got log rolling working, need to fix all the tests

lib/log4js.js

@@ -286,52 +286,44 @@ function consoleAppender (layout) {
  */
 function fileAppender (file, layout, logSize, numBackups, filePollInterval) {
     layout = layout || layouts.basicLayout;
-    var logFile = fs.createWriteStream(file, { flags: 'a', mode: 0644, encoding: 'utf8' });
+    numBackups = numBackups || 5;
+    filePollInterval = filePollInterval * 1000 || 30000;
 
-    if (logSize > 0) {
+    function setupLogRolling () {
-        setupLogRolling(logFile, file, logSize, numBackups || 5, (filePollInterval * 1000) || 30000);
-    }
-
-    //close the file on process exit.
-    process.on('exit', function() {
-        logFile.end();
-    });
-
-    return function(loggingEvent) {
-	logFile.write(layout(loggingEvent)+'\n');
-    };
-}
-
-function setupLogRolling (logFile, filename, logSize, numBackups, filePollInterval) {
         fs.watchFile(
-        filename,
+            file,
             {
                 persistent: false,
                 interval: filePollInterval
             },
             function (curr, prev) {
                 if (curr.size >= logSize) {
-                rollThatLog(logFile, filename, numBackups);
+                    rollThatLog();
                 }
             }
         );
     }
 
-function rollThatLog (logFile, filename, numBackups) {
+    function rollThatLog () {
-    //first close the current one.
-    logFile.end();
         //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))) {
+                if (fileExists(file + '.' + (i-1))) {
-                fs.renameSync(filename+'.'+(i-1), filename+'.'+i);
+                    console.debug("Renaming " + file + '.' + (i-1) + ' -> ' + file + '.' + i);
+                    fs.renameSync(file+'.'+(i-1), file+'.'+i);
                 }
             } else {
-            fs.renameSync(filename, filename+'.1');
+                console.debug("Renaming " + file + " -> " + file + ".1");
+                fs.renameSync(file, file+'.1');
             }
         }
-    //open it up again
+        //let's make a new file
-    logFile = fs.createWriteStream(filename, { flags: 'a', mode: 0644, encoding: "utf8" });
+        var newLogFileFD = fs.openSync(file, 'a', 0644)
+      , oldLogFileFD = logFile.fd;
+        console.debug("made a new logFile ", newLogFileFD);
+        logFile.fd = newLogFileFD;
+        console.debug("closing old log file fd ", oldLogFileFD);
+        fs.close(oldLogFileFD);
     }
 
     function fileExists (filename) {
@@ -343,6 +335,59 @@ function fileExists (filename) {
         }
     }
 
+    function openTheStream() {
+        console.debug("Creating the write Stream with file ", file);
+        var stream = fs.createWriteStream(file, { flags: 'a', mode: 0644, encoding: 'utf8' });
+        stream.on("open", function() {
+            canWrite = true;
+            console.debug("Stream is open, writing %d buffered events", logEventBuffer.length);
+            while (logEventBuffer.length > 0 && canWrite) {
+                canWrite = writeToLog(logEventBuffer.shift());
+            }
+        });
+        stream.on("error", function (err) {
+            console.error("Error happened ", err);
+        });
+        stream.on("drain", function() {
+            canWrite = true;
+            while (logEventBuffer.length > 0 && canWrite) {
+                canWrite = writeToLog(logEventBuffer.shift());
+            }
+        });
+        return stream;
+    }
+
+
+    var logEventBuffer = []
+  , canWrite = false
+  , logFile = openTheStream();
+
+    if (logSize > 0) {
+        setupLogRolling();
+    }
+
+    //close the file on process exit.
+    process.on('exit', function() {
+        console.debug("Buffer contains %d events", logEventBuffer.length);
+        logFile.end();
+        logFile.destroy();
+    });
+
+    function writeToLog(loggingEvent) {
+	return logFile.write(layout(loggingEvent)+'\n', "utf8");
+    }
+
+    return function(loggingEvent) {
+        //because the log stream is opened asynchronously, we don't want to write
+        //until it is ready.
+        if (canWrite) {
+            canWrite = writeToLog(loggingEvent);
+        } else {
+            logEventBuffer.push(loggingEvent);
+        }
+    };
+}
+
 function configure (configurationFileOrObject) {
     var config = configurationFileOrObject;
     if (typeof(config) === "string") {