/* -*- 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 "PerformanceStorageWorker.h"
#include "mozilla/dom/WorkerRef.h"
#include "mozilla/dom/WorkerRunnable.h"
#include "mozilla/dom/WorkerPrivate.h"

namespace mozilla {
namespace dom {

class PerformanceProxyData
{
public:
  PerformanceProxyData(UniquePtr<PerformanceTimingData>&& aData,
                       const nsAString& aInitiatorType,
                       const nsAString& aEntryName)
    : mData(std::move(aData))
    , mInitiatorType(aInitiatorType)
    , mEntryName(aEntryName)
  {}

  UniquePtr<PerformanceTimingData> mData;
  nsString mInitiatorType;
  nsString mEntryName;
};

namespace {

// Here we use control runnable because this code must be executed also when in
// a sync event loop
class PerformanceEntryAdder final : public WorkerControlRunnable
{
public:
  PerformanceEntryAdder(WorkerPrivate* aWorkerPrivate,
                        PerformanceStorageWorker* aStorage,
                        UniquePtr<PerformanceProxyData>&& aData)
    : WorkerControlRunnable(aWorkerPrivate, WorkerThreadUnchangedBusyCount)
    , mStorage(aStorage)
    , mData(std::move(aData))
  {}

  bool
  WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) override
  {
    mStorage->AddEntryOnWorker(std::move(mData));
    return true;
  }

  nsresult
  Cancel() override
  {
    mStorage->ShutdownOnWorker();
    return WorkerRunnable::Cancel();
  }

  bool
  PreDispatch(WorkerPrivate* aWorkerPrivate) override
  {
    return true;
  }

  void
  PostDispatch(WorkerPrivate* aWorkerPrivate, bool aDispatchResult) override
  {}

private:
  RefPtr<PerformanceStorageWorker> mStorage;
  UniquePtr<PerformanceProxyData> mData;
};

class PerformanceStorageWorkerHolder final : public WorkerHolder
{
  RefPtr<PerformanceStorageWorker> mStorage;

public:
  explicit PerformanceStorageWorkerHolder(PerformanceStorageWorker* aStorage)
    : WorkerHolder("PerformanceStorageWorkerHolder",
                   WorkerHolder::AllowIdleShutdownStart)
    , mStorage(aStorage)
  {}

  bool
  Notify(WorkerStatus aStatus) override
  {
    if (mStorage) {
      RefPtr<PerformanceStorageWorker> storage;
      storage.swap(mStorage);
      storage->ShutdownOnWorker();
    }

    return true;
  }
};

} // anonymous

/* static */ already_AddRefed<PerformanceStorageWorker>
PerformanceStorageWorker::Create(WorkerPrivate* aWorkerPrivate)
{
  MOZ_ASSERT(aWorkerPrivate);
  aWorkerPrivate->AssertIsOnWorkerThread();

  RefPtr<PerformanceStorageWorker> storage = new PerformanceStorageWorker();

  storage->mWorkerRef = WeakWorkerRef::Create(aWorkerPrivate, [storage]() {
    storage->ShutdownOnWorker();
  });

  // PerformanceStorageWorker is created at the creation time of the worker.
  MOZ_ASSERT(storage->mWorkerRef);

  return storage.forget();
}

PerformanceStorageWorker::PerformanceStorageWorker()
  : mMutex("PerformanceStorageWorker::mMutex")
{
}

PerformanceStorageWorker::~PerformanceStorageWorker() = default;

void
PerformanceStorageWorker::AddEntry(nsIHttpChannel* aChannel,
                                   nsITimedChannel* aTimedChannel)
{
  MOZ_ASSERT(NS_IsMainThread());

  MutexAutoLock lock(mMutex);

  if (!mWorkerRef) {
    return;
  }

  // If we have mWorkerRef, we haven't received the WorkerRef notification and
  // we haven't yet call ShutdownOnWorker, which uses the mutex.
  WorkerPrivate* workerPrivate = mWorkerRef->GetUnsafePrivate();
  MOZ_ASSERT(workerPrivate);

  nsAutoString initiatorType;
  nsAutoString entryName;

  UniquePtr<PerformanceTimingData> performanceTimingData(
    PerformanceTimingData::Create(aTimedChannel, aChannel, 0, initiatorType,
                                  entryName));
  if (!performanceTimingData) {
    return;
  }

  UniquePtr<PerformanceProxyData> data(
    new PerformanceProxyData(std::move(performanceTimingData), initiatorType,
                             entryName));

  RefPtr<PerformanceEntryAdder> r =
    new PerformanceEntryAdder(workerPrivate, this, std::move(data));
  Unused << NS_WARN_IF(!r->Dispatch());
}

void
PerformanceStorageWorker::ShutdownOnWorker()
{
  MutexAutoLock lock(mMutex);

  if (!mWorkerRef) {
    return;
  }

  MOZ_ASSERT(IsCurrentThreadRunningWorker());

  mWorkerRef = nullptr;
}

void
PerformanceStorageWorker::AddEntryOnWorker(UniquePtr<PerformanceProxyData>&& aData)
{
  RefPtr<Performance> performance;
  UniquePtr<PerformanceProxyData> data = std::move(aData);

  {
    MutexAutoLock lock(mMutex);

    if (!mWorkerRef) {
      return;
    }

    // We must have the workerPrivate because it is available until a notification
    // is received by WorkerRef and we use mutex to make the code protected.
    WorkerPrivate* workerPrivate = mWorkerRef->GetPrivate();
    MOZ_ASSERT(workerPrivate);

    WorkerGlobalScope* scope = workerPrivate->GlobalScope();
    performance = scope->GetPerformance();
  }

  if (NS_WARN_IF(!performance)) {
    return;
  }

  RefPtr<PerformanceResourceTiming> performanceEntry =
    new PerformanceResourceTiming(std::move(data->mData), performance,
                                 data->mEntryName);
  performanceEntry->SetInitiatorType(data->mInitiatorType);

  performance->InsertResourceEntry(performanceEntry);
}

} // namespace dom
} // namespace mozilla
