github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/cdc/model/codec/v1/convert.go (about)

     1  // Copyright 2021 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 v1
    15  
    16  import (
    17  	"bytes"
    18  
    19  	timodel "github.com/pingcap/tidb/pkg/parser/model"
    20  	"github.com/pingcap/tiflow/cdc/model"
    21  )
    22  
    23  // PreMarshal should be called before marshal a RedoLog.
    24  func PreMarshal(r *RedoLog) {
    25  	if r.RedoRow != nil && r.RedoRow.Row != nil {
    26  		adjustRowPreMarshal(r.RedoRow)
    27  	}
    28  	if r.RedoDDL != nil && r.RedoDDL.DDL != nil {
    29  		adjustDDLPreMarshal(r.RedoDDL)
    30  	}
    31  }
    32  
    33  func adjustRowPreMarshal(redoLog *RedoRowChangedEvent) {
    34  	row := redoLog.Row
    35  	for _, column := range row.Columns {
    36  		var redoColumn *RedoColumn
    37  		if column != nil {
    38  			// workaround msgp issue(Decode replaces empty slices with nil https://github.com/tinylib/msgp/issues/247)
    39  			// if []byte("") send with RowChangedEvent after UnmarshalMsg,
    40  			// the value will become nil, which is unexpected.
    41  			switch v := column.Value.(type) {
    42  			case []byte:
    43  				if bytes.Equal(v, []byte("")) {
    44  					column.Value = ""
    45  				}
    46  			}
    47  			redoColumn = &RedoColumn{Column: column, Flag: uint64(column.Flag)}
    48  		}
    49  		redoLog.Columns = append(redoLog.Columns, redoColumn)
    50  	}
    51  	for _, column := range row.PreColumns {
    52  		var redoColumn *RedoColumn
    53  		if column != nil {
    54  			switch v := column.Value.(type) {
    55  			case []byte:
    56  				if bytes.Equal(v, []byte("")) {
    57  					column.Value = ""
    58  				}
    59  			}
    60  			redoColumn = &RedoColumn{Column: column, Flag: uint64(column.Flag)}
    61  		}
    62  		redoLog.PreColumns = append(redoLog.PreColumns, redoColumn)
    63  	}
    64  }
    65  
    66  func adjustDDLPreMarshal(redoDDL *RedoDDLEvent) {
    67  	redoDDL.Type = byte(redoDDL.DDL.Type)
    68  }
    69  
    70  // PostUnmarshal should be called after unmarshal a RedoLog.
    71  func PostUnmarshal(r *RedoLog) {
    72  	if r.RedoRow != nil && r.RedoRow.Row != nil {
    73  		adjustRowPostUnmarshal(r.RedoRow)
    74  	}
    75  	if r.RedoDDL != nil && r.RedoDDL.DDL != nil {
    76  		adjustDDLPostUnmarshal(r.RedoDDL)
    77  	}
    78  }
    79  
    80  func adjustRowPostUnmarshal(redoLog *RedoRowChangedEvent) {
    81  	row := redoLog.Row
    82  	row.Columns = make([]*Column, 0, len(redoLog.Columns))
    83  	row.PreColumns = make([]*Column, 0, len(redoLog.PreColumns))
    84  	for _, column := range redoLog.PreColumns {
    85  		if column == nil {
    86  			row.PreColumns = append(row.PreColumns, nil)
    87  			continue
    88  		}
    89  		column.Column.Flag = model.ColumnFlagType(column.Flag)
    90  		row.PreColumns = append(row.PreColumns, column.Column)
    91  	}
    92  	for _, column := range redoLog.Columns {
    93  		if column == nil {
    94  			row.Columns = append(row.Columns, nil)
    95  			continue
    96  		}
    97  		column.Column.Flag = model.ColumnFlagType(column.Flag)
    98  		row.Columns = append(row.Columns, column.Column)
    99  	}
   100  }
   101  
   102  func adjustDDLPostUnmarshal(redoDDL *RedoDDLEvent) {
   103  	redoDDL.DDL.Type = timodel.ActionType(redoDDL.Type)
   104  }