Line data    Source code

       1              : /*-------------------------------------------------------------------------
       2              :  *
       3              :  * compat.c
       4              :  *              Reimplementations of various backend functions.
       5              :  *
       6              :  * Portions Copyright (c) 2013-2026, 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            0 : timestamptz_to_time_t(TimestampTz t)
      28              : {
      29            0 :         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            0 : }
      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            0 : timestamptz_to_str(TimestampTz t)
      50              : {
      51              :         static char buf[MAXDATELEN + 1];
      52            0 :         char            ts[MAXDATELEN + 1];
      53            0 :         char            zone[MAXDATELEN + 1];
      54            0 :         time_t          result = (time_t) timestamptz_to_time_t(t);
      55            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            0 :                          ts, (int) (t % USECS_PER_SEC), zone);
      62              : 
      63            0 :         return buf;
      64            0 : }