Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 427 insertions, 0 deletions

diff --git a/devtools/shared/discovery/discovery.js b/devtools/shared/discovery/discovery.js
new file mode 100644
index 0000000000..f7ec5a6860
--- /dev/null
+++ b/devtools/shared/discovery/discovery.js
@@ -0,0 +1,427 @@
+/* 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";
+
+/**
+ * This implements a UDP mulitcast device discovery protocol that:
+ *   * Is optimized for mobile devices
+ *   * Doesn't require any special schema for service info
+ *
+ * To ensure it works well on mobile devices, there is no heartbeat or other
+ * recurring transmission.
+ *
+ * Devices are typically in one of two groups: scanning for services or
+ * providing services (though they may be in both groups as well).
+ *
+ * Scanning devices listen on UPDATE_PORT for UDP multicast traffic.  When the
+ * scanning device wants to force an update of the services available, it sends
+ * a status packet to SCAN_PORT.
+ *
+ * Service provider devices listen on SCAN_PORT for any packets from scanning
+ * devices.  If one is recevied, the provider device sends a status packet
+ * (listing the services it offers) to UPDATE_PORT.
+ *
+ * Scanning devices purge any previously known devices after REPLY_TIMEOUT ms
+ * from that start of a scan if no reply is received during the most recent
+ * scan.
+ *
+ * When a service is registered, is supplies a regular object with any details
+ * about itself (a port number, for example) in a service-defined format, which
+ * is then available to scanning devices.
+ */
+
+const EventEmitter = require("resource://devtools/shared/event-emitter.js");
+
+const UDPSocket = Components.Constructor(
+  "@mozilla.org/network/udp-socket;1",
+  "nsIUDPSocket",
+  "init"
+);
+
+const SCAN_PORT = 50624;
+const UPDATE_PORT = 50625;
+const ADDRESS = "224.0.0.115";
+const REPLY_TIMEOUT = 5000;
+
+var logging = Services.prefs.getBoolPref("devtools.discovery.log");
+function log(msg) {
+  if (logging) {
+    console.log("DISCOVERY: " + msg);
+  }
+}
+
+/**
+ * Each Transport instance owns a single UDPSocket.
+ * @param port integer
+ *        The port to listen on for incoming UDP multicast packets.
+ */
+function Transport(port) {
+  EventEmitter.decorate(this);
+  try {
+    this.socket = new UDPSocket(
+      port,
+      false,
+      Services.scriptSecurityManager.getSystemPrincipal()
+    );
+    this.socket.joinMulticast(ADDRESS);
+    this.socket.asyncListen(this);
+  } catch (e) {
+    log("Failed to start new socket: " + e);
+  }
+}
+
+Transport.prototype = {
+  /**
+   * Send a object to some UDP port.
+   * @param object object
+   *        Object which is the message to send
+   * @param port integer
+   *        UDP port to send the message to
+   */
+  send(object, port) {
+    if (logging) {
+      log("Send to " + port + ":\n" + JSON.stringify(object, null, 2));
+    }
+    const message = JSON.stringify(object);
+    const rawMessage = Uint8Array.from(message, x => x.charCodeAt(0));
+    try {
+      this.socket.send(ADDRESS, port, rawMessage, rawMessage.length);
+    } catch (e) {
+      log("Failed to send message: " + e);
+    }
+  },
+
+  destroy() {
+    this.socket.close();
+  },
+
+  // nsIUDPSocketListener
+
+  onPacketReceived(socket, message) {
+    const messageData = message.data;
+    const object = JSON.parse(messageData);
+    object.from = message.fromAddr.address;
+    const port = message.fromAddr.port;
+    if (port == this.socket.port) {
+      log("Ignoring looped message");
+      return;
+    }
+    if (logging) {
+      log(
+        "Recv on " + this.socket.port + ":\n" + JSON.stringify(object, null, 2)
+      );
+    }
+    this.emit("message", object);
+  },
+
+  onStopListening() {},
+};
+
+/**
+ * Manages the local device's name.  The name can be generated in serveral
+ * platform-specific ways (see |_generate|).  The aim is for each device on the
+ * same local network to have a unique name.
+ */
+function LocalDevice() {
+  this._name = LocalDevice.UNKNOWN;
+  // Trigger |_get| to load name eagerly
+  this._get();
+}
+
+LocalDevice.UNKNOWN = "unknown";
+
+LocalDevice.prototype = {
+  _get() {
+    // Without Settings API, just generate a name and stop, since the value
+    // can't be persisted.
