The Tor Browser: browser/devtools/shared/test/leakhunt.js@6474c204b198 (annotated)

browser/devtools/shared/test/leakhunt.js@6474c204b198 (annotated)

browser/devtools/shared/test/leakhunt.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/. */
 /**
  * Memory leak hunter. Walks a tree of objects looking for DOM nodes.
  * Usage:
  * leakHunt({
  *   thing: thing,
  *   otherthing: otherthing
  * });
  */
 function leakHunt(root) {
   var path = [];
   var seen = [];
   try {
     var output = leakHunt.inner(root, path, seen);
     output.forEach(function(line) {
       dump(line + '\n');
     });
   }
   catch (ex) {
     dump(ex + '\n');
   }
 }
 leakHunt.inner = function LH_inner(root, path, seen) {
   var prefix = new Array(path.length).join('  ');
   var reply = [];
   function log(msg) {
     reply.push(msg);
   }
   var direct
   try {
     direct = Object.keys(root);
   }
   catch (ex) {
     log(prefix + '  Error enumerating: ' + ex);
     return reply;
   }
   try {
     var index = 0;
     for (var data of root) {
       var prop = '' + index;
       leakHunt.digProperty(prop, data, path, seen, direct, log);
       index++;
     }
   }
   catch (ex) { /* Ignore things that are not enumerable */ }
   for (var prop in root) {
     var data;
     try {
       data = root[prop];
     }
     catch (ex) {
       log(prefix + '  ' + prop + ' = Error: ' + ex.toString().substring(0, 30));
       continue;
     }
     leakHunt.digProperty(prop, data, path, seen, direct, log);
   }
   return reply;
 }
 leakHunt.hide = [ /^string$/, /^number$/, /^boolean$/, /^null/, /^undefined/ ];
 leakHunt.noRecurse = [
   /^string$/, /^number$/, /^boolean$/, /^null/, /^undefined/,
   /^Window$/, /^Document$/,
   /^XULDocument$/, /^XULElement$/,
   /^DOMWindow$/, /^HTMLDocument$/, /^HTML.*Element$/, /^ChromeWindow$/
 ];
 leakHunt.digProperty = function LH_digProperty(prop, data, path, seen, direct, log) {
   var newPath = path.slice();
   newPath.push(prop);
   var prefix = new Array(newPath.length).join('  ');
   var recurse = true;
   var message = leakHunt.getType(data);
   if (leakHunt.matchesAnyPattern(message, leakHunt.hide)) {
     return;
   }
   if (message === 'function' && direct.indexOf(prop) == -1) {
     return;
   }
   if (message === 'string') {
     var extra = data.length > 10 ? data.substring(0, 9) + '_' : data;
     message += ' "' + extra.replace(/\n/g, "|") + '"';
     recurse = false;
   }
   else if (leakHunt.matchesAnyPattern(message, leakHunt.noRecurse)) {
     message += ' (no recurse)'
     recurse = false;
   }
   else if (seen.indexOf(data) !== -1) {
     message += ' (already seen)';
     recurse = false;
   }
   if (recurse) {
     seen.push(data);
     var lines = leakHunt.inner(data, newPath, seen);
     if (lines.length == 0) {
       if (message !== 'function') {
         log(prefix + prop + ' = ' + message + ' { }');
       }
     }
     else {
       log(prefix + prop + ' = ' + message + ' {');
       lines.forEach(function(line) {
         log(line);
       });
       log(prefix + '}');
     }
   }
   else {
     log(prefix + prop + ' = ' + message);
   }
 };
 leakHunt.matchesAnyPattern = function LH_matchesAnyPattern(str, patterns) {
   var match = false;
   patterns.forEach(function(pattern) {
     if (str.match(pattern)) {
       match = true;
     }
   });
   return match;
 };
 leakHunt.getType = function LH_getType(data) {
   if (data === null) {
     return 'null';
   }
   if (data === undefined) {
     return 'undefined';
   }
   var type = typeof data;
   if (type === 'object' || type === 'Object') {
     type = leakHunt.getCtorName(data);
   }
   return type;
 };
 leakHunt.getCtorName = function LH_getCtorName(aObj) {
   try {
     if (aObj.constructor && aObj.constructor.name) {
       return aObj.constructor.name;
     }
   }
   catch (ex) {
     return 'UnknownObject';
   }
   // If that fails, use Objects toString which sometimes gives something
   // better than 'Object', and at least defaults to Object if nothing better
   return Object.prototype.toString.call(aObj).slice(8, -1);
 };