The Tor Browser: toolkit/devtools/server/actors/call-watcher.js@6474c204b198 (annotated)

toolkit/devtools/server/actors/call-watcher.js@6474c204b198 (annotated)

toolkit/devtools/server/actors/call-watcher.js

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 const {Cc, Ci, Cu, Cr} = require("chrome");
 const events = require("sdk/event/core");
 const {Promise: promise} = Cu.import("resource://gre/modules/Promise.jsm", {});
 const protocol = require("devtools/server/protocol");
 const {ContentObserver} = require("devtools/content-observer");
 const {on, once, off, emit} = events;
 const {method, Arg, Option, RetVal} = protocol;
 exports.register = function(handle) {
   handle.addTabActor(CallWatcherActor, "callWatcherActor");
 };
 exports.unregister = function(handle) {
   handle.removeTabActor(CallWatcherActor);
 };
 /**
  * Type describing a single function call in a stack trace.
  */
 protocol.types.addDictType("call-stack-item", {
   name: "string",
   file: "string",
   line: "number"
 });
 /**
  * Type describing an overview of a function call.
  */
 protocol.types.addDictType("call-details", {
   type: "number",
   name: "string",
   stack: "array:call-stack-item"
 });
 /**
  * This actor contains information about a function call, like the function
  * type, name, stack, arguments, returned value etc.
  */
 let FunctionCallActor = protocol.ActorClass({
   typeName: "function-call",
   /**
    * Creates the function call actor.
    *
    * @param DebuggerServerConnection conn
    *        The server connection.
    * @param DOMWindow window
    *        The content window.
    * @param string global
    *        The name of the global object owning this function, like
    *        "CanvasRenderingContext2D" or "WebGLRenderingContext".
    * @param object caller
    *        The object owning the function when it was called.
    *        For example, in `foo.bar()`, the caller is `foo`.
    * @param number type
    *        Either METHOD_FUNCTION, METHOD_GETTER or METHOD_SETTER.
    * @param string name
    *        The called function's name.
    * @param array stack
    *        The called function's stack, as a list of { name, file, line } objects.
    * @param array args
    *        The called function's arguments.
    * @param any result
    *        The value returned by the function call.
    */
   initialize: function(conn, [window, global, caller, type, name, stack, args, result]) {
     protocol.Actor.prototype.initialize.call(this, conn);
     this.details = {
       window: window,
       caller: caller,
       type: type,
       name: name,
       stack: stack,
       args: args,
       result: result
     };
     this.meta = {
       global: -1,
       previews: { caller: "", args: "" }
     };
     if (global == "WebGLRenderingContext") {
       this.meta.global = CallWatcherFront.CANVAS_WEBGL_CONTEXT;
     } else if (global == "CanvasRenderingContext2D") {
       this.meta.global = CallWatcherFront.CANVAS_2D_CONTEXT;
     } else if (global == "window") {
       this.meta.global = CallWatcherFront.UNKNOWN_SCOPE;
     } else {
       this.meta.global = CallWatcherFront.GLOBAL_SCOPE;
     }
     this.meta.previews.caller = this._generateCallerPreview();
     this.meta.previews.args = this._generateArgsPreview();
   },
   /**
    * Customize the marshalling of this actor to provide some generic information
    * directly on the Front instance.
    */
   form: function() {
     return {
       actor: this.actorID,
       type: this.details.type,
       name: this.details.name,
       file: this.details.stack[0].file,
       line: this.details.stack[0].line,
       callerPreview: this.meta.previews.caller,
       argsPreview: this.meta.previews.args
     };
   },
   /**
    * Gets more information about this function call, which is not necessarily
    * available on the Front instance.
    */
   getDetails: method(function() {
     let { type, name, stack } = this.details;
     // Since not all calls on the stack have corresponding owner files (e.g.
     // callbacks of a requestAnimationFrame etc.), there's no benefit in
     // returning them, as the user can't jump to the Debugger from them.
     for (let i = stack.length - 1;;) {
       if (stack[i].file) {
         break;
       }
       stack.pop();
       i--;
     }
     // XXX: Use grips for objects and serialize them properly, in order
     // to add the function's caller, arguments and return value. Bug 978957.
     return {
       type: type,
       name: name,
       stack: stack
     };
   }, {
     response: { info: RetVal("call-details") }
   }),
   /**
    * Serializes the caller's name so that it can be easily be transferred
    * as a string, but still be useful when displayed in a potential UI.
