btree_int2.c

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/*
 * contrib/btree_gist/btree_int2.c
 */
#include "postgres.h"
 
#include "btree_gist.h"
#include "btree_utils_num.h"
#include "common/int.h"
#include "utils/sortsupport.h"
 
typedef struct int16key
{
    int16       lower;
    int16       upper;
} int16KEY;
 
/* GiST support functions */
PG_FUNCTION_INFO_V1(gbt_int2_compress);
PG_FUNCTION_INFO_V1(gbt_int2_fetch);
PG_FUNCTION_INFO_V1(gbt_int2_union);
PG_FUNCTION_INFO_V1(gbt_int2_picksplit);
PG_FUNCTION_INFO_V1(gbt_int2_consistent);
PG_FUNCTION_INFO_V1(gbt_int2_distance);
PG_FUNCTION_INFO_V1(gbt_int2_penalty);
PG_FUNCTION_INFO_V1(gbt_int2_same);
PG_FUNCTION_INFO_V1(gbt_int2_sortsupport);
 
 
static bool
gbt_int2gt(const void *a, const void *b, FmgrInfo *flinfo)
{
    return (*((const int16 *) a) > *((const int16 *) b));
}
static bool
gbt_int2ge(const void *a, const void *b, FmgrInfo *flinfo)
{
    return (*((const int16 *) a) >= *((const int16 *) b));
}
static bool
gbt_int2eq(const void *a, const void *b, FmgrInfo *flinfo)
{
    return (*((const int16 *) a) == *((const int16 *) b));
}
static bool
gbt_int2le(const void *a, const void *b, FmgrInfo *flinfo)
{
    return (*((const int16 *) a) <= *((const int16 *) b));
}
static bool
gbt_int2lt(const void *a, const void *b, FmgrInfo *flinfo)
{
    return (*((const int16 *) a) < *((const int16 *) b));
}
 
static int
gbt_int2key_cmp(const void *a, const void *b, FmgrInfo *flinfo)
{
    int16KEY   *ia = (int16KEY *) (((const Nsrt *) a)->t);
    int16KEY   *ib = (int16KEY *) (((const Nsrt *) b)->t);
 
    if (ia->lower == ib->lower)
    {
        if (ia->upper == ib->upper)
            return 0;
 
        return (ia->upper > ib->upper) ? 1 : -1;
    }
 
    return (ia->lower > ib->lower) ? 1 : -1;
}
 
static float8
gbt_int2_dist(const void *a, const void *b, FmgrInfo *flinfo)
{
    return GET_FLOAT_DISTANCE(int16, a, b);
}
 
 
static const gbtree_ninfo tinfo =
{
    gbt_t_int2,
    sizeof(int16),
    4,                          /* sizeof(gbtreekey4) */
    gbt_int2gt,
    gbt_int2ge,
    gbt_int2eq,
    gbt_int2le,
    gbt_int2lt,
    gbt_int2key_cmp,
    gbt_int2_dist
};
 
 
PG_FUNCTION_INFO_V1(int2_dist);
Datum
int2_dist(PG_FUNCTION_ARGS)
{
    int16       a = PG_GETARG_INT16(0);
    int16       b = PG_GETARG_INT16(1);
    int16       r;
    int16       ra;
 
    if (pg_sub_s16_overflow(a, b, &r) ||
        r == PG_INT16_MIN)
        ereport(ERROR,
                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                 errmsg("smallint out of range")));
 
    ra = abs(r);
 
    PG_RETURN_INT16(ra);
}
 
 
/**************************************************
 * GiST support functions
 **************************************************/
 
Datum
gbt_int2_compress(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
 
    PG_RETURN_POINTER(gbt_num_compress(entry, &tinfo));
}
 
Datum
gbt_int2_fetch(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
 
    PG_RETURN_POINTER(gbt_num_fetch(entry, &tinfo));
}
 
Datum
gbt_int2_consistent(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
    int16       query = PG_GETARG_INT16(1);
    StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
 
    /* Oid      subtype = PG_GETARG_OID(3); */
    bool       *recheck = (bool *) PG_GETARG_POINTER(4);
    int16KEY   *kkk = (int16KEY *) DatumGetPointer(entry->key);
    GBT_NUMKEY_R key;
 
    /* All cases served by this function are exact */
    *recheck = false;
 
    key.lower = (GBT_NUMKEY *) &kkk->lower;
    key.upper = (GBT_NUMKEY *) &kkk->upper;
 
    PG_RETURN_BOOL(gbt_num_consistent(&key, &query, &strategy,
                                      GIST_LEAF(entry), &tinfo, fcinfo->flinfo));
}
 
Datum
gbt_int2_distance(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
    int16       query = PG_GETARG_INT16(1);
 
    /* Oid      subtype = PG_GETARG_OID(3); */
    int16KEY   *kkk = (int16KEY *) DatumGetPointer(entry->key);
    GBT_NUMKEY_R key;
 
    key.lower = (GBT_NUMKEY *) &kkk->lower;
    key.upper = (GBT_NUMKEY *) &kkk->upper;
 
    PG_RETURN_FLOAT8(gbt_num_distance(&key, &query, GIST_LEAF(entry),
                                      &tinfo, fcinfo->flinfo));
}
 
Datum
gbt_int2_union(PG_FUNCTION_ARGS)
{
    GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
    void       *out = palloc(sizeof(int16KEY));
 
    *(int *) PG_GETARG_POINTER(1) = sizeof(int16KEY);
    PG_RETURN_POINTER(gbt_num_union(out, entryvec, &tinfo, fcinfo->flinfo));
}
 
Datum
gbt_int2_penalty(PG_FUNCTION_ARGS)
{
    int16KEY   *origentry = (int16KEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(0))->key);
    int16KEY   *newentry = (int16KEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(1))->key);
    float      *result = (float *) PG_GETARG_POINTER(2);
 
    penalty_num(result, origentry->lower, origentry->upper, newentry->lower, newentry->upper);
 
    PG_RETURN_POINTER(result);
}
 
Datum
gbt_int2_picksplit(PG_FUNCTION_ARGS)
{
    PG_RETURN_POINTER(gbt_num_picksplit((GistEntryVector *) PG_GETARG_POINTER(0),
                                        (GIST_SPLITVEC *) PG_GETARG_POINTER(1),
                                        &tinfo, fcinfo->flinfo));
}
 
Datum
gbt_int2_same(PG_FUNCTION_ARGS)
{
    int16KEY   *b1 = (int16KEY *) PG_GETARG_POINTER(0);
    int16KEY   *b2 = (int16KEY *) PG_GETARG_POINTER(1);
    bool       *result = (bool *) PG_GETARG_POINTER(2);
 
    *result = gbt_num_same((void *) b1, (void *) b2, &tinfo, fcinfo->flinfo);
    PG_RETURN_POINTER(result);
}
 
static int
gbt_int2_ssup_cmp(Datum x, Datum y, SortSupport ssup)
{
    int16KEY   *arg1 = (int16KEY *) DatumGetPointer(x);
    int16KEY   *arg2 = (int16KEY *) DatumGetPointer(y);
 
    /* for leaf items we expect lower == upper, so only compare lower */
    if (arg1->lower < arg2->lower)
        return -1;
    else if (arg1->lower > arg2->lower)
        return 1;
    else
        return 0;
}
 
Datum
gbt_int2_sortsupport(PG_FUNCTION_ARGS)
{
    SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);
 
    ssup->comparator = gbt_int2_ssup_cmp;
    PG_RETURN_VOID();
}