Quelle  btree_bytea.c

/*
 * contrib/btree_gist/btree_bytea.c
 */
#include "postgres.h"

#include "btree_gist.h"
#include "btree_utils_var.h"
#include "utils/fmgrprotos.h"
#include "utils/sortsupport.h"

/* GiST support functions */
PG_FUNCTION_INFO_V1(gbt_bytea_compress);
PG_FUNCTION_INFO_V1(gbt_bytea_union);
PG_FUNCTION_INFO_V1(gbt_bytea_picksplit);
PG_FUNCTION_INFO_V1(gbt_bytea_consistent);
PG_FUNCTION_INFO_V1(gbt_bytea_penalty);
PG_FUNCTION_INFO_V1(gbt_bytea_same);
PG_FUNCTION_INFO_V1(gbt_bytea_sortsupport);


/* define for comparison */

static bool
gbt_byteagt(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
 return DatumGetBool(DirectFunctionCall2(byteagt,
           PointerGetDatum(a),
           PointerGetDatum(b)));
}

static bool
gbt_byteage(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
 return DatumGetBool(DirectFunctionCall2(byteage,
           PointerGetDatum(a),
           PointerGetDatum(b)));
}

static bool
gbt_byteaeq(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
 return DatumGetBool(DirectFunctionCall2(byteaeq,
           PointerGetDatum(a),
           PointerGetDatum(b)));
}

static bool
gbt_byteale(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
 return DatumGetBool(DirectFunctionCall2(byteale,
           PointerGetDatum(a),
           PointerGetDatum(b)));
}

static bool
gbt_bytealt(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
 return DatumGetBool(DirectFunctionCall2(bytealt,
           PointerGetDatum(a),
           PointerGetDatum(b)));
}

static int32
gbt_byteacmp(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
 return DatumGetInt32(DirectFunctionCall2(byteacmp,
            PointerGetDatum(a),
            PointerGetDatum(b)));
}

static const gbtree_vinfo tinfo =
{
 gbt_t_bytea,
 0,
 true,
 gbt_byteagt,
 gbt_byteage,
 gbt_byteaeq,
 gbt_byteale,
 gbt_bytealt,
 gbt_byteacmp,
 NULL
};


/**************************************************
 * GiST support functions
 **************************************************/

Datum
gbt_bytea_compress(PG_FUNCTION_ARGS)
{
 GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);

 PG_RETURN_POINTER(gbt_var_compress(entry, &tinfo));
}

Datum
gbt_bytea_consistent(PG_FUNCTION_ARGS)
{
 GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
 void    *query = DatumGetByteaP(PG_GETARG_DATUM(1));
 StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);

 /* Oid subtype = PG_GETARG_OID(3); */
 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_bytea_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_bytea_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);
}

Datum
gbt_bytea_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_bytea_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);

 PG_RETURN_POINTER(gbt_var_penalty(result, o, n, PG_GET_COLLATION(),
           &tinfo, fcinfo->flinfo));
}

static int
gbt_bytea_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 xkey = gbt_var_key_readable(key1);
 GBT_VARKEY_R ykey = gbt_var_key_readable(key2);
 Datum  result;

 /* for leaf items we expect lower == upper, so only compare lower */
 result = DirectFunctionCall2(byteacmp,
         PointerGetDatum(xkey.lower),
         PointerGetDatum(ykey.lower));

 GBT_FREE_IF_COPY(key1, x);
 GBT_FREE_IF_COPY(key2, y);

 return DatumGetInt32(result);
}

Datum
gbt_bytea_sortsupport(PG_FUNCTION_ARGS)
{
 SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);

 ssup->comparator = gbt_bytea_ssup_cmp;
 ssup->ssup_extra = NULL;

 PG_RETURN_VOID();
}