Persist logging config across invocations

lib/log4js.js

@@ -44,17 +44,13 @@
  * @static
  * Website: http://log4js.berlios.de
  */
-module.exports = function (fileSystem, standardOutput, configPaths) {
 var events = require('events'),
 path = require('path'),
 sys = require('sys'),
-    fs = fileSystem || require('fs'),
-    standardOutput = standardOutput || sys.puts,
-    configPaths = configPaths || require.paths,
 DEFAULT_CATEGORY = '[default]',
 ALL_CATEGORIES = '[all]',
-    loggers = {},
 appenders = {},
+loggers = {},
 levels = {
     ALL: new Level(Number.MIN_VALUE, "ALL", "grey"),
     TRACE: new Level(5000, "TRACE", "blue"),
@@ -66,22 +62,22 @@ module.exports = function (fileSystem, standardOutput, configPaths) {
     OFF: new Level(Number.MAX_VALUE, "OFF", "grey")  
 },
 appenderMakers = {
-	"file": function(config) {
+    "file": function(config, fileAppender) {
 	var layout;
 	if (config.layout) {
 	    layout = layoutMakers[config.layout.type](config.layout);
 	}
 	return fileAppender(config.filename, layout, config.maxLogSize, config.backups, config.pollInterval);
     },
-	"console": function(config) {
+    "console": function(config, fileAppender, consoleAppender) {
 	var layout;
 	if (config.layout) {
 	    layout = layoutMakers[config.layout.type](config.layout);
 	}
 	return consoleAppender(layout);
     },
-	"logLevelFilter": function(config) {
+    "logLevelFilter": function(config, fileAppender, consoleAppender) {
-	    var appender = appenderMakers[config.appender.type](config.appender);
+	var appender = appenderMakers[config.appender.type](config.appender, fileAppender, consoleAppender);
 	return logLevelFilter(config.level, appender);
     }
 },
@@ -158,10 +154,11 @@ module.exports = function (fileSystem, standardOutput, configPaths) {
 	    loggers[category].addListener("log", appender);
 	}
     });
+    appenders.count = appenders.count ? appenders.count++ : 1;
 }
 
 function clearAppenders () {
-	appenders = [];
+    appenders = {};
     for (var logger in loggers) {
 	if (loggers.hasOwnProperty(logger)) {
 	    loggers[logger].removeAllListeners("log");
@@ -169,42 +166,11 @@ module.exports = function (fileSystem, standardOutput, configPaths) {
     }
 }
 
-    function configure (configurationFile) {
+function configureAppenders(appenderList, fileAppender, consoleAppender) {
-        if (configurationFile) {
-            try {
-	        var config = JSON.parse(fs.readFileSync(configurationFile, "utf8"));
-	        configureAppenders(config.appenders);
-	        configureLevels(config.levels);
-            } catch (e) {
-                throw new Error("Problem reading log4js config file " + configurationFile + ". Error was " + e.message);
-            }
-        }
-    }
-
-    function findConfiguration() {
-        //add current directory onto the list of configPaths
-        var paths = ['.'].concat(configPaths);
-        //add this module's directory to the end of the list, so that we pick up the default config
-        paths.push(__dirname);
-        var pathsWithConfig = paths.filter( function (pathToCheck) {
-            try {
-                fs.statSync(path.join(pathToCheck, "log4js.json"));
-                return true;
-            } catch (e) {
-                return false;
-            }
-        });
-        if (pathsWithConfig.length > 0) {
-            return path.join(pathsWithConfig[0], 'log4js.json');
-        }
-        return undefined;
-    }
-
-    function configureAppenders(appenderList) {
     clearAppenders();
     if (appenderList) {
 	appenderList.forEach(function(appenderConfig) {
-		var appender = appenderMakers[appenderConfig.type](appenderConfig);
+	    var appender = appenderMakers[appenderConfig.type](appenderConfig, fileAppender, consoleAppender);
 	    if (appender) {
 		addAppender(appender, appenderConfig.category);    
 	    } else {
@@ -338,78 +304,6 @@ module.exports = function (fileSystem, standardOutput, configPaths) {
     return getLogger(DEFAULT_CATEGORY); 
 }
 
