The Tor Browser: toolkit/components/search/nsSearchSuggestions.js@925c144e1f1f (annotated)

toolkit/components/search/nsSearchSuggestions.js@925c144e1f1f (annotated)

toolkit/components/search/nsSearchSuggestions.js

Fri, 16 Jan 2015 18:13:44 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Fri, 16 Jan 2015 18:13:44 +0100
branch: TOR_BUG_9701
changeset 14: 925c144e1f1f
permissions: -rw-r--r--

Integrate suggestion from review to improve consistency with existing code.

 /* 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/. */
 const SEARCH_RESPONSE_SUGGESTION_JSON = "application/x-suggestions+json";
 const BROWSER_SUGGEST_PREF = "browser.search.suggest.enabled";
 const XPCOM_SHUTDOWN_TOPIC              = "xpcom-shutdown";
 const NS_PREFBRANCH_PREFCHANGE_TOPIC_ID = "nsPref:changed";
 const Cc = Components.classes;
 const Ci = Components.interfaces;
 const Cr = Components.results;
 const Cu = Components.utils;
 const HTTP_OK                    = 200;
 const HTTP_INTERNAL_SERVER_ERROR = 500;
 const HTTP_BAD_GATEWAY           = 502;
 const HTTP_SERVICE_UNAVAILABLE   = 503;
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/nsFormAutoCompleteResult.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 /**
  * SuggestAutoComplete is a base class that implements nsIAutoCompleteSearch
  * and can collect results for a given search by using the search URL supplied
  * by the subclass. We do it this way since the AutoCompleteController in
  * Mozilla requires a unique XPCOM Service for every search provider, even if
  * the logic for two providers is identical.
  * @constructor
  */
 function SuggestAutoComplete() {
   this._init();
 }
 SuggestAutoComplete.prototype = {
   _init: function() {
     this._addObservers();
     this._suggestEnabled = Services.prefs.getBoolPref(BROWSER_SUGGEST_PREF);
   },
   get _suggestionLabel() {
     delete this._suggestionLabel;
     let bundle = Services.strings.createBundle("chrome://global/locale/search/search.properties");
     return this._suggestionLabel = bundle.GetStringFromName("suggestion_label");
   },
   /**
    * Search suggestions will be shown if this._suggestEnabled is true.
    */
   _suggestEnabled: null,
   /*************************************************************************
    * Server request backoff implementation fields below
    * These allow us to throttle requests if the server is getting hammered.
    **************************************************************************/
   /**
    * This is an array that contains the timestamps (in unixtime) of
    * the last few backoff-triggering errors.
    */
   _serverErrorLog: [],
   /**
    * If we receive this number of backoff errors within the amount of time
    * specified by _serverErrorPeriod, then we initiate backoff.
    */
   _maxErrorsBeforeBackoff: 3,
   /**
    * If we receive enough consecutive errors (where "enough" is defined by
    * _maxErrorsBeforeBackoff above) within this time period,
    * we trigger the backoff behavior.
    */
   _serverErrorPeriod: 600000,  // 10 minutes in milliseconds
   /**
    * If we get another backoff error immediately after timeout, we increase the
    * backoff to (2 x old period) + this value.
    */
   _serverErrorTimeoutIncrement: 600000,  // 10 minutes in milliseconds
   /**
    * The current amount of time to wait before trying a server request
    * after receiving a backoff error.
    */
   _serverErrorTimeout: 0,
   /**
    * Time (in unixtime) after which we're allowed to try requesting again.
    */
   _nextRequestTime: 0,
   /**
    * The last engine we requested against (so that we can tell if the
    * user switched engines).
    */
   _serverErrorEngine: null,
   /**
    * The XMLHttpRequest object.
    * @private
    */
   _request: null,
   /**
    * The object implementing nsIAutoCompleteObserver that we notify when
    * we have found results
    * @private
    */
   _listener: null,
   /**
    * If this is true, we'll integrate form history results with the
    * suggest results.
    */
   _includeFormHistory: true,
   /**
    * True if a request for remote suggestions was sent. This is used to
    * differentiate between the "_request is null because the request has
    * already returned a result" and "_request is null because no request was
    * sent" cases.
    */
   _sentSuggestRequest: false,
   /**
    * This is the callback for the suggest timeout timer.
    */
   notify: function SAC_notify(timer) {
     // FIXME: bug 387341
     // Need to break the cycle between us and the timer.
     this._formHistoryTimer = null;
     // If this._listener is null, we've already sent out suggest results, so
     // nothing left to do here.
     if (!this._listener)
       return;
     // Otherwise, the XMLHTTPRequest for suggest results is taking too long,
     // so send out the form history results and cancel the request.
     this._listener.onSearchResult(this, this._formHistoryResult);
     this._reset();
   },
   /**
    * This determines how long (in ms) we should wait before giving up on
    * the suggestions and just showing local form history results.
