Add Basilisk

1 files changed, 449 insertions, 0 deletions

diff --git a/application/basilisk/components/translation/BingTranslator.jsm b/application/basilisk/components/translation/BingTranslator.jsm
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+++ b/application/basilisk/components/translation/BingTranslator.jsm
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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";
+
+const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
+
+this.EXPORTED_SYMBOLS = [ "BingTranslator" ];
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/Log.jsm");
+Cu.import("resource://gre/modules/Promise.jsm");
+Cu.import("resource://gre/modules/Task.jsm");
+Cu.import("resource://services-common/utils.js");
+Cu.import("resource://gre/modules/Http.jsm");
+
+// The maximum amount of net data allowed per request on Bing's API.
+const MAX_REQUEST_DATA = 5000; // Documentation says 10000 but anywhere
+                               // close to that is refused by the service.
+
+// The maximum number of chunks allowed to be translated in a single
+// request.
+const MAX_REQUEST_CHUNKS = 1000; // Documentation says 2000.
+
+// Self-imposed limit of 15 requests. This means that a page that would need
+// to be broken in more than 15 requests won't be fully translated.
+// The maximum amount of data that we will translate for a single page
+// is MAX_REQUESTS * MAX_REQUEST_DATA.
+const MAX_REQUESTS = 15;
+
+/**
+ * Translates a webpage using Bing's Translation API.
+ *
+ * @param translationDocument  The TranslationDocument object that represents
+ *                             the webpage to be translated
+ * @param sourceLanguage       The source language of the document
+ * @param targetLanguage       The target language for the translation
+ *
+ * @returns {Promise}          A promise that will resolve when the translation
+ *                             task is finished.
+ */
+this.BingTranslator = function(translationDocument, sourceLanguage, targetLanguage) {
+  this.translationDocument = translationDocument;
+  this.sourceLanguage = sourceLanguage;
+  this.targetLanguage = targetLanguage;
+  this._pendingRequests = 0;
+  this._partialSuccess = false;
+  this._serviceUnavailable = false;
+  this._translatedCharacterCount = 0;
+};
+
+this.BingTranslator.prototype = {
+  /**
+   * Performs the translation, splitting the document into several chunks
+   * respecting the data limits of the API.
+   *
+   * @returns {Promise}          A promise that will resolve when the translation
+   *                             task is finished.
+   */
+  translate() {
+    return Task.spawn(function *() {
+      let currentIndex = 0;
+      this._onFinishedDeferred = Promise.defer();
+
+      // Let's split the document into various requests to be sent to
+      // Bing's Translation API.
+      for (let requestCount = 0; requestCount < MAX_REQUESTS; requestCount++) {
+        // Generating the text for each request can be expensive, so
+        // let's take the opportunity of the chunkification process to
+        // allow for the event loop to attend other pending events
+        // before we continue.
+        yield CommonUtils.laterTickResolvingPromise();
+
+        // Determine the data for the next request.
+        let request = this._generateNextTranslationRequest(currentIndex);
+
+        // Create a real request to the server, and put it on the
+        // pending requests list.
+        let bingRequest = new BingRequest(request.data,
+                                          this.sourceLanguage,
+                                          this.targetLanguage);
+        this._pendingRequests++;
+        bingRequest.fireRequest().then(this._chunkCompleted.bind(this),
+                                       this._chunkFailed.bind(this));
+
+        currentIndex = request.lastIndex;
+        if (request.finished) {
+          break;
+        }
+      }
+
+      return this._onFinishedDeferred.promise;
+    }.bind(this));
+  },
+
+  /**
+   * Resets the expiration time of the current token, in order to
+   * force the token manager to ask for a new token during the next request.
+   */
+  _resetToken() {
+    // Force the token manager to get update token
+    BingTokenManager._currentExpiryTime = 0;
+  },
+
+  /**
+   * Function called when a request sent to the server completed successfully.
+   * This function handles calling the function to parse the result and the
+   * function to resolve the promise returned by the public `translate()`
+   * method when there's no pending request left.
+   *
+   * @param   request   The BingRequest sent to the server.
+   */
+  _chunkCompleted(bingRequest) {
+    if (this._parseChunkResult(bingRequest)) {
+      this._partialSuccess = true;
+      // Count the number of characters successfully translated.
+      this._translatedCharacterCount += bingRequest.characterCount;
+    }
+
+    this._checkIfFinished();
+  },
+
+  /**
+   * Function called when a request sent to the server has failed.
+   * This function handles deciding if the error is transient or means the
+   * service is unavailable (zero balance on the key or request credentials are
+   * not in an active state) and calling the function to resolve the promise
+   * returned by the public `translate()` method when there's no pending.
+   * request left.
+   *
+   * @param   aError   [optional] The XHR object of the request that failed.