-    function consoleAppender (layout) {
-	layout = layout || colouredLayout;
-	return function(loggingEvent) {
-	    standardOutput(layout(loggingEvent));
-	};  
-    }
-
-    /**
-     * File Appender writing the logs to a text file. Supports rolling of logs by size.
-     * 
-     * @param file file log messages will be written to
-     * @param layout a function that takes a logevent and returns a string (defaults to basicLayout).
-     * @param logSize - the maximum size (in bytes) for a log file, if not provided then logs won't be rotated.
-     * @param numBackups - the number of log files to keep after logSize has been reached (default 5)
-     * @param filePollInterval - the time in seconds between file size checks (default 30s)
-     */
-    function fileAppender (file, layout, logSize, numBackups, filePollInterval) {
-	layout = layout || basicLayout;	
-	//syncs are generally bad, but we need 
-	//the file to be open before we start doing any writing.
-	var logFile = fs.openSync(file, 'a', 0644);
-
-        if (logSize > 0) {
-            setupLogRolling(logFile, file, logSize, numBackups || 5, (filePollInterval * 1000) || 30000);
-        }
-	
-	return function(loggingEvent) {
-	    fs.write(logFile, layout(loggingEvent)+'\n', null, "utf8");
-	};
-    }
-
-    function setupLogRolling (logFile, filename, logSize, numBackups, filePollInterval) {
-        fs.watchFile(filename, 
-                     { 
-                         persistent: false, 
-                         interval: filePollInterval 
-                     },
-                     function (curr, prev) {
-                         if (curr.size >= logSize) {
-                             rollThatLog(logFile, filename, numBackups);
-                         }
-                     }
-                    );
-    }
-
-    function rollThatLog (logFile, filename, numBackups) {
-        //doing all of this fs stuff sync, because I don't want to lose any log events.
-        //first close the current one.
-        fs.closeSync(logFile);
-        //roll the backups (rename file.n-1 to file.n, where n <= numBackups)
-        for (var i=numBackups; i > 0; i--) {
-            if (i > 1) {
-                if (fileExists(filename + '.' + (i-1))) {
-                    fs.renameSync(filename+'.'+(i-1), filename+'.'+i);
-                }
-            } else {
-                fs.renameSync(filename, filename+'.1');
-            }
-        }
-        //open it up again
-        logFile = fs.openSync(filename, 'a', 0644);
-    }
-
-    function fileExists (filename) {
-        try {
-            fs.statSync(filename);
-            return true;
-        } catch (e) {
-            return false;
-        }
-    }
-
 function logLevelFilter (levelString, appender) {
     var level = Level.toLevel(levelString);
     return function(logEvent) {
@@ -618,6 +512,116 @@ module.exports = function (fileSystem, standardOutput, configPaths) {
 
 };
 
+
+module.exports = function (fileSystem, standardOutput, configPaths) {
+    var fs = fileSystem || require('fs'),
+    standardOutput = standardOutput || sys.puts,
+    configPaths = configPaths || require.paths;
+
+
+    function consoleAppender (layout) {
+	layout = layout || colouredLayout;
+	return function(loggingEvent) {
+	    standardOutput(layout(loggingEvent));
+	};  
+    }
+
+    /**
+     * File Appender writing the logs to a text file. Supports rolling of logs by size.
+     * 
+     * @param file file log messages will be written to
+     * @param layout a function that takes a logevent and returns a string (defaults to basicLayout).
+     * @param logSize - the maximum size (in bytes) for a log file, if not provided then logs won't be rotated.
+     * @param numBackups - the number of log files to keep after logSize has been reached (default 5)
+     * @param filePollInterval - the time in seconds between file size checks (default 30s)
+     */
+    function fileAppender (file, layout, logSize, numBackups, filePollInterval) {
+	layout = layout || basicLayout;	
+	//syncs are generally bad, but we need 
+	//the file to be open before we start doing any writing.
+	var logFile = fs.openSync(file, 'a', 0644);
+
+        if (logSize > 0) {
+            setupLogRolling(logFile, file, logSize, numBackups || 5, (filePollInterval * 1000) || 30000);
+        }
+	
+	return function(loggingEvent) {
+	    fs.write(logFile, layout(loggingEvent)+'\n', null, "utf8");
+	};
+    }
+
+    function setupLogRolling (logFile, filename, logSize, numBackups, filePollInterval) {
+        fs.watchFile(filename, 
+                     { 
+                         persistent: false, 
+                         interval: filePollInterval 
+                     },
+                     function (curr, prev) {
+                         if (curr.size >= logSize) {
+                             rollThatLog(logFile, filename, numBackups);
+                         }
+                     }
+                    );
+    }
+
+    function rollThatLog (logFile, filename, numBackups) {
+        //doing all of this fs stuff sync, because I don't want to lose any log events.
+        //first close the current one.
+        fs.closeSync(logFile);
+        //roll the backups (rename file.n-1 to file.n, where n <= numBackups)
+        for (var i=numBackups; i > 0; i--) {
+            if (i > 1) {
+                if (fileExists(filename + '.' + (i-1))) {
+                    fs.renameSync(filename+'.'+(i-1), filename+'.'+i);
+                }
+            } else {
+                fs.renameSync(filename, filename+'.1');
+            }
+        }
+        //open it up again
+        logFile = fs.openSync(filename, 'a', 0644);
+    }
+
+    function fileExists (filename) {
+        try {
+            fs.statSync(filename);
+            return true;
+        } catch (e) {
+            return false;
+        }
+    }
+
+    function configure (configurationFile) {
+	if (configurationFile) {
+            try {
+	        var config = JSON.parse(fs.readFileSync(configurationFile, "utf8"));
+	        configureAppenders(config.appenders, fileAppender, consoleAppender);
+	        configureLevels(config.levels);
+            } catch (e) {
+                throw new Error("Problem reading log4js config file " + configurationFile + ". Error was \"" + e.message + "\" ("+e.stack+")");
+            }
+        }
+    }
+
+    function findConfiguration() {
+        //add current directory onto the list of configPaths
+        var paths = ['.'].concat(configPaths);
+        //add this module's directory to the end of the list, so that we pick up the default config
+        paths.push(__dirname);
+        var pathsWithConfig = paths.filter( function (pathToCheck) {
+            try {
+                fs.statSync(path.join(pathToCheck, "log4js.json"));
+                return true;
+            } catch (e) {
+                return false;
+            }
+        });
+        if (pathsWithConfig.length > 0) {
+            return path.join(pathsWithConfig[0], 'log4js.json');
+        }
+        return undefined;
+    }
+
     function replaceConsole(logger) {
         function replaceWith (fn) {
             return function() {
@@ -634,10 +638,13 @@ module.exports = function (fileSystem, standardOutput, configPaths) {
 
