elog.c

 * is intended for use in error callback subroutines that are editorializing
 * on the layout of the error report.
 */
int
internalerrquery(const char *query)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];

	/* we don't bother incrementing recursion_depth */
	CHECK_STACK_DEPTH();

	if (edata->internalquery)
	{
		pfree(edata->internalquery);
		edata->internalquery = NULL;
	}

	if (query)
		edata->internalquery = MemoryContextStrdup(ErrorContext, query);

	return 0;					/* return value does not matter */
}

/*
 * geterrcode --- return the currently set SQLSTATE error code
 *
 * This is only intended for use in error callback subroutines, since there
 * is no other place outside elog.c where the concept is meaningful.
 */
int
geterrcode(void)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];

	/* we don't bother incrementing recursion_depth */
	CHECK_STACK_DEPTH();

	return edata->sqlerrcode;
}

/*
 * geterrposition --- return the currently set error position (0 if none)
 *
 * This is only intended for use in error callback subroutines, since there
 * is no other place outside elog.c where the concept is meaningful.
 */
int
geterrposition(void)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];

	/* we don't bother incrementing recursion_depth */
	CHECK_STACK_DEPTH();

	return edata->cursorpos;
}

/*
 * getinternalerrposition --- same for internal error position
 *
 * This is only intended for use in error callback subroutines, since there
 * is no other place outside elog.c where the concept is meaningful.
 */
int
getinternalerrposition(void)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];

	/* we don't bother incrementing recursion_depth */
	CHECK_STACK_DEPTH();

	return edata->internalpos;
}


/*
 * elog_start --- startup for old-style API
 *
 * All that we do here is stash the hidden filename/lineno/funcname
 * arguments into a stack entry.
 *
 * We need this to be separate from elog_finish because there's no other
 * portable way to deal with inserting extra arguments into the elog call.
 * (If macros with variable numbers of arguments were portable, it'd be
 * easy, but they aren't.)
 */
void
elog_start(const char *filename, int lineno, const char *funcname)
{
	ErrorData  *edata;

	if (++errordata_stack_depth >= ERRORDATA_STACK_SIZE)
	{
		/*
		 * Wups, stack not big enough.	We treat this as a PANIC condition
		 * because it suggests an infinite loop of errors during error
		 * recovery.  Note that the message is intentionally not localized,
		 * else failure to convert it to client encoding could cause further
		 * recursion.
		 */
		errordata_stack_depth = -1;		/* make room on stack */
		ereport(PANIC, (errmsg_internal("ERRORDATA_STACK_SIZE exceeded")));
	}

	edata = &errordata[errordata_stack_depth];
	edata->filename = filename;
	edata->lineno = lineno;
	edata->funcname = funcname;
	/* errno is saved now so that error parameter eval can't change it */
	edata->saved_errno = errno;
}

/*
 * elog_finish --- finish up for old-style API
 */
void
elog_finish(int elevel, const char *fmt,...)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];
	MemoryContext oldcontext;

	CHECK_STACK_DEPTH();

	/*
	 * Do errstart() to see if we actually want to report the message.
	 */
	errordata_stack_depth--;
	errno = edata->saved_errno;
	if (!errstart(elevel, edata->filename, edata->lineno, edata->funcname, NULL))
		return;					/* nothing to do */

	/*
	 * Format error message just like errmsg_internal().
	 */
	recursion_depth++;
	oldcontext = MemoryContextSwitchTo(ErrorContext);

	EVALUATE_MESSAGE(message, false, false);

	MemoryContextSwitchTo(oldcontext);
	recursion_depth--;

	/*
	 * And let errfinish() finish up.
	 */
	errfinish(0);
}

/*
 * Actual output of the top-of-stack error message
 *
 * In the ereport(ERROR) case this is called from PostgresMain (or not at all,
 * if the error is caught by somebody).  For all other severity levels this
 * is called by errfinish.
 */
void
EmitErrorReport(void)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];
	MemoryContext oldcontext;

	recursion_depth++;
	CHECK_STACK_DEPTH();
	oldcontext = MemoryContextSwitchTo(ErrorContext);