+   */
+  _chunkFailed(aError) {
+    if (aError instanceof Ci.nsIXMLHttpRequest &&
+        [400, 401].indexOf(aError.status) != -1) {
+      let body = aError.responseText;
+      if (body && body.includes("TranslateApiException") &&
+          (body.includes("balance") || body.includes("active state")))
+        this._serviceUnavailable = true;
+    }
+
+    this._checkIfFinished();
+  },
+
+  /**
+   * Function called when a request sent to the server has completed.
+   * This function handles resolving the promise
+   * returned by the public `translate()` method when all chunks are completed.
+   */
+  _checkIfFinished() {
+    // Check if all pending requests have been
+    // completed and then resolves the promise.
+    // If at least one chunk was successful, the
+    // promise will be resolved positively which will
+    // display the "Success" state for the infobar. Otherwise,
+    // the "Error" state will appear.
+    if (--this._pendingRequests == 0) {
+      if (this._partialSuccess) {
+        this._onFinishedDeferred.resolve({
+          characterCount: this._translatedCharacterCount
+        });
+      } else {
+        let error = this._serviceUnavailable ? "unavailable" : "failure";
+        this._onFinishedDeferred.reject(error);
+      }
+    }
+  },
+
+  /**
+   * This function parses the result returned by Bing's Http.svc API,
+   * which is a XML file that contains a number of elements. To our
+   * particular interest, the only part of the response that matters
+   * are the <TranslatedText> nodes, which contains the resulting
+   * items that were sent to be translated.
+   *
+   * @param   request      The request sent to the server.
+   * @returns boolean      True if parsing of this chunk was successful.
+   */
+  _parseChunkResult(bingRequest) {
+    let results;
+    try {
+      let doc = bingRequest.networkRequest.responseXML;
+      results = doc.querySelectorAll("TranslatedText");
+    } catch (e) {
+      return false;
+    }
+
+    let len = results.length;
+    if (len != bingRequest.translationData.length) {
+      // This should never happen, but if the service returns a different number
+      // of items (from the number of items submitted), we can't use this chunk
+      // because all items would be paired incorrectly.
+      return false;
+    }
+
+    let error = false;
+    for (let i = 0; i < len; i++) {
+      try {
+        let result = results[i].firstChild.nodeValue;
+        let root = bingRequest.translationData[i][0];
+
+        if (root.isSimpleRoot) {
+          // Workaround for Bing's service problem in which "&" chars in
+          // plain-text TranslationItems are double-escaped.
+          result = result.replace(/&amp;/g, "&");
+        }
+
+        root.parseResult(result);
+      } catch (e) { error = true; }
+    }
+
+    return !error;
+  },
+
+  /**
+   * This function will determine what is the data to be used for
+   * the Nth request we are generating, based on the input params.
+   *
+   * @param startIndex What is the index, in the roots list, that the
+   *                   chunk should start.
+   */
+  _generateNextTranslationRequest(startIndex) {
+    let currentDataSize = 0;
+    let currentChunks = 0;
+    let output = [];
+    let rootsList = this.translationDocument.roots;
+
+    for (let i = startIndex; i < rootsList.length; i++) {
+      let root = rootsList[i];
+      let text = this.translationDocument.generateTextForItem(root);
+      if (!text) {
+        continue;
+      }
+
+      text = escapeXML(text);
+      let newCurSize = currentDataSize + text.length;
+      let newChunks = currentChunks + 1;
+
+      if (newCurSize > MAX_REQUEST_DATA ||
+          newChunks > MAX_REQUEST_CHUNKS) {
+
+        // If we've reached the API limits, let's stop accumulating data
+        // for this request and return. We return information useful for
+        // the caller to pass back on the next call, so that the function
+        // can keep working from where it stopped.
+        return {
+          data: output,
+          finished: false,
+          lastIndex: i
+        };
+      }
+
+      currentDataSize = newCurSize;
+      currentChunks = newChunks;
+      output.push([root, text]);
+    }
+
+    return {
+      data: output,
+      finished: true,
+      lastIndex: 0
+    };
+  }
+};
+
+/**
+ * Represents a request (for 1 chunk) sent off to Bing's service.
+ *
+ * @params translationData  The data to be used for this translation,
+ *                          generated by the generateNextTranslationRequest...
+ *                          function.
+ * @param sourceLanguage    The source language of the document.
+ * @param targetLanguage    The target language for the translation.
+ *
+ */
+function BingRequest(translationData, sourceLanguage, targetLanguage) {
+  this.translationData = translationData;
+  this.sourceLanguage = sourceLanguage;
+  this.targetLanguage = targetLanguage;
+  this.characterCount = 0;
+}
+
+BingRequest.prototype = {
+  /**
+   * Initiates the request
+   */
+  fireRequest() {
+    return Task.spawn(function *() {
+      // Prepare authentication.
+      let token = yield BingTokenManager.getToken();
+      let auth = "Bearer " + token;
+
+      // Prepare URL.
