Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

1 files changed, 849 insertions, 0 deletions

diff --git a/devtools/client/devtools-client.js b/devtools/client/devtools-client.js
new file mode 100644
index 0000000000..128790732a
--- /dev/null
+++ b/devtools/client/devtools-client.js
@@ -0,0 +1,849 @@
+/* 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 DevToolsUtils = require("resource://devtools/shared/DevToolsUtils.js");
+const {
+  getStack,
+  callFunctionWithAsyncStack,
+} = require("resource://devtools/shared/platform/stack.js");
+const EventEmitter = require("resource://devtools/shared/event-emitter.js");
+const {
+  UnsolicitedNotifications,
+} = require("resource://devtools/client/constants.js");
+
+loader.lazyRequireGetter(
+  this,
+  "Authentication",
+  "resource://devtools/shared/security/auth.js"
+);
+loader.lazyRequireGetter(
+  this,
+  "DebuggerSocket",
+  "resource://devtools/shared/security/socket.js",
+  true
+);
+loader.lazyRequireGetter(
+  this,
+  "EventEmitter",
+  "resource://devtools/shared/event-emitter.js"
+);
+
+loader.lazyRequireGetter(
+  this,
+  ["createRootFront", "Front"],
+  "resource://devtools/shared/protocol.js",
+  true
+);
+
+loader.lazyRequireGetter(
+  this,
+  "ObjectFront",
+  "resource://devtools/client/fronts/object.js",
+  true
+);
+
+/**
+ * Creates a client for the remote debugging protocol server. This client
+ * provides the means to communicate with the server and exchange the messages
+ * required by the protocol in a traditional JavaScript API.
+ */
+function DevToolsClient(transport) {
+  this._transport = transport;
+  this._transport.hooks = this;
+
+  this._pendingRequests = new Map();
+  this._activeRequests = new Map();
+  this._eventsEnabled = true;
+
+  this.traits = {};
+
+  this.request = this.request.bind(this);
+
+  /*
+   * As the first thing on the connection, expect a greeting packet from
+   * the connection's root actor.
+   */
+  this.mainRoot = null;
+  this.expectReply("root", packet => {
+    if (packet.error) {
+      console.error("Error when waiting for root actor", packet);
+      return;
+    }
+
+    this.mainRoot = createRootFront(this, packet);
+
+    this.emit("connected", packet.applicationType, packet.traits);
+  });
+}
+
+// Expose these to save callers the trouble of importing DebuggerSocket
+DevToolsClient.socketConnect = function (options) {
+  // Defined here instead of just copying the function to allow lazy-load
+  return DebuggerSocket.connect(options);
+};
+DevToolsUtils.defineLazyGetter(DevToolsClient, "Authenticators", () => {
+  return Authentication.Authenticators;
+});
+DevToolsUtils.defineLazyGetter(DevToolsClient, "AuthenticationResult", () => {
+  return Authentication.AuthenticationResult;
+});
+
+DevToolsClient.prototype = {
+  /**
+   * Connect to the server and start exchanging protocol messages.
+   *
+   * @return Promise
+   *         Resolves once connected with an array whose first element
+   *         is the application type, by default "browser", and the second
+   *         element is the traits object (help figure out the features
+   *         and behaviors of the server we connect to. See RootActor).
+   */
+  connect() {
+    return new Promise(resolve => {
+      this.once("connected", (applicationType, traits) => {
+        this.traits = traits;
+        resolve([applicationType, traits]);
+      });
+
+      this._transport.ready();
+    });
+  },
+
+  /**
+   * Shut down communication with the debugging server.
+   *
+   * @return Promise
+   *         Resolves after the underlying transport is closed.
+   */
+  close() {
+    if (this._transportClosed) {
+      return Promise.resolve();
+    }
+    if (this._closePromise) {
+      return this._closePromise;
+    }
+    // Immediately set the destroy promise,
+    // as the following code is fully synchronous and can be reentrant.
