github.com/matrixorigin/matrixone@v1.2.0/pkg/sql/parsers/tree/select_lock.go (about)

     1  // Copyright 2023 Matrix Origin
     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 tree
    16  
    17  // SelectLockType is the lock type for SelectStmt.
    18  type SelectLockType int
    19  
    20  // Select lock types.
    21  const (
    22  	SelectLockNone SelectLockType = iota
    23  	SelectLockForUpdate
    24  	SelectLockForShare
    25  	SelectLockForUpdateNoWait
    26  	SelectLockForUpdateWaitN
    27  	SelectLockForShareNoWait
    28  	SelectLockForUpdateSkipLocked
    29  	SelectLockForShareSkipLocked
    30  )
    31  
    32  // String implements fmt.Stringer.
    33  func (n SelectLockType) String() string {
    34  	switch n {
    35  	case SelectLockNone:
    36  		return "none"
    37  	case SelectLockForUpdate:
    38  		return "for update"
    39  	case SelectLockForShare:
    40  		return "for share"
    41  	case SelectLockForUpdateNoWait:
    42  		return "for update nowait"
    43  	case SelectLockForUpdateWaitN:
    44  		return "for update wait"
    45  	case SelectLockForShareNoWait:
    46  		return "for share nowait"
    47  	case SelectLockForUpdateSkipLocked:
    48  		return "for update skip locked"
    49  	case SelectLockForShareSkipLocked:
    50  		return "for share skip locked"
    51  	}
    52  	return "unsupported select lock type"
    53  }
    54  
    55  type SelectLockInfo struct {
    56  	LockType SelectLockType
    57  	WaitSec  uint64
    58  	Tables   []*TableName
    59  }
    60  
    61  func (node *SelectLockInfo) Format(ctx *FmtCtx) {
    62  	ctx.WriteString(node.LockType.String())
    63  }