code review: simplify needlessly complicated logger buffering code

src/js/logger.js

@@ -1,7 +1,7 @@
 /*******************************************************************************
 
     uMatrix - a browser extension to block requests.
-    Copyright (C) 2015 Raymond Hill
+    Copyright (C) 2015-2017 Raymond Hill
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -19,37 +19,17 @@
     Home: https://github.com/gorhill/uBlock
 */
 
-/* global µMatrix */
+'use strict';
 
 /******************************************************************************/
 /******************************************************************************/
 
 µMatrix.logger = (function() {
 
-'use strict';
-
-/******************************************************************************/
-/******************************************************************************/
-
     var LogEntry = function(args) {
         this.init(args);
     };
 
-/******************************************************************************/
-
-var logEntryFactory = function(args) {
-    var entry = logEntryJunkyard.pop();
-    if ( entry ) {
-        return entry.init(args);
-    }
-    return new LogEntry(args);
-};
-
-var logEntryJunkyard = [];
-var logEntryJunkyardMax = 100;
-
-/******************************************************************************/
-
     LogEntry.prototype.init = function(args) {
         this.tstamp = Date.now();
         this.tab = args[0] || '';
@@ -58,144 +38,51 @@ LogEntry.prototype.init = function(args) {
         this.d1 = args[3];
         this.d2 = args[4];
         this.d3 = args[5];
-    return this;
-};
-
-/******************************************************************************/
-
-LogEntry.prototype.dispose = function() {
-    this.tstamp = 0;
-    this.tab = this.cat = '';
-    this.d0 = this.d1 = this.d2 = this.d3 = undefined;
-    if ( logEntryJunkyard.length < logEntryJunkyardMax ) {
-        logEntryJunkyard.push(this);
-    }
-};
-
-/******************************************************************************/
-/******************************************************************************/
-
-var LogBuffer = function() {
-    this.lastReadTime = 0;
-    this.size = 50;
-    this.buffer = new Array(this.size);
-    this.readPtr = 0;
-    this.writePtr = 0;
-};
-
-/******************************************************************************/
-
-LogBuffer.prototype.dispose = function() {
-    var entry;
-    var i = this.buffer.length;
-    while ( i-- ) {
-        entry = this.buffer[i];
-        if ( entry instanceof LogEntry ) {
-            entry.dispose();
-        }
-    }
-    this.buffer = null;
-    return null;
-};
-
-/******************************************************************************/
-
-LogBuffer.prototype.writeOne = function(args) {
-    // Reusing log entry = less memory churning
-    var entry = this.buffer[this.writePtr];
-    if ( entry instanceof LogEntry === false ) {
-        this.buffer[this.writePtr] = logEntryFactory(args);
-    } else {
-        entry.init(args);
-    }
-    this.writePtr += 1;
-    if ( this.writePtr === this.size ) {
-        this.writePtr = 0;
-    }
-    // Grow the buffer between 1.5x-2x the current size
-    if ( this.writePtr === this.readPtr ) {
-        var toMove = this.buffer.slice(0, this.writePtr);
-        var minSize = Math.ceil(this.size * 1.5);
-        this.size += toMove.length;
-        if ( this.size < minSize ) {
-            this.buffer = this.buffer.concat(toMove, new Array(minSize - this.size));
-            this.writePtr = this.size;
-        } else {
-            this.buffer = this.buffer.concat(toMove);
-            this.writePtr = 0;
-        }
-        this.size = this.buffer.length;
-    }
-};
-
-/******************************************************************************/
-
-LogBuffer.prototype.readAll = function() {
-    var out;
-    if ( this.readPtr < this.writePtr ) {
-        out = this.buffer.slice(this.readPtr, this.writePtr);
-    } else if ( this.writePtr < this.readPtr ) {
-        out = this.buffer.slice(this.readPtr).concat(this.buffer.slice(0, this.writePtr));
-    } else {
-        out = [];
-    }
-    this.readPtr = this.writePtr;
-    this.lastReadTime = Date.now();
-    return out;
     };
 
-/******************************************************************************/
-/******************************************************************************/
+    var buffer = null;
+    var lastReadTime = 0;
+    var writePtr = 0;
 
-// Tab id to log buffer instances
-var logBuffer = null;
-
-// After 60 seconds without being read, a buffer will be considered unused, and
-// thus removed from memory.
+    // After 60 seconds without being read, a buffer will be considered
+    // unused, and thus removed from memory.
     var logBufferObsoleteAfter = 60 * 1000;
 
-/******************************************************************************/
-
     var janitor = function() {
         if (
-        logBuffer !== null &&
-        logBuffer.lastReadTime < (Date.now() - logBufferObsoleteAfter)
+            buffer !== null &&
+            lastReadTime < (Date.now() - logBufferObsoleteAfter)
         ) {
-        logBuffer = logBuffer.dispose();
+            buffer = null;
+            writePtr = 0;
         }
-    if ( logBuffer !== null ) {
+        if ( buffer !== null ) {
             vAPI.setTimeout(janitor, logBufferObsoleteAfter);
         }
     };
 
-/******************************************************************************/
-
-var writeOne = function() {
-    if ( logBuffer !== null ) {
-        logBuffer.writeOne(arguments);
+    return {
+        writeOne: function() {
+            if ( buffer === null ) { return; }
+            if ( writePtr === buffer.length ) {
+                buffer.push(new LogEntry(arguments));
+            } else {
+                buffer[writePtr].init(arguments);
             }
-};
-
-/******************************************************************************/
-
-var readAll = function() {
-    if ( logBuffer === null ) {
-        logBuffer = new LogBuffer();
+            writePtr += 1;
+        },
+        readAll: function() {
+            if ( buffer === null ) {
+                buffer = [];
                 vAPI.setTimeout(janitor, logBufferObsoleteAfter);
             }
-    return logBuffer.readAll();
-};
-
-/******************************************************************************/
-
-return {
-    writeOne: writeOne,
-    readAll: readAll
+            var out = buffer.slice(0, writePtr);
+            writePtr = 0;
+            lastReadTime = Date.now();
+            return out;
+        }
     };
 
-/******************************************************************************/
-/******************************************************************************/
-
 })();
 
 /******************************************************************************/