postgresql/contrib/pg_upgrade/util.c
Tom Lane 09ac603c36 Work around unportable behavior of malloc(0) and realloc(NULL, 0).
On some platforms these functions return NULL, rather than the more common
practice of returning a pointer to a zero-sized block of memory.  Hack our
various wrapper functions to hide the difference by substituting a size
request of 1.  This is probably not so important for the callers, who
should never touch the block anyway if they asked for size 0 --- but it's
important for the wrapper functions themselves, which mistakenly treated
the NULL result as an out-of-memory failure.  This broke at least pg_dump
for the case of no user-defined aggregates, as per report from
Matthew Carrington.

Back-patch to 9.2 to fix the pg_dump issue.  Given the lack of previous
complaints, it seems likely that there is no live bug in previous releases,
even though some of these functions were in place before that.
2012-10-02 17:32:42 -04:00

308 lines
5.3 KiB
C

/*
* util.c
*
* utility functions
*
* Copyright (c) 2010-2012, PostgreSQL Global Development Group
* contrib/pg_upgrade/util.c
*/
#include "postgres.h"
#include "pg_upgrade.h"
#include <signal.h>
LogOpts log_opts;
/*
* report_status()
*
* Displays the result of an operation (ok, failed, error message,...)
*/
void
report_status(eLogType type, const char *fmt,...)
{
va_list args;
char message[MAX_STRING];
va_start(args, fmt);
vsnprintf(message, sizeof(message), fmt, args);
va_end(args);
pg_log(type, "%s\n", message);
}
/*
* prep_status
*
* Displays a message that describes an operation we are about to begin.
* We pad the message out to MESSAGE_WIDTH characters so that all of the "ok" and
* "failed" indicators line up nicely.
*
* A typical sequence would look like this:
* prep_status("about to flarb the next %d files", fileCount );
*
* if(( message = flarbFiles(fileCount)) == NULL)
* report_status(PG_REPORT, "ok" );
* else
* pg_log(PG_FATAL, "failed - %s\n", message );
*/
void
prep_status(const char *fmt,...)
{
va_list args;
char message[MAX_STRING];
va_start(args, fmt);
vsnprintf(message, sizeof(message), fmt, args);
va_end(args);
if (strlen(message) > 0 && message[strlen(message) - 1] == '\n')
pg_log(PG_REPORT, "%s", message);
else
pg_log(PG_REPORT, "%-" MESSAGE_WIDTH "s", message);
}
void
pg_log(eLogType type, char *fmt,...)
{
va_list args;
char message[MAX_STRING];
va_start(args, fmt);
vsnprintf(message, sizeof(message), fmt, args);
va_end(args);
/* PG_VERBOSE is only output in verbose mode */
/* fopen() on log_opts.internal might have failed, so check it */
if ((type != PG_VERBOSE || log_opts.verbose) && log_opts.internal != NULL)
{
/*
* There's nothing much we can do about it if fwrite fails, but some
* platforms declare fwrite with warn_unused_result. Do a little
* dance with casting to void to shut up the compiler in such cases.
*/
size_t rc;
rc = fwrite(message, strlen(message), 1, log_opts.internal);
/* if we are using OVERWRITE_MESSAGE, add newline to log file */
if (strchr(message, '\r') != NULL)
rc = fwrite("\n", 1, 1, log_opts.internal);
(void) rc;
fflush(log_opts.internal);
}
switch (type)
{
case PG_VERBOSE:
if (log_opts.verbose)
printf("%s", _(message));
break;
case PG_REPORT:
case PG_WARNING:
printf("%s", _(message));
break;
case PG_FATAL:
printf("\n%s", _(message));
printf("Failure, exiting\n");
exit(1);
break;
default:
break;
}
fflush(stdout);
}
void
check_ok(void)
{
/* all seems well */
report_status(PG_REPORT, "ok");
fflush(stdout);
}
/*
* quote_identifier()
* Properly double-quote a SQL identifier.
*
* The result should be pg_free'd, but most callers don't bother because
* memory leakage is not a big deal in this program.
*/
char *
quote_identifier(const char *s)
{
char *result = pg_malloc(strlen(s) * 2 + 3);
char *r = result;
*r++ = '"';
while (*s)
{
if (*s == '"')
*r++ = *s;
*r++ = *s;
s++;
}
*r++ = '"';
*r++ = '\0';
return result;
}
/*
* get_user_info()
* (copied from initdb.c) find the current user
*/
int
get_user_info(char **user_name)
{
int user_id;
#ifndef WIN32
struct passwd *pw = getpwuid(geteuid());
user_id = geteuid();
#else /* the windows code */
struct passwd_win32
{
int pw_uid;
char pw_name[128];
} pass_win32;
struct passwd_win32 *pw = &pass_win32;
DWORD pwname_size = sizeof(pass_win32.pw_name) - 1;
GetUserName(pw->pw_name, &pwname_size);
user_id = 1;
#endif
*user_name = pg_strdup(pw->pw_name);
return user_id;
}
void *
pg_malloc(size_t size)
{
void *p;
/* Avoid unportable behavior of malloc(0) */
if (size == 0)
size = 1;
p = malloc(size);
if (p == NULL)
pg_log(PG_FATAL, "%s: out of memory\n", os_info.progname);
return p;
}
void *
pg_realloc(void *ptr, size_t size)
{
void *p;
/* Avoid unportable behavior of realloc(NULL, 0) */
if (ptr == NULL && size == 0)
size = 1;
p = realloc(ptr, size);
if (p == NULL)
pg_log(PG_FATAL, "%s: out of memory\n", os_info.progname);
return p;
}
void
pg_free(void *ptr)
{
if (ptr != NULL)
free(ptr);
}
char *
pg_strdup(const char *s)
{
char *result = strdup(s);
if (result == NULL)
pg_log(PG_FATAL, "%s: out of memory\n", os_info.progname);
return result;
}
/*
* getErrorText()
*
* Returns the text of the error message for the given error number
*
* This feature is factored into a separate function because it is
* system-dependent.
*/
const char *
getErrorText(int errNum)
{
#ifdef WIN32
_dosmaperr(GetLastError());
#endif
return pg_strdup(strerror(errNum));
}
/*
* str2uint()
*
* convert string to oid
*/
unsigned int
str2uint(const char *str)
{
return strtoul(str, NULL, 10);
}
/*
* pg_putenv()
*
* This is like putenv(), but takes two arguments.
* It also does unsetenv() if val is NULL.
*/
void
pg_putenv(const char *var, const char *val)
{
if (val)
{
#ifndef WIN32
char *envstr = (char *) pg_malloc(strlen(var) +
strlen(val) + 2);
sprintf(envstr, "%s=%s", var, val);
putenv(envstr);
/*
* Do not free envstr because it becomes part of the environment on
* some operating systems. See port/unsetenv.c::unsetenv.
*/
#else
SetEnvironmentVariableA(var, val);
#endif
}
else
{
#ifndef WIN32
unsetenv(var);
#else
SetEnvironmentVariableA(var, "");
#endif
}
}