btree_enum.c

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/*
 * contrib/btree_gist/btree_enum.c
 */
#include "postgres.h"
 
#include "btree_gist.h"
#include "btree_utils_num.h"
#include "fmgr.h"
#include "utils/fmgrprotos.h"
#include "utils/fmgroids.h"
#include "utils/sortsupport.h"
 
/* enums are really Oids, so we just use the same structure */
 
typedef struct
{
    Oid         lower;
    Oid         upper;
} oidKEY;
 
/* GiST support functions */
PG_FUNCTION_INFO_V1(gbt_enum_compress);
PG_FUNCTION_INFO_V1(gbt_enum_fetch);
PG_FUNCTION_INFO_V1(gbt_enum_union);
PG_FUNCTION_INFO_V1(gbt_enum_picksplit);
PG_FUNCTION_INFO_V1(gbt_enum_consistent);
PG_FUNCTION_INFO_V1(gbt_enum_penalty);
PG_FUNCTION_INFO_V1(gbt_enum_same);
PG_FUNCTION_INFO_V1(gbt_enum_sortsupport);
 
 
static bool
gbt_enumgt(const void *a, const void *b, FmgrInfo *flinfo)
{
    return DatumGetBool(CallerFInfoFunctionCall2(enum_gt, flinfo, InvalidOid,
                                                 ObjectIdGetDatum(*((const Oid *) a)),
                                                 ObjectIdGetDatum(*((const Oid *) b))));
}
static bool
gbt_enumge(const void *a, const void *b, FmgrInfo *flinfo)
{
    return DatumGetBool(CallerFInfoFunctionCall2(enum_ge, flinfo, InvalidOid,
                                                 ObjectIdGetDatum(*((const Oid *) a)),
                                                 ObjectIdGetDatum(*((const Oid *) b))));
}
static bool
gbt_enumeq(const void *a, const void *b, FmgrInfo *flinfo)
{
    return (*((const Oid *) a) == *((const Oid *) b));
}
static bool
gbt_enumle(const void *a, const void *b, FmgrInfo *flinfo)
{
    return DatumGetBool(CallerFInfoFunctionCall2(enum_le, flinfo, InvalidOid,
                                                 ObjectIdGetDatum(*((const Oid *) a)),
                                                 ObjectIdGetDatum(*((const Oid *) b))));
}
static bool
gbt_enumlt(const void *a, const void *b, FmgrInfo *flinfo)
{
    return DatumGetBool(CallerFInfoFunctionCall2(enum_lt, flinfo, InvalidOid,
                                                 ObjectIdGetDatum(*((const Oid *) a)),
                                                 ObjectIdGetDatum(*((const Oid *) b))));
}
 
static int
gbt_enumkey_cmp(const void *a, const void *b, FmgrInfo *flinfo)
{
    oidKEY     *ia = (oidKEY *) (((const Nsrt *) a)->t);
    oidKEY     *ib = (oidKEY *) (((const Nsrt *) b)->t);
 
    if (ia->lower == ib->lower)
    {
        if (ia->upper == ib->upper)
            return 0;
 
        return DatumGetInt32(CallerFInfoFunctionCall2(enum_cmp, flinfo, InvalidOid,
                                                      ObjectIdGetDatum(ia->upper),
                                                      ObjectIdGetDatum(ib->upper)));
    }
 
    return DatumGetInt32(CallerFInfoFunctionCall2(enum_cmp, flinfo, InvalidOid,
                                                  ObjectIdGetDatum(ia->lower),
                                                  ObjectIdGetDatum(ib->lower)));
}
 
static const gbtree_ninfo tinfo =
{
    gbt_t_enum,
    sizeof(Oid),
    8,                          /* sizeof(gbtreekey8) */
    gbt_enumgt,
    gbt_enumge,
    gbt_enumeq,
    gbt_enumle,
    gbt_enumlt,
    gbt_enumkey_cmp,
    NULL                        /* no KNN support at least for now */
};
 
 
/**************************************************
 * GiST support functions
 **************************************************/
 
Datum
gbt_enum_compress(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
 
    PG_RETURN_POINTER(gbt_num_compress(entry, &tinfo));
}
 
Datum
gbt_enum_fetch(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
 
    PG_RETURN_POINTER(gbt_num_fetch(entry, &tinfo));
}
 
Datum
gbt_enum_consistent(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
    Oid         query = PG_GETARG_OID(1);
    StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
 
    /* Oid      subtype = PG_GETARG_OID(3); */
    bool       *recheck = (bool *) PG_GETARG_POINTER(4);
    oidKEY     *kkk = (oidKEY *) 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_enum_union(PG_FUNCTION_ARGS)
{
    GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
    void       *out = palloc(sizeof(oidKEY));
 
    *(int *) PG_GETARG_POINTER(1) = sizeof(oidKEY);
    PG_RETURN_POINTER(gbt_num_union(out, entryvec, &tinfo, fcinfo->flinfo));
}
 
Datum
gbt_enum_penalty(PG_FUNCTION_ARGS)
{
    oidKEY     *origentry = (oidKEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(0))->key);
    oidKEY     *newentry = (oidKEY *) 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_enum_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_enum_same(PG_FUNCTION_ARGS)
{
    oidKEY     *b1 = (oidKEY *) PG_GETARG_POINTER(0);
    oidKEY     *b2 = (oidKEY *) 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_enum_ssup_cmp(Datum x, Datum y, SortSupport ssup)
{
    oidKEY     *arg1 = (oidKEY *) DatumGetPointer(x);
    oidKEY     *arg2 = (oidKEY *) DatumGetPointer(y);
 
    /* for leaf items we expect lower == upper, so only compare lower */
    return DatumGetInt32(CallerFInfoFunctionCall2(enum_cmp,
                                                  ssup->ssup_extra,
                                                  InvalidOid,
                                                  arg1->lower,
                                                  arg2->lower));
}
 
Datum
gbt_enum_sortsupport(PG_FUNCTION_ARGS)
{
    SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);
    FmgrInfo   *flinfo;
 
    ssup->comparator = gbt_enum_ssup_cmp;
 
    /*
     * Since gbt_enum_ssup_cmp() uses enum_cmp() like the rest of the
     * comparison functions, it also needs to pass flinfo when calling it. The
     * caller to a SortSupport comparison function doesn't provide an FmgrInfo
     * struct, so look it up now, save it in ssup_extra and use it in
     * gbt_enum_ssup_cmp() later.
     */
    flinfo = MemoryContextAlloc(ssup->ssup_cxt, sizeof(FmgrInfo));
    fmgr_info_cxt(F_ENUM_CMP, flinfo, ssup->ssup_cxt);
    ssup->ssup_extra = flinfo;
 
    PG_RETURN_VOID();
}