+    this._generate();
+  },
+
+  /**
+   * Generate a new device name from various platform-specific properties.
+   * Triggers the |name| setter to persist if needed.
+   */
+  _generate() {
+    if (Services.appinfo.widgetToolkit == "android") {
+      // For Firefox for Android, use the device's model name.
+      // TODO: Bug 1180997: Find the right way to expose an editable name
+      this.name = Services.sysinfo.get("device");
+    } else {
+      this.name = Services.dns.myHostName;
+    }
+  },
+
+  get name() {
+    return this._name;
+  },
+
+  set name(name) {
+    this._name = name;
+    log("Device: " + this._name);
+  },
+};
+
+function Discovery() {
+  EventEmitter.decorate(this);
+
+  this.localServices = {};
+  this.remoteServices = {};
+  this.device = new LocalDevice();
+  this.replyTimeout = REPLY_TIMEOUT;
+
+  // Defaulted to Transport, but can be altered by tests
+  this._factories = { Transport };
+
+  this._transports = {
+    scan: null,
+    update: null,
+  };
+  this._expectingReplies = {
+    from: new Set(),
+  };
+
+  this._onRemoteScan = this._onRemoteScan.bind(this);
+  this._onRemoteUpdate = this._onRemoteUpdate.bind(this);
+  this._purgeMissingDevices = this._purgeMissingDevices.bind(this);
+}
+
+Discovery.prototype = {
+  /**
+   * Add a new service offered by this device.
+   * @param service string
+   *        Name of the service
+   * @param info object
+   *        Arbitrary data about the service to announce to scanning devices
+   */
+  addService(service, info) {
+    log("ADDING LOCAL SERVICE");
+    if (Object.keys(this.localServices).length === 0) {
+      this._startListeningForScan();
+    }
+    this.localServices[service] = info;
+  },
+
+  /**
+   * Remove a service offered by this device.
+   * @param service string
+   *        Name of the service
+   */
+  removeService(service) {
+    delete this.localServices[service];
+    if (Object.keys(this.localServices).length === 0) {
+      this._stopListeningForScan();
+    }
+  },
+
+  /**
+   * Scan for service updates from other devices.
+   */
+  scan() {
+    this._startListeningForUpdate();
+    this._waitForReplies();
+    // TODO Bug 1027457: Use timer to debounce
+    this._sendStatusTo(SCAN_PORT);
+  },
+
+  /**
+   * Get a list of all remote devices currently offering some service.:w
+   */
+  getRemoteDevices() {
+    const devices = new Set();
+    for (const service in this.remoteServices) {
+      for (const device in this.remoteServices[service]) {
+        devices.add(device);
+      }
+    }
+    return [...devices];
+  },
+
+  /**
+   * Get a list of all remote devices currently offering a particular service.
+   */
+  getRemoteDevicesWithService(service) {
+    const devicesWithService = this.remoteServices[service] || {};
+    return Object.keys(devicesWithService);
+  },
+
+  /**
+   * Get service info (any details registered by the remote device) for a given
+   * service on a device.
+   */
+  getRemoteService(service, device) {
+    const devicesWithService = this.remoteServices[service] || {};
+    return devicesWithService[device];
+  },
+
+  _waitForReplies() {
+    clearTimeout(this._expectingReplies.timer);
+    this._expectingReplies.from = new Set(this.getRemoteDevices());
+    this._expectingReplies.timer = setTimeout(
+      this._purgeMissingDevices,
+      this.replyTimeout
+    );
+  },
+
+  get Transport() {
+    return this._factories.Transport;
+  },
+
+  _startListeningForScan() {
+    if (this._transports.scan) {
+      // Already listening
+      return;
+    }
+    log("LISTEN FOR SCAN");
+    this._transports.scan = new this.Transport(SCAN_PORT);
+    this._transports.scan.on("message", this._onRemoteScan);
+  },
+
+  _stopListeningForScan() {
+    if (!this._transports.scan) {
+      // Not listening
+      return;
+    }
+    this._transports.scan.off("message", this._onRemoteScan);
+    this._transports.scan.destroy();
+    this._transports.scan = null;
+  },
+
+  _startListeningForUpdate() {
+    if (this._transports.update) {
+      // Already listening
+      return;
+    }
+    log("LISTEN FOR UPDATE");
+    this._transports.update = new this.Transport(UPDATE_PORT);
+    this._transports.update.on("message", this._onRemoteUpdate);
+  },
+
+  _stopListeningForUpdate() {
+    if (!this._transports.update) {
+      // Not listening
+      return;
+    }
+    this._transports.update.off("message", this._onRemoteUpdate);
+    this._transports.update.destroy();
+    this._transports.update = null;
+  },
+
+  _restartListening() {
+    if (this._transports.scan) {
+      this._stopListeningForScan();
+      this._startListeningForScan();
+    }
+    if (this._transports.update) {
+      this._stopListeningForUpdate();
+      this._startListeningForUpdate();
+    }
+  },
+
+  /**
+   * When sending message, we can use either transport, so just pick the first
+   * one currently alive.
