michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /**
michael@0:  * Memory leak hunter. Walks a tree of objects looking for DOM nodes.
michael@0:  * Usage:
michael@0:  * leakHunt({
michael@0:  *   thing: thing,
michael@0:  *   otherthing: otherthing
michael@0:  * });
michael@0:  */
michael@0: function leakHunt(root) {
michael@0:   var path = [];
michael@0:   var seen = [];
michael@0: 
michael@0:   try {
michael@0:     var output = leakHunt.inner(root, path, seen);
michael@0:     output.forEach(function(line) {
michael@0:       dump(line + '\n');
michael@0:     });
michael@0:   }
michael@0:   catch (ex) {
michael@0:     dump(ex + '\n');
michael@0:   }
michael@0: }
michael@0: 
michael@0: leakHunt.inner = function LH_inner(root, path, seen) {
michael@0:   var prefix = new Array(path.length).join('  ');
michael@0: 
michael@0:   var reply = [];
michael@0:   function log(msg) {
michael@0:     reply.push(msg);
michael@0:   }
michael@0: 
michael@0:   var direct
michael@0:   try {
michael@0:     direct = Object.keys(root);
michael@0:   }
michael@0:   catch (ex) {
michael@0:     log(prefix + '  Error enumerating: ' + ex);
michael@0:     return reply;
michael@0:   }
michael@0: 
michael@0:   try {
michael@0:     var index = 0;
michael@0:     for (var data of root) {
michael@0:       var prop = '' + index;
michael@0:       leakHunt.digProperty(prop, data, path, seen, direct, log);
michael@0:       index++;
michael@0:     }
michael@0:   }
michael@0:   catch (ex) { /* Ignore things that are not enumerable */ }
michael@0: 
michael@0:   for (var prop in root) {
michael@0:     var data;
michael@0:     try {
michael@0:       data = root[prop];
michael@0:     }
michael@0:     catch (ex) {
michael@0:       log(prefix + '  ' + prop + ' = Error: ' + ex.toString().substring(0, 30));
michael@0:       continue;
michael@0:     }
michael@0: 
michael@0:     leakHunt.digProperty(prop, data, path, seen, direct, log);
michael@0:   }
michael@0: 
michael@0:   return reply;
michael@0: }
michael@0: 
michael@0: leakHunt.hide = [ /^string$/, /^number$/, /^boolean$/, /^null/, /^undefined/ ];
michael@0: 
michael@0: leakHunt.noRecurse = [
michael@0:   /^string$/, /^number$/, /^boolean$/, /^null/, /^undefined/,
michael@0:   /^Window$/, /^Document$/,
michael@0:   /^XULDocument$/, /^XULElement$/,
michael@0:   /^DOMWindow$/, /^HTMLDocument$/, /^HTML.*Element$/, /^ChromeWindow$/
michael@0: ];
michael@0: 
michael@0: leakHunt.digProperty = function LH_digProperty(prop, data, path, seen, direct, log) {
michael@0:   var newPath = path.slice();
michael@0:   newPath.push(prop);
michael@0:   var prefix = new Array(newPath.length).join('  ');
michael@0: 
michael@0:   var recurse = true;
michael@0:   var message = leakHunt.getType(data);
michael@0: 
michael@0:   if (leakHunt.matchesAnyPattern(message, leakHunt.hide)) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   if (message === 'function' && direct.indexOf(prop) == -1) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   if (message === 'string') {
michael@0:     var extra = data.length > 10 ? data.substring(0, 9) + '_' : data;
michael@0:     message += ' "' + extra.replace(/\n/g, "|") + '"';
michael@0:     recurse = false;
michael@0:   }
michael@0:   else if (leakHunt.matchesAnyPattern(message, leakHunt.noRecurse)) {
michael@0:     message += ' (no recurse)'
michael@0:     recurse = false;
michael@0:   }
michael@0:   else if (seen.indexOf(data) !== -1) {
michael@0:     message += ' (already seen)';
michael@0:     recurse = false;
michael@0:   }
michael@0: 
michael@0:   if (recurse) {
michael@0:     seen.push(data);
michael@0:     var lines = leakHunt.inner(data, newPath, seen);
michael@0:     if (lines.length == 0) {
michael@0:       if (message !== 'function') {
michael@0:         log(prefix + prop + ' = ' + message + ' { }');
michael@0:       }
michael@0:     }
michael@0:     else {
michael@0:       log(prefix + prop + ' = ' + message + ' {');
michael@0:       lines.forEach(function(line) {
michael@0:         log(line);
michael@0:       });
michael@0:       log(prefix + '}');
michael@0:     }
michael@0:   }
michael@0:   else {
michael@0:     log(prefix + prop + ' = ' + message);
michael@0:   }
michael@0: };
michael@0: 
michael@0: leakHunt.matchesAnyPattern = function LH_matchesAnyPattern(str, patterns) {
michael@0:   var match = false;
michael@0:   patterns.forEach(function(pattern) {
michael@0:     if (str.match(pattern)) {
michael@0:       match = true;
michael@0:     }
michael@0:   });
michael@0:   return match;
michael@0: };
michael@0: 
michael@0: leakHunt.getType = function LH_getType(data) {
michael@0:   if (data === null) {
michael@0:     return 'null';
michael@0:   }
michael@0:   if (data === undefined) {
michael@0:     return 'undefined';
michael@0:   }
michael@0: 
michael@0:   var type = typeof data;
michael@0:   if (type === 'object' || type === 'Object') {
michael@0:     type = leakHunt.getCtorName(data);
michael@0:   }
michael@0: 
michael@0:   return type;
michael@0: };
michael@0: 
michael@0: leakHunt.getCtorName = function LH_getCtorName(aObj) {
michael@0:   try {
michael@0:     if (aObj.constructor && aObj.constructor.name) {
michael@0:       return aObj.constructor.name;
michael@0:     }
michael@0:   }
michael@0:   catch (ex) {
michael@0:     return 'UnknownObject';
michael@0:   }
michael@0: 
michael@0:   // If that fails, use Objects toString which sometimes gives something
michael@0:   // better than 'Object', and at least defaults to Object if nothing better
michael@0:   return Object.prototype.toString.call(aObj).slice(8, -1);
michael@0: };