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Diffstat (limited to 'dom/downloads/DownloadsIPC.jsm')
| -rw-r--r-- | dom/downloads/DownloadsIPC.jsm | 224 |
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(); |