TLA  Line data    Source code

       1                 : /*-------------------------------------------------------------------------
       2                 :  *
       3                 :  * compat.c
       4                 :  *      Reimplementations of various backend functions.
       5                 :  *
       6                 :  * Portions Copyright (c) 2013-2023, PostgreSQL Global Development Group
       7                 :  *
       8                 :  * IDENTIFICATION
       9                 :  *      src/bin/pg_waldump/compat.c
      10                 :  *
      11                 :  * This file contains client-side implementations for various backend
      12                 :  * functions that the rm_desc functions in *desc.c files rely on.
      13                 :  *
      14                 :  *-------------------------------------------------------------------------
      15                 :  */
      16                 : 
      17                 : /* ugly hack, same as in e.g pg_controldata */
      18                 : #define FRONTEND 1
      19                 : #include "postgres.h"
      20                 : 
      21                 : #include <time.h>
      22                 : 
      23                 : #include "utils/datetime.h"
      24                 : 
      25                 : /* copied from timestamp.c */
      26                 : pg_time_t
      27 UBC           0 : timestamptz_to_time_t(TimestampTz t)
      28                 : {
      29                 :     pg_time_t   result;
      30                 : 
      31               0 :     result = (pg_time_t) (t / USECS_PER_SEC +
      32                 :                           ((POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY));
      33               0 :     return result;
      34                 : }
      35                 : 
      36                 : /*
      37                 :  * Stopgap implementation of timestamptz_to_str that doesn't depend on backend
      38                 :  * infrastructure.  This will work for timestamps that are within the range
      39                 :  * of the platform time_t type.  (pg_time_t is compatible except for possibly
      40                 :  * being wider.)
      41                 :  *
      42                 :  * XXX the return value points to a static buffer, so beware of using more
      43                 :  * than one result value concurrently.
      44                 :  *
      45                 :  * XXX: The backend timestamp infrastructure should instead be split out and
      46                 :  * moved into src/common.  That's a large project though.
      47                 :  */
      48                 : const char *
      49 UNC           0 : timestamptz_to_str(TimestampTz t)
      50                 : {
      51                 :     static char buf[MAXDATELEN + 1];
      52                 :     char        ts[MAXDATELEN + 1];
      53                 :     char        zone[MAXDATELEN + 1];
      54               0 :     time_t      result = (time_t) timestamptz_to_time_t(t);
      55 UBC           0 :     struct tm  *ltime = localtime(&result);
      56                 : 
      57               0 :     strftime(ts, sizeof(ts), "%Y-%m-%d %H:%M:%S", ltime);
      58               0 :     strftime(zone, sizeof(zone), "%Z", ltime);
      59                 : 
      60               0 :     snprintf(buf, sizeof(buf), "%s.%06d %s",
      61 UNC           0 :              ts, (int) (t % USECS_PER_SEC), zone);
      62                 : 
      63 UBC           0 :     return buf;
      64                 : }