Add m-esr52 at 52.6.0

1 files changed, 224 insertions, 0 deletions

diff --git a/dom/downloads/DownloadsIPC.jsm b/dom/downloads/DownloadsIPC.jsm
new file mode 100644
index 000000000..0e290abf4
--- /dev/null
+++ b/dom/downloads/DownloadsIPC.jsm
@@ -0,0 +1,224 @@
+/* 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 Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+
+this.EXPORTED_SYMBOLS = ["DownloadsIPC"];
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/Promise.jsm");
+
+XPCOMUtils.defineLazyServiceGetter(this, "cpmm",
+                                   "@mozilla.org/childprocessmessagemanager;1",
+                                   "nsIMessageSender");
+
+/**
+  * This module lives in the child process and receives the ipc messages
+  * from the parent. It saves the download's state and redispatch changes
+  * to DOM objects using an observer notification.
+  *
+  * This module needs to be loaded once and only once per process.
+  */
+
+function debug(aStr) {
+#ifdef MOZ_DEBUG
+  dump("-*- DownloadsIPC.jsm : " + aStr + "\n");
+#endif
+}
+
+const ipcMessages = ["Downloads:Added",
+                     "Downloads:Removed",
+                     "Downloads:Changed",
+                     "Downloads:GetList:Return",
+                     "Downloads:Remove:Return",
+                     "Downloads:Pause:Return",
+                     "Downloads:Resume:Return",
+                     "Downloads:Adopt:Return"];
+
+this.DownloadsIPC = {
+  downloads: {},
+
+  init: function() {
+    debug("init");
+    Services.obs.addObserver(this, "xpcom-shutdown", false);
+    ipcMessages.forEach((aMessage) => {
+      cpmm.addMessageListener(aMessage, this);
+    });
+
+    // We need to get the list of current downloads.
+    this.ready = false;
+    this.getListPromises = [];
+    this.downloadPromises = {};
+    cpmm.sendAsyncMessage("Downloads:GetList", {});
+    this._promiseId = 0;
+  },
+
+  notifyChanges: function(aId) {
+    // TODO: use the subject instead of stringifying.
+    if (this.downloads[aId]) {
+      debug("notifyChanges notifying changes for " + aId);
+      Services.obs.notifyObservers(null, "downloads-state-change-" + aId,
+                                   JSON.stringify(this.downloads[aId]));
+    } else {
+      debug("notifyChanges failed for " + aId)
+    }
+  },
+
+  _updateDownloadsArray: function(aDownloads) {
+    this.downloads = [];
+    // We actually have an array of downloads.
+    aDownloads.forEach((aDownload) => {
+      this.downloads[aDownload.id] = aDownload;
+    });
+  },
+
+  receiveMessage: function(aMessage) {
+    let download = aMessage.data;
+    debug("message: " + aMessage.name);
+    switch(aMessage.name) {
+      case "Downloads:GetList:Return":
+        this._updateDownloadsArray(download);
+
+        if (!this.ready) {
+          this.getListPromises.forEach(aPromise =>
+                                       aPromise.resolve(this.downloads));
+          this.getListPromises.length = 0;
+        }
+        this.ready = true;
+        break;
+      case "Downloads:Added":
+        this.downloads[download.id] = download;
+        this.notifyChanges(download.id);
+        break;
+      case "Downloads:Removed":
+        if (this.downloads[download.id]) {
+          this.downloads[download.id] = download;
+          this.notifyChanges(download.id);
+          delete this.downloads[download.id];
+        }
+        break;
+      case "Downloads:Changed":
+        // Only update properties that actually changed.
+        let cached = this.downloads[download.id];
+        if (!cached) {
+          debug("No download found for " + download.id);
+          return;
+        }
+        let props = ["totalBytes", "currentBytes", "url", "path", "state",
+                     "contentType", "startTime"];
+        let changed = false;
+
+        props.forEach((aProp) => {
+          if (download[aProp] && (download[aProp] != cached[aProp])) {
+            cached[aProp] = download[aProp];
+            changed = true;
+          }
+        });
+
+        // Updating the error property. We always get a 'state' change as
+        // well.
+        cached.error = download.error;
+
+        if (changed) {
+          this.notifyChanges(download.id);
+        }
+        break;
+      case "Downloads:Remove:Return":
+      case "Downloads:Pause:Return":
+      case "Downloads:Resume:Return":
+      case "Downloads:Adopt:Return":
+        if (this.downloadPromises[download.promiseId]) {
+          if (!download.error) {
+            this.downloadPromises[download.promiseId].resolve(download);
+          } else {
+            this.downloadPromises[download.promiseId].reject(download);
+          }
+          delete this.downloadPromises[download.promiseId];
+        }
+        break;
+    }
+  },
+
+  /**
+    * Returns a promise that is resolved with the list of current downloads.
+    */
+  getDownloads: function() {
+    debug("getDownloads()");
+    let deferred = Promise.defer();
+    if (this.ready) {
+      debug("Returning existing list.");
+      deferred.resolve(this.downloads);
+    } else {
+      this.getListPromises.push(deferred);
+    }
+    return deferred.promise;
+  },
+
+  /**
+   * Void function to trigger removal of completed downloads.
+   */
+  clearAllDone: function() {
+    debug("clearAllDone");
+    cpmm.sendAsyncMessage("Downloads:ClearAllDone", {});
+  },
+
+  promiseId: function() {
+    return this._promiseId++;
+  },
+
+  remove: function(aId) {
+    debug("remove " + aId);
+    let deferred = Promise.defer();
+    let pId = this.promiseId();
+    this.downloadPromises[pId] = deferred;
+    cpmm.sendAsyncMessage("Downloads:Remove",
+                          { id: aId, promiseId: pId });
+    return deferred.promise;
+  },
+
+  pause: function(aId) {
+    debug("pause " + aId);
+    let deferred = Promise.defer();
+    let pId = this.promiseId();
+    this.downloadPromises[pId] = deferred;
+    cpmm.sendAsyncMessage("Downloads:Pause",
+                          { id: aId, promiseId: pId });
+    return deferred.promise;
+  },
+
+  resume: function(aId) {
+    debug("resume " + aId);
+    let deferred = Promise.defer();
+    let pId = this.promiseId();
+    this.downloadPromises[pId] = deferred;
+    cpmm.sendAsyncMessage("Downloads:Resume",
+                          { id: aId, promiseId: pId });
+    return deferred.promise;
+  },
+
+  adoptDownload: function(aJsonDownload) {
+    debug("adoptDownload");
+    let deferred = Promise.defer();
+    let pId = this.promiseId();
+    this.downloadPromises[pId] = deferred;
+    cpmm.sendAsyncMessage("Downloads:Adopt",
+                          { jsonDownload: aJsonDownload, promiseId: pId });
+    return deferred.promise;
+  },
+
+  observe: function(aSubject, aTopic, aData) {
+    if (aTopic == "xpcom-shutdown") {
+      ipcMessages.forEach((aMessage) => {
+        cpmm.removeMessageListener(aMessage, this);
+      });
+    }
+  }
+};
+
+DownloadsIPC.init();