)
BTCycleId	_bt_start_vacuum (Relation rel)
void	_bt_end_vacuum (Relation rel)
void	_bt_end_vacuum_callback (int code, Datum arg)
Size	BTreeShmemSize (void)
void	BTreeShmemInit (void)
bytea *	btoptions (Datum reloptions, bool validate)
bool	btproperty (Oid index_oid, int attno, IndexAMProperty prop, const char *propname, bool *res, bool *isnull)
IndexTuple	_bt_nonkey_truncate (Relation rel, IndexTuple itup)
bool	_bt_check_natts (Relation rel, Page page, OffsetNumber offnum)

Variables
static BTVacInfo *	btvacinfo

Typedef Documentation

BTOneVacInfo

typedef struct BTOneVacInfo BTOneVacInfo

BTSortArrayContext

typedef struct BTSortArrayContext BTSortArrayContext

BTVacInfo

typedef struct BTVacInfo BTVacInfo

Function Documentation

_bt_advance_array_keys()

bool _bt_advance_array_keys	(	IndexScanDesc	scan,
		ScanDirection	dir
	)

Definition at line 558 of file nbtutils.c.

References _bt_parallel_advance_array_keys(), BTScanOpaqueData::arrayKeyData, BTScanOpaqueData::arrayKeys, BTArrayKeyInfo::cur_elem, BTArrayKeyInfo::elem_values, i, BTArrayKeyInfo::num_elems, BTScanOpaqueData::numArrayKeys, IndexScanDescData::opaque, IndexScanDescData::parallel_scan, BTArrayKeyInfo::scan_key, ScanDirectionIsBackward, and ScanKeyData::sk_argument.

Referenced by btgetbitmap(), and btgettuple().

{
    BTScanOpaque so = (BTScanOpaque) scan->opaque;
    bool        found = false;
    int         i;

    /*
     * We must advance the last array key most quickly, since it will
     * correspond to the lowest-order index column among the available
     * qualifications. This is necessary to ensure correct ordering of output
     * when there are multiple array keys.
     */
    for (i = so->numArrayKeys - 1; i >= 0; i--)
    {
        BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i];
        ScanKey     skey = &so->arrayKeyData[curArrayKey->scan_key];
        int         cur_elem = curArrayKey->cur_elem;
        int         num_elems = curArrayKey->num_elems;

        if (ScanDirectionIsBackward(dir))
        {
            if (--cur_elem < 0)
            {
                cur_elem = num_elems - 1;
                found = false;  /* need to advance next array key */
            }
            else
                found = true;
        }
        else
        {
            if (++cur_elem >= num_elems)
            {
                cur_elem = 0;
                found = false;  /* need to advance next array key */
            }
            else
                found = true;
        }

        curArrayKey->cur_elem = cur_elem;
        skey->sk_argument = curArrayKey->elem_values[cur_elem];
        if (found)
            break;
    }

    /* advance parallel scan */
    if (scan->parallel_scan != NULL)
        _bt_parallel_advance_array_keys(scan);

    return found;
}

_bt_check_natts()

bool _bt_check_natts	(	Relation	rel,
		Page	page,
		OffsetNumber	offnum
	)

Definition at line 2134 of file nbtutils.c.

References Assert, BT_N_KEYS_OFFSET_MASK, BTreeTupleGetNAtts, FirstOffsetNumber, INDEX_ALT_TID_MASK, INDEX_MAX_KEYS, IndexRelationGetNumberOfAttributes, IndexRelationGetNumberOfKeyAttributes, ItemPointerGetOffsetNumber, P_FIRSTDATAKEY, P_HIKEY, P_IGNORE, P_ISLEAF, P_RIGHTMOST, PageGetItem, PageGetItemId, PageGetMaxOffsetNumber, PageGetSpecialPointer, StaticAssertStmt, IndexTupleData::t_info, and IndexTupleData::t_tid.

Referenced by _bt_compare(), and bt_target_page_check().

{
    int16           natts = IndexRelationGetNumberOfAttributes(rel);
    int16           nkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
    BTPageOpaque    opaque = (BTPageOpaque) PageGetSpecialPointer(page);
    IndexTuple      itup;

    /*
     * We cannot reliably test a deleted or half-deleted page, since they have
     * dummy high keys
     */
    if (P_IGNORE(opaque))
        return true;

    Assert(offnum >= FirstOffsetNumber &&
           offnum <= PageGetMaxOffsetNumber(page));
    /*
     * Mask allocated for number of keys in index tuple must be able to fit
     * maximum possible number of index attributes
     */
    StaticAssertStmt(BT_N_KEYS_OFFSET_MASK >= INDEX_MAX_KEYS,
                     "BT_N_KEYS_OFFSET_MASK can't fit INDEX_MAX_KEYS");

    itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, offnum));

    if (P_ISLEAF(opaque))
    {
        if (offnum >= P_FIRSTDATAKEY(opaque))
        {
            /*
             * Leaf tuples that are not the page high key (non-pivot tuples)
             * should never be truncated
             */
            return BTreeTupleGetNAtts(itup, rel) == natts;
        }
        else
        {
            /*
             * Rightmost page doesn't contain a page high key, so tuple was
             * checked above as ordinary leaf tuple
             */
            Assert(!P_RIGHTMOST(opaque));

            /* Page high key tuple contains only key attributes */
            return BTreeTupleGetNAtts(itup, rel) == nkeyatts;
        }
    }
    else  /* !P_ISLEAF(opaque) */
    {
        if (offnum == P_FIRSTDATAKEY(opaque))
        {
            /*
             * The first tuple on any internal page (possibly the first after
             * its high key) is its negative infinity tuple.  Negative infinity
             * tuples are always truncated to zero attributes.  They are a
             * particular kind of pivot tuple.
             *
             * The number of attributes won't be explicitly represented if the
             * negative infinity tuple was generated during a page split that
             * occurred with a version of Postgres before v11.  There must be a
             * problem when there is an explicit representation that is
             * non-zero, or when there is no explicit representation and the
             * tuple is evidently not a pre-pg_upgrade tuple.
             *
             * Prior to v11, downlinks always had P_HIKEY as their offset.  Use
             * that to decide if the tuple is a pre-v11 tuple.
             */
            return BTreeTupleGetNAtts(itup, rel) == 0 ||
                    ((itup->t_info & INDEX_ALT_TID_MASK) == 0 &&
                     ItemPointerGetOffsetNumber(&(itup->t_tid)) == P_HIKEY);
        }
        else
        {
            /*
             * Tuple contains only key attributes despite on is it page high
             * key or not
             */
            return BTreeTupleGetNAtts(itup, rel) == nkeyatts;
        }

    }
}

_bt_check_rowcompare()

static bool _bt_check_rowcompare ( ScanKey  skey, IndexTuple  tuple, TupleDesc  tupdesc, ScanDirection  dir, bool *  continuescan  )

static

Definition at line 1565 of file nbtutils.c.

References Assert, BTGreaterEqualStrategyNumber, BTGreaterStrategyNumber, BTLessEqualStrategyNumber, BTLessStrategyNumber, DatumGetInt32, DatumGetPointer, elog, ERROR, FunctionCall2Coll(), index_getattr, ScanDirectionIsBackward, ScanDirectionIsForward, ScanKeyData::sk_argument, ScanKeyData::sk_attno, SK_BT_DESC, SK_BT_NULLS_FIRST, SK_BT_REQBKWD, SK_BT_REQFWD, ScanKeyData::sk_collation, ScanKeyData::sk_flags, ScanKeyData::sk_func, SK_ISNULL, SK_ROW_END, SK_ROW_MEMBER, and ScanKeyData::sk_strategy.

Referenced by _bt_checkkeys().

{
    ScanKey     subkey = (ScanKey) DatumGetPointer(skey->sk_argument);
    int32       cmpresult = 0;
    bool        result;

    /* First subkey should be same as the header says */
    Assert(subkey->sk_attno == skey->sk_attno);

    /* Loop over columns of the row condition */
    for (;;)
    {
        Datum       datum;
        bool        isNull;

        Assert(subkey->sk_flags & SK_ROW_MEMBER);

        datum = index_getattr(tuple,
                              subkey->sk_attno,
                              tupdesc,
                              &isNull);

        if (isNull)
        {
            if (subkey->sk_flags & SK_BT_NULLS_FIRST)
            {
                /*
                 * Since NULLs are sorted before non-NULLs, we know we have
                 * reached the lower limit of the range of values for this
                 * index attr.  On a backward scan, we can stop if this qual
                 * is one of the "must match" subset.  We can stop regardless
                 * of whether the qual is > or <, so long as it's required,
                 * because it's not possible for any future tuples to pass. On
                 * a forward scan, however, we must keep going, because we may
                 * have initially positioned to the start of the index.
                 */
                if ((subkey->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)) &&
                    ScanDirectionIsBackward(dir))
                    *continuescan = false;
            }
            else
            {
                /*
                 * Since NULLs are sorted after non-NULLs, we know we have
                 * reached the upper limit of the range of values for this
                 * index attr.  On a forward scan, we can stop if this qual is
                 * one of the "must match" subset.  We can stop regardless of
                 * whether the qual is > or <, so long as it's required,
                 * because it's not possible for any future tuples to pass. On
                 * a backward scan, however, we must keep going, because we
                 * may have initially positioned to the end of the index.
                 */
                if ((subkey->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)) &&
                    ScanDirectionIsForward(dir))
                    *continuescan = false;
            }

