Added functionality to reload configuration file periodically.

README.md

@@ -52,7 +52,10 @@ Output:
 
 You can either configure the appenders and log levels manually (as above), or provide a 
 configuration file (`log4js.configure('path/to/file.json')`) explicitly, or just let log4js look for a file called `log4js.json` (it looks in the current directory first, then the require paths, and finally looks for the default config included in the same directory as the `log4js.js` file). 
-An example file can be found in `test/log4js.json`. An example config file with log rolling is in `test/with-log-rolling.json`
+An example file can be found in `test/log4js.json`. An example config file with log rolling is in `test/with-log-rolling.json`.
+By default, the configuration file is checked for changes every 60 seconds, and if changed, reloaded. This allows changes to logging levels
+to occur without restarting the application.
+
 You can also pass an object to the configure function, which has the same properties as the json versions.
 
 ## connect/express logger

lib/log4js.js

@@ -173,6 +173,10 @@ function configureLevels(levels) {
                 getLogger(category).setLevel(levels[category]);
             }
         }
+    } else {
+        for (l in loggers) {
+            loggers[l].setLevel();
+        }
     }
 }
 
@@ -343,21 +347,6 @@ function fileExists (filename) {
     }
 }
 
-function configure (configurationFileOrObject) {
-    var config = configurationFileOrObject;
-    if (typeof(config) === "string") {
-	config = JSON.parse(fs.readFileSync(config, "utf8"));
-    }
-    if (config) {
-	try {
-	    configureAppenders(config.appenders, fileAppender, consoleAppender);
-	    configureLevels(config.levels);
-        } catch (e) {
-	    throw new Error("Problem reading log4js config " + sys.inspect(config) + ". Error was \"" + e.message + "\" ("+e.stack+")");
-        }
-    }
-}
-
 function findConfiguration() {
     //add current directory onto the list of configPaths
     var paths = ['.'].concat(require.paths);
@@ -377,6 +366,79 @@ function findConfiguration() {
     return undefined;
 }
 
+function loadConfigurationFile(filename) {
+    filename = filename || findConfiguration();
+    if (filename) {
+        return JSON.parse(fs.readFileSync(filename, "utf8"));
+    }
+    return undefined;
+}
+
+function configureOnceOff(config) {
+    if (config) {
+        try {
+            configureAppenders(config.appenders, fileAppender, consoleAppender);
+            configureLevels(config.levels);
+        } catch (e) {
+            throw new Error("Problem reading log4js config " + sys.inspect(config) + ". Error was \"" + e.message + "\" ("+e.stack+")");
+        }
+    }
+}
+
+var configState = {};
+
+function reloadConfiguration() {
+    var filename = configState.filename || findConfiguration(),
+    mtime;
+    if (!filename) {
+        // can't find anything to reload
+        return;
+    }
+    try {
+        mtime = fs.statSync(filename).mtime;
+    } catch (e) {
+        getLogger('log4js').warn('Failed to load configuration file ' + filename);
+        return;
+    }
+    if (configState.lastFilename && configState.lastFilename === filename) {
+        if (mtime.getTime() > configState.lastMTime.getTime()) {
+            configState.lastMTime = mtime;
+        } else {
+            filename = null;
+        }
+    } else {
+        configState.lastFilename = filename;
+        configState.lastMTime = mtime;
+    }
+    configureOnceOff(loadConfigurationFile(filename));
+}
+
+function initReloadConfiguration(filename, options) {
+    if (configState.timerId) {
+        clearInterval(configState.timerId);
+        delete configState.timerId;
+    }
+    configState.filename = filename;
+    configState.timerId = setInterval(reloadConfiguration, options.reloadSecs*1000);
+}
+
+function configure (configurationFileOrObject, options) {
+    var config = configurationFileOrObject;
+    if (config === undefined || config === null || typeof(config) === 'string') {
+        options = options || { reloadSecs: 60 };
+        if (options.reloadSecs) {
+            initReloadConfiguration(config, options);
+        }
+        configureOnceOff(loadConfigurationFile(config));
+    } else {
+        options = options || {};
+        if (options.reloadSecs) {
+            getLogger('log4js').warn('Ignoring configuration reload parameter for "object" configuration.');
+        }
+        configureOnceOff(config);
+    }
+}
+
 function replaceConsole(logger) {
     function replaceWith(fn) {
         return function() {

test/logging.js

@@ -545,6 +545,71 @@ vows.describe('log4js').addBatch({
 
             assert.equal(logEvent.data[0], "This should go to the appender defined in firstLog4js");
         }
+    },
+    'configuration reload' : {
+        topic: function() {
+            var pathsChecked = [],
+            messages = [],
+            logger,
+            modulePath = require('path').normalize(__dirname + '/../lib/log4js.json'),
+            fakeFS = {
+                config: { appenders: [ { type: 'console', layout: { type: 'messagePassThrough' } } ],
+                          levels: { 'a-test' : 'INFO' } },
+                readFileSync: function (file, encoding) {
+                    assert.equal(file, modulePath);
+                    assert.equal(encoding, 'utf8');
+                    return JSON.stringify(fakeFS.config);
+                },
+                statSync: function (path) {
+                    pathsChecked.push(path);
+                    if (path === modulePath) {
+                        return { mtime: new Date() };
+                    } else {
+                        throw new Error("no such file");
+                    }
+                }
+            },
+            fakeConsole = {
+                log : function (msg) { messages.push(msg); },
+                info: this.log,
+                warn: this.log,
+                debug: this.log,
+                error: this.log
+            },
+            setIntervalCallback,
+            fakeSetInterval = function(cb, timeout) {
+                setIntervalCallback = cb;
+            },
+            log4js = sandbox.require(
+                '../lib/log4js',
+                {
+                    requires: {
+                        'fs': fakeFS
+                    },
+                    globals: {
+                        'console': fakeConsole,
+                        'setInterval' : fakeSetInterval,
+                    }
+                }
+            );
+
+            logger = log4js.getLogger('a-test');
+            logger.info("info1");
+            logger.debug("debug2 - should be ignored");
+            delete fakeFS.config.levels;
+            setIntervalCallback();
+            logger.info("info3");
+            logger.debug("debug4");
+
+            return [ pathsChecked, messages, modulePath ];
+        },
+        'should configure log4js from first log4js.json found': function(args) {
+            var messages = args[1];
+            assert.length(messages, 3);
+            assert.equal(messages[0], 'info1');
+            assert.equal(messages[1], 'info3'); 
+            assert.equal(messages[2], 'debug4');
+        }
     }
 
 }).export(module);