/* 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 "mozilla/dom/cache/CacheChild.h"

#include "CacheWorkerRef.h"
#include "mozilla/dom/cache/ActorUtils.h"
#include "mozilla/dom/cache/Cache.h"
#include "mozilla/dom/cache/CacheOpChild.h"

namespace mozilla::dom::cache {

// Declared in ActorUtils.h
already_AddRefed<PCacheChild> AllocPCacheChild(ActorChild* aParentActor) {
  return MakeAndAddRef<CacheChild>(aParentActor);
}

// Declared in ActorUtils.h
void DeallocPCacheChild(PCacheChild* aActor) { delete aActor; }

CacheChild::CacheChild(ActorChild* aParentActor)
    : mParentActor(aParentActor),
      mListener(nullptr),
      mLocked(false),
      mDelayedDestroy(false) {
  MOZ_COUNT_CTOR(cache::CacheChild);
}

CacheChild::~CacheChild() {
  MOZ_COUNT_DTOR(cache::CacheChild);
  NS_ASSERT_OWNINGTHREAD(CacheChild);
  MOZ_DIAGNOSTIC_ASSERT(!mListener);
  MOZ_DIAGNOSTIC_ASSERT(!mLocked);
}

void CacheChild::SetListener(CacheChildListener* aListener) {
  NS_ASSERT_OWNINGTHREAD(CacheChild);
  MOZ_DIAGNOSTIC_ASSERT(!mListener);
  mListener = aListener;
  MOZ_DIAGNOSTIC_ASSERT(mListener);
}

void CacheChild::ClearListener() {
  NS_ASSERT_OWNINGTHREAD(CacheChild);
  MOZ_DIAGNOSTIC_ASSERT(mListener);
  mListener = nullptr;
}

void CacheChild::StartDestroyFromListener() {
  NS_ASSERT_OWNINGTHREAD(CacheChild);

  // The listener should be held alive by any async operations, so if it
  // is going away then there must not be any child actors.  This in turn
  // ensures that StartDestroy() will not trigger the delayed path.
  MOZ_DIAGNOSTIC_ASSERT(NumChildActors() == 0);
  StartDestroy();
}

void CacheChild::DestroyInternal() {
  CacheChildListener* listener = mListener;

  // StartDestroy() can get called from either Cache or the WorkerRef.
  // Theoretically we can get double called if the right race happens.  Handle
  // that by just ignoring the second StartDestroy() call.
  if (!listener) {
    return;
  }

  listener->OnActorDestroy(this);

  // Cache listener should call ClearListener() in OnActorDestroy()
  MOZ_DIAGNOSTIC_ASSERT(!mListener);

  // Start actor destruction from parent process
  QM_WARNONLY_TRY(OkIf(SendTeardown()));
}

void CacheChild::StartDestroy() {
  NS_ASSERT_OWNINGTHREAD(CacheChild);

  if (NumChildActors() != 0 || mLocked) {
    mDelayedDestroy = true;
    return;
  }

  DestroyInternal();
}

void CacheChild::ActorDestroy(ActorDestroyReason aReason) {
  NS_ASSERT_OWNINGTHREAD(CacheChild);
  CacheChildListener* listener = mListener;
  if (listener) {
    listener->OnActorDestroy(this);
    // Cache listener should call ClearListener() in OnActorDestroy()
    MOZ_DIAGNOSTIC_ASSERT(!mListener);
  }

  if (mParentActor) {
    mParentActor->NoteDeletedActor();
  }

  RemoveWorkerRef();
}

void CacheChild::NoteDeletedActor() {
  // Check to see if DestroyInternal was delayed because there were still active
  // CacheOpChilds when StartDestroy was called from WorkerRef notification. If
  // the last CacheOpChild is getting destructed; it's the time for us to
  // SendTearDown to the other side.
  if (NumChildActors() == 0 && mDelayedDestroy && !mLocked) DestroyInternal();
}

already_AddRefed<PCacheOpChild> CacheChild::AllocPCacheOpChild(
    const CacheOpArgs& aOpArgs) {
  MOZ_CRASH("CacheOpChild should be manually constructed.");
  return nullptr;
}

void CacheChild::Lock() {
  NS_ASSERT_OWNINGTHREAD(CacheChild);
  MOZ_DIAGNOSTIC_ASSERT(!mLocked);
  mLocked = true;
}

void CacheChild::Unlock() {
  NS_ASSERT_OWNINGTHREAD(CacheChild);
  MOZ_DIAGNOSTIC_ASSERT(mLocked);
  mLocked = false;
}

}  // namespace mozilla::dom::cache