1 files changed, 225 insertions, 0 deletions
diff --git a/devtools/shared/resources/legacy-target-watchers/legacy-workers-watcher.js b/devtools/shared/resources/legacy-target-watchers/legacy-workers-watcher.js
new file mode 100644
index 0000000000..0b0b07a897
--- /dev/null
+++ b/devtools/shared/resources/legacy-target-watchers/legacy-workers-watcher.js
@@ -0,0 +1,225 @@
+/* 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";
+
+loader.lazyRequireGetter(
+  this,
+  "TargetList",
+  "devtools/shared/resources/target-list",
+  true
+);
+
+const {
+  LegacyProcessesWatcher,
+} = require("devtools/shared/resources/legacy-target-watchers/legacy-processes-watcher");
+
+class LegacyWorkersWatcher {
+  constructor(targetList, onTargetAvailable, onTargetDestroyed) {
+    this.targetList = targetList;
+    this.rootFront = targetList.rootFront;
+
+    this.onTargetAvailable = onTargetAvailable;
+    this.onTargetDestroyed = onTargetDestroyed;
+
+    this.targetsByProcess = new WeakMap();
+    this.targetsListeners = new WeakMap();
+
+    this._onProcessAvailable = this._onProcessAvailable.bind(this);
+    this._onProcessDestroyed = this._onProcessDestroyed.bind(this);
+  }
+
+  async _onProcessAvailable({ targetFront }) {
+    this.targetsByProcess.set(targetFront, new Set());
+    // Listen for worker which will be created later
+    const listener = this._workerListChanged.bind(this, targetFront);
+    this.targetsListeners.set(targetFront, listener);
+
+    // If this is the browser toolbox, we have to listen from the RootFront
+    // (see comment in _workerListChanged)
+    const front = targetFront.isParentProcess ? this.rootFront : targetFront;
+    front.on("workerListChanged", listener);
+
+    // We also need to process the already existing workers
+    await this._workerListChanged(targetFront);
+  }
+
+  async _onProcessDestroyed({ targetFront }) {
+    const existingTargets = this.targetsByProcess.get(targetFront);
+
+    // Process the new list to detect the ones being destroyed
+    // Force destroying the targets
+    for (const target of existingTargets) {
+      this.onTargetDestroyed(target);
+
+      target.destroy();
+      existingTargets.delete(target);
+    }
+    this.targetsByProcess.delete(targetFront);
+    this.targetsListeners.delete(targetFront);
+  }
+
+  _supportWorkerTarget(workerTarget) {
+    // subprocess workers are ignored because they take several seconds to
+    // attach to when opening the browser toolbox. See bug 1594597.
+    // When attaching we get the following error:
+    // JavaScript error: resource://devtools/server/startup/worker.js,
+    //   line 37: NetworkError: WorkerDebuggerGlobalScope.loadSubScript: Failed to load worker script at resource://devtools/shared/worker/loader.js (nsresult = 0x805e0006)
+    return (
+      workerTarget.isDedicatedWorker &&
+      !workerTarget.url.startsWith(
+        "resource://gre/modules/subprocess/subprocess_worker"
+      )
+    );
+  }
+
+  async _workerListChanged(targetFront) {
+    // If we're in the Browser Toolbox, query workers from the Root Front instead of the
+    // ParentProcessTarget as the ParentProcess Target filters out the workers to only
+    // show the one from the top level window, whereas we expect the one from all the
+    // windows, and also the window-less ones.
+    // TODO: For Content Toolbox, expose SW of the page, maybe optionally?
+    const front = targetFront.isParentProcess ? this.rootFront : targetFront;
+    if (!front || front.isDestroyed() || this.targetList.isDestroyed()) {
+      return;
+    }
+
+    const { workers } = await front.listWorkers();
+
+    // Fetch the list of already existing worker targets for this process target front.
+    const existingTargets = this.targetsByProcess.get(targetFront);
+    if (!existingTargets) {
+      // unlisten was called while processing the workerListChanged callback.