	/* Send to server log, if enabled */
	if (edata->output_to_server)
		send_message_to_server_log(edata);

	/* Send to client, if enabled */
	if (edata->output_to_client)
		send_message_to_frontend(edata);

	MemoryContextSwitchTo(oldcontext);
	recursion_depth--;
}

/*
 * CopyErrorData --- obtain a copy of the topmost error stack entry
 *
 * This is only for use in error handler code.	The data is copied into the
 * current memory context, so callers should always switch away from
 * ErrorContext first; otherwise it will be lost when FlushErrorState is done.
 */
ErrorData *
CopyErrorData(void)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];
	ErrorData  *newedata;

	/*
	 * we don't increment recursion_depth because out-of-memory here does not
	 * indicate a problem within the error subsystem.
	 */
	CHECK_STACK_DEPTH();

	Assert(CurrentMemoryContext != ErrorContext);

	/* Copy the struct itself */
	newedata = (ErrorData *) palloc(sizeof(ErrorData));
	memcpy(newedata, edata, sizeof(ErrorData));

	/* Make copies of separately-allocated fields */
	if (newedata->message)
		newedata->message = pstrdup(newedata->message);
	if (newedata->detail)
		newedata->detail = pstrdup(newedata->detail);
	if (newedata->detail_log)
		newedata->detail_log = pstrdup(newedata->detail_log);
	if (newedata->hint)
		newedata->hint = pstrdup(newedata->hint);
	if (newedata->context)
		newedata->context = pstrdup(newedata->context);
	if (newedata->internalquery)
		newedata->internalquery = pstrdup(newedata->internalquery);

	return newedata;
}

/*
 * FreeErrorData --- free the structure returned by CopyErrorData.
 *
 * Error handlers should use this in preference to assuming they know all
 * the separately-allocated fields.
 */
void
FreeErrorData(ErrorData *edata)
{
	if (edata->message)
		pfree(edata->message);
	if (edata->detail)
		pfree(edata->detail);
	if (edata->detail_log)
		pfree(edata->detail_log);
	if (edata->hint)
		pfree(edata->hint);
	if (edata->context)
		pfree(edata->context);
	if (edata->internalquery)
		pfree(edata->internalquery);
	pfree(edata);
}

/*
 * FlushErrorState --- flush the error state after error recovery
 *
 * This should be called by an error handler after it's done processing
 * the error; or as soon as it's done CopyErrorData, if it intends to
 * do stuff that is likely to provoke another error.  You are not "out" of
 * the error subsystem until you have done this.
 */
void
FlushErrorState(void)
{
	/*
	 * Reset stack to empty.  The only case where it would be more than one
	 * deep is if we serviced an error that interrupted construction of
	 * another message.  We assume control escaped out of that message
	 * construction and won't ever go back.
	 */
	errordata_stack_depth = -1;
	recursion_depth = 0;
	/* Delete all data in ErrorContext */
	MemoryContextResetAndDeleteChildren(ErrorContext);
}

/*
 * ReThrowError --- re-throw a previously copied error
 *
 * A handler can do CopyErrorData/FlushErrorState to get out of the error
 * subsystem, then do some processing, and finally ReThrowError to re-throw
 * the original error.	This is slower than just PG_RE_THROW() but should
 * be used if the "some processing" is likely to incur another error.
 */
void
ReThrowError(ErrorData *edata)
{
	ErrorData  *newedata;

	Assert(edata->elevel == ERROR);

	/* Push the data back into the error context */
	recursion_depth++;
	MemoryContextSwitchTo(ErrorContext);

	if (++errordata_stack_depth >= ERRORDATA_STACK_SIZE)
	{
		/*
		 * Wups, stack not big enough.	We treat this as a PANIC condition
		 * because it suggests an infinite loop of errors during error
		 * recovery.
		 */
		errordata_stack_depth = -1;		/* make room on stack */
		ereport(PANIC, (errmsg_internal("ERRORDATA_STACK_SIZE exceeded")));
	}

	newedata = &errordata[errordata_stack_depth];
	memcpy(newedata, edata, sizeof(ErrorData));

