Line data    Source code

       1              : /*-------------------------------------------------------------------------
       2              :  *
       3              :  * tablesample.c
       4              :  *        Support functions for TABLESAMPLE feature
       5              :  *
       6              :  * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
       7              :  * Portions Copyright (c) 1994, Regents of the University of California
       8              :  *
       9              :  *
      10              :  * IDENTIFICATION
      11              :  *        src/backend/access/tablesample/tablesample.c
      12              :  *
      13              :  * -------------------------------------------------------------------------
      14              :  */
      15              : 
      16              : #include "postgres.h"
      17              : 
      18              : #include "access/tsmapi.h"
      19              : 
      20              : 
      21              : /*
      22              :  * GetTsmRoutine --- get a TsmRoutine struct by invoking the handler.
      23              :  *
      24              :  * This is a convenience routine that's just meant to check for errors.
      25              :  */
      26              : TsmRoutine *
      27          629 : GetTsmRoutine(Oid tsmhandler)
      28              : {
      29              :     Datum       datum;
      30              :     TsmRoutine *routine;
      31              : 
      32          629 :     datum = OidFunctionCall1(tsmhandler, PointerGetDatum(NULL));
      33          629 :     routine = (TsmRoutine *) DatumGetPointer(datum);
      34              : 
      35          629 :     if (routine == NULL || !IsA(routine, TsmRoutine))
      36            0 :         elog(ERROR, "tablesample handler function %u did not return a TsmRoutine struct",
      37              :              tsmhandler);
      38              : 
      39          629 :     return routine;
      40              : }