elog.c

来自「postgresql8.3.4源码,开源数据库」· C语言 代码 · 共 2,491 行 · 第 1/5 页

	 */
	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->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->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->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;
	}
}


#ifndef PG_SYSLOG_LIMIT
#define PG_SYSLOG_LIMIT 128
#endif

/*
 * 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			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;
	}


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

/*
 * Format tag info for log lines; append to the provided buffer.
 */
static void
log_line_prefix(StringInfo buf)
{
	/* 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 '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);