smgrtype.c

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/*-------------------------------------------------------------------------
 *
 * smgrtype.c
 *    storage manager type
 *
 * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/storage/smgr/smgrtype.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "storage/smgr.h"


typedef struct smgrid
{
    const char *smgr_name;
} smgrid;

/*
 *  StorageManager[] -- List of defined storage managers.
 */
static const smgrid StorageManager[] = {
    {"magnetic disk"}
};

static const int NStorageManagers = lengthof(StorageManager);


Datum
smgrin(PG_FUNCTION_ARGS)
{
    char       *s = PG_GETARG_CSTRING(0);
    int16       i;

    for (i = 0; i < NStorageManagers; i++)
    {
        if (strcmp(s, StorageManager[i].smgr_name) == 0)
            PG_RETURN_INT16(i);
    }
    elog(ERROR, "unrecognized storage manager name \"%s\"", s);
    PG_RETURN_INT16(0);
}

Datum
smgrout(PG_FUNCTION_ARGS)
{
    int16       i = PG_GETARG_INT16(0);
    char       *s;

    if (i >= NStorageManagers || i < 0)
        elog(ERROR, "invalid storage manager ID: %d", i);

    s = pstrdup(StorageManager[i].smgr_name);
    PG_RETURN_CSTRING(s);
}

Datum
smgreq(PG_FUNCTION_ARGS)
{
    int16       a = PG_GETARG_INT16(0);
    int16       b = PG_GETARG_INT16(1);

    PG_RETURN_BOOL(a == b);
}

Datum
smgrne(PG_FUNCTION_ARGS)
{
    int16       a = PG_GETARG_INT16(0);
    int16       b = PG_GETARG_INT16(1);

    PG_RETURN_BOOL(a != b);
}