import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

toolkit/components/url-classifier/content/xml-fetcher.js

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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/.
+
+// A simple class that encapsulates a request. You'll notice the
+// style here is different from the rest of the extension; that's
+// because this was re-used from really old code we had. At some
+// point it might be nice to replace this with something better
+// (e.g., something that has explicit onerror handler, ability
+// to set headers, and so on).
+
+/**
+ * Because we might be in a component, we can't just assume that
+ * XMLHttpRequest exists. So we use this tiny factory function to wrap the
+ * XPCOM version.
+ *
+ * @return XMLHttpRequest object
+ */
+this.PROT_NewXMLHttpRequest = function PROT_NewXMLHttpRequest() {
+  var Cc = Components.classes;
+  var Ci = Components.interfaces;
+  var request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
+                .createInstance(Ci.nsIXMLHttpRequest);
+  // Need the following so we get onerror/load/progresschange
+  request.QueryInterface(Ci.nsIJSXMLHttpRequest);
+  return request;
+}
+
+/**
+ * A helper class that does HTTP GETs and calls back a function with
+ * the content it receives. Asynchronous, so uses a closure for the
+ * callback.
+ *
+ * Note, that XMLFetcher is only used for SafeBrowsing, therefore
+ * we inherit from nsILoadContext, so we can use the callbacks on the
+ * channel to separate the safebrowsing cookie based on a reserved
+ * appId.
+ * @constructor
+ */
+this.PROT_XMLFetcher = function PROT_XMLFetcher() {
+  this.debugZone = "xmlfetcher";
+  this._request = PROT_NewXMLHttpRequest();
+  // implements nsILoadContext
+  this.appId = Ci.nsIScriptSecurityManager.SAFEBROWSING_APP_ID;
+  this.isInIsolatedMozBrowserElement = false;
+  this.usePrivateBrowsing = false;
+  this.isContent = false;
+}
+
+PROT_XMLFetcher.prototype = {
+  /**
+   * Function that will be called back upon fetch completion.
+   */
+  _callback: null,
+
+
+  /**
+   * Fetches some content.
+   *
+   * @param page URL to fetch
+   * @param callback Function to call back when complete.
+   */
+  get: function(page, callback) {
+    this._request.abort();                // abort() is asynchronous, so
+    this._request = PROT_NewXMLHttpRequest();
+    this._callback = callback;
+    var asynchronous = true;
+    this._request.loadInfo.originAttributes = {
+      appId: this.appId,
+      inIsolatedMozBrowser: this.isInIsolatedMozBrowserElement
+    };
+    this._request.open("GET", page, asynchronous);
+    this._request.channel.notificationCallbacks = this;
+
+    // Create a closure
+    var self = this;
+    this._request.addEventListener("readystatechange", function() {
+      self.readyStateChange(self);
+    }, false);
+
+    this._request.send(null);
+  },
+
+  cancel: function() {
+    this._request.abort();
+    this._request = null;
+  },
+
+  /**
+   * Called periodically by the request to indicate some state change. 4
+   * means content has been received.
+   */
+  readyStateChange: function(fetcher) {
+    if (fetcher._request.readyState != 4)
+      return;
+
+    // If the request fails, on trunk we get status set to
+    // NS_ERROR_NOT_AVAILABLE.  On 1.8.1 branch we get an exception
+    // forwarded from nsIHttpChannel::GetResponseStatus.  To be consistent
+    // between branch and trunk, we send back NS_ERROR_NOT_AVAILABLE for
+    // http failures.
+    var responseText = null;
+    var status = Components.results.NS_ERROR_NOT_AVAILABLE;
+    try {
+      G_Debug(this, "xml fetch status code: \"" +
+              fetcher._request.status + "\"");
+      status = fetcher._request.status;
+      responseText = fetcher._request.responseText;
+    } catch(e) {
+      G_Debug(this, "Caught exception trying to read xmlhttprequest " +
+              "status/response.");
+      G_Debug(this, e);
+    }
+    if (fetcher._callback)
+      fetcher._callback(responseText, status);
+  },
+
+  // nsIInterfaceRequestor
+  getInterface: function(iid) {
+    return this.QueryInterface(iid);
+  },
+
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIInterfaceRequestor,
+                                         Ci.nsISupports,
+                                         Ci.nsILoadContext])
+};