btree_numeric.c

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/*
 * contrib/btree_gist/btree_numeric.c
 *
 * Support for numeric data type.
 */
#include "postgres.h"
 
#include <float.h>
 
#include "btree_gist.h"
#include "btree_utils_var.h"
#include "utils/builtins.h"
#include "utils/numeric.h"
#include "utils/rel.h"
#include "utils/sortsupport.h"
 
/* GiST support functions */
PG_FUNCTION_INFO_V1(gbt_numeric_compress);
PG_FUNCTION_INFO_V1(gbt_numeric_union);
PG_FUNCTION_INFO_V1(gbt_numeric_picksplit);
PG_FUNCTION_INFO_V1(gbt_numeric_consistent);
PG_FUNCTION_INFO_V1(gbt_numeric_penalty);
PG_FUNCTION_INFO_V1(gbt_numeric_same);
PG_FUNCTION_INFO_V1(gbt_numeric_sortsupport);
 
 
/* define for comparison */
 
static bool
gbt_numeric_gt(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetBool(DirectFunctionCall2(numeric_gt,
                                            PointerGetDatum(a),
                                            PointerGetDatum(b)));
}
 
static bool
gbt_numeric_ge(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetBool(DirectFunctionCall2(numeric_ge,
                                            PointerGetDatum(a),
                                            PointerGetDatum(b)));
}
 
static bool
gbt_numeric_eq(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetBool(DirectFunctionCall2(numeric_eq,
                                            PointerGetDatum(a),
                                            PointerGetDatum(b)));
}
 
static bool
gbt_numeric_le(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetBool(DirectFunctionCall2(numeric_le,
                                            PointerGetDatum(a),
                                            PointerGetDatum(b)));
}
 
static bool
gbt_numeric_lt(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetBool(DirectFunctionCall2(numeric_lt,
                                            PointerGetDatum(a),
                                            PointerGetDatum(b)));
}
 
static int32
gbt_numeric_cmp(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetInt32(DirectFunctionCall2(numeric_cmp,
                                             PointerGetDatum(a),
                                             PointerGetDatum(b)));
}
 
 
/*
 * We could conceivably support internal-key truncation here, but it would
 * require custom truncation code, and most values wouldn't be long enough
 * to make it worthwhile.
 */
static const gbtree_vinfo tinfo =
{
    gbt_t_numeric,
    false,                      /* no truncation permitted */
    gbt_numeric_gt,
    gbt_numeric_ge,
    gbt_numeric_eq,
    gbt_numeric_le,
    gbt_numeric_lt,
    gbt_numeric_cmp,
    NULL
};
 
 
/**************************************************
 * GiST support functions
 **************************************************/
 
Datum
gbt_numeric_compress(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
 
    PG_RETURN_POINTER(gbt_var_compress(entry, &tinfo));
}
 
Datum
gbt_numeric_consistent(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
    void       *query = DatumGetNumeric(PG_GETARG_DATUM(1));
    StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
#ifdef NOT_USED
    Oid         subtype = PG_GETARG_OID(3);
#endif
    bool       *recheck = (bool *) PG_GETARG_POINTER(4);
    bool        retval;
    GBT_VARKEY *key = (GBT_VARKEY *) DatumGetPointer(entry->key);
    GBT_VARKEY_R r = gbt_var_key_readable(key);
 
    /* All cases served by this function are exact */
    *recheck = false;
 
    retval = gbt_var_consistent(&r, query, strategy, PG_GET_COLLATION(),
                                GIST_LEAF(entry), &tinfo, fcinfo->flinfo);
    PG_RETURN_BOOL(retval);
}
 
Datum
gbt_numeric_union(PG_FUNCTION_ARGS)
{
    GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
    int32      *size = (int *) PG_GETARG_POINTER(1);
 
    PG_RETURN_POINTER(gbt_var_union(entryvec, size, PG_GET_COLLATION(),
                                    &tinfo, fcinfo->flinfo));
}
 
Datum
gbt_numeric_same(PG_FUNCTION_ARGS)
{
    Datum       d1 = PG_GETARG_DATUM(0);
    Datum       d2 = PG_GETARG_DATUM(1);
    bool       *result = (bool *) PG_GETARG_POINTER(2);
 