+    this._closePromise = this.once("closed");
+
+    // Disable detach event notifications, because event handlers will be in a
+    // cleared scope by the time they run.
+    this._eventsEnabled = false;
+
+    if (this._transport) {
+      this._transport.close();
+      this._transport = null;
+    }
+
+    return this._closePromise;
+  },
+
+  /**
+   * Release an object actor.
+   *
+   * @param string actor
+   *        The actor ID to send the request to.
+   */
+  release(to) {
+    return this.request({
+      to,
+      type: "release",
+    });
+  },
+
+  /**
+   * Send a request to the debugging server.
+   *
+   * @param packet object
+   *        A JSON packet to send to the debugging server.
+   * @param onResponse function
+   *        If specified, will be called with the JSON response packet when
+   *        debugging server responds.
+   * @return Request
+   *         This object emits a number of events to allow you to respond to
+   *         different parts of the request lifecycle.
+   *         It is also a Promise object, with a `then` method, that is resolved
+   *         whenever a JSON or a Bulk response is received; and is rejected
+   *         if the response is an error.
+   *         Note: This return value can be ignored if you are using JSON alone,
+   *         because the callback provided in |onResponse| will be bound to the
+   *         "json-reply" event automatically.
+   *
+   *         Events emitted:
+   *         * json-reply: The server replied with a JSON packet, which is
+   *           passed as event data.
+   *         * bulk-reply: The server replied with bulk data, which you can read
+   *           using the event data object containing:
+   *           * actor:  Name of actor that received the packet
+   *           * type:   Name of actor's method that was called on receipt
+   *           * length: Size of the data to be read
+   *           * stream: This input stream should only be used directly if you
+   *                     can ensure that you will read exactly |length| bytes
+   *                     and will not close the stream when reading is complete
+   *           * done:   If you use the stream directly (instead of |copyTo|
+   *                     below), you must signal completion by resolving /
+   *                     rejecting this promise.  If it's rejected, the
+   *                     transport will be closed.  If an Error is supplied as a
+   *                     rejection value, it will be logged via |dumpn|.  If you
+   *                     do use |copyTo|, resolving is taken care of for you
+   *                     when copying completes.
+   *           * copyTo: A helper function for getting your data out of the
+   *                     stream that meets the stream handling requirements
+   *                     above, and has the following signature:
+   *             @param  output nsIAsyncOutputStream
+   *                     The stream to copy to.
+   *             @return Promise
+   *                     The promise is resolved when copying completes or
+   *                     rejected if any (unexpected) errors occur.
+   *                     This object also emits "progress" events for each chunk
+   *                     that is copied.  See stream-utils.js.
+   */
+  request(packet, onResponse) {
+    if (!this.mainRoot) {
+      throw Error("Have not yet received a hello packet from the server.");
+    }
+    const type = packet.type || "";
+    if (!packet.to) {
+      throw Error("'" + type + "' request packet has no destination.");
+    }
+
+    // The onResponse callback might modify the response, so we need to call
+    // it and resolve the promise with its result if it's truthy.
+    const safeOnResponse = response => {
+      if (!onResponse) {
+        return response;
+      }
+      return onResponse(response) || response;
+    };
+
+    if (this._transportClosed) {
+      const msg =
+        "'" +
+        type +
+        "' request packet to " +
+        "'" +
+        packet.to +
+        "' " +
+        "can't be sent as the connection is closed.";
+      const resp = { error: "connectionClosed", message: msg };
+      return Promise.reject(safeOnResponse(resp));
+    }
+
+    const request = new Request(packet);
+    request.format = "json";
+    request.stack = getStack();
+
+    // Implement a Promise like API on the returned object
+    // that resolves/rejects on request response
+    const promise = new Promise((resolve, reject) => {
+      function listenerJson(resp) {
+        removeRequestListeners();
+        resp = safeOnResponse(resp);
+        if (resp.error) {
+          reject(resp);
+        } else {
+          resolve(resp);
+        }
+      }
+      function listenerBulk(resp) {
+        removeRequestListeners();
+        resolve(safeOnResponse(resp));
+      }
+
+      const removeRequestListeners = () => {
+        request.off("json-reply", listenerJson);
+        request.off("bulk-reply", listenerBulk);
+      };
+
+      request.on("json-reply", listenerJson);
+      request.on("bulk-reply", listenerBulk);
+    });
+
+    this._sendOrQueueRequest(request);
+    request.then = promise.then.bind(promise);
+    request.catch = promise.catch.bind(promise);
+
+    return request;
+  },
+
+  /**
+   * Transmit streaming data via a bulk request.