	/* Make copies of separately-allocated fields */
	if (newedata->message)
		newedata->message = pstrdup(newedata->message);
	if (newedata->detail)
		newedata->detail = pstrdup(newedata->detail);
	if (newedata->detail_log)
		newedata->detail_log = pstrdup(newedata->detail_log);
	if (newedata->hint)
		newedata->hint = pstrdup(newedata->hint);
	if (newedata->context)
		newedata->context = pstrdup(newedata->context);
	if (newedata->internalquery)
		newedata->internalquery = pstrdup(newedata->internalquery);

	recursion_depth--;
	PG_RE_THROW();
}

/*
 * pg_re_throw --- out-of-line implementation of PG_RE_THROW() macro
 */
void
pg_re_throw(void)
{
	/* If possible, throw the error to the next outer setjmp handler */
	if (PG_exception_stack != NULL)
		siglongjmp(*PG_exception_stack, 1);
	else
	{
		/*
		 * If we get here, elog(ERROR) was thrown inside a PG_TRY block, which
		 * we have now exited only to discover that there is no outer setjmp
		 * handler to pass the error to.  Had the error been thrown outside
		 * the block to begin with, we'd have promoted the error to FATAL, so
		 * the correct behavior is to make it FATAL now; that is, emit it and
		 * then call proc_exit.
		 */
		ErrorData  *edata = &errordata[errordata_stack_depth];

		Assert(errordata_stack_depth >= 0);
		Assert(edata->elevel == ERROR);
		edata->elevel = FATAL;

		/*
		 * At least in principle, the increase in severity could have changed
		 * where-to-output decisions, so recalculate.  This should stay in
		 * sync with errstart(), which see for comments.
		 */
		if (IsPostmasterEnvironment)
			edata->output_to_server = is_log_level_output(FATAL,
														  log_min_messages);
		else
			edata->output_to_server = (FATAL >= log_min_messages);
		if (whereToSendOutput == DestRemote)
		{
			if (ClientAuthInProgress)
				edata->output_to_client = true;
			else
				edata->output_to_client = (FATAL >= client_min_messages);
		}

		/*
		 * We can use errfinish() for the rest, but we don't want it to call
		 * any error context routines a second time.  Since we know we are
		 * about to exit, it should be OK to just clear the context stack.
		 */
		error_context_stack = NULL;

		errfinish(0);
	}

	/* We mustn't return... */
	ExceptionalCondition("pg_re_throw tried to return", "FailedAssertion",
						 __FILE__, __LINE__);

	/*
	 * Since ExceptionalCondition isn't declared noreturn because of
	 * TrapMacro(), we need this to keep gcc from complaining.
	 */
	abort();
}


/*
 * Initialization of error output file
 */
void
DebugFileOpen(void)
{
	int			fd,
				istty;

	if (OutputFileName[0])
	{
		/*
		 * A debug-output file name was given.
		 *
		 * Make sure we can write the file, and find out if it's a tty.
		 */
		if ((fd = open(OutputFileName, O_CREAT | O_APPEND | O_WRONLY,
					   0666)) < 0)
			ereport(FATAL,
					(errcode_for_file_access(),
				  errmsg("could not open file \"%s\": %m", OutputFileName)));
		istty = isatty(fd);
		close(fd);

		/*
		 * Redirect our stderr to the debug output file.
		 */
		if (!freopen(OutputFileName, "a", stderr))
			ereport(FATAL,
					(errcode_for_file_access(),
					 errmsg("could not reopen file \"%s\" as stderr: %m",
							OutputFileName)));

		/*
		 * If the file is a tty and we're running under the postmaster, try to
		 * send stdout there as well (if it isn't a tty then stderr will block
		 * out stdout, so we may as well let stdout go wherever it was going
		 * before).
		 */
		if (istty && IsUnderPostmaster)
			if (!freopen(OutputFileName, "a", stdout))
				ereport(FATAL,
						(errcode_for_file_access(),
						 errmsg("could not reopen file \"%s\" as stdout: %m",
								OutputFileName)));
	}
}