    *
    * @return string
    *         The caller's name as a string.
    */
   _generateCallerPreview: function() {
     let global = this.meta.global;
     if (global == CallWatcherFront.CANVAS_WEBGL_CONTEXT) {
       return "gl";
     }
     if (global == CallWatcherFront.CANVAS_2D_CONTEXT) {
       return "ctx";
     }
     return "";
   },
   /**
    * Serializes the arguments so that they can be easily be transferred
    * as a string, but still be useful when displayed in a potential UI.
    *
    * @return string
    *         The arguments as a string.
    */
   _generateArgsPreview: function() {
     let { caller, args } = this.details;
     let { global } = this.meta;
     // XXX: All of this sucks. Make this smarter, so that the frontend
     // can inspect each argument, be it object or primitive. Bug 978960.
     let serializeArgs = () => args.map(arg => {
       if (typeof arg == "undefined") {
         return "undefined";
       }
       if (typeof arg == "function") {
         return "Function";
       }
       if (typeof arg == "object") {
         return "Object";
       }
       if (global == CallWatcherFront.CANVAS_WEBGL_CONTEXT) {
         // XXX: This doesn't handle combined bitmasks. Bug 978964.
         return getEnumsLookupTable("webgl", caller)[arg] || arg;
       }
       if (global == CallWatcherFront.CANVAS_2D_CONTEXT) {
         return getEnumsLookupTable("2d", caller)[arg] || arg;
       }
       return arg;
     });
     return serializeArgs().join(", ");
   }
 });
 /**
  * The corresponding Front object for the FunctionCallActor.
  */
 let FunctionCallFront = protocol.FrontClass(FunctionCallActor, {
   initialize: function(client, form) {
     protocol.Front.prototype.initialize.call(this, client, form);
   },
   /**
    * Adds some generic information directly to this instance,
    * to avoid extra roundtrips.
    */
   form: function(form) {
     this.actorID = form.actor;
     this.type = form.type;
     this.name = form.name;
     this.file = form.file;
     this.line = form.line;
     this.callerPreview = form.callerPreview;
     this.argsPreview = form.argsPreview;
   }
 });
 /**
  * This actor observes function calls on certain objects or globals.
  */
 let CallWatcherActor = exports.CallWatcherActor = protocol.ActorClass({
   typeName: "call-watcher",
   initialize: function(conn, tabActor) {
     protocol.Actor.prototype.initialize.call(this, conn);
     this.tabActor = tabActor;
     this._onGlobalCreated = this._onGlobalCreated.bind(this);
     this._onGlobalDestroyed = this._onGlobalDestroyed.bind(this);
     this._onContentFunctionCall = this._onContentFunctionCall.bind(this);
   },
   destroy: function(conn) {
     protocol.Actor.prototype.destroy.call(this, conn);
     this.finalize();
   },
   /**
    * Starts waiting for the current tab actor's document global to be
    * created, in order to instrument the specified objects and become
    * aware of everything the content does with them.
    */
   setup: method(function({ tracedGlobals, tracedFunctions, startRecording, performReload }) {
     if (this._initialized) {
       return;
     }
     this._initialized = true;
     this._functionCalls = [];
     this._tracedGlobals = tracedGlobals || [];
     this._tracedFunctions = tracedFunctions || [];
     this._contentObserver = new ContentObserver(this.tabActor);
     on(this._contentObserver, "global-created", this._onGlobalCreated);
     on(this._contentObserver, "global-destroyed", this._onGlobalDestroyed);
     if (startRecording) {
       this.resumeRecording();
     }
     if (performReload) {
       this.tabActor.window.location.reload();
     }
   }, {
     request: {
       tracedGlobals: Option(0, "nullable:array:string"),
       tracedFunctions: Option(0, "nullable:array:string"),
       startRecording: Option(0, "boolean"),
       performReload: Option(0, "boolean")
     },
     oneway: true
   }),
   /**
    * Stops listening for document global changes and puts this actor
    * to hibernation. This method is called automatically just before the
    * actor is destroyed.