            /*
             * In any case, this indextuple doesn't match the qual.
             */
            return false;
        }

        if (subkey->sk_flags & SK_ISNULL)
        {
            /*
             * Unlike the simple-scankey case, this isn't a disallowed case.
             * But it can never match.  If all the earlier row comparison
             * columns are required for the scan direction, we can stop the
             * scan, because there can't be another tuple that will succeed.
             */
            if (subkey != (ScanKey) DatumGetPointer(skey->sk_argument))
                subkey--;
            if ((subkey->sk_flags & SK_BT_REQFWD) &&
                ScanDirectionIsForward(dir))
                *continuescan = false;
            else if ((subkey->sk_flags & SK_BT_REQBKWD) &&
                     ScanDirectionIsBackward(dir))
                *continuescan = false;
            return false;
        }

        /* Perform the test --- three-way comparison not bool operator */
        cmpresult = DatumGetInt32(FunctionCall2Coll(&subkey->sk_func,
                                                    subkey->sk_collation,
                                                    datum,
                                                    subkey->sk_argument));

        if (subkey->sk_flags & SK_BT_DESC)
            cmpresult = -cmpresult;

        /* Done comparing if unequal, else advance to next column */
        if (cmpresult != 0)
            break;

        if (subkey->sk_flags & SK_ROW_END)
            break;
        subkey++;
    }

    /*
     * At this point cmpresult indicates the overall result of the row
     * comparison, and subkey points to the deciding column (or the last
     * column if the result is "=").
     */
    switch (subkey->sk_strategy)
    {
            /* EQ and NE cases aren't allowed here */
        case BTLessStrategyNumber:
            result = (cmpresult < 0);
            break;
        case BTLessEqualStrategyNumber:
            result = (cmpresult <= 0);
            break;
        case BTGreaterEqualStrategyNumber:
            result = (cmpresult >= 0);
            break;
        case BTGreaterStrategyNumber:
            result = (cmpresult > 0);
            break;
        default:
            elog(ERROR, "unrecognized RowCompareType: %d",
                 (int) subkey->sk_strategy);
            result = 0;         /* keep compiler quiet */
            break;
    }

    if (!result)
    {
        /*
         * Tuple fails this qual.  If it's a required qual for the current
         * scan direction, then we can conclude no further tuples will pass,
         * either.  Note we have to look at the deciding column, not
         * necessarily the first or last column of the row condition.
         */
        if ((subkey->sk_flags & SK_BT_REQFWD) &&
            ScanDirectionIsForward(dir))
            *continuescan = false;
        else if ((subkey->sk_flags & SK_BT_REQBKWD) &&
                 ScanDirectionIsBackward(dir))
            *continuescan = false;
    }

    return result;
}

_bt_checkkeys()

IndexTuple _bt_checkkeys	(	IndexScanDesc	scan,
		Page	page,
		OffsetNumber	offnum,
		ScanDirection	dir,
		bool *	continuescan
	)

Definition at line 1370 of file nbtutils.c.

References _bt_check_rowcompare(), Assert, BTreeTupleGetNAtts, DatumGetBool, FunctionCall2Coll(), IndexScanDescData::ignore_killed_tuples, index_getattr, IndexScanDescData::indexRelation, ItemIdIsDead, BTScanOpaqueData::keyData, BTScanOpaqueData::numberOfKeys, IndexScanDescData::opaque, P_FIRSTDATAKEY, PageGetItem, PageGetItemId, PageGetMaxOffsetNumber, PageGetSpecialPointer, RelationGetDescr, ScanDirectionIsBackward, ScanDirectionIsForward, ScanKeyData::sk_argument, ScanKeyData::sk_attno, SK_BT_NULLS_FIRST, SK_BT_REQBKWD, SK_BT_REQFWD, ScanKeyData::sk_collation, ScanKeyData::sk_flags, ScanKeyData::sk_func, SK_ISNULL, SK_ROW_HEADER, SK_SEARCHNOTNULL, SK_SEARCHNULL, and test().

Referenced by _bt_readpage().

{
    ItemId      iid = PageGetItemId(page, offnum);
    bool        tuple_alive;
    IndexTuple  tuple;
    TupleDesc   tupdesc;
    BTScanOpaque so;
    int         keysz;
    int         ikey;
    ScanKey     key;

    *continuescan = true;       /* default assumption */

    /*
     * If the scan specifies not to return killed tuples, then we treat a
     * killed tuple as not passing the qual.  Most of the time, it's a win to
     * not bother examining the tuple's index keys, but just return
     * immediately with continuescan = true to proceed to the next tuple.
     * However, if this is the last tuple on the page, we should check the
     * index keys to prevent uselessly advancing to the next page.
     */
    if (scan->ignore_killed_tuples && ItemIdIsDead(iid))
    {
        /* return immediately if there are more tuples on the page */
        if (ScanDirectionIsForward(dir))
        {
            if (offnum < PageGetMaxOffsetNumber(page))
                return NULL;
        }
        else
        {
            BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page);

            if (offnum > P_FIRSTDATAKEY(opaque))
                return NULL;
        }

        /*
         * OK, we want to check the keys so we can set continuescan correctly,
         * but we'll return NULL even if the tuple passes the key tests.
         */
        tuple_alive = false;
    }
    else
        tuple_alive = true;

    tuple = (IndexTuple) PageGetItem(page, iid);

    tupdesc = RelationGetDescr(scan->indexRelation);
    so = (BTScanOpaque) scan->opaque;
    keysz = so->numberOfKeys;

    for (key = so->keyData, ikey = 0; ikey < keysz; key++, ikey++)
    {
        Datum       datum;
        bool        isNull;
        Datum       test;

        Assert(key->sk_attno <= BTreeTupleGetNAtts(tuple, scan->indexRelation));
        /* row-comparison keys need special processing */
        if (key->sk_flags & SK_ROW_HEADER)
        {
            if (_bt_check_rowcompare(key, tuple, tupdesc, dir, continuescan))
                continue;
            return NULL;
        }

        datum = index_getattr(tuple,
                              key->sk_attno,
                              tupdesc,
                              &isNull);

        if (key->sk_flags & SK_ISNULL)
        {
            /* Handle IS NULL/NOT NULL tests */
            if (key->sk_flags & SK_SEARCHNULL)
            {
                if (isNull)
                    continue;   /* tuple satisfies this qual */
            }
            else
            {
                Assert(key->sk_flags & SK_SEARCHNOTNULL);
                if (!isNull)
                    continue;   /* tuple satisfies this qual */
            }

            /*
             * Tuple fails this qual.  If it's a required qual for the current
             * scan direction, then we can conclude no further tuples will
             * pass, either.
             */
            if ((key->sk_flags & SK_BT_REQFWD) &&
                ScanDirectionIsForward(dir))
                *continuescan = false;
            else if ((key->sk_flags & SK_BT_REQBKWD) &&
                     ScanDirectionIsBackward(dir))
                *continuescan = false;

            /*
             * In any case, this indextuple doesn't match the qual.
             */
            return NULL;
        }

        if (isNull)
        {
            if (key->sk_flags & SK_BT_NULLS_FIRST)
            {
                /*
                 * Since NULLs are sorted before non-NULLs, we know we have
                 * reached the lower limit of the range of values for this
                 * index attr.  On a backward scan, we can stop if this qual
                 * is one of the "must match" subset.  We can stop regardless
                 * of whether the qual is > or <, so long as it's required,
                 * because it's not possible for any future tuples to pass. On
                 * a forward scan, however, we must keep going, because we may
                 * have initially positioned to the start of the index.
                 */
                if ((key->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)) &&
                    ScanDirectionIsBackward(dir))
                    *continuescan = false;
            }
            else
            {
                /*
                 * Since NULLs are sorted after non-NULLs, we know we have
                 * reached the upper limit of the range of values for this
                 * index attr.  On a forward scan, we can stop if this qual is
                 * one of the "must match" subset.  We can stop regardless of
                 * whether the qual is > or <, so long as it's required,
                 * because it's not possible for any future tuples to pass. On
                 * a backward scan, however, we must keep going, because we
                 * may have initially positioned to the end of the index.
                 */
                if ((key->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)) &&
                    ScanDirectionIsForward(dir))
                    *continuescan = false;
            }

            /*
             * In any case, this indextuple doesn't match the qual.
             */
            return NULL;
        }

        test = FunctionCall2Coll(&key->sk_func, key->sk_collation,
                                 datum, key->sk_argument);

        if (!DatumGetBool(test))
        {
            /*
             * Tuple fails this qual.  If it's a required qual for the current
             * scan direction, then we can conclude no further tuples will
             * pass, either.
             *
             * Note: because we stop the scan as soon as any required equality
             * qual fails, it is critical that equality quals be used for the
             * initial positioning in _bt_first() when they are available. See
             * comments in _bt_first().
             */
            if ((key->sk_flags & SK_BT_REQFWD) &&
                ScanDirectionIsForward(dir))
                *continuescan = false;
            else if ((key->sk_flags & SK_BT_REQBKWD) &&
                     ScanDirectionIsBackward(dir))
                *continuescan = false;

            /*
             * In any case, this indextuple doesn't match the qual.
             */
            return NULL;
        }
    }

    /* Check for failure due to it being a killed tuple. */
    if (!tuple_alive)
        return NULL;

    /* If we get here, the tuple passes all index quals. */
    return tuple;
}

_bt_compare_array_elements()

static int _bt_compare_array_elements ( const void *  a, const void *  b, void *  arg  )

static

Definition at line 510 of file nbtutils.c.