+   *
+   * This method initiates the bulk send process by queuing up the header data.
+   * The caller receives eventual access to a stream for writing.
+   *
+   * Since this opens up more options for how the server might respond (it could
+   * send back either JSON or bulk data), and the returned Request object emits
+   * events for different stages of the request process that you may want to
+   * react to.
+   *
+   * @param request Object
+   *        This is modeled after the format of JSON packets above, but does not
+   *        actually contain the data, but is instead just a routing header:
+   *          * actor:  Name of actor that will receive the packet
+   *          * type:   Name of actor's method that should be called on receipt
+   *          * length: Size of the data to be sent
+   * @return Request
+   *         This object emits a number of events to allow you to respond to
+   *         different parts of the request lifecycle.
+   *
+   *         Events emitted:
+   *         * bulk-send-ready: Ready to send bulk data to the server, using the
+   *           event data object containing:
+   *           * stream:   This output stream should only be used directly if
+   *                       you can ensure that you will write exactly |length|
+   *                       bytes and will not close the stream when writing is
+   *                       complete
+   *           * done:     If you use the stream directly (instead of |copyFrom|
+   *                       below), you must signal completion by resolving /
+   *                       rejecting this promise.  If it's rejected, the
+   *                       transport will be closed.  If an Error is supplied as
+   *                       a rejection value, it will be logged via |dumpn|.  If
+   *                       you do use |copyFrom|, resolving is taken care of for
+   *                       you when copying completes.
+   *           * copyFrom: A helper function for getting your data onto the
+   *                       stream that meets the stream handling requirements
+   *                       above, and has the following signature:
+   *             @param  input nsIAsyncInputStream
+   *                     The stream to copy from.
+   *             @return Promise
+   *                     The promise is resolved when copying completes or
+   *                     rejected if any (unexpected) errors occur.
+   *                     This object also emits "progress" events for each chunk
+   *                     that is copied.  See stream-utils.js.
+   *         * json-reply: The server replied with a JSON packet, which is
+   *           passed as event data.
+   *         * bulk-reply: The server replied with bulk data, which you can read
+   *           using the event data object containing:
+   *           * actor:  Name of actor that received the packet
+   *           * type:   Name of actor's method that was called on receipt
+   *           * length: Size of the data to be read
+   *           * stream: This input stream should only be used directly if you
+   *                     can ensure that you will read exactly |length| bytes
+   *                     and will not close the stream when reading is complete
+   *           * done:   If you use the stream directly (instead of |copyTo|
+   *                     below), you must signal completion by resolving /
+   *                     rejecting this promise.  If it's rejected, the
+   *                     transport will be closed.  If an Error is supplied as a
+   *                     rejection value, it will be logged via |dumpn|.  If you
+   *                     do use |copyTo|, resolving is taken care of for you
+   *                     when copying completes.
+   *           * copyTo: A helper function for getting your data out of the
+   *                     stream that meets the stream handling requirements
+   *                     above, and has the following signature:
+   *             @param  output nsIAsyncOutputStream
+   *                     The stream to copy to.
+   *             @return Promise
+   *                     The promise is resolved when copying completes or
+   *                     rejected if any (unexpected) errors occur.
+   *                     This object also emits "progress" events for each chunk
+   *                     that is copied.  See stream-utils.js.
