github.com/vescale/zgraph@v0.0.0-20230410094002-959c02d50f95/storage/mvcc/constants.go (about)

     1  // Copyright 2022 zGraph Authors. All rights reserved.
     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  package mvcc
    16  
    17  import "math"
    18  
    19  // Key layout:
    20  // ...
    21  // Key_lock        -- (0)
    22  // Key_verMax      -- (1)
    23  // ...
    24  // Key_ver+1       -- (2)
    25  // Key_ver         -- (3)
    26  // Key_ver-1       -- (4)
    27  // ...
    28  // Key_0           -- (5)
    29  // NextKey_lock    -- (6)
    30  // NextKey_verMax  -- (7)
    31  // ...
    32  // NextKey_ver+1   -- (8)
    33  // NextKey_ver     -- (9)
    34  // NextKey_ver-1   -- (10)
    35  // ...
    36  // NextKey_0       -- (11)
    37  // ...
    38  // EOF
    39  
    40  const LockVer = math.MaxUint64