YugabyteDB (2.13.0.0-b42, bfc6a6643e7399ac8a0e81d06a3ee6d6571b33ab)

// Copyright (c) YugaByte, Inc.

//

// 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 YB_DOCDB_TRANSACTION_STATUS_CACHE_H

#define YB_DOCDB_TRANSACTION_STATUS_CACHE_H

#include "yb/common/read_hybrid_time.h"

#include "yb/common/transaction.h"

namespace yb {

namespace docdb {

// Caches transaction statuses fetched by single IntentAwareIterator.

// Thread safety is not required, because IntentAwareIterator is used in a single thread only.

class TransactionStatusCache {

 public:

  TransactionStatusCache(const TransactionOperationContext& txn_context_opt,

                         const ReadHybridTime& read_time,

                         CoarseTimePoint deadline)

      : txn_context_opt_(txn_context_opt), read_time_(read_time), deadline_(deadline) {}

  // Returns transaction commit time if already committed by the specified time or HybridTime::kMin

  // otherwise.

  Result<CommitMetadata> GetCommitData(const TransactionId& transaction_id);

 private:

  struct GetCommitDataResult;

  boost::optional<CommitMetadata> GetLocalCommitData(const TransactionId& transaction_id);

  Result<GetCommitDataResult> DoGetCommitData(const TransactionId& transaction_id);

  const TransactionOperationContext& txn_context_opt_;

  ReadHybridTime read_time_;

  CoarseTimePoint deadline_;

  std::unordered_map<TransactionId, CommitMetadata, TransactionIdHash> cache_;

};

} // namespace docdb

} // namespace yb

#endif  // YB_DOCDB_TRANSACTION_STATUS_CACHE_H