References BTSortArrayContext::collation, compare(), DatumGetInt32, BTSortArrayContext::flinfo, FunctionCall2Coll(), and BTSortArrayContext::reverse.

Referenced by _bt_sort_array_elements().

{
    Datum       da = *((const Datum *) a);
    Datum       db = *((const Datum *) b);
    BTSortArrayContext *cxt = (BTSortArrayContext *) arg;
    int32       compare;

    compare = DatumGetInt32(FunctionCall2Coll(&cxt->flinfo,
                                              cxt->collation,
                                              da, db));
    if (cxt->reverse)
        compare = -compare;
    return compare;
}

_bt_compare_scankey_args()

static bool _bt_compare_scankey_args ( IndexScanDesc  scan, ScanKey  op, ScanKey  leftarg, ScanKey  rightarg, bool *  result  )

static

Definition at line 1046 of file nbtutils.c.

References Assert, BTCommuteStrategyNumber, BTEqualStrategyNumber, BTGreaterEqualStrategyNumber, BTGreaterStrategyNumber, BTLessEqualStrategyNumber, BTLessStrategyNumber, DatumGetBool, elog, ERROR, FunctionCall2Coll(), get_opcode(), get_opfamily_member(), IndexScanDescData::indexRelation, InvalidOid, OidFunctionCall2Coll(), OidIsValid, RelationData::rd_opcintype, RelationData::rd_opfamily, RegProcedureIsValid, ScanKeyData::sk_argument, ScanKeyData::sk_attno, SK_BT_DESC, SK_BT_NULLS_FIRST, ScanKeyData::sk_collation, ScanKeyData::sk_flags, ScanKeyData::sk_func, SK_ISNULL, SK_SEARCHNOTNULL, SK_SEARCHNULL, ScanKeyData::sk_strategy, and ScanKeyData::sk_subtype.

Referenced by _bt_preprocess_keys().

{
    Relation    rel = scan->indexRelation;
    Oid         lefttype,
                righttype,
                optype,
                opcintype,
                cmp_op;
    StrategyNumber strat;

    /*
     * First, deal with cases where one or both args are NULL.  This should
     * only happen when the scankeys represent IS NULL/NOT NULL conditions.
     */
    if ((leftarg->sk_flags | rightarg->sk_flags) & SK_ISNULL)
    {
        bool        leftnull,
                    rightnull;

        if (leftarg->sk_flags & SK_ISNULL)
        {
            Assert(leftarg->sk_flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
            leftnull = true;
        }
        else
            leftnull = false;
        if (rightarg->sk_flags & SK_ISNULL)
        {
            Assert(rightarg->sk_flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
            rightnull = true;
        }
        else
            rightnull = false;

        /*
         * We treat NULL as either greater than or less than all other values.
         * Since true > false, the tests below work correctly for NULLS LAST
         * logic.  If the index is NULLS FIRST, we need to flip the strategy.
         */
        strat = op->sk_strategy;
        if (op->sk_flags & SK_BT_NULLS_FIRST)
            strat = BTCommuteStrategyNumber(strat);

        switch (strat)
        {
            case BTLessStrategyNumber:
                *result = (leftnull < rightnull);
                break;
            case BTLessEqualStrategyNumber:
                *result = (leftnull <= rightnull);
                break;
            case BTEqualStrategyNumber:
                *result = (leftnull == rightnull);
                break;
            case BTGreaterEqualStrategyNumber:
                *result = (leftnull >= rightnull);
                break;
            case BTGreaterStrategyNumber:
                *result = (leftnull > rightnull);
                break;
            default:
                elog(ERROR, "unrecognized StrategyNumber: %d", (int) strat);
                *result = false;    /* keep compiler quiet */
                break;
        }
        return true;
    }

    /*
     * The opfamily we need to worry about is identified by the index column.
     */
    Assert(leftarg->sk_attno == rightarg->sk_attno);

    opcintype = rel->rd_opcintype[leftarg->sk_attno - 1];

    /*
     * Determine the actual datatypes of the ScanKey arguments.  We have to
     * support the convention that sk_subtype == InvalidOid means the opclass
     * input type; this is a hack to simplify life for ScanKeyInit().
     */
    lefttype = leftarg->sk_subtype;
    if (lefttype == InvalidOid)
        lefttype = opcintype;
    righttype = rightarg->sk_subtype;
    if (righttype == InvalidOid)
        righttype = opcintype;
    optype = op->sk_subtype;
    if (optype == InvalidOid)
        optype = opcintype;

    /*
     * If leftarg and rightarg match the types expected for the "op" scankey,
     * we can use its already-looked-up comparison function.
     */
    if (lefttype == opcintype && righttype == optype)
    {
        *result = DatumGetBool(FunctionCall2Coll(&op->sk_func,
                                                 op->sk_collation,
                                                 leftarg->sk_argument,
                                                 rightarg->sk_argument));
        return true;
    }

    /*
     * Otherwise, we need to go to the syscache to find the appropriate
     * operator.  (This cannot result in infinite recursion, since no
     * indexscan initiated by syscache lookup will use cross-data-type
     * operators.)
     *
     * If the sk_strategy was flipped by _bt_fix_scankey_strategy, we have to
     * un-flip it to get the correct opfamily member.
     */
    strat = op->sk_strategy;
    if (op->sk_flags & SK_BT_DESC)
        strat = BTCommuteStrategyNumber(strat);

    cmp_op = get_opfamily_member(rel->rd_opfamily[leftarg->sk_attno - 1],
                                 lefttype,
                                 righttype,
                                 strat);
    if (OidIsValid(cmp_op))
    {
        RegProcedure cmp_proc = get_opcode(cmp_op);

        if (RegProcedureIsValid(cmp_proc))
        {
            *result = DatumGetBool(OidFunctionCall2Coll(cmp_proc,
                                                        op->sk_collation,
                                                        leftarg->sk_argument,
                                                        rightarg->sk_argument));
            return true;
        }
    }

    /* Can't make the comparison */
    *result = false;            /* suppress compiler warnings */
    return false;
}

_bt_end_vacuum()

void _bt_end_vacuum

(

Relation

rel

)

Definition at line 1976 of file nbtutils.c.

References LockRelId::dbId, i, LockInfoData::lockRelId, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), BTVacInfo::num_vacuums, RelationData::rd_lockInfo, LockRelId::relId, BTOneVacInfo::relid, and BTVacInfo::vacuums.

Referenced by _bt_end_vacuum_callback(), and btbulkdelete().

{
    int         i;

    LWLockAcquire(BtreeVacuumLock, LW_EXCLUSIVE);

    /* Find the array entry */
    for (i = 0; i < btvacinfo->num_vacuums; i++)
    {
        BTOneVacInfo *vac = &btvacinfo->vacuums[i];

        if (vac->relid.relId == rel->rd_lockInfo.lockRelId.relId &&
            vac->relid.dbId == rel->rd_lockInfo.lockRelId.dbId)
        {
            /* Remove it by shifting down the last entry */
            *vac = btvacinfo->vacuums[btvacinfo->num_vacuums - 1];
            btvacinfo->num_vacuums--;
            break;
        }
    }

    LWLockRelease(BtreeVacuumLock);
}

_bt_end_vacuum_callback()

void _bt_end_vacuum_callback	(	int	code,
		Datum	arg
	)

Definition at line 2004 of file nbtutils.c.

References _bt_end_vacuum(), and DatumGetPointer.

Referenced by btbulkdelete().

{
    _bt_end_vacuum((Relation) DatumGetPointer(arg));
}

_bt_find_extreme_element()

static Datum _bt_find_extreme_element ( IndexScanDesc  scan, ScanKey  skey, StrategyNumber  strat, Datum *  elems, int  nelems  )

static

Definition at line 375 of file nbtutils.c.

References Assert, DatumGetBool, elog, ERROR, BTSortArrayContext::flinfo, fmgr_info(), FunctionCall2Coll(), get_opcode(), get_opfamily_member(), i, IndexScanDescData::indexRelation, InvalidOid, OidIsValid, RelationData::rd_opcintype, RelationData::rd_opfamily, RegProcedureIsValid, ScanKeyData::sk_attno, ScanKeyData::sk_collation, and ScanKeyData::sk_subtype.

Referenced by _bt_preprocess_array_keys().

