tsquery_op.c

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/*-------------------------------------------------------------------------
 *
 * tsquery_op.c
 *    Various operations with tsquery
 *
 * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
 *
 *
 * IDENTIFICATION
 *    src/backend/utils/adt/tsquery_op.c
 *
 *-------------------------------------------------------------------------
 */

#include "postgres.h"

#include "tsearch/ts_utils.h"

Datum
tsquery_numnode(PG_FUNCTION_ARGS)
{
    TSQuery     query = PG_GETARG_TSQUERY(0);
    int         nnode = query->size;

    PG_FREE_IF_COPY(query, 0);
    PG_RETURN_INT32(nnode);
}

static QTNode *
join_tsqueries(TSQuery a, TSQuery b, int8 operator)
{
    QTNode     *res = (QTNode *) palloc0(sizeof(QTNode));

    res->flags |= QTN_NEEDFREE;

    res->valnode = (QueryItem *) palloc0(sizeof(QueryItem));
    res->valnode->type = QI_OPR;
    res->valnode->qoperator.oper = operator;

    res->child = (QTNode **) palloc0(sizeof(QTNode *) * 2);
    res->child[0] = QT2QTN(GETQUERY(b), GETOPERAND(b));
    res->child[1] = QT2QTN(GETQUERY(a), GETOPERAND(a));
    res->nchild = 2;

    return res;
}

Datum
tsquery_and(PG_FUNCTION_ARGS)
{
    TSQuery     a = PG_GETARG_TSQUERY_COPY(0);
    TSQuery     b = PG_GETARG_TSQUERY_COPY(1);
    QTNode     *res;
    TSQuery     query;

    if (a->size == 0)
    {
        PG_FREE_IF_COPY(a, 1);
        PG_RETURN_POINTER(b);
    }
    else if (b->size == 0)
    {
        PG_FREE_IF_COPY(b, 1);
        PG_RETURN_POINTER(a);
    }

    res = join_tsqueries(a, b, OP_AND);

    query = QTN2QT(res);

    QTNFree(res);
    PG_FREE_IF_COPY(a, 0);
    PG_FREE_IF_COPY(b, 1);

    PG_RETURN_TSQUERY(query);
}

Datum
tsquery_or(PG_FUNCTION_ARGS)
{
    TSQuery     a = PG_GETARG_TSQUERY_COPY(0);
    TSQuery     b = PG_GETARG_TSQUERY_COPY(1);
    QTNode     *res;
    TSQuery     query;

    if (a->size == 0)
    {
        PG_FREE_IF_COPY(a, 1);
        PG_RETURN_POINTER(b);
    }
    else if (b->size == 0)
    {
        PG_FREE_IF_COPY(b, 1);
        PG_RETURN_POINTER(a);
    }

    res = join_tsqueries(a, b, OP_OR);

    query = QTN2QT(res);

    QTNFree(res);
    PG_FREE_IF_COPY(a, 0);
    PG_FREE_IF_COPY(b, 1);

    PG_RETURN_POINTER(query);
}

Datum
tsquery_not(PG_FUNCTION_ARGS)
{
    TSQuery     a = PG_GETARG_TSQUERY_COPY(0);
    QTNode     *res;
    TSQuery     query;

    if (a->size == 0)
        PG_RETURN_POINTER(a);

    res = (QTNode *) palloc0(sizeof(QTNode));

    res->flags |= QTN_NEEDFREE;

    res->valnode = (QueryItem *) palloc0(sizeof(QueryItem));
    res->valnode->type = QI_OPR;
    res->valnode->qoperator.oper = OP_NOT;

    res->child = (QTNode **) palloc0(sizeof(QTNode *));
    res->child[0] = QT2QTN(GETQUERY(a), GETOPERAND(a));
    res->nchild = 1;

    query = QTN2QT(res);

    QTNFree(res);
    PG_FREE_IF_COPY(a, 0);

