src/backend/storage/smgr/smgrtype.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * smgrtype.c
   4  *        storage manager type
   5  *
   6  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        $PostgreSQL$
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15 #include "postgres.h"
  16
  17 #include "storage/smgr.h"
  18
  19
  20 typedef struct smgrid
  21 {
  22         const char *smgr_name;
  23 } smgrid;
  24
  25 /*
  26  *      StorageManager[] -- List of defined storage managers.
  27  */
  28 static const smgrid StorageManager[] = {
  29         {"magnetic disk"}
  30 };
  31
  32 static const int NStorageManagers = lengthof(StorageManager);
  33
  34
  35 Datum
  36 smgrin(PG_FUNCTION_ARGS)
  37 {
  38         char       *s = PG_GETARG_CSTRING(0);
  39         int16           i;
  40
  41         for (i = 0; i < NStorageManagers; i++)
  42         {
  43                 if (strcmp(s, StorageManager[i].smgr_name) == 0)
  44                         PG_RETURN_INT16(i);
  45         }
  46         elog(ERROR, "unrecognized storage manager name \"%s\"", s);
  47         PG_RETURN_INT16(0);
  48 }
  49
  50 Datum
  51 smgrout(PG_FUNCTION_ARGS)
  52 {
  53         int16           i = PG_GETARG_INT16(0);
  54         char       *s;
  55
  56         if (i >= NStorageManagers || i < 0)
  57                 elog(ERROR, "invalid storage manager id: %d", i);
  58
  59         s = pstrdup(StorageManager[i].smgr_name);
  60         PG_RETURN_CSTRING(s);
  61 }
  62
  63 Datum
  64 smgreq(PG_FUNCTION_ARGS)
  65 {
  66         int16           a = PG_GETARG_INT16(0);
  67         int16           b = PG_GETARG_INT16(1);
  68
  69         PG_RETURN_BOOL(a == b);
  70 }
  71
  72 Datum
  73 smgrne(PG_FUNCTION_ARGS)
  74 {
  75         int16           a = PG_GETARG_INT16(0);
  76         int16           b = PG_GETARG_INT16(1);
  77
  78         PG_RETURN_BOOL(a != b);
  79 }