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+/* 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 = ["SearchSuggestionController"];
+
+const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/Promise.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "NS_ASSERT", "resource://gre/modules/debug.js");
+
+const SEARCH_RESPONSE_SUGGESTION_JSON = "application/x-suggestions+json";
+const DEFAULT_FORM_HISTORY_PARAM = "searchbar-history";
+const HTTP_OK = 200;
+const REMOTE_TIMEOUT = 500; // maximum time (ms) to wait before giving up on a remote suggestions
+const BROWSER_SUGGEST_PREF = "browser.search.suggest.enabled";
+
+/**
+ * Remote search suggestions will be shown if gRemoteSuggestionsEnabled
+ * is true. Global because only one pref observer is needed for all instances.
+ */
+var gRemoteSuggestionsEnabled = Services.prefs.getBoolPref(BROWSER_SUGGEST_PREF);
+Services.prefs.addObserver(BROWSER_SUGGEST_PREF, function(aSubject, aTopic, aData) {
+ gRemoteSuggestionsEnabled = Services.prefs.getBoolPref(BROWSER_SUGGEST_PREF);
+}, false);
+
+/**
+ * SearchSuggestionController.jsm exists as a helper module to allow multiple consumers to request and display
+ * search suggestions from a given engine, regardless of the base implementation. Much of this
+ * code was originally in nsSearchSuggestions.js until it was refactored to separate it from the
+ * nsIAutoCompleteSearch dependency.
+ * One instance of SearchSuggestionController should be used per field since form history results are cached.
+ */
+
+/**
+ * @param {function} [callback] - Callback for search suggestion results. You can use the promise
+ * returned by the search method instead if you prefer.
+ * @constructor
+ */
+this.SearchSuggestionController = function SearchSuggestionController(callback = null) {
+ this._callback = callback;
+};
+
+this.SearchSuggestionController.prototype = {
+ /**
+ * The maximum number of local form history results to return. This limit is
+ * only enforced if remote results are also returned.
+ */
+ maxLocalResults: 5,
+
+ /**
+ * The maximum number of remote search engine results to return.
+ * We'll actually only display at most
+ * maxRemoteResults - <displayed local results count> remote results.
+ */
+ maxRemoteResults: 10,
+
+ /**
+ * The maximum time (ms) to wait before giving up on a remote suggestions.
+ */
+ remoteTimeout: REMOTE_TIMEOUT,
+
+ /**
+ * The additional parameter used when searching form history.
+ */
+ formHistoryParam: DEFAULT_FORM_HISTORY_PARAM,
+
+ // Private properties
+ /**
+ * The last form history result used to improve the performance of subsequent searches.
+ * This shouldn't be used for any other purpose as it is never cleared and therefore could be stale.
+ */
+ _formHistoryResult: null,
+
+ /**
+ * The remote server timeout timer, if applicable. The timer starts when form history
+ * search is completed.
+ */
+ _remoteResultTimer: null,
+
+ /**
+ * The deferred for the remote results before its promise is resolved.
+ */
+ _deferredRemoteResult: null,
+
+ /**
+ * The optional result callback registered from the constructor.
+ */
+ _callback: null,
+
+ /**
+ * The XMLHttpRequest object for remote results.
+ */
+ _request: null,
+
+ // Public methods
+
+ /**
+ * Fetch search suggestions from all of the providers. Fetches in progress will be stopped and
+ * results from them will not be provided.
+ *
+ * @param {string} searchTerm - the term to provide suggestions for
+ * @param {bool} privateMode - whether the request is being made in the context of private browsing
+ * @param {nsISearchEngine} engine - search engine for the suggestions.
+ * @param {int} userContextId - the userContextId of the selected tab.
+ *
+ * @return {Promise} resolving to an object containing results or null.
+ */
+ fetch: function(searchTerm, privateMode, engine, userContextId) {
+ // There is no smart filtering from previous results here (as there is when looking through
+ // history/form data) because the result set returned by the server is different for every typed
+ // value - e.g. "ocean breathes" does not return a subset of the results returned for "ocean".
+
+ this.stop();
+
+ if (!Services.search.isInitialized) {
+ throw new Error("Search not initialized yet (how did you get here?)");
+ }
+ if (typeof privateMode === "undefined") {
+ throw new Error("The privateMode argument is required to avoid unintentional privacy leaks");
+ }
+ if (!(engine instanceof Ci.nsISearchEngine)) {
+ throw new Error("Invalid search engine");
+ }
+ if (!this.maxLocalResults && !this.maxRemoteResults) {
+ throw new Error("Zero results expected, what are you trying to do?");
+ }
+ if (this.maxLocalResults < 0 || this.maxRemoteResults < 0) {
+ throw new Error("Number of requested results must be positive");
+ }
+
+ // Array of promises to resolve before returning results.
