/*
Copyright 2020 The OneFlow Authors. All rights reserved.

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.
*/
#ifndef ONEFLOW_CORE_LAZY_ACTOR_REGISTER_SLOT_H_
#define ONEFLOW_CORE_LAZY_ACTOR_REGISTER_SLOT_H_

#include "oneflow/core/register/register_manager.h"

namespace oneflow {

class RegstSlot final {
 public:
  OF_DISALLOW_COPY_AND_MOVE(RegstSlot);
  RegstSlot() : regst_desc_id2regsts_(), available_regst_desc_cnt_(0), is_inited_(false) {}
  ~RegstSlot() = default;

  bool is_inited() const { return is_inited_; }
  size_t total_regst_desc_cnt() const { return regst_desc_id2regsts_.size(); }
  size_t available_regst_desc_cnt() const { return available_regst_desc_cnt_; }

  bool IsCurSlotReady() const { return available_regst_desc_cnt() == total_regst_desc_cnt(); }
  bool HasRegstDescId(int64_t regst_desc_id) const;
  const std::deque<Regst*>& RegstDeq4RegstDescId(int64_t regst_desc_id) const;
  void ForEachFrontRegst(std::function<void(Regst*)>) const;
  void ForEachFrontRegst(std::function<void(int64_t regst_desc_id, Regst*)>) const;
  void ForEachRegstDeq(std::function<void(const std::deque<Regst*>&)>) const;
  void ForChosenFrontRegst(std::function<bool(int64_t)>, std::function<void(Regst*)>) const;
  void ForChosenFrontRegst(std::function<bool(int64_t)>,
                           std::function<void(int64_t regst_desc_id, Regst*)>) const;
  void ForChosenRegstDeq(std::function<bool(int64_t)>,
                         std::function<void(const std::deque<Regst*>&)>) const;
  void ForChosenRegstDeq(
      std::function<bool(int64_t)>,
      std::function<void(int64_t regst_desc_id, const std::deque<Regst*>&)>) const;

  Regst* Front(int64_t regst_desc_id) const;
  Regst* SoleFront() const;
  Regst* FirstFront() const;

  // 0: success, -1: cannot find regst_desc_id
  int TryPushBackRegst(Regst* regst);
  int TryPushBackRegst(Regst* regst, int64_t regst_desc_id);
  int TryPopFrontRegst(int64_t regst_desc_id);

  void PopFrontRegsts(const std::vector<int64_t>& regst_desc_ids);

  void InitedDone();
  void InsertRegstDescId(int64_t regst_desc_id);

 private:
  HashMap<int64_t, std::deque<Regst*>> regst_desc_id2regsts_;
  size_t available_regst_desc_cnt_;
  bool is_inited_;
};

}  // namespace oneflow

#endif  // ONEFLOW_CORE_LAZY_ACTOR_REGISTER_SLOT_H_
