From 55fdc480ea764b5fd0bd7dfc9e048b0be90de404 Mon Sep 17 00:00:00 2001
From: Jim Tupper <git@tupper.org.uk>
Date: Fri, 26 Feb 2016 23:12:20 +0000
Subject: [PATCH] Refactoring and adding in support for fast json serialisation
 without cycle checking

---
 lib/rotatingfilestream.js | 82 +++++++++++++++++++++++----------------
 package.json              |  1 -
 2 files changed, 49 insertions(+), 34 deletions(-)

diff --git a/lib/rotatingfilestream.js b/lib/rotatingfilestream.js
index e347b07..1898b81 100644
--- a/lib/rotatingfilestream.js
+++ b/lib/rotatingfilestream.js
@@ -31,12 +31,31 @@ function RotatingFileStream(options) {
     var stream = null;
     var streambytesWritten = 0;
 
+    // Copied from bunyan source
+    function safeCycles() {
+        var seen = [];
+        return function (key, val) {
+            if (!val || typeof (val) !== 'object') {
+                return val;
+            }
+            if (seen.indexOf(val) !== -1) {
+                return '[Circular]';
+            }
+            seen.push(val);
+            return val;
+        };
+    }
+
     function nullJsonify(textlog) {
         return textlog;
     }
 
     function fastJsonify(rawlog) {
-        return JSON.stringify(rawlog, bunyan.safeCycles()) + '\n';
+        return JSON.stringify(rawlog, safeCycles()) + '\n';
+    }
+
+    function fastUnsafeJsonify(rawlog) {
+        return JSON.stringify(rawlog) + '\n';
     }
 
     function orderedJsonify(rawlog) {
@@ -52,7 +71,7 @@ function RotatingFileStream(options) {
             log[k] = rawlog[k];
         }
 
-        return JSON.stringify(log, bunyan.safeCycles()) + '\n';
+        return JSON.stringify(log, safeCycles()) + '\n';
     }
 
     function chooseJsonify(log) {
@@ -64,6 +83,8 @@ function RotatingFileStream(options) {
             jsonify = nullJsonify;
         } else if (options.fieldOrder) {
             jsonify = orderedJsonify;
+        } else if (options.noCyclesCheck) {
+            jsonify = fastUnsafeJsonify;
         } else {
             jsonify = fastJsonify;
         }
@@ -73,8 +94,8 @@ function RotatingFileStream(options) {
 
     var jsonify = chooseJsonify;
 
-    var forceWrite = false;
     function writer(logs, callback) {
+        var written = -1; // the index of the last successful write
         for (var i = 0; stream && i < logs.length; i += 1) {
             var str = jsonify(logs[i]);
 
@@ -82,35 +103,26 @@ function RotatingFileStream(options) {
 
             streambytesWritten += writeBuffer.byteLength;
 
-            if (forceWrite) {
-                // This log entry gets written regardless - don't emit
-                forceWrite = false;
-            } else {
-                base.emit('data', { bytesWritten: streambytesWritten });
-            }
-
-            if (!stream) {
-                // This log entry caused a rotation
-                // We can't write it, force it to be written
-                // Next time round
-                forceWrite = true;
-                break;
-            }
+            base.emit('data', { bytesWritten: streambytesWritten });
 
-            try {
-                stream.write(writeBuffer, function (err) {
-                if (err) {
+            if (stream) {
+                try {
+                    stream.write(writeBuffer, function (err) {
+                        if (err) {
+                            base.emit('error', err);
+                        }
+                    });
+                } catch (err) {
                     base.emit('error', err);
                 }
-                });
-            } catch (err) {
-                base.emit('error', err);
+
+                written = i;
             }
         }
 
         // If we didn't get all the way through the array, unshift the remaining
         // records back onto our queue in reverse order
-        for (var rollback = logs.length -1; rollback >= i; rollback -= 1) {
+        for (var rollback = logs.length -1; rollback > written; rollback -= 1) {
             writeQueue.unshift(logs[rollback]);
         }
 
@@ -155,23 +167,27 @@ function RotatingFileStream(options) {
         });
     }
 
-    var rotating = false;
-    function rotate() {
-        if (rotating) {
-            return;
-        } else {
-            rotating = true;
-        }
+    function rotateActual() {
+
+        base.once('data', function () {
+            rotateFunction = rotateActual;
+        });
+
+        rotateFunction = function () {};
 
         rotator.rotate(function (err, newstream, filePath) {
             if (err) {
                 base.emit('error', err);
             }
-
-            rotating = false;
         });
     }
 
+    var rotateFunction = rotateActual;
+
+    function rotate() {
+        rotateFunction();
+    }
+
     function write(s, callback) {
         writeQueue.push(s, callback);
     }
diff --git a/package.json b/package.json
index 76e1ef0..1ee1422 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,6 @@
     "logging",
     "log4j",
     "json",
-    "bunyan",
     "rotating",
     "rotate"
   ],