Files
tubestation/toolkit/components/url-classifier/content/map.js
brettw@gmail.com 32a4ecd9ac Bug 333894 (for tony@ponderer.org) r+a=ben
flesh out details interfaces for managing black/white lists
2006-05-02 21:57:35 +00:00

233 lines
7.2 KiB
JavaScript

/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Google Safe Browsing.
*
* The Initial Developer of the Original Code is Google Inc.
* Portions created by the Initial Developer are Copyright (C) 2006
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Fritz Schneider <fritz@google.com> (original author)
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
// This is a map over which you can iterate (you can't get an iterator
// for an Object used as a map). It is important to have an iterable
// map if you have a large numbe ofkeys and you wish to process them
// in chunks, for example on a thread.
//
// This Map's operations are all O(1) plus the time of the native
// operations on its arrays and object. The tradeoff for this speed is
// that the size of the map is always non-decreasing. That is, when an
// item is remove()'d, it is merely marked as invalid and not actually
// removed.
//
// This map is not safe if your keys are objects (they'll get
// stringified to the same value in non-debug builds).
//
// Interface:
// insert(key, value)
// remove(key)
// exists(key)
// getList() // This is our poor man's iterator
// forEach(someFunc)
// replace(otherMap) // Clones otherMap, replacing the current map
// count // readonly attribute
//
// TODO: we could easily have this map periodically compact itself so as
// to eliminate the size tradeoff.
/**
* Create a new Map
*
* @constructor
* @param opt_name A string used to name the map
*/
function G_Map(opt_name) {
this.debugZone = "map";
this.name = "noname";
// We store key/value pairs sequentially in membersArray
this.membersArray_ = [];
// In membersMap we map from keys to indices in the membersArray
this.membersMap_ = {};
this.count_ = 0;
// set to true to allow list manager to update
this.needsUpdate = false;
}
/**
* Add an item
*
* @param key An key to add (overwrites previous key)
* @param value The value to store at that key
*/
G_Map.prototype.insert = function(key, value) {
if (key == null)
throw new Error("Can't use null as a key");
else if (typeof key == "object")
throw new Error("This class is not objectsafe; use ObjectSafeMap");
if (value === undefined)
throw new Error("Can't store undefined values in this map");
// Get rid of the old value, if there was one, and increment count if not
var oldIndexInArray = this.membersMap_[key];
if (typeof oldIndexInArray == "number")
this.membersArray_[oldIndexInArray] = undefined;
else
this.count_++;
var indexInArray = this.membersArray_.length;
this.membersArray_.push({ "key": key, "value": value});
this.membersMap_[key] = indexInArray;
}
/**
* Remove a key from the map
*
* @param key The key to remove
* @returns Boolean indicating if the key was removed
*/
G_Map.prototype.remove = function(key) {
var indexInArray = this.membersMap_[key];
if (indexInArray === undefined)
return false;
this.count_--;
delete this.membersMap_[key];
// We could slice here, but that could be expensive if the map large
this.membersArray_[indexInArray] = undefined;
return true;
}
/**
* Private lookup function
*
* @param key The key to look up
* @returns The value at that key or undefined if it doesn't exist
*/
G_Map.prototype.find_ = function(key) {
var indexInArray = this.membersMap_[key];
return ((indexInArray === undefined) ?
undefined :
this.membersArray_[indexInArray].value);
}
/**
* Public lookup function
*
* @param key The key to look up
* @returns The value at that key or undefined if it doesn't exist
*/
G_Map.prototype.exists = function(key) {
return this.find_(key);
}
/**
* Return the list of the keys we have. Use findValue to get the associated
* value.
*
* TODO: its probably better to expose a real iterator, but this works
* TODO: getting keys and values is a pain, do something more clever
*
* @returns Array of items in the map, some entries of which might be
* undefined. Each item is an object with members key and
* value
*/
G_Map.prototype.getKeys = function(count) {
var ret = [];
for (var i = 0; i < this.membersArray_.length; ++i) {
ret.push(this.membersArray_[i].key);
}
count.value = ret.length;
return ret;
}
G_Map.prototype.findValue = function(key) {
return this.find_(key);
}
/**
* Replace one map with the content of another
*
* IMPORTANT NOTE: This method copies references to objects, it does
* NOT copy the objects themselves.
*
* @param other Reference to a G_Map that we should clone
*/
G_Map.prototype.replace = function(other) {
this.membersMap_ = {};
this.membersArray_ = [];
// TODO Make this faster, and possibly run it on a thread
var lst = {};
var otherList = other.getList(lst);
for (var i = 0; i < otherList.length; i++)
if (otherList[i]) {
var index = this.membersArray_.length;
this.membersArray_.push(otherList[i]);
this.membersMap_[otherList[i].key] = index;
}
this.count_ = other.count;
}
/**
* Apply a function to each of the key value pairs.
*
* @param func Function to apply to the map's key value pairs
*/
G_Map.prototype.forEach = function(func) {
if (typeof func != "function")
throw new Error("argument to forEach is not a function, it's a(n) " +
typeof func);
for (var i = 0; i < this.membersArray_.length; i++)
if (this.membersArray_[i])
func(this.membersArray_[i].key, this.membersArray_[i].value);
}
G_Map.prototype.QueryInterface = function(iid) {
if (iid.equals(Components.interfaces.nsISupports) ||
iid.equals(Components.interfaces.nsIUrlClassifierTable))
return this;
Components.returnCode = Components.results.NS_ERROR_NO_INTERFACE;
return null;
}
/**
* Readonly count attribute.
* @returns The number of keys in the map
*/
G_Map.prototype.__defineGetter__('count', function() {
return this.count_;
});