Add multiprocess appender, pending tests

lib/appenders/multiprocess.js

@@ -0,0 +1,77 @@
+var log4js = require('../log4js');
+var layouts = require('../layouts');
+var net = require('net');
+var util = require('util');
+
+var LogServer = function createLogServer(config) {
+  var actualAppender = config.actualAppender;
+  var server = net.createServer(function serverCreated(clientSocket) {
+    clientSocket.on('connect', function clientConnected() {
+      var logMessage = '';
+      clientSocket.on('data', function chunkReceived(chunk) {
+        logMessage += chunk;
+      });
+      clientSocket.on('end', function gotChunks() {
+        try {
+          var loggingEvent = JSON.parse(logMessage);
+          deserializeLoggingEvent(loggingEvent);
+          actualAppender(loggingEvent);
+        } catch (e) {
+          // JSON.parse failed, just log the contents probably a naughty.
+          actualAppender(createLoggingEvent('ERROR', 'Unable to parse log: ' + logMessage));
+        }
+      })
+    });
+  });
+  server.listen(config.loggerPort || 5000, config.loggerHost || 'localhost');
+}
+
+function createLoggingEvent(level, message) {
+  return {
+    startTime: new Date(),
+    categoryName: 'log4js',
+    level: { toString: function () {
+      return level;
+    }},
+    data: [ message ]
+  };
+}
+
+function deserializeLoggingEvent(loggingEvent) {
+  loggingEvent.startTime = new Date(loggingEvent.startTime);
+  loggingEvent.level.toString = function levelToString() {
+    return loggingEvent.level.levelStr;
+  };
+}
+
+function workerAppender(config) {
+  return function log(loggingEvent) {
+    var socket = net.createConnection(config.loggerPort || 5000, config.loggerHost || 'localhost');
+    socket.on('connect', function socketConnected() {
+      socket.end(JSON.stringify(loggingEvent), 'utf8');
+    });
+  };
+}
+
+function createAppender(config) {
+  if (config.mode === 'master') {
+    var server = new LogServer(config);
+    return config.actualAppender;
+  } else {
+    return workerAppender(config);
+  }
+}
+
+function configure(config) {
+  var actualAppender;
+  if (config.appender && config.mode === 'master') {
+    log4js.loadAppender(config.appender.type);
+    actualAppender = log4js.appenderMakers[config.appender.type](config.appender);
+    config.actualAppender = actualAppender;
+  }
+  return createAppender(config);
+}
+
+exports.name = 'multiprocess';
+exports.appender = createAppender;
+exports.configure = configure;