{
    Relation    rel = scan->indexRelation;
    Oid         elemtype,
                cmp_op;
    RegProcedure cmp_proc;
    FmgrInfo    flinfo;
    Datum       result;
    int         i;

    /*
     * Determine the nominal datatype of the array elements.  We have to
     * support the convention that sk_subtype == InvalidOid means the opclass
     * input type; this is a hack to simplify life for ScanKeyInit().
     */
    elemtype = skey->sk_subtype;
    if (elemtype == InvalidOid)
        elemtype = rel->rd_opcintype[skey->sk_attno - 1];

    /*
     * Look up the appropriate comparison operator in the opfamily.
     *
     * Note: it's possible that this would fail, if the opfamily is
     * incomplete, but it seems quite unlikely that an opfamily would omit
     * non-cross-type comparison operators for any datatype that it supports
     * at all.
     */
    cmp_op = get_opfamily_member(rel->rd_opfamily[skey->sk_attno - 1],
                                 elemtype,
                                 elemtype,
                                 strat);
    if (!OidIsValid(cmp_op))
        elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
             strat, elemtype, elemtype,
             rel->rd_opfamily[skey->sk_attno - 1]);
    cmp_proc = get_opcode(cmp_op);
    if (!RegProcedureIsValid(cmp_proc))
        elog(ERROR, "missing oprcode for operator %u", cmp_op);

    fmgr_info(cmp_proc, &flinfo);

    Assert(nelems > 0);
    result = elems[0];
    for (i = 1; i < nelems; i++)
    {
        if (DatumGetBool(FunctionCall2Coll(&flinfo,
                                           skey->sk_collation,
                                           elems[i],
                                           result)))
            result = elems[i];
    }

    return result;
}

_bt_fix_scankey_strategy()

static bool _bt_fix_scankey_strategy ( ScanKey  skey, int16 *  indoption  )

static

Definition at line 1210 of file nbtutils.c.

References Assert, BTCommuteStrategyNumber, BTEqualStrategyNumber, BTGreaterStrategyNumber, BTLessStrategyNumber, DatumGetPointer, InvalidOid, ScanKeyData::sk_argument, ScanKeyData::sk_attno, SK_BT_DESC, SK_BT_INDOPTION_SHIFT, SK_BT_NULLS_FIRST, ScanKeyData::sk_collation, ScanKeyData::sk_flags, SK_ISNULL, SK_ROW_END, SK_ROW_HEADER, SK_ROW_MEMBER, SK_SEARCHNOTNULL, SK_SEARCHNULL, ScanKeyData::sk_strategy, and ScanKeyData::sk_subtype.

Referenced by _bt_preprocess_keys().

{
    int         addflags;

    addflags = indoption[skey->sk_attno - 1] << SK_BT_INDOPTION_SHIFT;

    /*
     * We treat all btree operators as strict (even if they're not so marked
     * in pg_proc). This means that it is impossible for an operator condition
     * with a NULL comparison constant to succeed, and we can reject it right
     * away.
     *
     * However, we now also support "x IS NULL" clauses as search conditions,
     * so in that case keep going. The planner has not filled in any
     * particular strategy in this case, so set it to BTEqualStrategyNumber
     * --- we can treat IS NULL as an equality operator for purposes of search
     * strategy.
     *
     * Likewise, "x IS NOT NULL" is supported.  We treat that as either "less
     * than NULL" in a NULLS LAST index, or "greater than NULL" in a NULLS
     * FIRST index.
     *
     * Note: someday we might have to fill in sk_collation from the index
     * column's collation.  At the moment this is a non-issue because we'll
     * never actually call the comparison operator on a NULL.
     */
    if (skey->sk_flags & SK_ISNULL)
    {
        /* SK_ISNULL shouldn't be set in a row header scankey */
        Assert(!(skey->sk_flags & SK_ROW_HEADER));

        /* Set indoption flags in scankey (might be done already) */
        skey->sk_flags |= addflags;

        /* Set correct strategy for IS NULL or NOT NULL search */
        if (skey->sk_flags & SK_SEARCHNULL)
        {
            skey->sk_strategy = BTEqualStrategyNumber;
            skey->sk_subtype = InvalidOid;
            skey->sk_collation = InvalidOid;
        }
        else if (skey->sk_flags & SK_SEARCHNOTNULL)
        {
            if (skey->sk_flags & SK_BT_NULLS_FIRST)
                skey->sk_strategy = BTGreaterStrategyNumber;
            else
                skey->sk_strategy = BTLessStrategyNumber;
            skey->sk_subtype = InvalidOid;
            skey->sk_collation = InvalidOid;
        }
        else
        {
            /* regular qual, so it cannot be satisfied */
            return false;
        }

        /* Needn't do the rest */
        return true;
    }

    /* Adjust strategy for DESC, if we didn't already */
    if ((addflags & SK_BT_DESC) && !(skey->sk_flags & SK_BT_DESC))
        skey->sk_strategy = BTCommuteStrategyNumber(skey->sk_strategy);
    skey->sk_flags |= addflags;

    /* If it's a row header, fix row member flags and strategies similarly */
    if (skey->sk_flags & SK_ROW_HEADER)
    {
        ScanKey     subkey = (ScanKey) DatumGetPointer(skey->sk_argument);

        for (;;)
        {
            Assert(subkey->sk_flags & SK_ROW_MEMBER);
            addflags = indoption[subkey->sk_attno - 1] << SK_BT_INDOPTION_SHIFT;
            if ((addflags & SK_BT_DESC) && !(subkey->sk_flags & SK_BT_DESC))
                subkey->sk_strategy = BTCommuteStrategyNumber(subkey->sk_strategy);
            subkey->sk_flags |= addflags;
            if (subkey->sk_flags & SK_ROW_END)
                break;
            subkey++;
        }
    }

    return true;
}

_bt_freeskey()

void _bt_freeskey

(

ScanKey

skey

)

Definition at line 166 of file nbtutils.c.

References pfree().

Referenced by _bt_doinsert(), _bt_load(), tuplesort_begin_cluster(), and tuplesort_begin_index_btree().

{
    pfree(skey);
}

_bt_freestack()

void _bt_freestack

(

BTStack

stack

)

Definition at line 175 of file nbtutils.c.

References BTStackData::bts_parent, and pfree().

Referenced by _bt_doinsert(), and _bt_first().

{
    BTStack     ostack;

    while (stack != NULL)
    {
        ostack = stack;
        stack = stack->bts_parent;
        pfree(ostack);
    }
}

_bt_killitems()

void _bt_killitems

(

IndexScanDesc

scan

)

Definition at line 1744 of file nbtutils.c.

References _bt_getbuf(), _bt_relbuf(), Assert, BT_READ, BTP_HAS_GARBAGE, BTScanPosIsPinned, BTScanPosIsValid, buf, BTScanPosData::buf, BUFFER_LOCK_UNLOCK, BufferGetLSNAtomic(), BufferGetPage, BufferIsValid, BTScanPosData::currPage, BTScanOpaqueData::currPos, BTScanPosData::firstItem, BTScanPosItem::heapTid, i, BTScanPosItem::indexOffset, IndexScanDescData::indexRelation, ItemIdMarkDead, ItemPointerEquals(), BTScanPosData::items, BTScanOpaqueData::killedItems, LockBuffer(), BTScanPosData::lsn, MarkBufferDirtyHint(), BTScanOpaqueData::numKilled, OffsetNumberNext, IndexScanDescData::opaque, P_FIRSTDATAKEY, PageGetItem, PageGetItemId, PageGetMaxOffsetNumber, PageGetSpecialPointer, and IndexTupleData::t_tid.

Referenced by _bt_steppage(), btendscan(), btrescan(), and btrestrpos().

{
    BTScanOpaque so = (BTScanOpaque) scan->opaque;
    Page        page;
    BTPageOpaque opaque;
    OffsetNumber minoff;
    OffsetNumber maxoff;
    int         i;
    int         numKilled = so->numKilled;
    bool        killedsomething = false;

    Assert(BTScanPosIsValid(so->currPos));

    /*
     * Always reset the scan state, so we don't look for same items on other
     * pages.
     */
    so->numKilled = 0;

    if (BTScanPosIsPinned(so->currPos))
    {
        /*
         * We have held the pin on this page since we read the index tuples,
         * so all we need to do is lock it.  The pin will have prevented
         * re-use of any TID on the page, so there is no need to check the
         * LSN.
         */
        LockBuffer(so->currPos.buf, BT_READ);

        page = BufferGetPage(so->currPos.buf);
    }
    else
    {
        Buffer      buf;

        /* Attempt to re-read the buffer, getting pin and lock. */
        buf = _bt_getbuf(scan->indexRelation, so->currPos.currPage, BT_READ);

        /* It might not exist anymore; in which case we can't hint it. */
        if (!BufferIsValid(buf))
            return;

        page = BufferGetPage(buf);
        if (BufferGetLSNAtomic(buf) == so->currPos.lsn)
            so->currPos.buf = buf;
        else
        {
            /* Modified while not pinned means hinting is not safe. */
            _bt_relbuf(scan->indexRelation, buf);
            return;
        }
    }

    opaque = (BTPageOpaque) PageGetSpecialPointer(page);
    minoff = P_FIRSTDATAKEY(opaque);
    maxoff = PageGetMaxOffsetNumber(page);

    for (i = 0; i < numKilled; i++)
    {
        int         itemIndex = so->killedItems[i];
        BTScanPosItem *kitem = &so->currPos.items[itemIndex];
        OffsetNumber offnum = kitem->indexOffset;