#ifdef HAVE_SYSLOG

/*
 * Set or update the parameters for syslog logging
 */
void
set_syslog_parameters(const char *ident, int facility)
{
	/*
	 * guc.c is likely to call us repeatedly with same parameters, so don't
	 * thrash the syslog connection unnecessarily.	Also, we do not re-open
	 * the connection until needed, since this routine will get called whether
	 * or not Log_destination actually mentions syslog.
	 *
	 * Note that we make our own copy of the ident string rather than relying
	 * on guc.c's.  This may be overly paranoid, but it ensures that we cannot
	 * accidentally free a string that syslog is still using.
	 */
	if (syslog_ident == NULL || strcmp(syslog_ident, ident) != 0 ||
		syslog_facility != facility)
	{
		if (openlog_done)
		{
			closelog();
			openlog_done = false;
		}
		if (syslog_ident)
			free(syslog_ident);
		syslog_ident = strdup(ident);
		/* if the strdup fails, we will cope in write_syslog() */
		syslog_facility = facility;
	}
}


/*
 * Write a message line to syslog
 */
static void
write_syslog(int level, const char *line)
{
	static unsigned long seq = 0;

	int			len;
	const char *nlpos;

	/* Open syslog connection if not done yet */
	if (!openlog_done)
	{
		openlog(syslog_ident ? syslog_ident : "postgres",
				LOG_PID | LOG_NDELAY | LOG_NOWAIT,
				syslog_facility);
		openlog_done = true;
	}

	/*
	 * We add a sequence number to each log message to suppress "same"
	 * messages.
	 */
	seq++;

	/*
	 * Our problem here is that many syslog implementations don't handle long
	 * messages in an acceptable manner. While this function doesn't help that
	 * fact, it does work around by splitting up messages into smaller pieces.
	 *
	 * We divide into multiple syslog() calls if message is too long or if the
	 * message contains embedded newline(s).
	 */
	len = strlen(line);
	nlpos = strchr(line, '\n');
	if (len > PG_SYSLOG_LIMIT || nlpos != NULL)
	{
		int			chunk_nr = 0;

		while (len > 0)
		{
			char		buf[PG_SYSLOG_LIMIT + 1];
			int			buflen;
			int			i;

			/* if we start at a newline, move ahead one char */
			if (line[0] == '\n')
			{
				line++;
				len--;
				/* we need to recompute the next newline's position, too */
				nlpos = strchr(line, '\n');
				continue;
			}

			/* copy one line, or as much as will fit, to buf */
			if (nlpos != NULL)
				buflen = nlpos - line;
			else
				buflen = len;
			buflen = Min(buflen, PG_SYSLOG_LIMIT);
			memcpy(buf, line, buflen);
			buf[buflen] = '\0';

			/* trim to multibyte letter boundary */
			buflen = pg_mbcliplen(buf, buflen, buflen);
			if (buflen <= 0)
				return;
			buf[buflen] = '\0';

			/* already word boundary? */
			if (line[buflen] != '\0' &&
				!isspace((unsigned char) line[buflen]))
			{
				/* try to divide at word boundary */
				i = buflen - 1;
				while (i > 0 && !isspace((unsigned char) buf[i]))
					i--;

				if (i > 0)		/* else couldn't divide word boundary */
				{
					buflen = i;
					buf[i] = '\0';
				}
			}

			chunk_nr++;

			syslog(level, "[%lu-%d] %s", seq, chunk_nr, buf);
			line += buflen;
			len -= buflen;
		}
	}
	else
	{
		/* message short enough */
		syslog(level, "[%lu] %s", seq, line);
	}
}
#endif   /* HAVE_SYSLOG */