    */
   finalize: method(function() {
     if (!this._initialized) {
       return;
     }
     this._initialized = false;
     this._contentObserver.stopListening();
     off(this._contentObserver, "global-created", this._onGlobalCreated);
     off(this._contentObserver, "global-destroyed", this._onGlobalDestroyed);
     this._tracedGlobals = null;
     this._tracedFunctions = null;
     this._contentObserver = null;
   }, {
     oneway: true
   }),
   /**
    * Returns whether the instrumented function calls are currently recorded.
    */
   isRecording: method(function() {
     return this._recording;
   }, {
     response: RetVal("boolean")
   }),
   /**
    * Starts recording function calls.
    */
   resumeRecording: method(function() {
     this._recording = true;
   }),
   /**
    * Stops recording function calls.
    */
   pauseRecording: method(function() {
     this._recording = false;
     return this._functionCalls;
   }, {
     response: { calls: RetVal("array:function-call") }
   }),
   /**
    * Erases all the recorded function calls.
    * Calling `resumeRecording` or `pauseRecording` does not erase history.
    */
   eraseRecording: method(function() {
     this._functionCalls = [];
   }),
   /**
    * Lightweight listener invoked whenever an instrumented function is called
    * while recording. We're doing this to avoid the event emitter overhead,
    * since this is expected to be a very hot function.
    */
   onCall: function() {},
   /**
    * Invoked whenever the current tab actor's document global is created.
    */
   _onGlobalCreated: function(window) {
     let self = this;
     this._tracedWindowId = ContentObserver.GetInnerWindowID(window);
     let unwrappedWindow = XPCNativeWrapper.unwrap(window);
     let callback = this._onContentFunctionCall;
     for (let global of this._tracedGlobals) {
       let prototype = unwrappedWindow[global].prototype;
       let properties = Object.keys(prototype);
       properties.forEach(name => overrideSymbol(global, prototype, name, callback));
     }
     for (let name of this._tracedFunctions) {
       overrideSymbol("window", unwrappedWindow, name, callback);
     }
     /**
      * Instruments a method, getter or setter on the specified target object to
      * invoke a callback whenever it is called.
      */
     function overrideSymbol(global, target, name, callback) {
       let propertyDescriptor = Object.getOwnPropertyDescriptor(target, name);
       if (propertyDescriptor.get || propertyDescriptor.set) {
         overrideAccessor(global, target, name, propertyDescriptor, callback);
         return;
       }
       if (propertyDescriptor.writable && typeof propertyDescriptor.value == "function") {
         overrideFunction(global, target, name, propertyDescriptor, callback);
         return;
       }
     }
     /**
      * Instruments a function on the specified target object.
      */
     function overrideFunction(global, target, name, descriptor, callback) {
       let originalFunc = target[name];
       Object.defineProperty(target, name, {
         value: function(...args) {
           let result = originalFunc.apply(this, args);
           if (self._recording) {
             let stack = getStack(name);
             let type = CallWatcherFront.METHOD_FUNCTION;
             callback(unwrappedWindow, global, this, type, name, stack, args, result);
           }
           return result;
         },
         configurable: descriptor.configurable,
         enumerable: descriptor.enumerable,
         writable: true
       });
     }
     /**
      * Instruments a getter or setter on the specified target object.
      */
     function overrideAccessor(global, target, name, descriptor, callback) {
       let originalGetter = target.__lookupGetter__(name);
       let originalSetter = target.__lookupSetter__(name);
       Object.defineProperty(target, name, {
         get: function(...args) {
           if (!originalGetter) return undefined;
           let result = originalGetter.apply(this, args);
           if (self._recording) {
             let stack = getStack(name);
             let type = CallWatcherFront.GETTER_FUNCTION;
             callback(unwrappedWindow, global, this, type, name, stack, args, result);
           }
           return result;
         },
         set: function(...args) {
           if (!originalSetter) return;
           originalSetter.apply(this, args);
           if (self._recording) {
             let stack = getStack(name);
             let type = CallWatcherFront.SETTER_FUNCTION;
             callback(unwrappedWindow, global, this, type, name, stack, args, undefined);
           }
         },
         configurable: descriptor.configurable,
         enumerable: descriptor.enumerable
       });
     }
     /**
      * Stores the relevant information about calls on the stack when
      * a function is called.
