btree_float8.c

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/*
 * contrib/btree_gist/btree_float8.c
 */
#include "postgres.h"
 
#include "btree_gist.h"
#include "btree_utils_num.h"
#include "utils/float.h"
#include "utils/rel.h"
#include "utils/sortsupport.h"
 
typedef struct float8key
{
    float8      lower;
    float8      upper;
} float8KEY;
 
/* GiST support functions */
PG_FUNCTION_INFO_V1(gbt_float8_compress);
PG_FUNCTION_INFO_V1(gbt_float8_fetch);
PG_FUNCTION_INFO_V1(gbt_float8_union);
PG_FUNCTION_INFO_V1(gbt_float8_picksplit);
PG_FUNCTION_INFO_V1(gbt_float8_consistent);
PG_FUNCTION_INFO_V1(gbt_float8_distance);
PG_FUNCTION_INFO_V1(gbt_float8_penalty);
PG_FUNCTION_INFO_V1(gbt_float8_same);
PG_FUNCTION_INFO_V1(gbt_float8_sortsupport);
 
 
/*
 * Use the NaN-aware comparators from utils/float.h, so that our results
 * will agree with standard btree indexes.  Note that penalty and distance
 * functions below must also cope with NaNs, in particular with the policy
 * that all NaNs are equal.
 */
static bool
gbt_float8gt(const void *a, const void *b, FmgrInfo *flinfo)
{
    return float8_gt(*((const float8 *) a), *((const float8 *) b));
}
static bool
gbt_float8ge(const void *a, const void *b, FmgrInfo *flinfo)
{
    return float8_ge(*((const float8 *) a), *((const float8 *) b));
}
static bool
gbt_float8eq(const void *a, const void *b, FmgrInfo *flinfo)
{
    return float8_eq(*((const float8 *) a), *((const float8 *) b));
}
static bool
gbt_float8le(const void *a, const void *b, FmgrInfo *flinfo)
{
    return float8_le(*((const float8 *) a), *((const float8 *) b));
}
static bool
gbt_float8lt(const void *a, const void *b, FmgrInfo *flinfo)
{
    return float8_lt(*((const float8 *) a), *((const float8 *) b));
}
 
static int
gbt_float8key_cmp(const void *a, const void *b, FmgrInfo *flinfo)
{
    float8KEY  *ia = (float8KEY *) (((const Nsrt *) a)->t);
    float8KEY  *ib = (float8KEY *) (((const Nsrt *) b)->t);
    int         res;
 
    res = float8_cmp_internal(ia->lower, ib->lower);
    if (res != 0)
        return res;
    return float8_cmp_internal(ia->upper, ib->upper);
}
 
static float8
gbt_float8_dist(const void *a, const void *b, FmgrInfo *flinfo)
{
    float8      arg1 = *(const float8 *) a;
    float8      arg2 = *(const float8 *) b;
    float8      r;
 
    r = arg1 - arg2;
    if (unlikely(isinf(r)) && !isinf(arg1) && !isinf(arg2))
        float_overflow_error();
    if (unlikely(isnan(r)))
    {
        if (isnan(arg1) && isnan(arg2))
            r = 0.0;            /* treat NaNs as equal */
        else if (isnan(arg1) || isnan(arg2))
            r = get_float8_infinity();  /* max dist for NaN vs non-NaN */
        else
            r = 0.0;            /* must be Inf - Inf case */
    }
    return fabs(r);
}
 
 
static const gbtree_ninfo tinfo =
{
    gbt_t_float8,
    sizeof(float8),
    16,                         /* sizeof(gbtreekey16) */
    gbt_float8gt,
    gbt_float8ge,
    gbt_float8eq,
    gbt_float8le,
    gbt_float8lt,
    gbt_float8key_cmp,
    gbt_float8_dist
};
 
 
PG_FUNCTION_INFO_V1(float8_dist);
Datum
float8_dist(PG_FUNCTION_ARGS)
{
    float8      a = PG_GETARG_FLOAT8(0);
    float8      b = PG_GETARG_FLOAT8(1);
    float8      r;
 
    r = a - b;
    if (unlikely(isinf(r)) && !isinf(a) && !isinf(b))
        float_overflow_error();
    if (unlikely(isnan(r)))
    {
        if (isnan(a) && isnan(b))
            r = 0.0;            /* treat NaNs as equal */
        else if (isnan(a) || isnan(b))
            r = get_float8_infinity();  /* max dist for NaN vs non-NaN */
        else
            r = 0.0;            /* must be Inf - Inf case */
    }
    PG_RETURN_FLOAT8(fabs(r));
}
 
 
/**************************************************
 * GiST support functions
 **************************************************/
 
Datum
gbt_float8_compress(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
 
    PG_RETURN_POINTER(gbt_num_compress(entry, &tinfo));
}
 
Datum
gbt_float8_fetch(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
 
    PG_RETURN_POINTER(gbt_num_fetch(entry, &tinfo));
}
 
Datum
gbt_float8_consistent(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
    float8      query = PG_GETARG_FLOAT8(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);
    float8KEY  *kkk = (float8KEY *) 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_float8_distance(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
    float8      query = PG_GETARG_FLOAT8(1);
#ifdef NOT_USED
    Oid         subtype = PG_GETARG_OID(3);
#endif
    float8KEY  *kkk = (float8KEY *) 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_float8_union(PG_FUNCTION_ARGS)
{
    GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
    void       *out = palloc(sizeof(float8KEY));
 
    *(int *) PG_GETARG_POINTER(1) = sizeof(float8KEY);
    PG_RETURN_POINTER(gbt_num_union(out, entryvec, &tinfo, fcinfo->flinfo));
}
 
Datum
gbt_float8_penalty(PG_FUNCTION_ARGS)
{
    float8KEY  *origentry = (float8KEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(0))->key);
    float8KEY  *newentry = (float8KEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(1))->key);
    float      *result = (float *) PG_GETARG_POINTER(2);
 
    float_penalty_num(result, origentry->lower, origentry->upper, newentry->lower, newentry->upper);
 
    PG_RETURN_POINTER(result);
}
 
Datum
gbt_float8_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_float8_same(PG_FUNCTION_ARGS)
{
    float8KEY  *b1 = (float8KEY *) PG_GETARG_POINTER(0);
    float8KEY  *b2 = (float8KEY *) 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_float8_ssup_cmp(Datum x, Datum y, SortSupport ssup)
{
    float8KEY  *arg1 = (float8KEY *) DatumGetPointer(x);
    float8KEY  *arg2 = (float8KEY *) DatumGetPointer(y);
 
    /* for leaf items we expect lower == upper, so only compare lower */
    return float8_cmp_internal(arg1->lower, arg2->lower);
}
 
Datum
gbt_float8_sortsupport(PG_FUNCTION_ARGS)
{
    SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);
 
    ssup->comparator = gbt_float8_ssup_cmp;
    ssup->ssup_extra = NULL;
 
    PG_RETURN_VOID();
}