// Copyright (c) 2018 PaddlePaddle 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.

#pragma once

#include <memory>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "paddle/fluid/framework/details/op_handle_base.h"

namespace paddle {
namespace framework {
namespace details {

class OpGraphView {
 public:
  explicit OpGraphView(const std::vector<OpHandleBase *> &ops);

  std::unordered_set<OpHandleBase *> AllOps() const;

  const std::unordered_set<OpHandleBase *> &PendingOps(OpHandleBase *op) const;

  bool HasOp(OpHandleBase *op) const;

 private:
  void Build(const std::vector<OpHandleBase *> &ops);
  void EnforceHasOp(OpHandleBase *op) const;

  std::unordered_map<OpHandleBase *, std::unordered_set<OpHandleBase *>>
      preceding_ops_;
  std::unordered_map<OpHandleBase *, std::unordered_set<OpHandleBase *>>
      pending_ops_;
};

}  // namespace details
}  // namespace framework
}  // namespace paddle
