The Tor Browser: toolkit/modules/Dict.jsm@6474c204b198 (annotated)

toolkit/modules/Dict.jsm@6474c204b198 (annotated)

toolkit/modules/Dict.jsm

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";
 this.EXPORTED_SYMBOLS = ["Dict"];
 /**
  * Transforms a given key into a property name guaranteed not to collide with
  * any built-ins.
  */
 function convert(aKey) {
   return ":" + aKey;
 }
 /**
  * Transforms a property into a key suitable for providing to the outside world.
  */
 function unconvert(aProp) {
   return aProp.substr(1);
 }
 /**
  * A dictionary of strings to arbitrary JS objects. This should be used whenever
  * the keys are potentially arbitrary, to avoid collisions with built-in
  * properties.
  *
  * @param aInitial An object containing the initial keys and values of this
  *                 dictionary. Only the "own" enumerable properties of the
  *                 object are considered.
  *                 If |aInitial| is a string, it is assumed to be JSON and parsed into an object.
  */
 this.Dict = function Dict(aInitial) {
   if (aInitial === undefined)
     aInitial = {};
   if (typeof aInitial == "string")
     aInitial = JSON.parse(aInitial);
   var items = {}, count = 0;
   // That we don't look up the prototype chain is guaranteed by Iterator.
   for (var [key, val] in Iterator(aInitial)) {
     items[convert(key)] = val;
     count++;
   }
   this._state = {count: count, items: items};
   return Object.freeze(this);
 }
 Dict.prototype = Object.freeze({
   /**
    * The number of items in the dictionary.
    */
   get count() {
     return this._state.count;
   },
   /**
    * Gets the value for a key from the dictionary. If the key is not a string,
    * it will be converted to a string before the lookup happens.
    *
    * @param aKey The key to look up
    * @param [aDefault] An optional default value to return if the key is not
    *                   present. Defaults to |undefined|.
    * @returns The item, or aDefault if it isn't found.
    */
   get: function Dict_get(aKey, aDefault) {
     var prop = convert(aKey);
     var items = this._state.items;
     return items.hasOwnProperty(prop) ? items[prop] : aDefault;
   },
   /**
    * Sets the value for a key in the dictionary. If the key is a not a string,
    * it will be converted to a string before the set happens.
    */
   set: function Dict_set(aKey, aValue) {
     var prop = convert(aKey);
     var items = this._state.items;
     if (!items.hasOwnProperty(prop))
       this._state.count++;
     items[prop] = aValue;
   },
   /**
    * Sets a lazy getter function for a key's value. If the key is a not a string,
    * it will be converted to a string before the set happens.
    * @param aKey
    *        The key to set
    * @param aThunk
    *        A getter function to be called the first time the value for aKey is
    *        retrieved. It is guaranteed that aThunk wouldn't be called more
    *        than once.  Note that the key value may be retrieved either
    *        directly, by |get|, or indirectly, by |listvalues| or by iterating
    *        |values|.  For the later, the value is only retrieved if and when
    *        the iterator gets to the value in question.  Also note that calling
    *        |has| for a lazy-key does not invoke aThunk.
    *
    * @note No context is provided for aThunk when it's invoked.
    *       Use Function.bind if you wish to run it in a certain context.
    */
   setAsLazyGetter: function Dict_setAsLazyGetter(aKey, aThunk) {
     let prop = convert(aKey);
     let items = this._state.items;
     if (!items.hasOwnProperty(prop))
       this._state.count++;
     Object.defineProperty(items, prop, {
       get: function() {
         delete items[prop];
         return items[prop] = aThunk();
       },
       configurable: true,
       enumerable: true
     });
   },
   /**
    * Returns whether a key is set as a lazy getter.  This returns
    * true only if the getter function was not called already.
    * @param aKey
    *        The key to look up.
    * @returns whether aKey is set as a lazy getter.
    */
   isLazyGetter: function Dict_isLazyGetter(aKey) {
     let descriptor = Object.getOwnPropertyDescriptor(this._state.items,
                                                      convert(aKey));
     return (descriptor && descriptor.get != null);
   },
   /**
    * Returns whether a key is in the dictionary. If the key is a not a string,
    * it will be converted to a string before the lookup happens.
    */
   has: function Dict_has(aKey) {
     return (this._state.items.hasOwnProperty(convert(aKey)));
   },
   /**
    * Deletes a key from the dictionary. If the key is a not a string, it will be
    * converted to a string before the delete happens.
    *
    * @returns true if the key was found, false if it wasn't.
    */
   del: function Dict_del(aKey) {
     var prop = convert(aKey);
     if (this._state.items.hasOwnProperty(prop)) {
       delete this._state.items[prop];
       this._state.count--;
       return true;
     }
     return false;
   },
   /**
    * Returns a shallow copy of this dictionary.
    */
   copy: function Dict_copy() {
     var newItems = {};
     for (var [key, val] in this.items)
       newItems[key] = val;
     return new Dict(newItems);
   },
   /*
    * List and iterator functions
    *
    * No guarantees whatsoever are made about the order of elements.
    */
   /**
    * Returns a list of all the keys in the dictionary in an arbitrary order.
    */
   listkeys: function Dict_listkeys() {
     return [unconvert(k) for (k in this._state.items)];
   },
   /**
    * Returns a list of all the values in the dictionary in an arbitrary order.
    */
   listvalues: function Dict_listvalues() {
     var items = this._state.items;
     return [items[k] for (k in items)];
   },
   /**
    * Returns a list of all the items in the dictionary as key-value pairs
    * in an arbitrary order.
    */
   listitems: function Dict_listitems() {
     var items = this._state.items;
     return [[unconvert(k), items[k]] for (k in items)];
   },
   /**
    * Returns an iterator over all the keys in the dictionary in an arbitrary
    * order. No guarantees are made about what happens if the dictionary is
    * mutated during iteration.
    */
   get keys() {
     // If we don't capture this._state.items here then the this-binding will be
     // incorrect when the generator is executed
     var items = this._state.items;
     return (unconvert(k) for (k in items));
   },
   /**
    * Returns an iterator over all the values in the dictionary in an arbitrary
    * order. No guarantees are made about what happens if the dictionary is
    * mutated during iteration.
    */
   get values() {
     // If we don't capture this._state.items here then the this-binding will be
     // incorrect when the generator is executed
     var items = this._state.items;
     return (items[k] for (k in items));
   },
   /**
    * Returns an iterator over all the items in the dictionary as key-value pairs
    * in an arbitrary order. No guarantees are made about what happens if the
    * dictionary is mutated during iteration.
    */
   get items() {
     // If we don't capture this._state.items here then the this-binding will be
     // incorrect when the generator is executed
     var items = this._state.items;
     return ([unconvert(k), items[k]] for (k in items));
   },
   /**
    * Returns a String representation of this dictionary.
    */
   toString: function Dict_toString() {
     return "{" +
       [(key + ": " + val) for ([key, val] in this.items)].join(", ") +
       "}";
   },
   /**
    * Returns a JSON representation of this dictionary.
    */
   toJSON: function Dict_toJSON() {
     let obj = {};
     for (let [key, item] of Iterator(this._state.items)) {
       obj[unconvert(key)] = item;
     }
     return JSON.stringify(obj);
   },
 });

The Tor Browser / annotate

toolkit/modules/Dict.jsm@6474c204b198 (annotated)

toolkit/modules/Dict.jsm