postgresql/contrib/pg_xlogdump/compat.c
Tom Lane 1418e6e07b Clean up "stopgap" implementation of timestamptz_to_str().
Use correct type for "result", fix bogus strftime argument, don't use
unnecessary static variables, improve comments.

Andres Freund and Tom Lane
2013-02-26 15:50:22 -05:00

100 lines
2.4 KiB
C

/*-------------------------------------------------------------------------
*
* compat.c
* Reimplementations of various backend functions.
*
* Portions Copyright (c) 2013, PostgreSQL Global Development Group
*
* IDENTIFICATION
* contrib/pg_xlogdump/compat.c
*
* This file contains client-side implementations for various backend
* functions that the rm_desc functions in *desc.c files rely on.
*
*-------------------------------------------------------------------------
*/
/* ugly hack, same as in e.g pg_controldata */
#define FRONTEND 1
#include "postgres.h"
#include <time.h>
#include "utils/datetime.h"
#include "lib/stringinfo.h"
/* copied from timestamp.c */
pg_time_t
timestamptz_to_time_t(TimestampTz t)
{
pg_time_t result;
#ifdef HAVE_INT64_TIMESTAMP
result = (pg_time_t) (t / USECS_PER_SEC +
((POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY));
#else
result = (pg_time_t) (t +
((POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY));
#endif
return result;
}
/*
* Stopgap implementation of timestamptz_to_str that doesn't depend on backend
* infrastructure. This will work for timestamps that are within the range
* of the platform time_t type. (pg_time_t is compatible except for possibly
* being wider.)
*
* XXX the return value points to a static buffer, so beware of using more
* than one result value concurrently.
*
* XXX: The backend timestamp infrastructure should instead be split out and
* moved into src/common. That's a large project though.
*/
const char *
timestamptz_to_str(TimestampTz dt)
{
static char buf[MAXDATELEN + 1];
char ts[MAXDATELEN + 1];
char zone[MAXDATELEN + 1];
time_t result = (time_t) timestamptz_to_time_t(dt);
struct tm *ltime = localtime(&result);
strftime(ts, sizeof(ts), "%Y-%m-%d %H:%M:%S", ltime);
strftime(zone, sizeof(zone), "%Z", ltime);
#ifdef HAVE_INT64_TIMESTAMP
sprintf(buf, "%s.%06d %s", ts, (int) (dt % USECS_PER_SEC), zone);
#else
sprintf(buf, "%s.%.6f %s", ts, fabs(dt - floor(dt)), zone);
#endif
return buf;
}
/*
* Provide a hacked up compat layer for StringInfos so xlog desc functions can
* be linked/called.
*/
void
appendStringInfo(StringInfo str, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
vprintf(fmt, args);
va_end(args);
}
void
appendStringInfoString(StringInfo str, const char *string)
{
appendStringInfo(str, "%s", string);
}
void
appendStringInfoChar(StringInfo str, char ch)
{
appendStringInfo(str, "%c", ch);
}