+   */
+  startBulkRequest(request) {
+    if (!this.mainRoot) {
+      throw Error("Have not yet received a hello packet from the server.");
+    }
+    if (!request.type) {
+      throw Error("Bulk packet is missing the required 'type' field.");
+    }
+    if (!request.actor) {
+      throw Error("'" + request.type + "' bulk packet has no destination.");
+    }
+    if (!request.length) {
+      throw Error("'" + request.type + "' bulk packet has no length.");
+    }
+
+    request = new Request(request);
+    request.format = "bulk";
+
+    this._sendOrQueueRequest(request);
+
+    return request;
+  },
+
+  /**
+   * If a new request can be sent immediately, do so.  Otherwise, queue it.
+   */
+  _sendOrQueueRequest(request) {
+    const actor = request.actor;
+    if (!this._activeRequests.has(actor)) {
+      this._sendRequest(request);
+    } else {
+      this._queueRequest(request);
+    }
+  },
+
+  /**
+   * Send a request.
+   * @throws Error if there is already an active request in flight for the same
+   *         actor.
+   */
+  _sendRequest(request) {
+    const actor = request.actor;
+    this.expectReply(actor, request);
+
+    if (request.format === "json") {
+      this._transport.send(request.request);
+      return;
+    }
+
+    this._transport.startBulkSend(request.request).then((...args) => {
+      request.emit("bulk-send-ready", ...args);
+    });
+  },
+
+  /**
+   * Queue a request to be sent later.  Queues are only drained when an in
+   * flight request to a given actor completes.
+   */
+  _queueRequest(request) {
+    const actor = request.actor;
+    const queue = this._pendingRequests.get(actor) || [];
+    queue.push(request);
+    this._pendingRequests.set(actor, queue);
+  },
+
+  /**
+   * Attempt the next request to a given actor (if any).
+   */
+  _attemptNextRequest(actor) {
+    if (this._activeRequests.has(actor)) {
+      return;
+    }
+    const queue = this._pendingRequests.get(actor);
+    if (!queue) {
+      return;
+    }
+    const request = queue.shift();
+    if (queue.length === 0) {
+      this._pendingRequests.delete(actor);
+    }
+    this._sendRequest(request);
+  },
+
+  /**
+   * Arrange to hand the next reply from |actor| to the handler bound to
+   * |request|.
+   *
+   * DevToolsClient.prototype.request / startBulkRequest usually takes care of
+   * establishing the handler for a given request, but in rare cases (well,
+   * greetings from new root actors, is the only case at the moment) we must be
+   * prepared for a "reply" that doesn't correspond to any request we sent.
+   */
+  expectReply(actor, request) {
+    if (this._activeRequests.has(actor)) {
+      throw Error("clashing handlers for next reply from " + actor);
+    }
+
+    // If a handler is passed directly (as it is with the handler for the root
+    // actor greeting), create a dummy request to bind this to.
+    if (typeof request === "function") {
+      const handler = request;
+      request = new Request();
+      request.on("json-reply", handler);
+    }
+
+    this._activeRequests.set(actor, request);
+  },
+
+  // Transport hooks.
+
+  /**
+   * Called by DebuggerTransport to dispatch incoming packets as appropriate.
+   *
+   * @param packet object
+   *        The incoming packet.
+   */
+  onPacket(packet) {
+    if (!packet.from) {
+      DevToolsUtils.reportException(
+        "onPacket",
+        new Error(
+          "Server did not specify an actor, dropping packet: " +
+            JSON.stringify(packet)
+        )
+      );
+      return;
+    }
+
+    // Check for "forwardingCancelled" here instead of using a front to handle it.
+    // This is necessary because we might receive this event while the client is closing,
+    // and the fronts have already been removed by that point.
+    if (
+      this.mainRoot &&
+      packet.from == this.mainRoot.actorID &&
+      packet.type == "forwardingCancelled"
+    ) {
+      this.purgeRequests(packet.prefix);
+      return;
+    }
+
+    // If we have a registered Front for this actor, let it handle the packet
+    // and skip all the rest of this unpleasantness.