    */
   _suggestionTimeout: 500,
   /**
    * This is the callback for that the form history service uses to
    * send us results.
    */
   onSearchResult: function SAC_onSearchResult(search, result) {
     this._formHistoryResult = result;
     if (this._request) {
       // We still have a pending request, wait a bit to give it a chance to
       // finish.
       this._formHistoryTimer = Cc["@mozilla.org/timer;1"].
                                createInstance(Ci.nsITimer);
       this._formHistoryTimer.initWithCallback(this, this._suggestionTimeout,
                                               Ci.nsITimer.TYPE_ONE_SHOT);
     } else if (!this._sentSuggestRequest) {
       // We didn't send a request, so just send back the form history results.
       this._listener.onSearchResult(this, this._formHistoryResult);
       this._reset();
     }
   },
   /**
    * This is the URI that the last suggest request was sent to.
    */
   _suggestURI: null,
   /**
    * Autocomplete results from the form history service get stored here.
    */
   _formHistoryResult: null,
   /**
    * This holds the suggest server timeout timer, if applicable.
    */
   _formHistoryTimer: null,
   /**
    * Maximum number of history items displayed. This is capped at 7
    * because the primary consumer (Firefox search bar) displays 10 rows
    * by default, and so we want to leave some space for suggestions
    * to be visible.
    */
   _historyLimit: 7,
   /**
    * This clears all the per-request state.
    */
   _reset: function SAC_reset() {
     // Don't let go of our listener and form history result if the timer is
     // still pending, the timer will call _reset() when it fires.
     if (!this._formHistoryTimer) {
       this._listener = null;
       this._formHistoryResult = null;
     }
     this._request = null;
   },
   /**
    * This sends an autocompletion request to the form history service,
    * which will call onSearchResults with the results of the query.
    */
   _startHistorySearch: function SAC_SHSearch(searchString, searchParam) {
     var formHistory =
       Cc["@mozilla.org/autocomplete/search;1?name=form-history"].
       createInstance(Ci.nsIAutoCompleteSearch);
     formHistory.startSearch(searchString, searchParam, this._formHistoryResult, this);
   },
   /**
    * Makes a note of the fact that we've received a backoff-triggering
    * response, so that we can adjust the backoff behavior appropriately.
    */
   _noteServerError: function SAC__noteServeError() {
     var currentTime = Date.now();
     this._serverErrorLog.push(currentTime);
     if (this._serverErrorLog.length > this._maxErrorsBeforeBackoff)
       this._serverErrorLog.shift();
     if ((this._serverErrorLog.length == this._maxErrorsBeforeBackoff) &&
         ((currentTime - this._serverErrorLog[0]) < this._serverErrorPeriod)) {
       // increase timeout, and then don't request until timeout is over
       this._serverErrorTimeout = (this._serverErrorTimeout * 2) +
                                  this._serverErrorTimeoutIncrement;
       this._nextRequestTime = currentTime + this._serverErrorTimeout;
     }
   },
   /**
    * Resets the backoff behavior; called when we get a successful response.
    */
   _clearServerErrors: function SAC__clearServerErrors() {
     this._serverErrorLog = [];
     this._serverErrorTimeout = 0;
     this._nextRequestTime = 0;
   },
   /**
    * This checks whether we should send a server request (i.e. we're not
    * in a error-triggered backoff period.
    *
    * @private
    */
   _okToRequest: function SAC__okToRequest() {
     return Date.now() > this._nextRequestTime;
   },
   /**
    * This checks to see if the new search engine is different
    * from the previous one, and if so clears any error state that might
    * have accumulated for the old engine.
    *
    * @param engine The engine that the suggestion request would be sent to.
    * @private
    */
   _checkForEngineSwitch: function SAC__checkForEngineSwitch(engine) {
     if (engine == this._serverErrorEngine)
       return;
     // must've switched search providers, clear old errors
     this._serverErrorEngine = engine;
     this._clearServerErrors();
   },
   /**
    * This returns true if the status code of the HTTP response
    * represents a backoff-triggering error.
    *
    * @param status  The status code from the HTTP response
    * @private
    */
   _isBackoffError: function SAC__isBackoffError(status) {
     return ((status == HTTP_INTERNAL_SERVER_ERROR) ||
             (status == HTTP_BAD_GATEWAY) ||
             (status == HTTP_SERVICE_UNAVAILABLE));
   },
   /**
    * Called when the 'readyState' of the XMLHttpRequest changes. We only care
    * about state 4 (COMPLETED) - handle the response data.
