// 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 SYNC_NOTIFIER_ACK_HANDLER_H_
#define SYNC_NOTIFIER_ACK_HANDLER_H_

#include <vector>

#include "sync/base/sync_export.h"

namespace invalidation {
class ObjectId;
}  // namespace invalidation

namespace syncer {

class AckHandle;

// An interface for classes that keep track of invalidation acknowledgements.
//
// We don't expect to support more than one "real" implementation of AckHandler,
// but this interface is very useful for testing and implementation hiding.
class SYNC_EXPORT AckHandler {
 public:
  AckHandler();
  virtual ~AckHandler() = 0;

  // Record the local acknowledgement of an invalidation identified by |handle|.
  virtual void Acknowledge(
      const invalidation::ObjectId& id,
      const AckHandle& handle) = 0;

  // Record the drop of an invalidation identified by |handle|.
  virtual void Drop(
      const invalidation::ObjectId& id,
      const AckHandle& handle) = 0;
};

}  // namespace syncer

#endif  // SYNC_NOTIFIER_ACK_HANDLER_H_