     }
 
+    //do we already have appenders?
+    if (!appenders.count) {
 	//set ourselves up if we can find a default log4js.json
 	configure(findConfiguration());
 	//replace console.log, etc with log4js versions
 	replaceConsole(getLogger("console"));
+    }
 
     return {
 	getLogger: getLogger,

test/logging.js

@@ -247,7 +247,9 @@ vows.describe('log4js').addBatch({
 
     'with no appenders defined' : {
         topic: function() {
-            var logger, message, log4js = require('../lib/log4js')(null, function (msg) { message = msg; } );
+            var logger, message, log4jsFn = require('../lib/log4js'), log4js;
+	    log4jsFn().clearAppenders();
+	    log4js = log4jsFn(null, function (msg) { message = msg; } );
 	    logger = log4js.getLogger("some-logger");
             logger.debug("This is a test");
             return message;
@@ -364,10 +366,15 @@ vows.describe('log4js').addBatch({
             },
             fakeConsoleLog = function (msg) { message = msg; }, 
             fakeRequirePath = [ '/a/b/c', '/some/other/path', '/path/to/config', '/some/later/directory' ],
-            log4js = require('../lib/log4js')(fakeFS, fakeConsoleLog, fakeRequirePath),
+	    log4jsFn = require('../lib/log4js'),
+            log4js, logger;
+	    
+	    log4jsFn().clearAppenders();
+	    log4js  = log4jsFn(fakeFS, fakeConsoleLog, fakeRequirePath);
             logger = log4js.getLogger('a-test');
             logger.debug("this is a test");
 
+
             return [ pathsChecked, message ];
         },
         
@@ -478,8 +485,8 @@ vows.describe('log4js').addBatch({
         topic: function() {
             var log4js = require('../lib/log4js')(), logEvents = [], logger;
             log4js.clearAppenders();
-            log4js.addAppender(log4js.logLevelFilter('ERROR', function(evt) { logEvents.push(evt); }));
+            log4js.addAppender(log4js.logLevelFilter('ERROR', function(evt) { logEvents.push(evt); }), "logLevelTest");
-            logger = log4js.getLogger();
+            logger = log4js.getLogger("logLevelTest");
             logger.debug('this should not trigger an event');
             logger.warn('neither should this');
             logger.error('this should, though');
@@ -535,6 +542,19 @@ vows.describe('log4js').addBatch({
             assert.equal(logEvent.message, "tracing");
             assert.equal(logEvent.level.toString(), "TRACE");
         }
+    },
+
+    'configuration persistence' : {
+	'should maintain appenders between requires': function () {
+	    var logEvent, firstLog4js = require('../lib/log4js')(), secondLog4js;
+	    firstLog4js.clearAppenders();
+	    firstLog4js.addAppender(function(evt) { logEvent = evt; });
+
+	    secondLog4js = require('../lib/log4js')();
+	    secondLog4js.getLogger().info("This should go to the appender defined in firstLog4js");
+	    
+	    assert.equal(logEvent.message, "This should go to the appender defined in firstLog4js");
+	}
     }
 
 }).export(module);