elog.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

#if defined(ENOTEMPTY) && (ENOTEMPTY != EEXIST) /* same code on AIX */
		case ENOTEMPTY: /* Directory not empty */
#endif
			edata->sqlerrcode = ERRCODE_WRONG_OBJECT_TYPE;
			break;

			/* Insufficient resources */
		case ENOSPC:			/* No space left on device */
			edata->sqlerrcode = ERRCODE_DISK_FULL;
			break;

		case ENFILE:			/* File table overflow */
		case EMFILE:			/* Too many open files */
			edata->sqlerrcode = ERRCODE_INSUFFICIENT_RESOURCES;
			break;

			/* Hardware failure */
		case EIO:				/* I/O error */
			edata->sqlerrcode = ERRCODE_IO_ERROR;
			break;

			/* All else is classified as internal errors */
		default:
			edata->sqlerrcode = ERRCODE_INTERNAL_ERROR;
			break;
	}

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

/*
 * errcode_for_socket_access --- add SQLSTATE error code to the current error
 *
 * The SQLSTATE code is chosen based on the saved errno value.	We assume
 * that the failing operation was some type of socket access.
 *
 * NOTE: the primary error message string should generally include %m
 * when this is used.
 */
int
errcode_for_socket_access(void)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];

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

	switch (edata->saved_errno)
	{
			/* Loss of connection */
		case EPIPE:
#ifdef ECONNRESET
		case ECONNRESET:
#endif
			edata->sqlerrcode = ERRCODE_CONNECTION_FAILURE;
			break;

			/* All else is classified as internal errors */
		default:
			edata->sqlerrcode = ERRCODE_INTERNAL_ERROR;
			break;
	}

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


/*
 * This macro handles expansion of a format string and associated parameters;
 * it's common code for errmsg(), errdetail(), etc.  Must be called inside
 * a routine that is declared like "const char *fmt, ..." and has an edata
 * pointer set up.	The message is assigned to edata->targetfield, or
 * appended to it if appendval is true.
 *
 * Note: we pstrdup the buffer rather than just transferring its storage
 * to the edata field because the buffer might be considerably larger than
 * really necessary.
 */
#define EVALUATE_MESSAGE(targetfield, appendval)  \
	{ \
		char		   *fmtbuf; \
		StringInfoData	buf; \
		/* Internationalize the error format string */ \
		fmt = _(fmt); \
		/* Expand %m in format string */ \
		fmtbuf = expand_fmt_string(fmt, edata); \
		initStringInfo(&buf); \
		if ((appendval) && edata->targetfield) \
			appendStringInfo(&buf, "%s\n", edata->targetfield); \
		/* Generate actual output --- have to use appendStringInfoVA */ \
		for (;;) \
		{ \
			va_list		args; \
			bool		success; \
			va_start(args, fmt); \
			success = appendStringInfoVA(&buf, fmtbuf, args); \
			va_end(args); \
			if (success) \
				break; \
			enlargeStringInfo(&buf, buf.maxlen); \
		} \
		/* Done with expanded fmt */ \
		pfree(fmtbuf); \
		/* Save the completed message into the stack item */ \
		if (edata->targetfield) \
			pfree(edata->targetfield); \
		edata->targetfield = pstrdup(buf.data); \
		pfree(buf.data); \
	}


/*
 * errmsg --- add a primary error message text to the current error
 *
 * In addition to the usual %-escapes recognized by printf, "%m" in
 * fmt is replaced by the error message for the caller's value of errno.
 *
 * Note: no newline is needed at the end of the fmt string, since
 * ereport will provide one for the output methods that need it.
 */
int
errmsg(const char *fmt,...)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];
	MemoryContext oldcontext;

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

	EVALUATE_MESSAGE(message, false);

	MemoryContextSwitchTo(oldcontext);
	recursion_depth--;
	return 0;					/* return value does not matter */
}


/*
 * errmsg_internal --- add a primary error message text to the current error
 *
 * This is exactly like errmsg() except that strings passed to errmsg_internal
 * are customarily left out of the internationalization message dictionary.
 * This should be used for "can't happen" cases that are probably not worth
 * spending translation effort on.
 */
int
errmsg_internal(const char *fmt,...)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];
	MemoryContext oldcontext;

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

	EVALUATE_MESSAGE(message, false);

	MemoryContextSwitchTo(oldcontext);
	recursion_depth--;
	return 0;					/* return value does not matter */
}


/*
 * errdetail --- add a detail error message text to the current error
 */
int
errdetail(const char *fmt,...)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];
	MemoryContext oldcontext;

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

	EVALUATE_MESSAGE(detail, false);

	MemoryContextSwitchTo(oldcontext);
	recursion_depth--;
	return 0;					/* return value does not matter */
}


/*
 * errhint --- add a hint error message text to the current error
 */
int
errhint(const char *fmt,...)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];
	MemoryContext oldcontext;

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

	EVALUATE_MESSAGE(hint, false);

	MemoryContextSwitchTo(oldcontext);
	recursion_depth--;
	return 0;					/* return value does not matter */
}


/*
 * errcontext --- add a context error message text to the current error
 *
 * Unlike other cases, multiple calls are allowed to build up a stack of
 * context information.  We assume earlier calls represent more-closely-nested
 * states.
 */
int
errcontext(const char *fmt,...)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];
	MemoryContext oldcontext;

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

	EVALUATE_MESSAGE(context, true);

	MemoryContextSwitchTo(oldcontext);
	recursion_depth--;
	return 0;					/* return value does not matter */
}


/*
 * errfunction --- add reporting function name to the current error
 *
 * This is used when backwards compatibility demands that the function
 * name appear in messages sent to old-protocol clients.  Note that the
 * passed string is expected to be a non-freeable constant string.
 */
int
errfunction(const char *funcname)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];

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

	edata->funcname = funcname;
	edata->show_funcname = true;

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

/*
 * errposition --- add cursor position to the current error
 */
int
errposition(int cursorpos)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];

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

	edata->cursorpos = cursorpos;

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

/*
 * internalerrposition --- add internal cursor position to the current error
 */
int
internalerrposition(int cursorpos)
{
	ErrorData  *edata = &errordata[errordata_stack_depth];

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

	edata->internalpos = cursorpos;

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

/*
 * internalerrquery --- add internal query text to the current error
 *
 * Can also pass NULL to drop the internal query text entry.  This case
 * 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 */
}

/*
 * 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.
		 */
		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))
		return;					/* nothing to do */

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

	EVALUATE_MESSAGE(message, 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->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.
 */