github.com/KinWaiYuen/client-go/v2@v2.5.4/tikv/unionstore_export.go (about)

     1  // Copyright 2021 TiKV Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // NOTE: The code in this file is based on code from the
    16  // TiDB project, licensed under the Apache License v 2.0
    17  //
    18  // https://github.com/pingcap/tidb/tree/cc5e161ac06827589c4966674597c137cc9e809c/store/tikv/txn.go
    19  //
    20  
    21  // Copyright 2016 PingCAP, Inc.
    22  //
    23  // Licensed under the Apache License, Version 2.0 (the "License");
    24  // you may not use this file except in compliance with the License.
    25  // You may obtain a copy of the License at
    26  //
    27  //     http://www.apache.org/licenses/LICENSE-2.0
    28  //
    29  // Unless required by applicable law or agreed to in writing, software
    30  // distributed under the License is distributed on an "AS IS" BASIS,
    31  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    32  // See the License for the specific language governing permissions and
    33  // limitations under the License.
    34  
    35  package tikv
    36  
    37  import "github.com/KinWaiYuen/client-go/v2/internal/unionstore"
    38  
    39  // Getter is the interface for the Get method.
    40  type Getter = unionstore.Getter
    41  
    42  // Iterator is the interface for a iterator on KV store.
    43  type Iterator = unionstore.Iterator
    44  
    45  // MemDB is rollbackable Red-Black Tree optimized for transaction states buffer use scenario.
    46  // You can think MemDB is a combination of two separate tree map, one for key => value and another for key => keyFlags.
    47  //
    48  // The value map is rollbackable, that means you can use the `Staging`, `Release` and `Cleanup` API to safely modify KVs.
    49  //
    50  // The flags map is not rollbackable. There are two types of flag, persistent and non-persistent.
    51  // When discarding a newly added KV in `Cleanup`, the non-persistent flags will be cleared.
    52  // If there are persistent flags associated with key, we will keep this key in node without value.
    53  type MemDB = unionstore.MemDB