    *result = gbt_var_same(d1, d2, PG_GET_COLLATION(), &tinfo, fcinfo->flinfo);
    PG_RETURN_POINTER(result);
}
 
Datum
gbt_numeric_penalty(PG_FUNCTION_ARGS)
{
    GISTENTRY  *o = (GISTENTRY *) PG_GETARG_POINTER(0);
    GISTENTRY  *n = (GISTENTRY *) PG_GETARG_POINTER(1);
    float      *result = (float *) PG_GETARG_POINTER(2);
 
    Numeric     us,
                os,
                ds;
 
    GBT_VARKEY *org = (GBT_VARKEY *) DatumGetPointer(o->key);
    GBT_VARKEY *newe = (GBT_VARKEY *) DatumGetPointer(n->key);
    Datum       uni;
    GBT_VARKEY_R rk,
                ok,
                uk;
 
    rk = gbt_var_key_readable(org);
    uni = PointerGetDatum(gbt_var_key_copy(&rk));
    gbt_var_bin_union(&uni, newe, PG_GET_COLLATION(), &tinfo, fcinfo->flinfo);
    ok = gbt_var_key_readable(org);
    uk = gbt_var_key_readable((GBT_VARKEY *) DatumGetPointer(uni));
 
    us = DatumGetNumeric(DirectFunctionCall2(numeric_sub,
                                             PointerGetDatum(uk.upper),
                                             PointerGetDatum(uk.lower)));
 
    os = DatumGetNumeric(DirectFunctionCall2(numeric_sub,
                                             PointerGetDatum(ok.upper),
                                             PointerGetDatum(ok.lower)));
 
    ds = DatumGetNumeric(DirectFunctionCall2(numeric_sub,
                                             NumericGetDatum(us),
                                             NumericGetDatum(os)));
 
    if (numeric_is_nan(us))
    {
        if (numeric_is_nan(os))
            *result = 0.0;
        else
            *result = 1.0;
    }
    else
    {
        Numeric     nul = int64_to_numeric(0);
 
        *result = 0.0;
 
        if (DatumGetBool(DirectFunctionCall2(numeric_gt, NumericGetDatum(ds), NumericGetDatum(nul))))
        {
            *result += FLT_MIN;
            os = DatumGetNumeric(DirectFunctionCall2(numeric_div,
                                                     NumericGetDatum(ds),
                                                     NumericGetDatum(us)));
            *result += (float4) DatumGetFloat8(DirectFunctionCall1(numeric_float8_no_overflow, NumericGetDatum(os)));
        }
    }
 
    if (*result > 0)
        *result *= (FLT_MAX / (((GISTENTRY *) PG_GETARG_POINTER(0))->rel->rd_att->natts + 1));
 
    PG_RETURN_POINTER(result);
}
 
Datum
gbt_numeric_picksplit(PG_FUNCTION_ARGS)
{
    GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
    GIST_SPLITVEC *v = (GIST_SPLITVEC *) PG_GETARG_POINTER(1);
 
    gbt_var_picksplit(entryvec, v, PG_GET_COLLATION(),
                      &tinfo, fcinfo->flinfo);
    PG_RETURN_POINTER(v);
}
 
static int
gbt_numeric_ssup_cmp(Datum x, Datum y, SortSupport ssup)
{
    GBT_VARKEY *key1 = PG_DETOAST_DATUM(x);
    GBT_VARKEY *key2 = PG_DETOAST_DATUM(y);
 
    GBT_VARKEY_R arg1 = gbt_var_key_readable(key1);
    GBT_VARKEY_R arg2 = gbt_var_key_readable(key2);
    Datum       result;
 
    /* for leaf items we expect lower == upper, so only compare lower */
    result = DirectFunctionCall2(numeric_cmp,
                                 PointerGetDatum(arg1.lower),
                                 PointerGetDatum(arg2.lower));
 
    GBT_FREE_IF_COPY(key1, x);
    GBT_FREE_IF_COPY(key2, y);
 
    return DatumGetInt32(result);
}
 
Datum
gbt_numeric_sortsupport(PG_FUNCTION_ARGS)
{
    SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);
 
    ssup->comparator = gbt_numeric_ssup_cmp;
    ssup->ssup_extra = NULL;
 
    PG_RETURN_VOID();
}