+      let url = getUrlParam("https://api.microsofttranslator.com/v2/Http.svc/TranslateArray",
+                            "browser.translation.bing.translateArrayURL");
+
+      // Prepare request headers.
+      let headers = [["Content-type", "text/xml"], ["Authorization", auth]];
+
+      // Prepare the request body.
+      let requestString =
+        "<TranslateArrayRequest>" +
+          "<AppId/>" +
+          "<From>" + this.sourceLanguage + "</From>" +
+          "<Options>" +
+            '<ContentType xmlns="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2">text/html</ContentType>' +
+            '<ReservedFlags xmlns="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2" />' +
+          "</Options>" +
+          '<Texts xmlns:s="http://schemas.microsoft.com/2003/10/Serialization/Arrays">';
+
+      for (let [, text] of this.translationData) {
+        requestString += "<s:string>" + text + "</s:string>";
+        this.characterCount += text.length;
+      }
+
+      requestString += "</Texts>" +
+          "<To>" + this.targetLanguage + "</To>" +
+        "</TranslateArrayRequest>";
+
+      // Set up request options.
+      let deferred = Promise.defer();
+      let options = {
+        onLoad: (function(responseText, xhr) {
+          deferred.resolve(this);
+        }).bind(this),
+        onError(e, responseText, xhr) {
+          deferred.reject(xhr);
+        },
+        postData: requestString,
+        headers
+      };
+
+      // Fire the request.
+      let request = httpRequest(url, options);
+
+      // Override the response MIME type.
+      request.overrideMimeType("text/xml");
+      this.networkRequest = request;
+      return deferred.promise;
+    }.bind(this));
+  }
+};
+
+/**
+ * Authentication Token manager for the API
+ */
+var BingTokenManager = {
+  _currentToken: null,
+  _currentExpiryTime: 0,
+  _pendingRequest: null,
+
+  /**
+   * Get a valid, non-expired token to be used for the API calls.
+   *
+   * @returns {Promise}  A promise that resolves with the token
+   *                     string once it is obtained. The token returned
+   *                     can be the same one used in the past if it is still
+   *                     valid.
+   */
+  getToken() {
+    if (this._pendingRequest) {
+      return this._pendingRequest;
+    }
+
+    let remainingMs = this._currentExpiryTime - new Date();
+    // Our existing token is still good for more than a minute, let's use it.
+    if (remainingMs > 60 * 1000) {
+      return Promise.resolve(this._currentToken);
+    }
+
+    return this._getNewToken();
+  },
+
+  /**
+   * Generates a new token from the server.
+   *
+   * @returns {Promise}  A promise that resolves with the token
+   *                     string once it is obtained.
+   */
+  _getNewToken() {
+    let url = getUrlParam("https://datamarket.accesscontrol.windows.net/v2/OAuth2-13",
+                          "browser.translation.bing.authURL");
+    let params = [
+      ["grant_type", "client_credentials"],
+      ["scope", "http://api.microsofttranslator.com"],
+      ["client_id",
+      getUrlParam("%BING_API_CLIENTID%", "browser.translation.bing.clientIdOverride")],
+      ["client_secret",
+      getUrlParam("%BING_API_KEY%", "browser.translation.bing.apiKeyOverride")]
+    ];
+
+    let deferred = Promise.defer();
+    let options = {
+      onLoad(responseText, xhr) {
+        BingTokenManager._pendingRequest = null;
+        try {
+          let json = JSON.parse(responseText);
+
+          if (json.error) {
+            deferred.reject(json.error);
+            return;
+          }
+
+          let token = json.access_token;
+          let expires_in = json.expires_in;
+          BingTokenManager._currentToken = token;
+          BingTokenManager._currentExpiryTime = new Date(Date.now() + expires_in * 1000);
+          deferred.resolve(token);
+        } catch (e) {
+          deferred.reject(e);
+        }
+      },
+      onError(e, responseText, xhr) {
+        BingTokenManager._pendingRequest = null;
+        deferred.reject(e);
+      },
+      postData: params
+    };
+
+    this._pendingRequest = deferred.promise;
+    httpRequest(url, options);
+
+    return deferred.promise;
+  }
+};
+
+/**
+ * Escape a string to be valid XML content.
+ */
+function escapeXML(aStr) {
+  return aStr.toString()
+             .replace(/&/g, "&amp;")
+             .replace(/\"/g, "&quot;")
+             .replace(/\'/g, "&apos;")
+             .replace(/</g, "&lt;")
+             .replace(/>/g, "&gt;");
+}
+
+/**
+ * Fetch an auth token (clientID or client secret), which may be overridden by
+ * a pref if it's set.
+ */
+function getUrlParam(paramValue, prefName) {
+  if (Services.prefs.getPrefType(prefName))
+    paramValue = Services.prefs.getCharPref(prefName);
+  paramValue = Services.urlFormatter.formatURL(paramValue);
+  return paramValue;
+}