        Assert(itemIndex >= so->currPos.firstItem &&
               itemIndex <= so->currPos.lastItem);
        if (offnum < minoff)
            continue;           /* pure paranoia */
        while (offnum <= maxoff)
        {
            ItemId      iid = PageGetItemId(page, offnum);
            IndexTuple  ituple = (IndexTuple) PageGetItem(page, iid);

            if (ItemPointerEquals(&ituple->t_tid, &kitem->heapTid))
            {
                /* found the item */
                ItemIdMarkDead(iid);
                killedsomething = true;
                break;          /* out of inner search loop */
            }
            offnum = OffsetNumberNext(offnum);
        }
    }

    /*
     * Since this can be redone later if needed, mark as dirty hint.
     *
     * Whenever we mark anything LP_DEAD, we also set the page's
     * BTP_HAS_GARBAGE flag, which is likewise just a hint.
     */
    if (killedsomething)
    {
        opaque->btpo_flags |= BTP_HAS_GARBAGE;
        MarkBufferDirtyHint(so->currPos.buf, true);
    }

    LockBuffer(so->currPos.buf, BUFFER_LOCK_UNLOCK);
}

_bt_mark_array_keys()

void _bt_mark_array_keys

(

IndexScanDesc

scan

)

Definition at line 617 of file nbtutils.c.

References BTScanOpaqueData::arrayKeys, BTArrayKeyInfo::cur_elem, i, BTArrayKeyInfo::mark_elem, BTScanOpaqueData::numArrayKeys, and IndexScanDescData::opaque.

Referenced by btmarkpos().

{
    BTScanOpaque so = (BTScanOpaque) scan->opaque;
    int         i;

    for (i = 0; i < so->numArrayKeys; i++)
    {
        BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i];

        curArrayKey->mark_elem = curArrayKey->cur_elem;
    }
}

_bt_mark_scankey_required()

static void _bt_mark_scankey_required ( ScanKey  skey )

static

Definition at line 1312 of file nbtutils.c.

References Assert, BTEqualStrategyNumber, BTGreaterEqualStrategyNumber, BTGreaterStrategyNumber, BTLessEqualStrategyNumber, BTLessStrategyNumber, DatumGetPointer, elog, ERROR, ScanKeyData::sk_argument, ScanKeyData::sk_attno, SK_BT_REQBKWD, SK_BT_REQFWD, ScanKeyData::sk_flags, SK_ROW_HEADER, SK_ROW_MEMBER, and ScanKeyData::sk_strategy.

Referenced by _bt_preprocess_keys().

{
    int         addflags;

    switch (skey->sk_strategy)
    {
        case BTLessStrategyNumber:
        case BTLessEqualStrategyNumber:
            addflags = SK_BT_REQFWD;
            break;
        case BTEqualStrategyNumber:
            addflags = SK_BT_REQFWD | SK_BT_REQBKWD;
            break;
        case BTGreaterEqualStrategyNumber:
        case BTGreaterStrategyNumber:
            addflags = SK_BT_REQBKWD;
            break;
        default:
            elog(ERROR, "unrecognized StrategyNumber: %d",
                 (int) skey->sk_strategy);
            addflags = 0;       /* keep compiler quiet */
            break;
    }

    skey->sk_flags |= addflags;

    if (skey->sk_flags & SK_ROW_HEADER)
    {
        ScanKey     subkey = (ScanKey) DatumGetPointer(skey->sk_argument);

        /* First subkey should be same column/operator as the header */
        Assert(subkey->sk_flags & SK_ROW_MEMBER);
        Assert(subkey->sk_attno == skey->sk_attno);
        Assert(subkey->sk_strategy == skey->sk_strategy);
        subkey->sk_flags |= addflags;
    }
}

_bt_mkscankey()

ScanKey _bt_mkscankey	(	Relation	rel,
		IndexTuple	itup
	)

Definition at line 62 of file nbtutils.c.

References arg, Assert, BTORDER_PROC, BTreeTupleGetNAtts, i, index_getattr, index_getprocinfo(), IndexRelationGetNumberOfAttributes, IndexRelationGetNumberOfKeyAttributes, InvalidOid, InvalidStrategy, palloc(), PG_USED_FOR_ASSERTS_ONLY, RelationData::rd_indcollation, RelationData::rd_indoption, RelationGetDescr, ScanKeyEntryInitializeWithInfo(), SK_BT_INDOPTION_SHIFT, and SK_ISNULL.

Referenced by _bt_doinsert(), _bt_pagedel(), bt_right_page_check_scankey(), and bt_target_page_check().

{
    ScanKey     skey;
    TupleDesc   itupdesc;
    int         indnatts PG_USED_FOR_ASSERTS_ONLY;
    int         indnkeyatts;
    int16      *indoption;
    int         i;

    itupdesc = RelationGetDescr(rel);
    indnatts = IndexRelationGetNumberOfAttributes(rel);
    indnkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
    indoption = rel->rd_indoption;

    Assert(indnkeyatts > 0);
    Assert(indnkeyatts <= indnatts);
    Assert(BTreeTupleGetNAtts(itup, rel) == indnatts ||
           BTreeTupleGetNAtts(itup, rel) == indnkeyatts);

    /*
     * We'll execute search using scan key constructed on key columns. Non-key
     * (INCLUDE index) columns are always omitted from scan keys.
     */
    skey = (ScanKey) palloc(indnkeyatts * sizeof(ScanKeyData));

    for (i = 0; i < indnkeyatts; i++)
    {
        FmgrInfo   *procinfo;
        Datum       arg;
        bool        null;
        int         flags;

        /*
         * We can use the cached (default) support procs since no cross-type
         * comparison can be needed.
         */
        procinfo = index_getprocinfo(rel, i + 1, BTORDER_PROC);
        arg = index_getattr(itup, i + 1, itupdesc, &null);
        flags = (null ? SK_ISNULL : 0) | (indoption[i] << SK_BT_INDOPTION_SHIFT);
        ScanKeyEntryInitializeWithInfo(&skey[i],
                                       flags,
                                       (AttrNumber) (i + 1),
                                       InvalidStrategy,
                                       InvalidOid,
                                       rel->rd_indcollation[i],
                                       procinfo,
                                       arg);
    }

    return skey;
}

_bt_mkscankey_nodata()

ScanKey _bt_mkscankey_nodata

(

Relation

rel

)

Definition at line 126 of file nbtutils.c.

References BTORDER_PROC, i, index_getprocinfo(), IndexRelationGetNumberOfKeyAttributes, InvalidOid, InvalidStrategy, palloc(), RelationData::rd_indcollation, RelationData::rd_indoption, ScanKeyEntryInitializeWithInfo(), SK_BT_INDOPTION_SHIFT, and SK_ISNULL.

Referenced by _bt_load(), tuplesort_begin_cluster(), and tuplesort_begin_index_btree().

{
    ScanKey     skey;
    int         indnkeyatts;
    int16      *indoption;
    int         i;

    indnkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
    indoption = rel->rd_indoption;

    skey = (ScanKey) palloc(indnkeyatts * sizeof(ScanKeyData));

    for (i = 0; i < indnkeyatts; i++)
    {
        FmgrInfo   *procinfo;
        int         flags;

        /*
         * We can use the cached (default) support procs since no cross-type
         * comparison can be needed.
         */
        procinfo = index_getprocinfo(rel, i + 1, BTORDER_PROC);
        flags = SK_ISNULL | (indoption[i] << SK_BT_INDOPTION_SHIFT);
        ScanKeyEntryInitializeWithInfo(&skey[i],
                                       flags,
                                       (AttrNumber) (i + 1),
                                       InvalidStrategy,
                                       InvalidOid,
                                       rel->rd_indcollation[i],
                                       procinfo,
                                       (Datum) 0);
    }

    return skey;
}

_bt_nonkey_truncate()

IndexTuple _bt_nonkey_truncate	(	Relation	rel,
		IndexTuple	itup
	)

Definition at line 2102 of file nbtutils.c.

References Assert, BTreeTupleGetNAtts, BTreeTupleSetNAtts, index_truncate_tuple(), IndexRelationGetNumberOfAttributes, IndexRelationGetNumberOfKeyAttributes, and RelationGetDescr.

Referenced by _bt_buildadd(), and _bt_split().

{
    int             nkeyattrs = IndexRelationGetNumberOfKeyAttributes(rel);
    IndexTuple      truncated;

    /*
     * We should only ever truncate leaf index tuples, which must have both key
     * and non-key attributes.  It's never okay to truncate a second time.
     */
    Assert(BTreeTupleGetNAtts(itup, rel) ==
           IndexRelationGetNumberOfAttributes(rel));

    truncated = index_truncate_tuple(RelationGetDescr(rel), itup, nkeyattrs);
    BTreeTupleSetNAtts(truncated, nkeyattrs);

    return truncated;
}

_bt_preprocess_array_keys()

void _bt_preprocess_array_keys

(

IndexScanDesc

scan

)

Definition at line 203 of file nbtutils.c.

