From cea3dc97d1ecd5769bd504ea284307d9e72750d0 Mon Sep 17 00:00:00 2001
From: Gareth Jones <gareth.jones@sensis.com.au>
Date: Thu, 24 Nov 2011 08:20:33 +1100
Subject: [PATCH] Changes to handle drain events not fired on write in linux &
 windows - should fix issue #44

---
 lib/appenders/file.js | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/lib/appenders/file.js b/lib/appenders/file.js
index 46263ba..6ea01ca 100644
--- a/lib/appenders/file.js
+++ b/lib/appenders/file.js
@@ -86,14 +86,15 @@ function fileAppender (file, layout, logSize, numBackups) {
     function openTheStream() {
         var stream = fs.createWriteStream(file, { flags: 'a', mode: 0644, encoding: 'utf8' });
         stream.on("open", function() {
-            if (logEventBuffer.length > 0) {
-                writeToLog(logEventBuffer.shift());
-            }
+            canWrite = true;
+            flushBuffer();
         });
         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());
             }
@@ -101,9 +102,15 @@ function fileAppender (file, layout, logSize, numBackups) {
         return stream;
     }
 
+    function flushBuffer() {
+        while (logEventBuffer.length > 0 && canWrite) {
+            writeToLog(logEventBuffer.shift());
+        }
+    }
 
     var logEventBuffer = []
-  , logFile = openTheStream();
+    , canWrite = false
+    , logFile = openTheStream();
 
     if (logSize > 0) {
         setupLogRolling();
@@ -111,6 +118,7 @@ function fileAppender (file, layout, logSize, numBackups) {
 
     //close the file on process exit.
     process.on('exit', function() {
+        flushBuffer();
         logFile.end();
         logFile.destroy();
     });
@@ -119,7 +127,7 @@ function fileAppender (file, layout, logSize, numBackups) {
         var logMessage = layout(loggingEvent)+'\n';
         //not entirely accurate, but it'll do.
         bytesWritten += logMessage.length;
-        logFile.write(logMessage, "utf8");
+        canWrite = logFile.write(logMessage, "utf8");
         if (bytesWritten >= logSize) {
             rollThatLog();
         }
@@ -127,6 +135,7 @@ function fileAppender (file, layout, logSize, numBackups) {
 
     return function(loggingEvent) {
         logEventBuffer.push(loggingEvent);
+        flushBuffer();
     };
 }