+ let promises = [];
+ this._searchString = searchTerm;
+
+ // Remote results
+ if (searchTerm && gRemoteSuggestionsEnabled && this.maxRemoteResults &&
+ engine.supportsResponseType(SEARCH_RESPONSE_SUGGESTION_JSON)) {
+ this._deferredRemoteResult = this._fetchRemote(searchTerm, engine, privateMode, userContextId);
+ promises.push(this._deferredRemoteResult.promise);
+ }
+
+ // Local results from form history
+ if (this.maxLocalResults) {
+ let deferredHistoryResult = this._fetchFormHistory(searchTerm);
+ promises.push(deferredHistoryResult.promise);
+ }
+
+ function handleRejection(reason) {
+ if (reason == "HTTP request aborted") {
+ // Do nothing since this is normal.
+ return null;
+ }
+ Cu.reportError("SearchSuggestionController rejection: " + reason);
+ return null;
+ }
+ return Promise.all(promises).then(this._dedupeAndReturnResults.bind(this), handleRejection);
+ },
+
+ /**
+ * Stop pending fetches so no results are returned from them.
+ *
+ * Note: If there was no remote results fetched, the fetching cannot be stopped and local results
+ * will still be returned because stopping relies on aborting the XMLHTTPRequest to reject the
+ * promise for Promise.all.
+ */
+ stop: function() {
+ if (this._request) {
+ this._request.abort();
+ } else if (!this.maxRemoteResults) {
+ Cu.reportError("SearchSuggestionController: Cannot stop fetching if remote results were not "+
+ "requested");
+ }
+ this._reset();
+ },
+
+ // Private methods
+
+ _fetchFormHistory: function(searchTerm) {
+ let deferredFormHistory = Promise.defer();
+
+ let acSearchObserver = {
+ // Implements nsIAutoCompleteSearch
+ onSearchResult: (search, result) => {
+ this._formHistoryResult = result;
+
+ if (this._request) {
+ this._remoteResultTimer = Cc["@mozilla.org/timer;1"].
+ createInstance(Ci.nsITimer);
+ this._remoteResultTimer.initWithCallback(this._onRemoteTimeout.bind(this),
+ this.remoteTimeout || REMOTE_TIMEOUT,
+ Ci.nsITimer.TYPE_ONE_SHOT);
+ }
+
+ switch (result.searchResult) {
+ case Ci.nsIAutoCompleteResult.RESULT_SUCCESS:
+ case Ci.nsIAutoCompleteResult.RESULT_NOMATCH:
+ if (result.searchString !== this._searchString) {
+ deferredFormHistory.resolve("Unexpected response, this._searchString does not match form history response");
+ return;
+ }
+ let fhEntries = [];
+ for (let i = 0; i < result.matchCount; ++i) {
+ fhEntries.push(result.getValueAt(i));
+ }
+ deferredFormHistory.resolve({
+ result: fhEntries,
+ formHistoryResult: result,
+ });
+ break;
+ case Ci.nsIAutoCompleteResult.RESULT_FAILURE:
+ case Ci.nsIAutoCompleteResult.RESULT_IGNORED:
+ deferredFormHistory.resolve("Form History returned RESULT_FAILURE or RESULT_IGNORED");
+ break;
+ }
+ },
+ };
+
+ let formHistory = Cc["@mozilla.org/autocomplete/search;1?name=form-history"].
+ createInstance(Ci.nsIAutoCompleteSearch);
+ formHistory.startSearch(searchTerm, this.formHistoryParam || DEFAULT_FORM_HISTORY_PARAM,
+ this._formHistoryResult,
+ acSearchObserver);
+ return deferredFormHistory;
+ },
+
+ /**
+ * Fetch suggestions from the search engine over the network.
+ */
+ _fetchRemote: function(searchTerm, engine, privateMode, userContextId) {
+ let deferredResponse = Promise.defer();
+ this._request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"].
+ createInstance(Ci.nsIXMLHttpRequest);
+ let submission = engine.getSubmission(searchTerm,
+ SEARCH_RESPONSE_SUGGESTION_JSON);
+ let method = (submission.postData ? "POST" : "GET");
+ this._request.open(method, submission.uri.spec, true);
+
+ this._request.setOriginAttributes({userContextId,
+ privateBrowsingId: privateMode ? 1 : 0});
+
+ this._request.mozBackgroundRequest = true; // suppress dialogs and fail silently
+
+ this._request.addEventListener("load", this._onRemoteLoaded.bind(this, deferredResponse));
+ this._request.addEventListener("error", (evt) => deferredResponse.resolve("HTTP error"));
+ // Reject for an abort assuming it's always from .stop() in which case we shouldn't return local
+ // or remote results for existing searches.
