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 file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /**
michael@0:  * PageThumbsProtocol.js
michael@0:  *
michael@0:  * This file implements the moz-page-thumb:// protocol and the corresponding
michael@0:  * channel delivering cached thumbnails.
michael@0:  *
michael@0:  * URL structure:
michael@0:  *
michael@0:  * moz-page-thumb://thumbnail?url=http%3A%2F%2Fwww.mozilla.org%2F
michael@0:  *
michael@0:  * This URL requests an image for 'http://www.mozilla.org/'.
michael@0:  */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: const Cu = Components.utils;
michael@0: const Cc = Components.classes;
michael@0: const Cr = Components.results;
michael@0: const Ci = Components.interfaces;
michael@0: 
michael@0: Cu.import("resource://gre/modules/PageThumbs.jsm");
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "Services",
michael@0:   "resource://gre/modules/Services.jsm");
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",
michael@0:   "resource://gre/modules/FileUtils.jsm");
michael@0: 
michael@0: /**
michael@0:  * Implements the thumbnail protocol handler responsible for moz-page-thumb: URIs.
michael@0:  */
michael@0: function Protocol() {
michael@0: }
michael@0: 
michael@0: Protocol.prototype = {
michael@0:   /**
michael@0:    * The scheme used by this protocol.
michael@0:    */
michael@0:   get scheme() PageThumbs.scheme,
michael@0: 
michael@0:   /**
michael@0:    * The default port for this protocol (we don't support ports).
michael@0:    */
michael@0:   get defaultPort() -1,
michael@0: 
michael@0:   /**
michael@0:    * The flags specific to this protocol implementation.
michael@0:    */
michael@0:   get protocolFlags() {
michael@0:     return Ci.nsIProtocolHandler.URI_DANGEROUS_TO_LOAD |
michael@0:            Ci.nsIProtocolHandler.URI_NORELATIVE |
michael@0:            Ci.nsIProtocolHandler.URI_NOAUTH;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Creates a new URI object that is suitable for loading by this protocol.
michael@0:    * @param aSpec The URI string in UTF8 encoding.
michael@0:    * @param aOriginCharset The charset of the document from which the URI originated.
michael@0:    * @return The newly created URI.
michael@0:    */
michael@0:   newURI: function Proto_newURI(aSpec, aOriginCharset) {
michael@0:     let uri = Cc["@mozilla.org/network/simple-uri;1"].createInstance(Ci.nsIURI);
michael@0:     uri.spec = aSpec;
michael@0:     return uri;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Constructs a new channel from the given URI for this protocol handler.
michael@0:    * @param aURI The URI for which to construct a channel.
michael@0:    * @return The newly created channel.
michael@0:    */
michael@0:   newChannel: function Proto_newChannel(aURI) {
michael@0:     let {url} = parseURI(aURI);
michael@0:     let file = PageThumbsStorage.getFilePathForURL(url);
michael@0:     let fileuri = Services.io.newFileURI(new FileUtils.File(file));
michael@0:     return Services.io.newChannelFromURI(fileuri);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Decides whether to allow a blacklisted port.
michael@0:    * @return Always false, we'll never allow ports.
michael@0:    */
michael@0:   allowPort: function () false,
michael@0: 
michael@0:   classID: Components.ID("{5a4ae9b5-f475-48ae-9dce-0b4c1d347884}"),
michael@0:   QueryInterface: XPCOMUtils.generateQI([Ci.nsIProtocolHandler])
michael@0: };
michael@0: 
michael@0: this.NSGetFactory = XPCOMUtils.generateNSGetFactory([Protocol]);
michael@0: 
michael@0: /**
michael@0:  * Parses a given URI and extracts all parameters relevant to this protocol.
michael@0:  * @param aURI The URI to parse.
michael@0:  * @return The parsed parameters.
michael@0:  */
michael@0: function parseURI(aURI) {
michael@0:   let {scheme, staticHost} = PageThumbs;
michael@0:   let re = new RegExp("^" + scheme + "://" + staticHost + ".*?\\?");
michael@0:   let query = aURI.spec.replace(re, "");
michael@0:   let params = {};
michael@0: 
michael@0:   query.split("&").forEach(function (aParam) {
michael@0:     let [key, value] = aParam.split("=").map(decodeURIComponent);
michael@0:     params[key.toLowerCase()] = value;
michael@0:   });
michael@0: 
michael@0:   return params;
michael@0: }