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/* ***** 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 Suggest Autocomplete Implementation for Firefox.
*
* 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):
* Ben Goodger <beng@google.com>
* Mike Connor <mconnor@mozilla.com>
* Joe Hughes <joe@retrovirus.com>
* Pamela Greene <pamg.bugs@gmail.com>
*
* 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 ***** */
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";
/**
* Metadata describing the Web Search suggest mode
*/
const SEARCH_SUGGEST_CONTRACTID =
"@mozilla.org/autocomplete/search;1?name=search-autocomplete";
const SEARCH_SUGGEST_CLASSNAME = "Remote Search Suggestions";
const SEARCH_SUGGEST_CLASSID =
Components.ID("{aa892eb4-ffbf-477d-9f9a-06c995ae9f27}");
const SEARCH_BUNDLE = "chrome://browser/locale/search.properties";
const Cc = Components.classes;
const Ci = Components.interfaces;
const Cr = Components.results;
const HTTP_OK = 200;
const HTTP_INTERNAL_SERVER_ERROR = 500;
const HTTP_BAD_GATEWAY = 502;
const HTTP_SERVICE_UNAVAILABLE = 503;
/**
* SuggestAutoCompleteResult contains the results returned by the Suggest
* service - it implements nsIAutoCompleteResult and is used by the auto-
* complete controller to populate the front end.
* @constructor
*/
function SuggestAutoCompleteResult(searchString,
searchResult,
defaultIndex,
errorDescription,
results,
comments,
formHistoryResult) {
this._searchString = searchString;
this._searchResult = searchResult;
this._defaultIndex = defaultIndex;
this._errorDescription = errorDescription;
this._results = results;
this._comments = comments;
this._formHistoryResult = formHistoryResult;
}
SuggestAutoCompleteResult.prototype = {
/**
* The user's query string
* @private
*/
_searchString: "",
/**
* The result code of this result object, see |get searchResult| for possible
* values.
* @private
*/
_searchResult: 0,
/**
* The default item that should be entered if none is selected
* @private
*/
_defaultIndex: 0,
/**
* The reason the search failed
* @private
*/
_errorDescription: "",
/**
* The list of words returned by the Suggest Service
* @private
*/
_results: [],
/**
* The list of Comments (number of results - or page titles) returned by the
* Suggest Service.
* @private
*/
_comments: [],
/**
* A reference to the form history nsIAutocompleteResult that we're wrapping.
* We use this to forward removeEntryAt calls as needed.
*/
_formHistoryResult: null,
/**
* @return the user's query string
*/
get searchString() {
return this._searchString;
},
/**
* @return the result code of this result object, either:
* RESULT_IGNORED (invalid searchString)
* RESULT_FAILURE (failure)
* RESULT_NOMATCH (no matches found)
* RESULT_SUCCESS (matches found)
*/
get searchResult() {
return this._searchResult;
},
/**
* @return the default item that should be entered if none is selected
*/
get defaultIndex() {
return this._defaultIndex;
},
/**
* @return the reason the search failed
*/
get errorDescription() {
return this._errorDescription;
},
/**
* @return the number of results
*/
get matchCount() {
return this._results.length;
},
/**
* Retrieves a result
* @param index the index of the result requested
* @return the result at the specified index
*/
getValueAt: function(index) {
return this._results[index];
},
/**
* Retrieves a comment (metadata instance)
* @param index the index of the comment requested
* @return the comment at the specified index
*/
getCommentAt: function(index) {
return this._comments[index];
},
/**
* Retrieves a style hint specific to a particular index.
* @param index the index of the style hint requested
* @return the style hint at the specified index
*/
getStyleAt: function(index) {
if (!this._comments[index])
return null; // not a category label, so no special styling
if (index == 0)
return "suggestfirst"; // category label on first line of results
return "suggesthint"; // category label on any other line of results
},
/**
* Removes a result from the resultset
* @param index the index of the result to remove
*/
removeValueAt: function(index, removeFromDatabase) {
// Forward the removeValueAt call to the underlying result if we have one
// Note: this assumes that the form history results were added to the top
// of our arrays.
if (removeFromDatabase && this._formHistoryResult &&
index < this._formHistoryResult.matchCount) {
// Delete the history result from the DB
this._formHistoryResult.removeValueAt(index, true);
}
this._results.splice(index, 1);
this._comments.splice(index, 1);
},
/**
* Part of nsISupports implementation.
* @param iid requested interface identifier
* @return this object (XPConnect handles the magic of telling the caller that
* we're the type it requested)
*/
QueryInterface: function(iid) {
if (!iid.equals(Ci.nsIAutoCompleteResult) &&
!iid.equals(Ci.nsISupports))
throw Cr.NS_ERROR_NO_INTERFACE;
return this;
}
};
/**
* 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._loadSuggestPref();
},
/**
* this._strings is the string bundle for message internationalization.
*/
get _strings() {
if (!this.__strings) {
var sbs = Cc["@mozilla.org/intl/stringbundle;1"].
getService(Ci.nsIStringBundleService);
this.__strings = sbs.createBundle(SEARCH_BUNDLE);
}
return this.__strings;
},
__strings: null,
/**
* Search suggestions will be shown if this._suggestEnabled is true.
*/
_loadSuggestPref: function SAC_loadSuggestPref() {
var prefService = Cc["@mozilla.org/preferences-service;1"].
getService(Ci.nsIPrefBranch);
this._suggestEnabled = prefService.getBoolPref(BROWSER_SUGGEST_PREF);
},
_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. If this gets
* called, it means that we've given up on receiving a reply from the
* search engine's suggestion server in a timely manner.