+    const front = this.getFrontByID(packet.from);
+    if (front) {
+      front.onPacket(packet);
+      return;
+    }
+
+    let activeRequest;
+    // See if we have a handler function waiting for a reply from this
+    // actor. (Don't count unsolicited notifications or pauses as
+    // replies.)
+    if (
+      this._activeRequests.has(packet.from) &&
+      !(packet.type in UnsolicitedNotifications)
+    ) {
+      activeRequest = this._activeRequests.get(packet.from);
+      this._activeRequests.delete(packet.from);
+    }
+
+    // If there is a subsequent request for the same actor, hand it off to the
+    // transport.  Delivery of packets on the other end is always async, even
+    // in the local transport case.
+    this._attemptNextRequest(packet.from);
+
+    // Only try to notify listeners on events, not responses to requests
+    // that lack a packet type.
+    if (packet.type) {
+      this.emit(packet.type, packet);
+    }
+
+    if (activeRequest) {
+      const emitReply = () => activeRequest.emit("json-reply", packet);
+      if (activeRequest.stack) {
+        callFunctionWithAsyncStack(
+          emitReply,
+          activeRequest.stack,
+          "DevTools RDP"
+        );
+      } else {
+        emitReply();
+      }
+    }
+  },
+
+  /**
+   * Called by the DebuggerTransport to dispatch incoming bulk packets as
+   * appropriate.
+   *
+   * @param packet object
+   *        The incoming packet, which contains:
+   *        * actor:  Name of actor that will receive the packet
+   *        * type:   Name of actor's method that should be called on receipt
+   *        * length: Size of the data to be read
+   *        * stream: This input stream should only be used directly if you can
+   *                  ensure that you will read exactly |length| bytes and will
+   *                  not close the stream when reading is complete
+   *        * done:   If you use the stream directly (instead of |copyTo|
+   *                  below), you must signal completion by resolving /
+   *                  rejecting this promise.  If it's rejected, the transport
+   *                  will be closed.  If an Error is supplied as a rejection
+   *                  value, it will be logged via |dumpn|.  If you do use
+   *                  |copyTo|, resolving is taken care of for you when copying
+   *                  completes.
+   *        * copyTo: A helper function for getting your data out of the stream
+   *                  that meets the stream handling requirements above, and has
+   *                  the following signature:
+   *          @param  output nsIAsyncOutputStream
+   *                  The stream to copy to.
+   *          @return Promise
+   *                  The promise is resolved when copying completes or rejected
+   *                  if any (unexpected) errors occur.
+   *                  This object also emits "progress" events for each chunk
+   *                  that is copied.  See stream-utils.js.
+   */
+  onBulkPacket(packet) {
+    const { actor } = packet;
+
+    if (!actor) {
+      DevToolsUtils.reportException(
+        "onBulkPacket",
+        new Error(
+          "Server did not specify an actor, dropping bulk packet: " +
+            JSON.stringify(packet)
+        )
+      );
+      return;
+    }
+
+    // See if we have a handler function waiting for a reply from this
+    // actor.
+    if (!this._activeRequests.has(actor)) {
+      return;
+    }
+
+    const activeRequest = this._activeRequests.get(actor);
+    this._activeRequests.delete(actor);
+
+    // If there is a subsequent request for the same actor, hand it off to the
+    // transport.  Delivery of packets on the other end is always async, even
+    // in the local transport case.
+    this._attemptNextRequest(actor);
+
+    activeRequest.emit("bulk-reply", packet);
+  },
+
+  /**
+   * Called by DebuggerTransport when the underlying stream is closed.
+   *
+   * @param status nsresult
+   *        The status code that corresponds to the reason for closing
+   *        the stream.