#ifdef WIN32
/*
 * Write a message line to the windows event log
 */
static void
write_eventlog(int level, const char *line, int len)
{
	WCHAR	   *utf16;
	int			eventlevel = EVENTLOG_ERROR_TYPE;
	static HANDLE evtHandle = INVALID_HANDLE_VALUE;

	if (evtHandle == INVALID_HANDLE_VALUE)
	{
		evtHandle = RegisterEventSource(NULL, "PostgreSQL");
		if (evtHandle == NULL)
		{
			evtHandle = INVALID_HANDLE_VALUE;
			return;
		}
	}

	switch (level)
	{
		case DEBUG5:
		case DEBUG4:
		case DEBUG3:
		case DEBUG2:
		case DEBUG1:
		case LOG:
		case COMMERROR:
		case INFO:
		case NOTICE:
			eventlevel = EVENTLOG_INFORMATION_TYPE;
			break;
		case WARNING:
			eventlevel = EVENTLOG_WARNING_TYPE;
			break;
		case ERROR:
		case FATAL:
		case PANIC:
		default:
			eventlevel = EVENTLOG_ERROR_TYPE;
			break;
	}

	/*
	 * Convert message to UTF16 text and write it with ReportEventW, but
	 * fall-back into ReportEventA if conversion failed.
	 *
	 * Also verify that we are not on our way into error recursion trouble due
	 * to error messages thrown deep inside pgwin32_toUTF16().
	 */
	if (GetDatabaseEncoding() != GetPlatformEncoding() &&
		!in_error_recursion_trouble())
	{
		utf16 = pgwin32_toUTF16(line, len, NULL);
		if (utf16)
		{
			ReportEventW(evtHandle,
						 eventlevel,
						 0,
						 0,		/* All events are Id 0 */
						 NULL,
						 1,
						 0,
						 (LPCWSTR *) &utf16,
						 NULL);

			pfree(utf16);
			return;
		}
	}
	ReportEventA(evtHandle,
				 eventlevel,
				 0,
				 0,				/* All events are Id 0 */
				 NULL,
				 1,
				 0,
				 &line,
				 NULL);
}
#endif   /* WIN32 */

static void
write_console(const char *line, int len)
{
#ifdef WIN32

	/*
	 * WriteConsoleW() will fail of stdout is redirected, so just fall through
	 * to writing unconverted to the logfile in this case.
	 */
	if (GetDatabaseEncoding() != GetPlatformEncoding() &&
		!in_error_recursion_trouble() &&
		!redirection_done)
	{
		WCHAR	   *utf16;
		int			utf16len;

		utf16 = pgwin32_toUTF16(line, len, &utf16len);
		if (utf16 != NULL)
		{
			HANDLE		stdHandle;
			DWORD		written;

			stdHandle = GetStdHandle(STD_ERROR_HANDLE);
			if (WriteConsoleW(stdHandle, utf16, utf16len, &written, NULL))
			{
				pfree(utf16);
				return;
			}

			/*
			 * In case WriteConsoleW() failed, fall back to writing the
			 * message unconverted.
			 */
			pfree(utf16);
		}
	}
#else

	/*
	 * Conversion on non-win32 platform is not implemented yet. It requires
	 * non-throw version of pg_do_encoding_conversion(), that converts
	 * unconvertable characters to '?' without errors.
	 */
#endif

	write(fileno(stderr), line, len);
}

/*
 * setup formatted_log_time, for consistent times between CSV and regular logs
 */
static void
setup_formatted_log_time(void)
{
	struct timeval tv;
	pg_time_t	stamp_time;
	pg_tz	   *tz;
	char		msbuf[8];

	gettimeofday(&tv, NULL);
	stamp_time = (pg_time_t) tv.tv_sec;

	/*
	 * Normally we print log timestamps in log_timezone, but during startup we
	 * could get here before that's set. If so, fall back to gmt_timezone
	 * (which guc.c ensures is set up before Log_line_prefix can become
	 * nonempty).
	 */
	tz = log_timezone ? log_timezone : gmt_timezone;

	pg_strftime(formatted_log_time, FORMATTED_TS_LEN,
	/* leave room for milliseconds... */
				"%Y-%m-%d %H:%M:%S     %Z",
				pg_localtime(&stamp_time, tz));