+      return;
+    }
+
+    // Process the new list to detect the ones being destroyed
+    // Force destroying the targets
+    for (const target of existingTargets) {
+      if (!workers.includes(target)) {
+        this.onTargetDestroyed(target);
+
+        target.destroy();
+        existingTargets.delete(target);
+      }
+    }
+
+    const promises = workers.map(workerTarget =>
+      this._processNewWorkerTarget(workerTarget, existingTargets)
+    );
+    await Promise.all(promises);
+  }
+
+  // This is overloaded for Service Workers, which records all SW targets,
+  // but only notify about a subset of them.
+  _recordWorkerTarget(workerTarget) {
+    return this._supportWorkerTarget(workerTarget);
+  }
+
+  async _processNewWorkerTarget(workerTarget, existingTargets) {
+    if (
+      !this._recordWorkerTarget(workerTarget) ||
+      existingTargets.has(workerTarget) ||
+      this.targetList.isDestroyed()
+    ) {
+      return;
+    }
+
+    // Add the new worker targets to the local list
+    existingTargets.add(workerTarget);
+
+    if (this._supportWorkerTarget(workerTarget)) {
+      await this.onTargetAvailable(workerTarget);
+    }
+  }
+
+  async listen() {
+    // Listen to the current target front.
+    this.target = this.targetList.targetFront;
+
+    if (this.target.isParentProcess) {
+      await this.targetList.watchTargets(
+        [TargetList.TYPES.PROCESS],
+        this._onProcessAvailable,
+        this._onProcessDestroyed
+      );
+
+      // The ParentProcessTarget front is considered to be a FRAME instead of a PROCESS.
+      // So process it manually here.
+      await this._onProcessAvailable({ targetFront: this.target });
+      return;
+    }
+
+    if (this._isSharedWorkerWatcher) {
+      // Here we're not in the browser toolbox, and SharedWorker targets are not supported
+      // in regular toolbox (See Bug 1607778)
+      return;
+    }
+
+    if (this._isServiceWorkerWatcher) {
+      this._legacyProcessesWatcher = new LegacyProcessesWatcher(
+        this.targetList,
+        async targetFront => {
+          // Service workers only live in content processes.
+          if (!targetFront.isParentProcess) {
+            await this._onProcessAvailable({ targetFront });
+          }
+        },
+        targetFront => {
+          if (!targetFront.isParentProcess) {
+            this._onProcessDestroyed({ targetFront });
+          }
+        }
+      );
+      await this._legacyProcessesWatcher.listen();
+      return;
+    }
+
+    // Here, we're handling Dedicated Workers in content toolbox.
+    this.targetsByProcess.set(this.target, new Set());
+    this._workerListChangedListener = this._workerListChanged.bind(
+      this,
+      this.target
+    );
+    this.target.on("workerListChanged", this._workerListChangedListener);
+    await this._workerListChanged(this.target);
+  }
+
+  _getProcessTargets() {
+    return this.targetList.getAllTargets([TargetList.TYPES.PROCESS]);
+  }
+
+  unlisten() {
+    // Stop listening for new process targets.
+    if (this.target.isParentProcess) {
+      this.targetList.unwatchTargets(
+        [TargetList.TYPES.PROCESS],
+        this._onProcessAvailable,
+        this._onProcessDestroyed
+      );
+    } else if (this._isServiceWorkerWatcher) {
+      this._legacyProcessesWatcher.unlisten();
+    }
+
+    // Cleanup the targetsByProcess/targetsListeners maps, and unsubscribe from
+    // all targetFronts. Process target fronts are either stored locally when
+    // watching service workers for the content toolbox, or can be retrieved via
+    // the TargetList API otherwise (see _getProcessTargets implementations).
+    if (this.target.isParentProcess || this._isServiceWorkerWatcher) {
+      for (const targetFront of this._getProcessTargets()) {
+        const listener = this.targetsListeners.get(targetFront);
+        targetFront.off("workerListChanged", listener);
+        this.targetsByProcess.delete(targetFront);
+        this.targetsListeners.delete(targetFront);
+      }
+    } else {
+      this.target.off("workerListChanged", this._workerListChangedListener);
+      delete this._workerListChangedListener;
+      this.targetsByProcess.delete(this.target);
+      this.targetsListeners.delete(this.target);
+    }
+  }
+}
+
+module.exports = { LegacyWorkersWatcher };