References _bt_find_extreme_element(), _bt_sort_array_elements(), ALLOCSET_SMALL_SIZES, AllocSetContextCreate, ARR_ELEMTYPE, BTScanOpaqueData::arrayContext, BTScanOpaqueData::arrayKeyData, BTScanOpaqueData::arrayKeys, Assert, BTEqualStrategyNumber, BTGreaterEqualStrategyNumber, BTGreaterStrategyNumber, BTLessEqualStrategyNumber, BTLessStrategyNumber, cur, CurrentMemoryContext, DatumGetArrayTypeP, deconstruct_array(), BTArrayKeyInfo::elem_values, elog, ERROR, get_typlenbyvalalign(), i, IndexScanDescData::indexRelation, IndexScanDescData::keyData, MemoryContextReset(), MemoryContextSwitchTo(), BTArrayKeyInfo::num_elems, BTScanOpaqueData::numArrayKeys, IndexScanDescData::numberOfKeys, IndexScanDescData::opaque, palloc(), palloc0(), RelationData::rd_indoption, BTArrayKeyInfo::scan_key, SK_ISNULL, SK_ROW_HEADER, SK_SEARCHARRAY, SK_SEARCHNOTNULL, and SK_SEARCHNULL.

Referenced by btrescan().

{
    BTScanOpaque so = (BTScanOpaque) scan->opaque;
    int         numberOfKeys = scan->numberOfKeys;
    int16      *indoption = scan->indexRelation->rd_indoption;
    int         numArrayKeys;
    ScanKey     cur;
    int         i;
    MemoryContext oldContext;

    /* Quick check to see if there are any array keys */
    numArrayKeys = 0;
    for (i = 0; i < numberOfKeys; i++)
    {
        cur = &scan->keyData[i];
        if (cur->sk_flags & SK_SEARCHARRAY)
        {
            numArrayKeys++;
            Assert(!(cur->sk_flags & (SK_ROW_HEADER | SK_SEARCHNULL | SK_SEARCHNOTNULL)));
            /* If any arrays are null as a whole, we can quit right now. */
            if (cur->sk_flags & SK_ISNULL)
            {
                so->numArrayKeys = -1;
                so->arrayKeyData = NULL;
                return;
            }
        }
    }

    /* Quit if nothing to do. */
    if (numArrayKeys == 0)
    {
        so->numArrayKeys = 0;
        so->arrayKeyData = NULL;
        return;
    }

    /*
     * Make a scan-lifespan context to hold array-associated data, or reset it
     * if we already have one from a previous rescan cycle.
     */
    if (so->arrayContext == NULL)
        so->arrayContext = AllocSetContextCreate(CurrentMemoryContext,
                                                 "BTree array context",
                                                 ALLOCSET_SMALL_SIZES);
    else
        MemoryContextReset(so->arrayContext);

    oldContext = MemoryContextSwitchTo(so->arrayContext);

    /* Create modifiable copy of scan->keyData in the workspace context */
    so->arrayKeyData = (ScanKey) palloc(scan->numberOfKeys * sizeof(ScanKeyData));
    memcpy(so->arrayKeyData,
           scan->keyData,
           scan->numberOfKeys * sizeof(ScanKeyData));

    /* Allocate space for per-array data in the workspace context */
    so->arrayKeys = (BTArrayKeyInfo *) palloc0(numArrayKeys * sizeof(BTArrayKeyInfo));

    /* Now process each array key */
    numArrayKeys = 0;
    for (i = 0; i < numberOfKeys; i++)
    {
        ArrayType  *arrayval;
        int16       elmlen;
        bool        elmbyval;
        char        elmalign;
        int         num_elems;
        Datum      *elem_values;
        bool       *elem_nulls;
        int         num_nonnulls;
        int         j;

        cur = &so->arrayKeyData[i];
        if (!(cur->sk_flags & SK_SEARCHARRAY))
            continue;

        /*
         * First, deconstruct the array into elements.  Anything allocated
         * here (including a possibly detoasted array value) is in the
         * workspace context.
         */
        arrayval = DatumGetArrayTypeP(cur->sk_argument);
        /* We could cache this data, but not clear it's worth it */
        get_typlenbyvalalign(ARR_ELEMTYPE(arrayval),
                             &elmlen, &elmbyval, &elmalign);
        deconstruct_array(arrayval,
                          ARR_ELEMTYPE(arrayval),
                          elmlen, elmbyval, elmalign,
                          &elem_values, &elem_nulls, &num_elems);

        /*
         * Compress out any null elements.  We can ignore them since we assume
         * all btree operators are strict.
         */
        num_nonnulls = 0;
        for (j = 0; j < num_elems; j++)
        {
            if (!elem_nulls[j])
                elem_values[num_nonnulls++] = elem_values[j];
        }

        /* We could pfree(elem_nulls) now, but not worth the cycles */

        /* If there's no non-nulls, the scan qual is unsatisfiable */
        if (num_nonnulls == 0)
        {
            numArrayKeys = -1;
            break;
        }

        /*
         * If the comparison operator is not equality, then the array qual
         * degenerates to a simple comparison against the smallest or largest
         * non-null array element, as appropriate.
         */
        switch (cur->sk_strategy)
        {
            case BTLessStrategyNumber:
            case BTLessEqualStrategyNumber:
                cur->sk_argument =
                    _bt_find_extreme_element(scan, cur,
                                             BTGreaterStrategyNumber,
                                             elem_values, num_nonnulls);
                continue;
            case BTEqualStrategyNumber:
                /* proceed with rest of loop */
                break;
            case BTGreaterEqualStrategyNumber:
            case BTGreaterStrategyNumber:
                cur->sk_argument =
                    _bt_find_extreme_element(scan, cur,
                                             BTLessStrategyNumber,
                                             elem_values, num_nonnulls);
                continue;
            default:
                elog(ERROR, "unrecognized StrategyNumber: %d",
                     (int) cur->sk_strategy);
                break;
        }

        /*
         * Sort the non-null elements and eliminate any duplicates.  We must
         * sort in the same ordering used by the index column, so that the
         * successive primitive indexscans produce data in index order.
         */
        num_elems = _bt_sort_array_elements(scan, cur,
                                            (indoption[cur->sk_attno - 1] & INDOPTION_DESC) != 0,
                                            elem_values, num_nonnulls);

        /*
         * And set up the BTArrayKeyInfo data.
         */
        so->arrayKeys[numArrayKeys].scan_key = i;
        so->arrayKeys[numArrayKeys].num_elems = num_elems;
        so->arrayKeys[numArrayKeys].elem_values = elem_values;
        numArrayKeys++;
    }

    so->numArrayKeys = numArrayKeys;

    MemoryContextSwitchTo(oldContext);
}

_bt_preprocess_keys()

void _bt_preprocess_keys

(

IndexScanDesc

scan

)

Definition at line 756 of file nbtutils.c.

References _bt_compare_scankey_args(), _bt_fix_scankey_strategy(), _bt_mark_scankey_required(), BTScanOpaqueData::arrayKeyData, Assert, BTEqualStrategyNumber, BTGreaterEqualStrategyNumber, BTGreaterStrategyNumber, BTLessEqualStrategyNumber, BTLessStrategyNumber, BTMaxStrategyNumber, cur, elog, ERROR, i, IndexScanDescData::indexRelation, IndexScanDescData::keyData, BTScanOpaqueData::keyData, IndexScanDescData::numberOfKeys, BTScanOpaqueData::numberOfKeys, IndexScanDescData::opaque, BTScanOpaqueData::qual_ok, RelationData::rd_indoption, ScanKeyData::sk_flags, SK_ROW_HEADER, and SK_SEARCHNULL.

Referenced by _bt_first(), and _bt_restore_array_keys().

{
    BTScanOpaque so = (BTScanOpaque) scan->opaque;
    int         numberOfKeys = scan->numberOfKeys;
    int16      *indoption = scan->indexRelation->rd_indoption;
    int         new_numberOfKeys;
    int         numberOfEqualCols;
    ScanKey     inkeys;
    ScanKey     outkeys;
    ScanKey     cur;
    ScanKey     xform[BTMaxStrategyNumber];
    bool        test_result;
    int         i,
                j;
    AttrNumber  attno;

    /* initialize result variables */
    so->qual_ok = true;
    so->numberOfKeys = 0;

    if (numberOfKeys < 1)
        return;                 /* done if qual-less scan */

    /*
     * Read so->arrayKeyData if array keys are present, else scan->keyData
     */
    if (so->arrayKeyData != NULL)
        inkeys = so->arrayKeyData;
    else
        inkeys = scan->keyData;

    outkeys = so->keyData;
    cur = &inkeys[0];
    /* we check that input keys are correctly ordered */
    if (cur->sk_attno < 1)
        elog(ERROR, "btree index keys must be ordered by attribute");

    /* We can short-circuit most of the work if there's just one key */
    if (numberOfKeys == 1)
    {
        /* Apply indoption to scankey (might change sk_strategy!) */
        if (!_bt_fix_scankey_strategy(cur, indoption))
            so->qual_ok = false;
        memcpy(outkeys, cur, sizeof(ScanKeyData));
        so->numberOfKeys = 1;
        /* We can mark the qual as required if it's for first index col */
        if (cur->sk_attno == 1)
            _bt_mark_scankey_required(outkeys);
        return;
    }

