remoting/webapp/base/js/console_wrapper.js

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 /**
   6  * @fileoverview
   7  * Intercept and record various classes of log messages. By default, such
   8  * messages will be reported by Chrome Developer Tools as coming from this
   9  * file, making source-line hyperlinks useless. To fix this click the "gear"
  10  * icon in Developer Tools, click "Manage framework blocking..." under
  11  * "Sources" and add console_wrapper.js as a "Blackbox" component.
  12  */
  13
  14
  15 /** @suppress {duplicate} */
  16 var remoting = remoting || {};
  17
  18 (function() {
  19
  20 /**
  21  * @constructor
  22  * @private
  23  */
  24 remoting.ConsoleWrapper = function() {
  25   console.assert(instance_ == null,
  26                  'Duplicate remoting.ConsoleWrapper constructor.');
  27   /** @private {number} The number of log entries to save. */
  28   this.historyMaxSize_ = 0;
  29   /** @private {Array<remoting.ConsoleWrapper.LogEntry>} */
  30   this.history_ = [];
  31   /** @private {Object<function(*)>} */
  32   this.savedMethods_ = {};
  33 };
  34
  35 /**
  36  * Activate the console wrapper for the specified log types.
  37  *
  38  * @param {number} historyMaxSize The number of log entries to keep.
  39  * @param {...remoting.ConsoleWrapper.LogType} var_logTypes The log types to
  40  *     intercept.
  41  * @suppress {reportUnknownTypes}
  42  */
  43 remoting.ConsoleWrapper.prototype.activate =
  44     function(historyMaxSize, var_logTypes) {
  45   this.historyMaxSize_ = historyMaxSize;
  46   this.history_ = [];
  47   // Restore previous wrappers.
  48   for (var key in remoting.ConsoleWrapper.LogType) {
  49     var type = remoting.ConsoleWrapper.LogType[key];
  50     if (this.savedMethods_[type]) {
  51       console[type] = this.savedMethods_[type];
  52       delete this.savedMethods_[type];
  53     }
  54   }
  55   // Activate new wrappers
  56   for (var i = 1; i < arguments.length; ++i) {
  57     var type = arguments[i];
  58     this.savedMethods_[type] = console[type];
  59     console[arguments[i]] = this.recordAndLog_.bind(this, arguments[i]);
  60   }
  61 };
  62
  63 /**
  64  * Deactivate the console wrapper for all log types.
  65  */
  66 remoting.ConsoleWrapper.prototype.deactivate = function() {
  67   this.activate(0);
  68 };
  69
  70 /**
  71  * @return {Array<remoting.ConsoleWrapper.LogEntry>} The most recent log
  72  *     entries as configured by activate().
  73  */
  74 remoting.ConsoleWrapper.prototype.getHistory = function() {
  75   return this.history_;
  76 };
  77
  78 /**
  79  * @param {remoting.ConsoleWrapper.LogType} type The type of log.
  80  * @param {...*} var_args The items to log.
  81  * @private
  82  * @suppress {reportUnknownTypes}
  83  */
  84 remoting.ConsoleWrapper.prototype.recordAndLog_ =
  85     function(type, var_args) {
  86   // Construct a new arguments array by removing the first argument.
  87   var args = Array.prototype.slice.call(arguments, 1);
  88   // Find the caller, ignoring the top-most stack frame.
  89   var caller = new base.Callstack().callstack[1];
  90   var location = 'unknown';
  91   if (caller) {
  92     location = caller.file + ':' + caller.line;
  93   }
  94   // Save to history.
  95   if (this.historyMaxSize_ > 0) {
  96     var log = {
  97       type: type,
  98       message: JSON.stringify(args),
  99       caller: location,
 100       timestamp: new Date()
 101     };
 102     // Only save assertions if they fail.
 103     if (log.type != 'assert' || !args[0]) {
 104       this.history_.push(log);
 105       if (this.history_.length > this.historyMaxSize_) {
 106         this.history_.shift();
 107       }
 108     }
 109   }
 110   // Log the message, appending the caller.
 111   // TODO(jamiewalch): Make the caller gray so that it's less intrusive. This
 112   // can be done using a %c formatter in the first argument, but care needs to
 113   // be taken to support the multi-argument case.
 114   args.push(location);
 115   this.savedMethods_[type].apply(console, args);
 116 }
 117
 118 /**
 119  * @type {remoting.ConsoleWrapper}
 120  */
 121 var instance_ = null;
 122
 123 /**
 124  * @return {remoting.ConsoleWrapper} The singleton ConsoleWrapper.
 125  */
 126 remoting.ConsoleWrapper.getInstance = function() {
 127   if (!instance_) {
 128     instance_ = new remoting.ConsoleWrapper();
 129   }
 130   return instance_;
 131 };
 132
 133 })();
 134
 135 /**
 136  * @typedef {{type: string, message: string, caller: string, timestamp: Date}}
 137  */
 138 remoting.ConsoleWrapper.LogEntry;
 139
 140 /**
 141  * @enum {string} The log types that can be intercepted. These must match the
 142  *     names of the corresponding console methods.
 143  */
 144 remoting.ConsoleWrapper.LogType = {
 145   LOG: 'log',
 146   WARN: 'warn',
 147   ERROR: 'error',
 148   ASSERT: 'assert'
 149 };