    PG_RETURN_POINTER(query);
}

static int
CompareTSQ(TSQuery a, TSQuery b)
{
    if (a->size != b->size)
    {
        return (a->size < b->size) ? -1 : 1;
    }
    else if (VARSIZE(a) != VARSIZE(b))
    {
        return (VARSIZE(a) < VARSIZE(b)) ? -1 : 1;
    }
    else if (a->size != 0)
    {
        QTNode     *an = QT2QTN(GETQUERY(a), GETOPERAND(a));
        QTNode     *bn = QT2QTN(GETQUERY(b), GETOPERAND(b));
        int         res = QTNodeCompare(an, bn);

        QTNFree(an);
        QTNFree(bn);

        return res;
    }

    return 0;
}

Datum
tsquery_cmp(PG_FUNCTION_ARGS)
{
    TSQuery     a = PG_GETARG_TSQUERY_COPY(0);
    TSQuery     b = PG_GETARG_TSQUERY_COPY(1);
    int         res = CompareTSQ(a, b);

    PG_FREE_IF_COPY(a, 0);
    PG_FREE_IF_COPY(b, 1);

    PG_RETURN_INT32(res);
}

#define CMPFUNC( NAME, CONDITION )              \
Datum                                           \
NAME(PG_FUNCTION_ARGS) {                        \
    TSQuery  a = PG_GETARG_TSQUERY_COPY(0);     \
    TSQuery  b = PG_GETARG_TSQUERY_COPY(1);     \
    int res = CompareTSQ(a,b);                  \
                                                \
    PG_FREE_IF_COPY(a,0);                       \
    PG_FREE_IF_COPY(b,1);                       \
                                                \
    PG_RETURN_BOOL( CONDITION );                \
}   \
/* keep compiler quiet - no extra ; */          \
extern int no_such_variable

CMPFUNC(tsquery_lt, res < 0);
CMPFUNC(tsquery_le, res <= 0);
CMPFUNC(tsquery_eq, res == 0);
CMPFUNC(tsquery_ge, res >= 0);
CMPFUNC(tsquery_gt, res > 0);
CMPFUNC(tsquery_ne, res != 0);

TSQuerySign
makeTSQuerySign(TSQuery a)
{
    int         i;
    QueryItem  *ptr = GETQUERY(a);
    TSQuerySign sign = 0;

    for (i = 0; i < a->size; i++)
    {
        if (ptr->type == QI_VAL)
            sign |= ((TSQuerySign) 1) << (((unsigned int) ptr->qoperand.valcrc) % TSQS_SIGLEN);
        ptr++;
    }

    return sign;
}

Datum
tsq_mcontains(PG_FUNCTION_ARGS)
{
    TSQuery     query = PG_GETARG_TSQUERY(0);
    TSQuery     ex = PG_GETARG_TSQUERY(1);
    TSQuerySign sq,
                se;
    int         i,
                j;
    QueryItem  *iq,
               *ie;

    if (query->size < ex->size)
    {
        PG_FREE_IF_COPY(query, 0);
        PG_FREE_IF_COPY(ex, 1);

        PG_RETURN_BOOL(false);
    }

    sq = makeTSQuerySign(query);
    se = makeTSQuerySign(ex);

    if ((sq & se) != se)
    {
        PG_FREE_IF_COPY(query, 0);
        PG_FREE_IF_COPY(ex, 1);

        PG_RETURN_BOOL(false);
    }

    iq = GETQUERY(query);
    ie = GETQUERY(ex);

    for (i = 0; i < ex->size; i++)
    {
        if (ie[i].type != QI_VAL)
            continue;
        for (j = 0; j < query->size; j++)
        {
            if (iq[j].type == QI_VAL &&
                ie[i].qoperand.valcrc == iq[j].qoperand.valcrc)
                break;
        }
        if (j >= query->size)
        {
            PG_FREE_IF_COPY(query, 0);
            PG_FREE_IF_COPY(ex, 1);

            PG_RETURN_BOOL(false);
        }
    }

    PG_FREE_IF_COPY(query, 0);
    PG_FREE_IF_COPY(ex, 1);

    PG_RETURN_BOOL(true);
}

Datum
tsq_mcontained(PG_FUNCTION_ARGS)
{
    PG_RETURN_DATUM(
                    DirectFunctionCall2(
                                        tsq_mcontains,
                                        PG_GETARG_DATUM(1),
                                        PG_GETARG_DATUM(0)
                                        )
        );
}