+   */
+  get _outgoingTransport() {
+    if (this._transports.scan) {
+      return this._transports.scan;
+    }
+    if (this._transports.update) {
+      return this._transports.update;
+    }
+    return null;
+  },
+
+  _sendStatusTo(port) {
+    const status = {
+      device: this.device.name,
+      services: this.localServices,
+    };
+    this._outgoingTransport.send(status, port);
+  },
+
+  _onRemoteScan() {
+    // Send my own status in response
+    log("GOT SCAN REQUEST");
+    this._sendStatusTo(UPDATE_PORT);
+  },
+
+  _onRemoteUpdate(update) {
+    log("GOT REMOTE UPDATE");
+
+    const remoteDevice = update.device;
+    const remoteHost = update.from;
+
+    // Record the reply as received so it won't be purged as missing
+    this._expectingReplies.from.delete(remoteDevice);
+
+    // First, loop over the known services
+    for (const service in this.remoteServices) {
+      const devicesWithService = this.remoteServices[service];
+      const hadServiceForDevice = !!devicesWithService[remoteDevice];
+      const haveServiceForDevice = service in update.services;
+      // If the remote device used to have service, but doesn't any longer, then
+      // it was deleted, so we remove it here.
+      if (hadServiceForDevice && !haveServiceForDevice) {
+        delete devicesWithService[remoteDevice];
+        log("REMOVED " + service + ", DEVICE " + remoteDevice);
+        this.emit(service + "-device-removed", remoteDevice);
+      }
+    }
+
+    // Second, loop over the services in the received update
+    for (const service in update.services) {
+      // Detect if this is a new device for this service
+      const newDevice =
+        !this.remoteServices[service] ||
+        !this.remoteServices[service][remoteDevice];
+
+      // Look up the service info we may have received previously from the same
+      // remote device
+      const devicesWithService = this.remoteServices[service] || {};
+      const oldDeviceInfo = devicesWithService[remoteDevice];
+
+      // Store the service info from the remote device
+      const newDeviceInfo = Cu.cloneInto(update.services[service], {});
+      newDeviceInfo.host = remoteHost;
+      devicesWithService[remoteDevice] = newDeviceInfo;
+      this.remoteServices[service] = devicesWithService;
+
+      // If this is a new service for the remote device, announce the addition
+      if (newDevice) {
+        log("ADDED " + service + ", DEVICE " + remoteDevice);
+        this.emit(service + "-device-added", remoteDevice, newDeviceInfo);
+      }
+
+      // If we've seen this service from the remote device, but the details have
+      // changed, announce the update
+      if (
+        !newDevice &&
+        JSON.stringify(oldDeviceInfo) != JSON.stringify(newDeviceInfo)
+      ) {
+        log("UPDATED " + service + ", DEVICE " + remoteDevice);
+        this.emit(service + "-device-updated", remoteDevice, newDeviceInfo);
+      }
+    }
+  },
+
+  _purgeMissingDevices() {
+    log("PURGING MISSING DEVICES");
+    for (const service in this.remoteServices) {
+      const devicesWithService = this.remoteServices[service];
+      for (const remoteDevice in devicesWithService) {
+        // If we're still expecting a reply from a remote device when it's time
+        // to purge, then the service is removed.
+        if (this._expectingReplies.from.has(remoteDevice)) {
+          delete devicesWithService[remoteDevice];
+          log("REMOVED " + service + ", DEVICE " + remoteDevice);
+          this.emit(service + "-device-removed", remoteDevice);
+        }
+      }
+    }
+  },
+};
+
+var discovery = new Discovery();
+
+module.exports = discovery;