+ this._request.addEventListener("abort", (evt) => deferredResponse.reject("HTTP request aborted"));
+
+ this._request.send(submission.postData);
+
+ return deferredResponse;
+ },
+
+ /**
+ * Called when the request completed successfully (thought the HTTP status could be anything)
+ * so we can handle the response data.
+ * @private
+ */
+ _onRemoteLoaded: function(deferredResponse) {
+ if (!this._request) {
+ deferredResponse.resolve("Got HTTP response after the request was cancelled");
+ return;
+ }
+
+ let status, serverResults;
+ try {
+ status = this._request.status;
+ } catch (e) {
+ // The XMLHttpRequest can throw NS_ERROR_NOT_AVAILABLE.
+ deferredResponse.resolve("Unknown HTTP status: " + e);
+ return;
+ }
+
+ if (status != HTTP_OK || this._request.responseText == "") {
+ deferredResponse.resolve("Non-200 status or empty HTTP response: " + status);
+ return;
+ }
+
+ try {
+ serverResults = JSON.parse(this._request.responseText);
+ } catch (ex) {
+ deferredResponse.resolve("Failed to parse suggestion JSON: " + ex);
+ return;
+ }
+
+ if (!serverResults[0] ||
+ this._searchString.localeCompare(serverResults[0], undefined,
+ { sensitivity: "base" })) {
+ // something is wrong here so drop remote results
+ deferredResponse.resolve("Unexpected response, this._searchString does not match remote response");
+ return;
+ }
+ let results = serverResults[1] || [];
+ deferredResponse.resolve({ result: results });
+ },
+
+ /**
+ * Called when this._remoteResultTimer fires indicating the remote request took too long.
+ */
+ _onRemoteTimeout: function () {
+ this._request = null;
+
+ // FIXME: bug 387341
+ // Need to break the cycle between us and the timer.
+ this._remoteResultTimer = null;
+
+ // The XMLHTTPRequest for suggest results is taking too long
+ // so send out the form history results and cancel the request.
+ if (this._deferredRemoteResult) {
+ this._deferredRemoteResult.resolve("HTTP Timeout");
+ this._deferredRemoteResult = null;
+ }
+ },
+
+ /**
+ * @param {Array} suggestResults - an array of result objects from different sources (local or remote)
+ * @return {Object}
+ */
+ _dedupeAndReturnResults: function(suggestResults) {
+ if (this._searchString === null) {
+ // _searchString can be null if stop() was called and remote suggestions
+ // were disabled (stopping if we are fetching remote suggestions will
+ // cause a promise rejection before we reach _dedupeAndReturnResults).
+ return null;
+ }
+
+ let results = {
+ term: this._searchString,
+ remote: [],
+ local: [],
+ formHistoryResult: null,
+ };
+
+ for (let result of suggestResults) {
+ if (typeof result === "string") { // Failure message
+ Cu.reportError("SearchSuggestionController: " + result);
+ } else if (result.formHistoryResult) { // Local results have a formHistoryResult property.
+ results.formHistoryResult = result.formHistoryResult;
+ results.local = result.result || [];
+ } else { // Remote result
+ results.remote = result.result || [];
+ }
+ }
+
+ // If we have remote results, cap the number of local results
+ if (results.remote.length) {
+ results.local = results.local.slice(0, this.maxLocalResults);
+ }
+
+ // We don't want things to appear in both history and suggestions so remove entries from
+ // remote results that are already in local.
+ if (results.remote.length && results.local.length) {
+ for (let i = 0; i < results.local.length; ++i) {
+ let term = results.local[i];
+ let dupIndex = results.remote.indexOf(term);
+ if (dupIndex != -1) {
+ results.remote.splice(dupIndex, 1);
+ }
+ }
+ }
+
+ // Trim the number of results to the maximum requested (now that we've pruned dupes).
+ results.remote =
+ results.remote.slice(0, this.maxRemoteResults - results.local.length);
+
+ if (this._callback) {
+ this._callback(results);
+ }
+ this._reset();
+
+ return results;
+ },
+
+ _reset: function() {
+ this._request = null;
+ if (this._remoteResultTimer) {
+ this._remoteResultTimer.cancel();
+ this._remoteResultTimer = null;
+ }
+ this._deferredRemoteResult = null;
+ this._searchString = null;
+ },
+};
+
+/**
+ * Determines whether the given engine offers search suggestions.
+ *
+ * @param {nsISearchEngine} engine - The search engine
+ * @return {boolean} True if the engine offers suggestions and false otherwise.
+ */
+this.SearchSuggestionController.engineOffersSuggestions = function(engine) {
+ return engine.supportsResponseType(SEARCH_RESPONSE_SUGGESTION_JSON);
+};