github.com/pingcap/ticdc@v0.0.0-20220526033649-485a10ef2652/cdc/model/mounter.go (about)

     1  // Copyright 2020 PingCAP, Inc.
     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  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package model
    15  
    16  import (
    17  	"context"
    18  )
    19  
    20  // PolymorphicEvent describes a event can be in multiple states
    21  type PolymorphicEvent struct {
    22  	StartTs uint64
    23  	// Commit or resolved TS
    24  	CRTs uint64
    25  
    26  	RawKV     *RawKVEntry
    27  	Row       *RowChangedEvent
    28  	ReplicaID uint64
    29  	finished  chan struct{}
    30  }
    31  
    32  // NewPolymorphicEvent creates a new PolymorphicEvent with a raw KV
    33  func NewPolymorphicEvent(rawKV *RawKVEntry) *PolymorphicEvent {
    34  	if rawKV.OpType == OpTypeResolved {
    35  		return NewResolvedPolymorphicEvent(rawKV.RegionID, rawKV.CRTs)
    36  	}
    37  	return &PolymorphicEvent{
    38  		StartTs:  rawKV.StartTs,
    39  		CRTs:     rawKV.CRTs,
    40  		RawKV:    rawKV,
    41  		finished: nil,
    42  	}
    43  }
    44  
    45  // NewResolvedPolymorphicEvent creates a new PolymorphicEvent with the resolved ts
    46  func NewResolvedPolymorphicEvent(regionID uint64, resolvedTs uint64) *PolymorphicEvent {
    47  	return &PolymorphicEvent{
    48  		CRTs:     resolvedTs,
    49  		RawKV:    &RawKVEntry{CRTs: resolvedTs, OpType: OpTypeResolved, RegionID: regionID},
    50  		Row:      nil,
    51  		finished: nil,
    52  	}
    53  }
    54  
    55  // RegionID returns the region ID where the event comes from.
    56  func (e *PolymorphicEvent) RegionID() uint64 {
    57  	return e.RawKV.RegionID
    58  }
    59  
    60  // SetUpFinishedChan creates an internal channel to support PrepareFinished and WaitPrepare
    61  func (e *PolymorphicEvent) SetUpFinishedChan() {
    62  	if e.finished == nil {
    63  		e.finished = make(chan struct{})
    64  	}
    65  }
    66  
    67  // PrepareFinished marks the prepare process is finished
    68  // In prepare process, Mounter will translate raw KV to row data
    69  func (e *PolymorphicEvent) PrepareFinished() {
    70  	if e.finished != nil {
    71  		close(e.finished)
    72  	}
    73  }
    74  
    75  // WaitPrepare waits for prepare process finished
    76  func (e *PolymorphicEvent) WaitPrepare(ctx context.Context) error {
    77  	if e.finished != nil {
    78  		select {
    79  		case <-ctx.Done():
    80  			return ctx.Err()
    81  		case <-e.finished:
    82  		}
    83  	}
    84  	return nil
    85  }