Bug 1636417 - Implement EventSourceActor. r=Honza,bomsy

Differential Revision: https://phabricator.services.mozilla.com/D75066

devtools/server/actors/network-monitor/eventsource-actor.js

@@ -0,0 +1,88 @@
+/* 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, Ci } = require("chrome");
+const { Actor, ActorClassWithSpec } = require("devtools/shared/protocol");
+const { eventSourceSpec } = require("devtools/shared/specs/eventsource");
+const { LongStringActor } = require("devtools/server/actors/string");
+
+const eventSourceEventService = Cc[
+  "@mozilla.org/eventsourceevent/service;1"
+].getService(Ci.nsIEventSourceEventService);
+
+/**
+ * This actor intercepts EventSource traffic for a specific window.
+ * @see devtools/shared/spec/eventsource.js for documentation.
+ */
+const EventSourceActor = ActorClassWithSpec(eventSourceSpec, {
+  initialize(conn, targetActor) {
+    Actor.prototype.initialize.call(this, conn);
+
+    this.targetActor = targetActor;
+    this.innerWindowID = null;
+
+    // Register for backend events.
+    this.onWindowReady = this.onWindowReady.bind(this);
+    this.targetActor.on("window-ready", this.onWindowReady);
+  },
+
+  onWindowReady({ isTopLevel }) {
+    if (isTopLevel) {
+      this.startListening();
+    }
+  },
+
+  destroy: function() {
+    this.targetActor.off("window-ready", this.onWindowReady);
+
+    this.stopListening();
+    Actor.prototype.destroy.call(this);
+  },
+
+  // Actor API.
+
+  startListening: function() {
+    this.stopListening();
+    this.innerWindowID = this.targetActor.window.windowUtils.currentInnerWindowID;
+    eventSourceEventService.addListener(this.innerWindowID, this);
+  },
+
+  stopListening() {
+    if (!this.innerWindowID) {
+      return;
+    }
+    if (eventSourceEventService.hasListenerFor(this.innerWindowID)) {
+      eventSourceEventService.removeListener(this.innerWindowID, this);
+    }
+
+    this.innerWindowID = null;
+  },
+
+  // Implement functions of nsIEventSourceEventService.
+
+  eventSourceConnectionOpened(httpChannelId) {
+    this.emit("serverEventSourceConnectionOpened", httpChannelId);
+  },
+
+  eventSourceConnectionClosed(httpChannelId) {
+    this.emit("serverEventSourceConnectionClosed", httpChannelId);
+  },
+
+  eventReceived(httpChannelId, eventName, lastEventId, data, retry, timeStamp) {
+    let payload = new LongStringActor(this.conn, data);
+    this.manage(payload);
+    payload = payload.form();
+    this.emit("serverEventReceived", httpChannelId, {
+      payload,
+      eventName,
+      lastEventId,
+      retry,
+      timeStamp,
+    });
+  },
+});
+
+exports.EventSourceActor = EventSourceActor;

devtools/server/actors/network-monitor/moz.build

@@ -10,6 +10,7 @@ DIRS += [
 
 DevToolsModules(
     'channel-event-sink.js',
+    'eventsource-actor.js',
     'network-event.js',
     'network-monitor.js',
     'network-observer.js',

devtools/server/actors/utils/actor-registry.js

@@ -263,6 +263,14 @@ const ActorRegistry = {
         type: { target: true },
       }
     );
+    this.registerModule(
+      "devtools/server/actors/network-monitor/eventsource-actor",
+      {
+        prefix: "eventSource",
+        constructor: "EventSourceActor",
+        type: { target: true },
+      }
+    );
     this.registerModule("devtools/server/actors/manifest", {
       prefix: "manifest",
       constructor: "ManifestActor",

devtools/shared/specs/eventsource.js

@@ -0,0 +1,43 @@
+/* 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 { Arg, generateActorSpec } = require("devtools/shared/protocol");
+
+const eventSourceSpec = generateActorSpec({
+  typeName: "eventSource",
+
+  /**
+   * The set of events the EventSourceActor emits over RDP.
+   */
+  events: {
+    // In order to avoid a naming collision, we rename the server event.
+    serverEventSourceConnectionOpened: {
+      type: "eventSourceConnectionOpened",
+      httpChannelId: Arg(0, "number"),
+    },
+    serverEventSourceConnectionClosed: {
+      type: "eventSourceConnectionClosed",
+      httpChannelId: Arg(0, "number"),
+    },
+    serverEventReceived: {
+      type: "eventReceived",
+      httpChannelId: Arg(0, "number"),
+      data: Arg(1, "json"),
+    },
+  },
+
+  methods: {
+    startListening: {
+      request: {},
+      oneway: true,
+    },
+    stopListening: {
+      request: {},
+      oneway: true,
+    },
+  },
+});
+
+exports.eventSourceSpec = eventSourceSpec;

devtools/shared/specs/moz.build

@@ -20,6 +20,7 @@ DevToolsModules(
     'css-properties.js',
     'device.js',
     'environment.js',
+    'eventsource.js',
     'frame.js',
     'framerate.js',
     'heap-snapshot-file.js',