+   */
+  onTransportClosed() {
+    if (this._transportClosed) {
+      return;
+    }
+    this._transportClosed = true;
+    this.emit("closed");
+
+    this.purgeRequests();
+
+    // The |_pools| array on the client-side currently is used only by
+    // protocol.js to store active fronts, mirroring the actor pools found in
+    // the server.  So, read all usages of "pool" as "protocol.js front".
+    //
+    // In the normal case where we shutdown cleanly, the toolbox tells each tool
+    // to close, and they each call |destroy| on any fronts they were using.
+    // When |destroy| is called on a protocol.js front, it also
+    // removes itself from the |_pools| array.  Once the toolbox has shutdown,
+    // the connection is closed, and we reach here.  All fronts (should have
+    // been) |destroy|ed, so |_pools| should empty.
+    //
+    // If the connection instead aborts unexpectedly, we may end up here with
+    // all fronts used during the life of the connection.  So, we call |destroy|
+    // on them clear their state, reject pending requests, and remove themselves
+    // from |_pools|.  This saves the toolbox from hanging indefinitely, in case
+    // it waits for some server response before shutdown that will now never
+    // arrive.
+    for (const pool of this._pools) {
+      pool.destroy();
+    }
+  },
+
+  /**
+   * Purge pending and active requests in this client.
+   *
+   * @param prefix string (optional)
+   *        If a prefix is given, only requests for actor IDs that start with the prefix
+   *        will be cleaned up.  This is useful when forwarding of a portion of requests
+   *        is cancelled on the server.
+   */
+  purgeRequests(prefix = "") {
+    const reject = function (type, request) {
+      // Server can send packets on its own and client only pass a callback
+      // to expectReply, so that there is no request object.
+      let msg;
+      if (request.request) {
+        msg =
+          "'" +
+          request.request.type +
+          "' " +
+          type +
+          " request packet" +
+          " to '" +
+          request.actor +
+          "' " +
+          "can't be sent as the connection just closed.";
+      } else {
+        msg =
+          "server side packet can't be received as the connection just closed.";
+      }
+      const packet = { error: "connectionClosed", message: msg };
+      request.emit("json-reply", packet);
+    };
+
+    let pendingRequestsToReject = [];
+    this._pendingRequests.forEach((requests, actor) => {
+      if (!actor.startsWith(prefix)) {
+        return;
+      }
+      this._pendingRequests.delete(actor);
+      pendingRequestsToReject = pendingRequestsToReject.concat(requests);
+    });
+    pendingRequestsToReject.forEach(request => reject("pending", request));
+
+    let activeRequestsToReject = [];
+    this._activeRequests.forEach((request, actor) => {
+      if (!actor.startsWith(prefix)) {
+        return;
+      }
+      this._activeRequests.delete(actor);
+      activeRequestsToReject = activeRequestsToReject.concat(request);
+    });
+    activeRequestsToReject.forEach(request => reject("active", request));
+
+    // Also purge protocol.js requests
+    const fronts = this.getAllFronts();
+
+    for (const front of fronts) {
+      if (!front.isDestroyed() && front.actorID.startsWith(prefix)) {
+        // Call Front.baseFrontClassDestroy nstead of Front.destroy in order to flush requests
+        // and nullify front.actorID immediately, even if Front.destroy is overloaded
+        // by an async function which would otherwise be able to try emitting new request
+        // after the purge.
+        front.baseFrontClassDestroy();
+      }
+    }
+  },
+
+  /**
+   * Search for all requests in process for this client, including those made via
+   * protocol.js and wait all of them to complete.  Since the requests seen when this is
+   * first called may in turn trigger more requests, we keep recursing through this
+   * function until there is no more activity.
+   *
+   * This is a fairly heavy weight process, so it's only meant to be used in tests.
+   *
+   * @return Promise
+   *         Resolved when all requests have settled.