    /*
     * Otherwise, do the full set of pushups.
     */
    new_numberOfKeys = 0;
    numberOfEqualCols = 0;

    /*
     * Initialize for processing of keys for attr 1.
     *
     * xform[i] points to the currently best scan key of strategy type i+1; it
     * is NULL if we haven't yet found such a key for this attr.
     */
    attno = 1;
    memset(xform, 0, sizeof(xform));

    /*
     * Loop iterates from 0 to numberOfKeys inclusive; we use the last pass to
     * handle after-last-key processing.  Actual exit from the loop is at the
     * "break" statement below.
     */
    for (i = 0;; cur++, i++)
    {
        if (i < numberOfKeys)
        {
            /* Apply indoption to scankey (might change sk_strategy!) */
            if (!_bt_fix_scankey_strategy(cur, indoption))
            {
                /* NULL can't be matched, so give up */
                so->qual_ok = false;
                return;
            }
        }

        /*
         * If we are at the end of the keys for a particular attr, finish up
         * processing and emit the cleaned-up keys.
         */
        if (i == numberOfKeys || cur->sk_attno != attno)
        {
            int         priorNumberOfEqualCols = numberOfEqualCols;

            /* check input keys are correctly ordered */
            if (i < numberOfKeys && cur->sk_attno < attno)
                elog(ERROR, "btree index keys must be ordered by attribute");

            /*
             * If = has been specified, all other keys can be eliminated as
             * redundant.  If we have a case like key = 1 AND key > 2, we can
             * set qual_ok to false and abandon further processing.
             *
             * We also have to deal with the case of "key IS NULL", which is
             * unsatisfiable in combination with any other index condition. By
             * the time we get here, that's been classified as an equality
             * check, and we've rejected any combination of it with a regular
             * equality condition; but not with other types of conditions.
             */
            if (xform[BTEqualStrategyNumber - 1])
            {
                ScanKey     eq = xform[BTEqualStrategyNumber - 1];

                for (j = BTMaxStrategyNumber; --j >= 0;)
                {
                    ScanKey     chk = xform[j];

                    if (!chk || j == (BTEqualStrategyNumber - 1))
                        continue;

                    if (eq->sk_flags & SK_SEARCHNULL)
                    {
                        /* IS NULL is contradictory to anything else */
                        so->qual_ok = false;
                        return;
                    }

                    if (_bt_compare_scankey_args(scan, chk, eq, chk,
                                                 &test_result))
                    {
                        if (!test_result)
                        {
                            /* keys proven mutually contradictory */
                            so->qual_ok = false;
                            return;
                        }
                        /* else discard the redundant non-equality key */
                        xform[j] = NULL;
                    }
                    /* else, cannot determine redundancy, keep both keys */
                }
                /* track number of attrs for which we have "=" keys */
                numberOfEqualCols++;
            }

            /* try to keep only one of <, <= */
            if (xform[BTLessStrategyNumber - 1]
                && xform[BTLessEqualStrategyNumber - 1])
            {
                ScanKey     lt = xform[BTLessStrategyNumber - 1];
                ScanKey     le = xform[BTLessEqualStrategyNumber - 1];

                if (_bt_compare_scankey_args(scan, le, lt, le,
                                             &test_result))
                {
                    if (test_result)
                        xform[BTLessEqualStrategyNumber - 1] = NULL;
                    else
                        xform[BTLessStrategyNumber - 1] = NULL;
                }
            }

            /* try to keep only one of >, >= */
            if (xform[BTGreaterStrategyNumber - 1]
                && xform[BTGreaterEqualStrategyNumber - 1])
            {
                ScanKey     gt = xform[BTGreaterStrategyNumber - 1];
                ScanKey     ge = xform[BTGreaterEqualStrategyNumber - 1];

                if (_bt_compare_scankey_args(scan, ge, gt, ge,
                                             &test_result))
                {
                    if (test_result)
                        xform[BTGreaterEqualStrategyNumber - 1] = NULL;
                    else
                        xform[BTGreaterStrategyNumber - 1] = NULL;
                }
            }

            /*
             * Emit the cleaned-up keys into the outkeys[] array, and then
             * mark them if they are required.  They are required (possibly
             * only in one direction) if all attrs before this one had "=".
             */
            for (j = BTMaxStrategyNumber; --j >= 0;)
            {
                if (xform[j])
                {
                    ScanKey     outkey = &outkeys[new_numberOfKeys++];

                    memcpy(outkey, xform[j], sizeof(ScanKeyData));
                    if (priorNumberOfEqualCols == attno - 1)
                        _bt_mark_scankey_required(outkey);
                }
            }

            /*
             * Exit loop here if done.
             */
            if (i == numberOfKeys)
                break;

            /* Re-initialize for new attno */
            attno = cur->sk_attno;
            memset(xform, 0, sizeof(xform));
        }

        /* check strategy this key's operator corresponds to */
        j = cur->sk_strategy - 1;

        /* if row comparison, push it directly to the output array */
        if (cur->sk_flags & SK_ROW_HEADER)
        {
            ScanKey     outkey = &outkeys[new_numberOfKeys++];

            memcpy(outkey, cur, sizeof(ScanKeyData));
            if (numberOfEqualCols == attno - 1)
                _bt_mark_scankey_required(outkey);

            /*
             * We don't support RowCompare using equality; such a qual would
             * mess up the numberOfEqualCols tracking.
             */
            Assert(j != (BTEqualStrategyNumber - 1));
            continue;
        }

        /* have we seen one of these before? */
        if (xform[j] == NULL)
        {
            /* nope, so remember this scankey */
            xform[j] = cur;
        }
        else
        {
            /* yup, keep only the more restrictive key */
            if (_bt_compare_scankey_args(scan, cur, cur, xform[j],
                                         &test_result))
            {
                if (test_result)
                    xform[j] = cur;
                else if (j == (BTEqualStrategyNumber - 1))
                {
                    /* key == a && key == b, but a != b */
                    so->qual_ok = false;
                    return;
                }
                /* else old key is more restrictive, keep it */
            }
            else
            {
                /*
                 * We can't determine which key is more restrictive.  Keep the
                 * previous one in xform[j] and push this one directly to the
                 * output array.
                 */
                ScanKey     outkey = &outkeys[new_numberOfKeys++];

                memcpy(outkey, cur, sizeof(ScanKeyData));
                if (numberOfEqualCols == attno - 1)
                    _bt_mark_scankey_required(outkey);
            }
        }
    }

    so->numberOfKeys = new_numberOfKeys;
}

_bt_restore_array_keys()

void _bt_restore_array_keys

(

IndexScanDesc

scan

)

Definition at line 636 of file nbtutils.c.

References _bt_preprocess_keys(), BTScanOpaqueData::arrayKeyData, BTScanOpaqueData::arrayKeys, Assert, BTArrayKeyInfo::cur_elem, BTArrayKeyInfo::elem_values, i, BTArrayKeyInfo::mark_elem, BTScanOpaqueData::numArrayKeys, IndexScanDescData::opaque, BTScanOpaqueData::qual_ok, BTArrayKeyInfo::scan_key, and ScanKeyData::sk_argument.

Referenced by btrestrpos().

{
    BTScanOpaque so = (BTScanOpaque) scan->opaque;
    bool        changed = false;
    int         i;

    /* Restore each array key to its position when the mark was set */
    for (i = 0; i < so->numArrayKeys; i++)
    {
        BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i];
        ScanKey     skey = &so->arrayKeyData[curArrayKey->scan_key];
        int         mark_elem = curArrayKey->mark_elem;

        if (curArrayKey->cur_elem != mark_elem)
        {
            curArrayKey->cur_elem = mark_elem;
            skey->sk_argument = curArrayKey->elem_values[mark_elem];
            changed = true;
        }
    }

    /*
     * If we changed any keys, we must redo _bt_preprocess_keys.  That might
     * sound like overkill, but in cases with multiple keys per index column
     * it seems necessary to do the full set of pushups.
     */
    if (changed)
    {
        _bt_preprocess_keys(scan);
        /* The mark should have been set on a consistent set of keys... */
        Assert(so->qual_ok);
    }
}

_bt_sort_array_elements()

static int _bt_sort_array_elements ( IndexScanDesc  scan, ScanKey  skey, bool  reverse, Datum *  elems, int  nelems  )

static

Definition at line 442 of file nbtutils.c.

References _bt_compare_array_elements(), BTORDER_PROC, BTSortArrayContext::collation, compare(), DatumGetInt32, elog, ERROR, BTSortArrayContext::flinfo, fmgr_info(), FunctionCall2Coll(), get_opfamily_proc(), i, IndexScanDescData::indexRelation, InvalidOid, qsort_arg(), RelationData::rd_opcintype, RelationData::rd_opfamily, RegProcedureIsValid, BTSortArrayContext::reverse, ScanKeyData::sk_attno, ScanKeyData::sk_collation, and ScanKeyData::sk_subtype.

Referenced by _bt_preprocess_array_keys().

