1 files changed, 120 insertions, 0 deletions
diff --git a/dom/serviceworkers/ServiceWorkerJobQueue.cpp b/dom/serviceworkers/ServiceWorkerJobQueue.cpp
new file mode 100644
index 0000000000..497265249a
--- /dev/null
+++ b/dom/serviceworkers/ServiceWorkerJobQueue.cpp
@@ -0,0 +1,120 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#include "ServiceWorkerJobQueue.h"
+
+#include "nsThreadUtils.h"
+#include "ServiceWorkerJob.h"
+#include "mozilla/dom/WorkerCommon.h"
+
+namespace mozilla::dom {
+
+class ServiceWorkerJobQueue::Callback final
+    : public ServiceWorkerJob::Callback {
+  RefPtr<ServiceWorkerJobQueue> mQueue;
+
+  ~Callback() = default;
+
+ public:
+  explicit Callback(ServiceWorkerJobQueue* aQueue) : mQueue(aQueue) {
+    MOZ_ASSERT(NS_IsMainThread());
+    MOZ_ASSERT(mQueue);
+  }
+
+  virtual void JobFinished(ServiceWorkerJob* aJob,
+                           ErrorResult& aStatus) override {
+    MOZ_ASSERT(NS_IsMainThread());
+    mQueue->JobFinished(aJob);
+  }
+
+  virtual void JobDiscarded(ErrorResult&) override {
+    // no-op; nothing to do.
+  }
+
+  NS_INLINE_DECL_REFCOUNTING(ServiceWorkerJobQueue::Callback, override)
+};
+
+ServiceWorkerJobQueue::~ServiceWorkerJobQueue() {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mJobList.IsEmpty());
+}
+
+void ServiceWorkerJobQueue::JobFinished(ServiceWorkerJob* aJob) {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aJob);
+
+  // XXX There are some corner cases where jobs can double-complete.  Until
+  // we track all these down we do a non-fatal assert in debug builds and
+  // a runtime check to verify the queue is in the correct state.
+  NS_ASSERTION(!mJobList.IsEmpty(),
+               "Job queue should contain the job that just completed.");
+  NS_ASSERTION(mJobList.SafeElementAt(0, nullptr) == aJob,
+               "Job queue should contain the job that just completed.");
+  if (NS_WARN_IF(mJobList.SafeElementAt(0, nullptr) != aJob)) {
+    return;
+  }
+
+  mJobList.RemoveElementAt(0);
+
+  if (mJobList.IsEmpty()) {
+    return;
+  }
+
+  RunJob();
+}
+
+void ServiceWorkerJobQueue::RunJob() {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!mJobList.IsEmpty());
+  MOZ_ASSERT(mJobList[0]->GetState() == ServiceWorkerJob::State::Initial);
+
+  RefPtr<Callback> callback = new Callback(this);
+  mJobList[0]->Start(callback);
+}
+
+ServiceWorkerJobQueue::ServiceWorkerJobQueue() {
+  MOZ_ASSERT(NS_IsMainThread());
+}
+
+void ServiceWorkerJobQueue::ScheduleJob(ServiceWorkerJob* aJob) {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aJob);
+  MOZ_ASSERT(!mJobList.Contains(aJob));
+
+  if (mJobList.IsEmpty()) {
+    mJobList.AppendElement(aJob);
+    RunJob();
+    return;
+  }
+
+  MOZ_ASSERT(mJobList[0]->GetState() == ServiceWorkerJob::State::Started);
+
+  RefPtr<ServiceWorkerJob>& tailJob = mJobList[mJobList.Length() - 1];
+  if (!tailJob->ResultCallbacksInvoked() && aJob->IsEquivalentTo(tailJob)) {
+    tailJob->StealResultCallbacksFrom(aJob);
+    return;
+  }
+
+  mJobList.AppendElement(aJob);
+}
+
+void ServiceWorkerJobQueue::CancelAll() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  for (RefPtr<ServiceWorkerJob>& job : mJobList) {
+    job->Cancel();
+  }
+
+  // Remove jobs that are queued but not started since they should never
+  // run after being canceled.  This means throwing away all jobs except
+  // for the job at the front of the list.
+  if (!mJobList.IsEmpty()) {
+    MOZ_ASSERT(mJobList[0]->GetState() == ServiceWorkerJob::State::Started);
+    mJobList.TruncateLength(1);
+  }
+}
+
+}  // namespace mozilla::dom