+   */
+  waitForRequestsToSettle() {
+    let requests = [];
+
+    // Gather all pending and active requests in this client
+    // The request object supports a Promise API for completion (it has .then())
+    this._pendingRequests.forEach(requestsForActor => {
+      // Each value is an array of pending requests
+      requests = requests.concat(requestsForActor);
+    });
+    this._activeRequests.forEach(requestForActor => {
+      // Each value is a single active request
+      requests = requests.concat(requestForActor);
+    });
+
+    // protocol.js
+    const fronts = this.getAllFronts();
+
+    // For each front, wait for its requests to settle
+    for (const front of fronts) {
+      if (front.hasRequests()) {
+        requests.push(front.waitForRequestsToSettle());
+      }
+    }
+
+    // Abort early if there are no requests
+    if (!requests.length) {
+      return Promise.resolve();
+    }
+
+    return DevToolsUtils.settleAll(requests)
+      .catch(() => {
+        // One of the requests might have failed, but ignore that situation here and pipe
+        // both success and failure through the same path.  The important part is just that
+        // we waited.
+      })
+      .then(() => {
+        // Repeat, more requests may have started in response to those we just waited for
+        return this.waitForRequestsToSettle();
+      });
+  },
+
+  getAllFronts() {
+    // Use a Set because some fronts (like domwalker) seem to have multiple parents.
+    const fronts = new Set();
+    const poolsToVisit = [...this._pools];
+
+    // With protocol.js, each front can potentially have its own pools containing child
+    // fronts, forming a tree.  Descend through all the pools to locate all child fronts.
+    while (poolsToVisit.length) {
+      const pool = poolsToVisit.shift();
+      // `_pools` contains either Fronts or Pools, we only want to collect Fronts here.
+      // Front inherits from Pool which exposes `poolChildren`.
+      if (pool instanceof Front) {
+        fronts.add(pool);
+      }
+      for (const child of pool.poolChildren()) {
+        poolsToVisit.push(child);
+      }
+    }
+    return fronts;
+  },
+
+  /**
+   * Actor lifetime management, echos the server's actor pools.
+   */
+  __pools: null,
+  get _pools() {
+    if (this.__pools) {
+      return this.__pools;
+    }
+    this.__pools = new Set();
+    return this.__pools;
+  },
+
+  addActorPool(pool) {
+    this._pools.add(pool);
+  },
+  removeActorPool(pool) {
+    this._pools.delete(pool);
+  },
+
+  /**
+   * Return the Front for the Actor whose ID is the one passed in argument.
+   *
+   * @param {String} actorID: The actor ID to look for.
+   */
+  getFrontByID(actorID) {
+    const pool = this.poolFor(actorID);
+    return pool ? pool.getActorByID(actorID) : null;
+  },
+
+  poolFor(actorID) {
+    for (const pool of this._pools) {
+      if (pool.has(actorID)) {
+        return pool;
+      }
+    }
+    return null;
+  },
+
+  /**
+   * Creates an object front for this DevToolsClient and the grip in parameter,
+   * @param {Object} grip: The grip to create the ObjectFront for.
+   * @param {ThreadFront} threadFront
+   * @param {Front} parentFront: Optional front that will manage the object front.
+   *                             Defaults to threadFront.
+   * @returns {ObjectFront}
+   */
+  createObjectFront(grip, threadFront, parentFront) {
+    if (!parentFront) {
+      parentFront = threadFront;
+    }
+
+    return new ObjectFront(this, threadFront.targetFront, parentFront, grip);
+  },
+
+  get transport() {
+    return this._transport;
+  },
+
+  dumpPools() {
+    for (const pool of this._pools) {
+      console.log(`%c${pool.actorID}`, "font-weight: bold;", [
+        ...pool.__poolMap.keys(),
+      ]);
+    }
+  },
+};
+
+EventEmitter.decorate(DevToolsClient.prototype);
+
+class Request extends EventEmitter {
+  constructor(request) {
+    super();
+    this.request = request;
+  }
+
+  get actor() {
+    return this.request.to || this.request.actor;
+  }
+}
+
+module.exports = {
+  DevToolsClient,
+};