      */
     function getStack(caller) {
       try {
         // Using Components.stack wouldn't be a better idea, since it's
         // much slower because it attempts to retrieve the C++ stack as well.
         throw new Error();
       } catch (e) {
         var stack = e.stack;
       }
       // Of course, using a simple regex like /(.*?)@(.*):(\d*):\d*/ would be
       // much prettier, but this is a very hot function, so let's sqeeze
       // every drop of performance out of it.
       let calls = [];
       let callIndex = 0;
       let currNewLinePivot = stack.indexOf("\n") + 1;
       let nextNewLinePivot = stack.indexOf("\n", currNewLinePivot);
       while (nextNewLinePivot > 0) {
         let nameDelimiterIndex = stack.indexOf("@", currNewLinePivot);
         let columnDelimiterIndex = stack.lastIndexOf(":", nextNewLinePivot - 1);
         let lineDelimiterIndex = stack.lastIndexOf(":", columnDelimiterIndex - 1);
         if (!calls[callIndex]) {
           calls[callIndex] = { name: "", file: "", line: 0 };
         }
         if (!calls[callIndex + 1]) {
           calls[callIndex + 1] = { name: "", file: "", line: 0 };
         }
         if (callIndex > 0) {
           let file = stack.substring(nameDelimiterIndex + 1, lineDelimiterIndex);
           let line = stack.substring(lineDelimiterIndex + 1, columnDelimiterIndex);
           let name = stack.substring(currNewLinePivot, nameDelimiterIndex);
           calls[callIndex].name = name;
           calls[callIndex - 1].file = file;
           calls[callIndex - 1].line = line;
         } else {
           // Since the topmost stack frame is actually our overwritten function,
           // it will not have the expected name.
           calls[0].name = caller;
         }
         currNewLinePivot = nextNewLinePivot + 1;
         nextNewLinePivot = stack.indexOf("\n", currNewLinePivot);
         callIndex++;
       }
       return calls;
     }
   },
   /**
    * Invoked whenever the current tab actor's inner window is destroyed.
    */
   _onGlobalDestroyed: function(id) {
     if (this._tracedWindowId == id) {
       this.pauseRecording();
       this.eraseRecording();
     }
   },
   /**
    * Invoked whenever an instrumented function is called.
    */
   _onContentFunctionCall: function(...details) {
     let functionCall = new FunctionCallActor(this.conn, details);
     this._functionCalls.push(functionCall);
     this.onCall(functionCall);
   }
 });
 /**
  * The corresponding Front object for the CallWatcherActor.
  */
 let CallWatcherFront = exports.CallWatcherFront = protocol.FrontClass(CallWatcherActor, {
   initialize: function(client, { callWatcherActor }) {
     protocol.Front.prototype.initialize.call(this, client, { actor: callWatcherActor });
     client.addActorPool(this);
     this.manage(this);
   }
 });
 /**
  * Constants.
  */
 CallWatcherFront.METHOD_FUNCTION = 0;
 CallWatcherFront.GETTER_FUNCTION = 1;
 CallWatcherFront.SETTER_FUNCTION = 2;
 CallWatcherFront.GLOBAL_SCOPE = 0;
 CallWatcherFront.UNKNOWN_SCOPE = 1;
 CallWatcherFront.CANVAS_WEBGL_CONTEXT = 2;
 CallWatcherFront.CANVAS_2D_CONTEXT = 3;
 /**
  * A lookup table for cross-referencing flags or properties with their name
  * assuming they look LIKE_THIS most of the time.
  *
  * For example, when gl.clear(gl.COLOR_BUFFER_BIT) is called, the actual passed
  * argument's value is 16384, which we want identified as "COLOR_BUFFER_BIT".
  */
 var gEnumRegex = /^[A-Z_]+$/;
 var gEnumsLookupTable = {};
 function getEnumsLookupTable(type, object) {
   let cachedEnum = gEnumsLookupTable[type];
   if (cachedEnum) {
     return cachedEnum;
   }
   let table = gEnumsLookupTable[type] = {};
   for (let key in object) {
     if (key.match(gEnumRegex)) {
       table[object[key]] = key;
     }
   }
   return table;
 }