Merge branch 'flush-on-exit'

lib/log4js.js

@@ -44,17 +44,20 @@
  * Website: http://log4js.berlios.de
  */
 var events = require('events')
+, async = require('async')
 , fs = require('fs')
 , path = require('path')
 , util = require('util')
 , layouts = require('./layouts')
 , levels = require('./levels')
-, LoggingEvent = require('./logger').LoggingEvent
-, Logger = require('./logger').Logger
+, loggerModule = require('./logger')
+, LoggingEvent = loggerModule.LoggingEvent
+, Logger = loggerModule.Logger
 , ALL_CATEGORIES = '[all]'
 , appenders = {}
 , loggers = {}
 , appenderMakers = {}
+, appenderShutdowns = {}
 , defaultConfig =   {
   appenders: [
     { type: "console" }
@@ -303,9 +306,42 @@ function loadAppender(appender) {
     appenderModule = require(appender);
   }
   module.exports.appenders[appender] = appenderModule.appender.bind(appenderModule);
+  if (appenderModule.shutdown) {
+    appenderShutdowns[appender] = appenderModule.shutdown.bind(appenderModule);
+  }
   appenderMakers[appender] = appenderModule.configure.bind(appenderModule);
 }
 
+/**
+ * Shutdown all log appenders. This will first disable all writing to appenders
+ * and then call the shutdown function each appender.
+ *
+ * @params {Function} cb - The callback to be invoked once all appenders have
+ *  shutdown. If an error occurs, the callback will be given the error object
+ *  as the first argument.
+ * @returns {void}
+ */
+function shutdown(cb) {
+  // First, disable all writing to appenders. This prevents appenders from
+  // not being able to be drained because of run-away log writes.
+  loggerModule.disableAllLogWrites();
+
+  // Next, get all the shutdown functions for appenders as an array.
+  var shutdownFunctions = Object.keys(appenderShutdowns).reduce(
+    function(accum, category) {
+      return accum.concat(appenderShutdowns[category]);
+    }, []);
+
+  // Call each of the shutdown functions.
+  async.forEach(
+    shutdownFunctions,
+    function(shutdownFn, done) {
+      shutdownFn(done);
+    },
+		cb
+  );
+}
+
 module.exports = {
   getLogger: getLogger,
   getDefaultLogger: getDefaultLogger,
@@ -315,6 +351,7 @@ module.exports = {
   loadAppender: loadAppender,
   clearAppenders: clearAppenders,
   configure: configure,
+  shutdown: shutdown,
   
   replaceConsole: replaceConsole,
   restoreConsole: restoreConsole,