////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///     http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
////////////////////////////////////////////////////////////////////////////////

#ifndef ARANGOD_MMFILES_TRANSACTION_COLLECTION_H
#define ARANGOD_MMFILES_TRANSACTION_COLLECTION_H 1

#include "Basics/Common.h"
#include "Containers/SmallVector.h"
#include "StorageEngine/TransactionCollection.h"
#include "VocBase/AccessMode.h"
#include "VocBase/voc-types.h"

namespace arangodb {
struct MMFilesDocumentOperation;
namespace transaction {
class Methods;
}
class TransactionState;

/// @brief collection used in a transaction
class MMFilesTransactionCollection final : public TransactionCollection {
 public:
  MMFilesTransactionCollection(TransactionState* trx, TRI_voc_cid_t cid,
                               AccessMode::Type accessType, int nestingLevel);
  ~MMFilesTransactionCollection();

  /// @brief whether or not any write operations for the collection happened
  bool hasOperations() const override;

  void freeOperations(transaction::Methods* activeTrx, bool mustRollback) override;

  bool canAccess(AccessMode::Type accessType) const override;
  int use(int nestingLevel) override;
  void unuse(int nestingLevel) override;
  void release() override;

  void addOperation(MMFilesDocumentOperation* operation);

 private:
  /// @brief request a lock for a collection
  /// returns TRI_ERROR_LOCKED in case the lock was successfully acquired
  /// returns TRI_ERROR_NO_ERROR in case the lock does not need to be acquired
  /// and no other error occurred returns any other error code otherwise
  int doLock(AccessMode::Type, int nestingLevel) override;

  /// @brief request an unlock for a collection
  int doUnlock(AccessMode::Type, int nestingLevel) override;

 private:
  ::arangodb::containers::SmallVector<MMFilesDocumentOperation*, 64>::allocator_type::arena_type _arena;
  ::arangodb::containers::SmallVector<MMFilesDocumentOperation*, 64> _operations;
  TRI_voc_rid_t _originalRevision;  // collection revision at trx start
  bool _compactionLocked;  // was the compaction lock grabbed for the collection?
  bool _waitForSync;       // whether or not the collection has waitForSync
};

}  // namespace arangodb

#endif