    * @private
    */
   onReadyStateChange: function() {
     // xxx use the real const here
     if (!this._request || this._request.readyState != 4)
       return;
     try {
       var status = this._request.status;
     } catch (e) {
       // The XML HttpRequest can throw NS_ERROR_NOT_AVAILABLE.
       return;
     }
     if (this._isBackoffError(status)) {
       this._noteServerError();
       return;
     }
     var responseText = this._request.responseText;
     if (status != HTTP_OK || responseText == "")
       return;
     this._clearServerErrors();
     try {
       var serverResults = JSON.parse(responseText);
     } catch(ex) {
       Components.utils.reportError("Failed to parse JSON from " + this._suggestURI.spec + ": " + ex);
       return;
     }
     var searchString = serverResults[0] || "";
     var results = serverResults[1] || [];
     var comments = [];  // "comments" column values for suggestions
     var historyResults = [];
     var historyComments = [];
     // If form history is enabled and has results, add them to the list.
     if (this._includeFormHistory && this._formHistoryResult &&
         (this._formHistoryResult.searchResult ==
          Ci.nsIAutoCompleteResult.RESULT_SUCCESS)) {
       var maxHistoryItems = Math.min(this._formHistoryResult.matchCount, this._historyLimit);
       for (var i = 0; i < maxHistoryItems; ++i) {
         var term = this._formHistoryResult.getValueAt(i);
         // we don't want things to appear in both history and suggestions
         var dupIndex = results.indexOf(term);
         if (dupIndex != -1)
           results.splice(dupIndex, 1);
         historyResults.push(term);
         historyComments.push("");
       }
     }
     // fill out the comment column for the suggestions
     for (var i = 0; i < results.length; ++i)
       comments.push("");
     // if we have any suggestions, put a label at the top
     if (comments.length > 0)
       comments[0] = this._suggestionLabel;
     // now put the history results above the suggestions
     var finalResults = historyResults.concat(results);
     var finalComments = historyComments.concat(comments);
     // Notify the FE of our new results
     this.onResultsReady(searchString, finalResults, finalComments,
                         this._formHistoryResult);
     // Reset our state for next time.
     this._reset();
   },
   /**
    * Notifies the front end of new results.
    * @param searchString  the user's query string
    * @param results       an array of results to the search
    * @param comments      an array of metadata corresponding to the results
    * @private
    */
   onResultsReady: function(searchString, results, comments,
                            formHistoryResult) {
     if (this._listener) {
       var result = new FormAutoCompleteResult(
           searchString,
           Ci.nsIAutoCompleteResult.RESULT_SUCCESS,
 ,
           "",
           results,
           results,
           comments,
           formHistoryResult);
       this._listener.onSearchResult(this, result);
       // Null out listener to make sure we don't notify it twice, in case our
       // timer callback still hasn't run.
       this._listener = null;
     }
   },
   /**
    * Initiates the search result gathering process. Part of
    * nsIAutoCompleteSearch implementation.
    *
    * @param searchString    the user's query string
    * @param searchParam     unused, "an extra parameter"; even though
    *                        this parameter and the next are unused, pass
    *                        them through in case the form history
    *                        service wants them
    * @param previousResult  unused, a client-cached store of the previous
    *                        generated resultset for faster searching.
    * @param listener        object implementing nsIAutoCompleteObserver which
    *                        we notify when results are ready.
    */
   startSearch: function(searchString, searchParam, previousResult, listener) {
     // Don't reuse a previous form history result when it no longer applies.
     if (!previousResult)
       this._formHistoryResult = null;
     var formHistorySearchParam = searchParam.split("|")[0];
     // Receive the information about the privacy mode of the window to which
     // this search box belongs.  The front-end's search.xml bindings passes this
     // information in the searchParam parameter.  The alternative would have
     // been to modify nsIAutoCompleteSearch to add an argument to startSearch
     // and patch all of autocomplete to be aware of this, but the searchParam
     // argument is already an opaque argument, so this solution is hopefully
     // less hackish (although still gross.)
     var privacyMode = (searchParam.split("|")[1] == "private");
     // Start search immediately if possible, otherwise once the search
     // service is initialized
     if (Services.search.isInitialized) {
       this._triggerSearch(searchString, formHistorySearchParam, listener, privacyMode);
       return;
     }
     Services.search.init((function startSearch_cb(aResult) {
       if (!Components.isSuccessCode(aResult)) {
         Cu.reportError("Could not initialize search service, bailing out: " + aResult);
         return;
       }
       this._triggerSearch(searchString, formHistorySearchParam, listener, privacyMode);
     }).bind(this));
   },
   /**
    * Actual implementation of search.