{
    Relation    rel = scan->indexRelation;
    Oid         elemtype;
    RegProcedure cmp_proc;
    BTSortArrayContext cxt;
    int         last_non_dup;
    int         i;

    if (nelems <= 1)
        return nelems;          /* no work to do */

    /*
     * Determine the nominal datatype of the array elements.  We have to
     * support the convention that sk_subtype == InvalidOid means the opclass
     * input type; this is a hack to simplify life for ScanKeyInit().
     */
    elemtype = skey->sk_subtype;
    if (elemtype == InvalidOid)
        elemtype = rel->rd_opcintype[skey->sk_attno - 1];

    /*
     * Look up the appropriate comparison function in the opfamily.
     *
     * Note: it's possible that this would fail, if the opfamily is
     * incomplete, but it seems quite unlikely that an opfamily would omit
     * non-cross-type support functions for any datatype that it supports at
     * all.
     */
    cmp_proc = get_opfamily_proc(rel->rd_opfamily[skey->sk_attno - 1],
                                 elemtype,
                                 elemtype,
                                 BTORDER_PROC);
    if (!RegProcedureIsValid(cmp_proc))
        elog(ERROR, "missing support function %d(%u,%u) in opfamily %u",
             BTORDER_PROC, elemtype, elemtype,
             rel->rd_opfamily[skey->sk_attno - 1]);

    /* Sort the array elements */
    fmgr_info(cmp_proc, &cxt.flinfo);
    cxt.collation = skey->sk_collation;
    cxt.reverse = reverse;
    qsort_arg((void *) elems, nelems, sizeof(Datum),
              _bt_compare_array_elements, (void *) &cxt);

    /* Now scan the sorted elements and remove duplicates */
    last_non_dup = 0;
    for (i = 1; i < nelems; i++)
    {
        int32       compare;

        compare = DatumGetInt32(FunctionCall2Coll(&cxt.flinfo,
                                                  cxt.collation,
                                                  elems[last_non_dup],
                                                  elems[i]));
        if (compare != 0)
            elems[++last_non_dup] = elems[i];
    }

    return last_non_dup + 1;
}

_bt_start_array_keys()

void _bt_start_array_keys	(	IndexScanDesc	scan,
		ScanDirection	dir
	)

Definition at line 532 of file nbtutils.c.

References BTScanOpaqueData::arrayKeyData, BTScanOpaqueData::arrayKeys, Assert, BTArrayKeyInfo::cur_elem, BTArrayKeyInfo::elem_values, i, BTArrayKeyInfo::num_elems, BTScanOpaqueData::numArrayKeys, IndexScanDescData::opaque, BTArrayKeyInfo::scan_key, ScanDirectionIsBackward, and ScanKeyData::sk_argument.

Referenced by btgetbitmap(), and btgettuple().

{
    BTScanOpaque so = (BTScanOpaque) scan->opaque;
    int         i;

    for (i = 0; i < so->numArrayKeys; i++)
    {
        BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i];
        ScanKey     skey = &so->arrayKeyData[curArrayKey->scan_key];

        Assert(curArrayKey->num_elems > 0);
        if (ScanDirectionIsBackward(dir))
            curArrayKey->cur_elem = curArrayKey->num_elems - 1;
        else
            curArrayKey->cur_elem = 0;
        skey->sk_argument = curArrayKey->elem_values[curArrayKey->cur_elem];
    }
}

_bt_start_vacuum()

BTCycleId _bt_start_vacuum

(

Relation

rel

)

Definition at line 1919 of file nbtutils.c.

References BTVacInfo::cycle_ctr, BTOneVacInfo::cycleid, LockRelId::dbId, elog, ERROR, i, LockInfoData::lockRelId, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MAX_BT_CYCLE_ID, BTVacInfo::max_vacuums, BTVacInfo::num_vacuums, RelationData::rd_lockInfo, RelationGetRelationName, LockRelId::relId, BTOneVacInfo::relid, and BTVacInfo::vacuums.

Referenced by btbulkdelete().

{
    BTCycleId   result;
    int         i;
    BTOneVacInfo *vac;

    LWLockAcquire(BtreeVacuumLock, LW_EXCLUSIVE);

    /*
     * Assign the next cycle ID, being careful to avoid zero as well as the
     * reserved high values.
     */
    result = ++(btvacinfo->cycle_ctr);
    if (result == 0 || result > MAX_BT_CYCLE_ID)
        result = btvacinfo->cycle_ctr = 1;

    /* Let's just make sure there's no entry already for this index */
    for (i = 0; i < btvacinfo->num_vacuums; i++)
    {
        vac = &btvacinfo->vacuums[i];
        if (vac->relid.relId == rel->rd_lockInfo.lockRelId.relId &&
            vac->relid.dbId == rel->rd_lockInfo.lockRelId.dbId)
        {
            /*
             * Unlike most places in the backend, we have to explicitly
             * release our LWLock before throwing an error.  This is because
             * we expect _bt_end_vacuum() to be called before transaction
             * abort cleanup can run to release LWLocks.
             */
            LWLockRelease(BtreeVacuumLock);
            elog(ERROR, "multiple active vacuums for index \"%s\"",
                 RelationGetRelationName(rel));
        }
    }

    /* OK, add an entry */
    if (btvacinfo->num_vacuums >= btvacinfo->max_vacuums)
    {
        LWLockRelease(BtreeVacuumLock);
        elog(ERROR, "out of btvacinfo slots");
    }
    vac = &btvacinfo->vacuums[btvacinfo->num_vacuums];
    vac->relid = rel->rd_lockInfo.lockRelId;
    vac->cycleid = result;
    btvacinfo->num_vacuums++;

    LWLockRelease(BtreeVacuumLock);
    return result;
}

_bt_vacuum_cycleid()

BTCycleId _bt_vacuum_cycleid

(

Relation

rel

)

Definition at line 1885 of file nbtutils.c.

References BTOneVacInfo::cycleid, LockRelId::dbId, i, LockInfoData::lockRelId, LW_SHARED, LWLockAcquire(), LWLockRelease(), BTVacInfo::num_vacuums, RelationData::rd_lockInfo, LockRelId::relId, BTOneVacInfo::relid, and BTVacInfo::vacuums.

Referenced by _bt_split().

{
    BTCycleId   result = 0;
    int         i;

    /* Share lock is enough since this is a read-only operation */
    LWLockAcquire(BtreeVacuumLock, LW_SHARED);

    for (i = 0; i < btvacinfo->num_vacuums; i++)
    {
        BTOneVacInfo *vac = &btvacinfo->vacuums[i];

        if (vac->relid.relId == rel->rd_lockInfo.lockRelId.relId &&
            vac->relid.dbId == rel->rd_lockInfo.lockRelId.dbId)
        {
            result = vac->cycleid;
            break;
        }
    }

    LWLockRelease(BtreeVacuumLock);
    return result;
}

btoptions()

bytea* btoptions	(	Datum	reloptions,
		bool	validate
	)

Definition at line 2054 of file nbtutils.c.

References default_reloptions(), and RELOPT_KIND_BTREE.

Referenced by bthandler().

{
    return default_reloptions(reloptions, validate, RELOPT_KIND_BTREE);
}

btproperty()

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

Definition at line 2066 of file nbtutils.c.

References AMPROP_RETURNABLE.

Referenced by bthandler().

{
    switch (prop)
    {
        case AMPROP_RETURNABLE:
            /* answer only for columns, not AM or whole index */
            if (attno == 0)
                return false;
            /* otherwise, btree can always return data */
            *res = true;
            return true;

        default:
            return false;       /* punt to generic code */
    }
}

BTreeShmemInit()

void BTreeShmemInit

(

void

)

Definition at line 2026 of file nbtutils.c.

References Assert, BTreeShmemSize(), BTVacInfo::cycle_ctr, IsUnderPostmaster, BTVacInfo::max_vacuums, MaxBackends, BTVacInfo::num_vacuums, and ShmemInitStruct().

Referenced by CreateSharedMemoryAndSemaphores().

{
    bool        found;

    btvacinfo = (BTVacInfo *) ShmemInitStruct("BTree Vacuum State",
                                              BTreeShmemSize(),
                                              &found);

    if (!IsUnderPostmaster)
    {
        /* Initialize shared memory area */
        Assert(!found);

        /*
         * It doesn't really matter what the cycle counter starts at, but
         * having it always start the same doesn't seem good.  Seed with
         * low-order bits of time() instead.
         */
        btvacinfo->cycle_ctr = (BTCycleId) time(NULL);

        btvacinfo->num_vacuums = 0;
        btvacinfo->max_vacuums = MaxBackends;
    }
    else
        Assert(found);
}

BTreeShmemSize()

Size BTreeShmemSize

(

void

)

Definition at line 2013 of file nbtutils.c.

References add_size(), MaxBackends, mul_size(), and offsetof.

Referenced by BTreeShmemInit(), and CreateSharedMemoryAndSemaphores().

{
    Size        size;

    size = offsetof(BTVacInfo, vacuums);
    size = add_size(size, mul_size(MaxBackends, sizeof(BTOneVacInfo)));
    return size;
}

Variable Documentation

btvacinfo

BTVacInfo* btvacinfo

static

Definition at line 1872 of file nbtutils.c.