// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CC_LAYERS_DELEGATED_FRAME_RESOURCE_COLLECTION_H_
#define CC_LAYERS_DELEGATED_FRAME_RESOURCE_COLLECTION_H_

#include "base/containers/hash_tables.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/thread_checker.h"
#include "cc/base/cc_export.h"
#include "cc/resources/return_callback.h"
#include "cc/resources/returned_resource.h"
#include "cc/resources/transferable_resource.h"

namespace cc {
class BlockingTaskRunner;

class CC_EXPORT DelegatedFrameResourceCollectionClient {
 public:
  // Called to inform the client that returned resources can be
  // grabbed off the DelegatedFrameResourceCollection.
  virtual void UnusedResourcesAreAvailable() = 0;
};

class CC_EXPORT DelegatedFrameResourceCollection
    : public base::RefCounted<DelegatedFrameResourceCollection> {
 public:
  DelegatedFrameResourceCollection();

  void SetClient(DelegatedFrameResourceCollectionClient* client);

  void TakeUnusedResourcesForChildCompositor(ReturnedResourceArray* array);

  // Considers all resources as lost, and returns true if it held any resource
  // to lose.
  bool LoseAllResources();

  // Methods for DelegatedFrameProvider.
  void RefResources(const TransferableResourceArray& resources);
  void UnrefResources(const ReturnedResourceArray& returned);
  void ReceivedResources(const TransferableResourceArray& resources);
  ReturnCallback GetReturnResourcesCallbackForImplThread();

 private:
  friend class base::RefCounted<DelegatedFrameResourceCollection>;
  ~DelegatedFrameResourceCollection();

  DelegatedFrameResourceCollectionClient* client_;
  scoped_refptr<BlockingTaskRunner> main_thread_runner_;

  ReturnedResourceArray returned_resources_for_child_compositor_;
  bool lost_all_resources_;

  struct RefCount {
    int refs_to_return;
    int refs_to_wait_for;
  };
  typedef base::hash_map<unsigned, RefCount> ResourceIdRefCountMap;
  ResourceIdRefCountMap resource_id_ref_count_map_;

  base::ThreadChecker main_thread_checker_;
  base::WeakPtrFactory<DelegatedFrameResourceCollection> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(DelegatedFrameResourceCollection);
};

}  // namespace cc

#endif  // CC_LAYERS_DELEGATED_FRAME_RESOURCE_COLLECTION_H_