*/
notify: function SAC_notify(timer) {
// make sure we're still waiting for this response before sending
if ((timer != this._formHistoryTimer) || !this._listener)
return;
this._listener.onSearchResult(this, this._formHistoryResult);
this._formHistoryTimer = null;
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,
/**
* 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, previousResult) {
var formHistory =
Cc["@mozilla.org/autocomplete/search;1?name=form-history"].
createInstance(Ci.nsIAutoCompleteSearch);
formHistory.startSearch(searchString, searchParam, previousResult, this);
},
/**
* Makes a note of the fact that we've recieved 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();
// This is a modified version of Crockford's JSON sanitizer, obtained
// from http://www.json.org/js.html.
// This should use built-in functions once bug 340987 is fixed.
const JSON_STRING = /^("(\\.|[^"\\\n\r])*?"|[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t])+?$/;
var sandbox = new Components.utils.Sandbox(this._suggestURI.prePath);
function parseJSON(aString) {
try {
if (JSON_STRING.test(aString))
return Components.utils.evalInSandbox("(" + aString + ")", sandbox);
} catch (e) {}
return [];
};
var serverResults = parseJSON(responseText);
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)) {
for (var i = 0; i < this._formHistoryResult.matchCount; ++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._strings.GetStringFromName("suggestion_label");
// 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 SuggestAutoCompleteResult(
searchString,
Ci.nsIAutoCompleteResult.RESULT_SUCCESS,
0,
"",
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) {
var searchService = Cc["@mozilla.org/browser/search-service;1"].
getService(Ci.nsIBrowserSearchService);
// 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 = searchService.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, previousResult);
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);
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, previousResult);
}
},
/**
* 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._loadSuggestPref();
break;
case XPCOM_SHUTDOWN_TOPIC:
this._removeObservers();
break;
}
},
_addObservers: function SAC_addObservers() {
var prefService2 = Cc["@mozilla.org/preferences-service;1"].
getService(Ci.nsIPrefBranch2);
prefService2.addObserver(BROWSER_SUGGEST_PREF, this, false);
var os = Cc["@mozilla.org/observer-service;1"].
getService(Ci.nsIObserverService);
os.addObserver(this, XPCOM_SHUTDOWN_TOPIC, false);
},
_removeObservers: function SAC_removeObservers() {
var prefService2 = Cc["@mozilla.org/preferences-service;1"].
getService(Ci.nsIPrefBranch2);
prefService2.removeObserver(BROWSER_SUGGEST_PREF, this);
var os = Cc["@mozilla.org/observer-service;1"].
getService(Ci.nsIObserverService);
os.removeObserver(this, XPCOM_SHUTDOWN_TOPIC);
},
/**
* Part of nsISupports implementation.
* @param iid requested interface identifier
* @return this object (XPConnect handles the magic of telling the caller that
* we're the type it requested)
*/
QueryInterface: function(iid) {
if (!iid.equals(Ci.nsIAutoCompleteSearch) &&
!iid.equals(Ci.nsIAutoCompleteObserver) &&
!iid.equals(Ci.nsISupports))
throw Cr.NS_ERROR_NO_INTERFACE;
return this;
}
};
/**
* 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 = {
__proto__: SuggestAutoComplete.prototype,
serviceURL: ""
};
var gModule = {
/**
* Registers all the components supplied by this module. Part of nsIModule
* implementation.
* @param componentManager the XPCOM component manager
* @param location the location of the module on disk
* @param loaderString opaque loader specific string
* @param type loader type being used to load this module
*/
registerSelf: function(componentManager, location, loaderString, type) {
if (this._firstTime) {
this._firstTime = false;
throw Cr.NS_ERROR_FACTORY_REGISTER_AGAIN;
}
componentManager =
componentManager.QueryInterface(Ci.nsIComponentRegistrar);
for (var key in this.objects) {
var obj = this.objects[key];
componentManager.registerFactoryLocation(obj.CID, obj.className, obj.contractID,
location, loaderString, type);
}
},
/**
* Retrieves a Factory for the given ClassID. Part of nsIModule
* implementation.
* @param componentManager the XPCOM component manager
* @param cid the ClassID of the object for which a factory
* has been requested
* @param iid the IID of the interface requested
*/
getClassObject: function(componentManager, cid, iid) {
if (!iid.equals(Ci.nsIFactory))
throw Cr.NS_ERROR_NOT_IMPLEMENTED;
for (var key in this.objects) {
if (cid.equals(this.objects[key].CID))
return this.objects[key].factory;
}
throw Cr.NS_ERROR_NO_INTERFACE;
},
/**
* Create a Factory object that can construct an instance of an object.
* @param constructor the constructor used to create the object
* @private
*/
_makeFactory: function(constructor) {
function createInstance(outer, iid) {
if (outer != null)
throw Cr.NS_ERROR_NO_AGGREGATION;
return (new constructor()).QueryInterface(iid);
}
return { createInstance: createInstance };
},
/**
* Determines whether or not this module can be unloaded.
* @return returning true indicates that this module can be unloaded.
*/
canUnload: function(componentManager) {
return true;
}
};
/**
* Entry point for registering the components supplied by this JavaScript
* module.
* @param componentManager the XPCOM component manager
* @param location the location of this module on disk
*/
function NSGetModule(componentManager, location) {
// Metadata about the objects this module can construct
gModule.objects = {
search: {
CID: SEARCH_SUGGEST_CLASSID,
contractID: SEARCH_SUGGEST_CONTRACTID,
className: SEARCH_SUGGEST_CLASSNAME,
factory: gModule._makeFactory(SearchSuggestAutoComplete)
},
};
return gModule;
}