	/* 'paste' milliseconds into place... */
	sprintf(msbuf, ".%03d", (int) (tv.tv_usec / 1000));
	strncpy(formatted_log_time + 19, msbuf, 4);
}

/*
 * setup formatted_start_time
 */
static void
setup_formatted_start_time(void)
{
	pg_time_t	stamp_time = (pg_time_t) MyStartTime;
	pg_tz	   *tz;

	/*
	 * Normally we print log timestamps in log_timezone, but during startup we
	 * could get here before that's set. If so, fall back to gmt_timezone
	 * (which guc.c ensures is set up before Log_line_prefix can become
	 * nonempty).
	 */
	tz = log_timezone ? log_timezone : gmt_timezone;

	pg_strftime(formatted_start_time, FORMATTED_TS_LEN,
				"%Y-%m-%d %H:%M:%S %Z",
				pg_localtime(&stamp_time, tz));
}

/*
 * Format tag info for log lines; append to the provided buffer.
 */
static void
log_line_prefix(StringInfo buf, ErrorData *edata)
{
	/* static counter for line numbers */
	static long log_line_number = 0;

	/* has counter been reset in current process? */
	static int	log_my_pid = 0;

	int			format_len;
	int			i;

	/*
	 * This is one of the few places where we'd rather not inherit a static
	 * variable's value from the postmaster.  But since we will, reset it when
	 * MyProcPid changes. MyStartTime also changes when MyProcPid does, so
	 * reset the formatted start timestamp too.
	 */
	if (log_my_pid != MyProcPid)
	{
		log_line_number = 0;
		log_my_pid = MyProcPid;
		formatted_start_time[0] = '\0';
	}
	log_line_number++;

	if (Log_line_prefix == NULL)
		return;					/* in case guc hasn't run yet */

	format_len = strlen(Log_line_prefix);

	for (i = 0; i < format_len; i++)
	{
		if (Log_line_prefix[i] != '%')
		{
			/* literal char, just copy */
			appendStringInfoChar(buf, Log_line_prefix[i]);
			continue;
		}
		/* go to char after '%' */
		i++;
		if (i >= format_len)
			break;				/* format error - ignore it */

		/* process the option */
		switch (Log_line_prefix[i])
		{
			case 'a':
				if (MyProcPort)
				{
					const char *appname = application_name;

					if (appname == NULL || *appname == '\0')
						appname = _("[unknown]");
					appendStringInfo(buf, "%s", appname);
				}
				break;
			case 'u':
				if (MyProcPort)
				{
					const char *username = MyProcPort->user_name;

					if (username == NULL || *username == '\0')
						username = _("[unknown]");
					appendStringInfo(buf, "%s", username);
				}
				break;
			case 'd':
				if (MyProcPort)
				{
					const char *dbname = MyProcPort->database_name;

					if (dbname == NULL || *dbname == '\0')
						dbname = _("[unknown]");
					appendStringInfo(buf, "%s", dbname);
				}
				break;
			case 'c':
				appendStringInfo(buf, "%lx.%x", (long) (MyStartTime), MyProcPid);
				break;
			case 'p':
				appendStringInfo(buf, "%d", MyProcPid);
				break;
			case 'l':
				appendStringInfo(buf, "%ld", log_line_number);
				break;
			case 'm':
				setup_formatted_log_time();
				appendStringInfoString(buf, formatted_log_time);
				break;
			case 't':
				{
					pg_time_t	stamp_time = (pg_time_t) time(NULL);
					pg_tz	   *tz;
					char		strfbuf[128];

					tz = log_timezone ? log_timezone : gmt_timezone;

