Working version of fully-async log rolling file appender - tests need fixing though

lib/appenders/file.js

@@ -1,6 +1,7 @@
 var layouts = require('../layouts')
 , path = require('path')
-, fs = require('fs');
+, fs = require('fs')
+, streams = require('../streams');
 
 /**
  * File Appender writing the logs to a text file. Supports rolling of logs by size.
@@ -18,132 +19,29 @@ function fileAppender (file, layout, logSize, numBackups) {
     //there has to be at least one backup if logSize has been specified
     numBackups = numBackups === 0 ? 1 : numBackups;
 
-    function setupLogRolling () {
-        try {
-            var stat = fs.statSync(file);
-            bytesWritten = stat.size;
-            if (bytesWritten >= logSize) {
-                rollThatLog();
-            }
-        } catch (e) {
-            //file does not exist
-            bytesWritten = 0;
-        }
-    }
-
-    function rollThatLog () {
-        function index(filename) {
-            return parseInt(filename.substring((path.basename(file) + '.').length), 10) || 0;
-        }
-
-        var nameMatcher = new RegExp('^' + path.basename(file));
-        function justTheLogFiles (item) {
-            return nameMatcher.test(item);
-        }
-
-        function byIndex(a, b) {
-            if (index(a) > index(b)) {
-                return 1;
-            } else if (index(a) < index(b) ) {
-                return -1;
-            } else {
-                return 0;
-            }
-        }
-
-        function increaseFileIndex (fileToRename) {
-            var idx = index(fileToRename);
-            if (idx < numBackups) {
-                //on windows, you can get a EEXIST error if you rename a file to an existing file
-                //so, we'll try to delete the file we're renaming to first
-                try {
-                    fs.unlinkSync(file + '.' + (idx+1));
-                } catch (e) {
-                    //couldn't delete, but that could be because it doesn't exist
-                    //try renaming anyway
-                }
-                fs.renameSync(path.join(path.dirname(file), fileToRename), file + '.' + (idx + 1));
-            }
-        }
-
-        //roll the backups (rename file.n to file.n+1, where n <= numBackups)
-        fs.readdirSync(path.dirname(file))
-          .filter(justTheLogFiles)
-            .sort(byIndex)
-              .reverse()
-                .forEach(increaseFileIndex);
-
-        //let's make a new file
-        var newLogFileFD = fs.openSync(file, 'a', 0644)
-      , oldLogFileFD = logFile.fd;
-        logFile.fd = newLogFileFD;
-        fs.close(oldLogFileFD);
-        //reset the counter
-        bytesWritten = 0;
-    }
-
-    function fileExists (filename) {
-        try {
-            fs.statSync(filename);
-            return true;
-        } catch (e) {
-            return false;
-        }
-    }
-
-    function openTheStream() {
-        var stream = fs.createWriteStream(file, { flags: 'a', mode: 0644, encoding: 'utf8' });
-        stream.on("open", function() {
-            canWrite = true;
-            flushBuffer();
-        });
+    function openTheStream(file, fileSize, numFiles) {
+        var stream = new streams.BufferedWriteStream(
+            new streams.RollingFileStream(
+                file,
+                fileSize,
+                numFiles
+            )
+        );
         stream.on("error", function (err) {
             console.error("log4js.fileAppender - Writing to file %s, error happened ", file, err);
         });
-        stream.on("drain", function() {
-            canWrite = true;
-            flushBuffer();
-            if (logEventBuffer.length > 0) {
-                writeToLog(logEventBuffer.shift());
-            }
-        });
         return stream;
     }
 
-    function flushBuffer() {
-        while (logEventBuffer.length > 0 && canWrite) {
-            writeToLog(logEventBuffer.shift());
-        }
-    }
-
-    var logEventBuffer = []
-    , canWrite = false
-    , logFile = openTheStream();
-
-    if (logSize > 0) {
-        setupLogRolling();
-    }
+    var logFile = openTheStream(file, logSize, numBackups);
 
     //close the file on process exit.
     process.on('exit', function() {
-        flushBuffer();
         logFile.end();
-        logFile.destroy();
     });
 
-    function writeToLog(loggingEvent) {
-        var logMessage = layout(loggingEvent)+'\n';
-        //not entirely accurate, but it'll do.
-        bytesWritten += logMessage.length;
-        canWrite = logFile.write(logMessage, "utf8");
-        if (bytesWritten >= logSize) {
-            rollThatLog();
-        }
-    }
-
     return function(loggingEvent) {
-        logEventBuffer.push(loggingEvent);
-        flushBuffer();
+        logFile.write(layout(loggingEvent)+'\n', "utf8");
     };
 }