    */
   _triggerSearch: function(searchString, searchParam, listener, privacyMode) {
     // If there's an existing request, stop it. There is no smart filtering
     // here as there is when looking through history/form data because the
     // result set returned by the server is different for every typed value -
     // "ocean breathes" does not return a subset of the results returned for
     // "ocean", for example. This does nothing if there is no current request.
     this.stopSearch();
     this._listener = listener;
     var engine = Services.search.currentEngine;
     this._checkForEngineSwitch(engine);
     if (!searchString ||
         !this._suggestEnabled ||
         !engine.supportsResponseType(SEARCH_RESPONSE_SUGGESTION_JSON) ||
         !this._okToRequest()) {
       // We have an empty search string (user pressed down arrow to see
       // history), or search suggestions are disabled, or the current engine
       // has no suggest functionality, or we're in backoff mode; so just use
       // local history.
       this._sentSuggestRequest = false;
       this._startHistorySearch(searchString, searchParam);
       return;
     }
     // Actually do the search
     this._request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"].
                     createInstance(Ci.nsIXMLHttpRequest);
     var submission = engine.getSubmission(searchString,
                                           SEARCH_RESPONSE_SUGGESTION_JSON);
     this._suggestURI = submission.uri;
     var method = (submission.postData ? "POST" : "GET");
     this._request.open(method, this._suggestURI.spec, true);
     this._request.channel.notificationCallbacks = new AuthPromptOverride();
     if (this._request.channel instanceof Ci.nsIPrivateBrowsingChannel) {
       this._request.channel.setPrivate(privacyMode);
     }
     var self = this;
     function onReadyStateChange() {
       self.onReadyStateChange();
     }
     this._request.onreadystatechange = onReadyStateChange;
     this._request.send(submission.postData);
     if (this._includeFormHistory) {
       this._sentSuggestRequest = true;
       this._startHistorySearch(searchString, searchParam);
     }
   },
   /**
    * Ends the search result gathering process. Part of nsIAutoCompleteSearch
    * implementation.
    */
   stopSearch: function() {
     if (this._request) {
       this._request.abort();
       this._reset();
     }
   },
   /**
    * nsIObserver
    */
   observe: function SAC_observe(aSubject, aTopic, aData) {
     switch (aTopic) {
       case NS_PREFBRANCH_PREFCHANGE_TOPIC_ID:
         this._suggestEnabled = Services.prefs.getBoolPref(BROWSER_SUGGEST_PREF);
         break;
       case XPCOM_SHUTDOWN_TOPIC:
         this._removeObservers();
         break;
     }
   },
   _addObservers: function SAC_addObservers() {
     Services.prefs.addObserver(BROWSER_SUGGEST_PREF, this, false);
     Services.obs.addObserver(this, XPCOM_SHUTDOWN_TOPIC, false);
   },
   _removeObservers: function SAC_removeObservers() {
     Services.prefs.removeObserver(BROWSER_SUGGEST_PREF, this);
     Services.obs.removeObserver(this, XPCOM_SHUTDOWN_TOPIC);
   },
   // nsISupports
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIAutoCompleteSearch,
                                          Ci.nsIAutoCompleteObserver])
 };
 function AuthPromptOverride() {
 }
 AuthPromptOverride.prototype = {
   // nsIAuthPromptProvider
   getAuthPrompt: function (reason, iid) {
     // Return a no-op nsIAuthPrompt2 implementation.
     return {
       promptAuth: function () {
         throw Cr.NS_ERROR_NOT_IMPLEMENTED;
       },
       asyncPromptAuth: function () {
         throw Cr.NS_ERROR_NOT_IMPLEMENTED;
       }
     };
   },
   // nsIInterfaceRequestor
   getInterface: function SSLL_getInterface(iid) {
     return this.QueryInterface(iid);
   },
   // nsISupports
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIAuthPromptProvider,
                                          Ci.nsIInterfaceRequestor])
 };
 /**
  * SearchSuggestAutoComplete is a service implementation that handles suggest
  * results specific to web searches.
  * @constructor
  */
 function SearchSuggestAutoComplete() {
   // This calls _init() in the parent class (SuggestAutoComplete) via the
   // prototype, below.
   this._init();
 }
 SearchSuggestAutoComplete.prototype = {
   classID: Components.ID("{aa892eb4-ffbf-477d-9f9a-06c995ae9f27}"),
   __proto__: SuggestAutoComplete.prototype,
   serviceURL: ""
 };
 var component = [SearchSuggestAutoComplete];
 this.NSGetFactory = XPCOMUtils.generateNSGetFactory(component);