					pg_strftime(strfbuf, sizeof(strfbuf),
								"%Y-%m-%d %H:%M:%S %Z",
								pg_localtime(&stamp_time, tz));
					appendStringInfoString(buf, strfbuf);
				}
				break;
			case 's':
				if (formatted_start_time[0] == '\0')
					setup_formatted_start_time();
				appendStringInfoString(buf, formatted_start_time);
				break;
			case 'i':
				if (MyProcPort)
				{
					const char *psdisp;
					int			displen;

					psdisp = get_ps_display(&displen);
					appendBinaryStringInfo(buf, psdisp, displen);
				}
				break;
			case 'r':
				if (MyProcPort && MyProcPort->remote_host)
				{
					appendStringInfo(buf, "%s", MyProcPort->remote_host);
					if (MyProcPort->remote_port &&
						MyProcPort->remote_port[0] != '\0')
						appendStringInfo(buf, "(%s)",
										 MyProcPort->remote_port);
				}
				break;
			case 'h':
				if (MyProcPort && MyProcPort->remote_host)
					appendStringInfo(buf, "%s", MyProcPort->remote_host);
				break;
			case 'q':
				/* in postmaster and friends, stop if %q is seen */
				/* in a backend, just ignore */
				if (MyProcPort == NULL)
					i = format_len;
				break;
			case 'v':
				/* keep VXID format in sync with lockfuncs.c */
				if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
					appendStringInfo(buf, "%d/%u",
									 MyProc->backendId, MyProc->lxid);
				break;
			case 'x':
				appendStringInfo(buf, "%u", GetTopTransactionIdIfAny());
				break;
			case 'e':
				appendStringInfoString(buf, unpack_sql_state(edata->sqlerrcode));
				break;
			case '%':
				appendStringInfoChar(buf, '%');
				break;
			default:
				/* format error - ignore it */
				break;
		}
	}
}

/*
 * append a CSV'd version of a string to a StringInfo
 * We use the PostgreSQL defaults for CSV, i.e. quote = escape = '"'
 * If it's NULL, append nothing.
 */
static inline void
appendCSVLiteral(StringInfo buf, const char *data)
{
	const char *p = data;
	char		c;

	/* avoid confusing an empty string with NULL */
	if (p == NULL)
		return;

	appendStringInfoCharMacro(buf, '"');
	while ((c = *p++) != '\0')
	{
		if (c == '"')
			appendStringInfoCharMacro(buf, '"');
		appendStringInfoCharMacro(buf, c);
	}
	appendStringInfoCharMacro(buf, '"');
}

/*
 * Constructs the error message, depending on the Errordata it gets, in a CSV
 * format which is described in doc/src/sgml/config.sgml.
 */
static void
write_csvlog(ErrorData *edata)
{
	StringInfoData buf;
	bool		print_stmt = false;

	/* static counter for line numbers */
	static long log_line_number = 0;

	/* has counter been reset in current process? */
	static int	log_my_pid = 0;

	/*
	 * This is one of the few places where we'd rather not inherit a static
	 * variable's value from the postmaster.  But since we will, reset it when
	 * MyProcPid changes.
	 */
	if (log_my_pid != MyProcPid)
	{
		log_line_number = 0;
		log_my_pid = MyProcPid;
		formatted_start_time[0] = '\0';
	}
	log_line_number++;

	initStringInfo(&buf);

	/*
	 * timestamp with milliseconds
	 *
	 * Check if the timestamp is already calculated for the syslog message,
	 * and use it if so.  Otherwise, get the current timestamp.  This is done
	 * to put same timestamp in both syslog and csvlog messages.
	 */
	if (formatted_log_time[0] == '\0')
		setup_formatted_log_time();

	appendStringInfoString(&buf, formatted_log_time);
	appendStringInfoChar(&buf, ',');

	/* username */
	if (MyProcPort)
		appendCSVLiteral(&buf, MyProcPort->user_name);
	appendStringInfoChar(&buf, ',');

	/* database name */
	if (MyProcPort)
		appendCSVLiteral(&buf, MyProcPort->database_name);
	appendStringInfoChar(&buf, ',');

	/* Process id  */
	if (MyProcPid != 0)
		appendStringInfo(&buf, "%d", MyProcPid);