codec(ticdc): kafka simple encoding protocol support encoding checkpoint event.

pkg/config/sink_protocol.go

@@ -38,6 +38,7 @@ const (
 	ProtocolCraft
 	ProtocolOpen
 	ProtocolCsv
+	ProtocolSimple
 )
 
 // IsBatchEncode returns whether the protocol is a batch encoder.
@@ -66,6 +67,8 @@ func ParseSinkProtocolFromString(protocol string) (Protocol, error) {
 		return ProtocolOpen, nil
 	case "csv":
 		return ProtocolCsv, nil
+	case "simple":
+		return ProtocolSimple, nil
 	default:
 		return ProtocolUnknown, cerror.ErrSinkUnknownProtocol.GenWithStackByArgs(protocol)
 	}
@@ -90,6 +93,8 @@ func (p Protocol) String() string {
 		return "open-protocol"
 	case ProtocolCsv:
 		return "csv"
+	case ProtocolSimple:
+		return "simple"
 	default:
 		panic("unreachable")
 	}

pkg/sink/codec/simple/decoder.go

@@ -1,4 +1,4 @@
-// Copyright 2022 PingCAP, Inc.
+// Copyright 2023 PingCAP, Inc.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -14,33 +14,66 @@
 package simple
 
 import (
+	"encoding/json"
+
 	"github.com/pingcap/tiflow/cdc/model"
+	cerror "github.com/pingcap/tiflow/pkg/errors"
 )
 
-type decoder struct{}
+type decoder struct {
+	value []byte
+
+	msg *message
+}
 
 // NewDecoder returns a new decoder
 func NewDecoder() *decoder {
-	// TODO implement me
-	panic("implement me")
+	return &decoder{}
 }
 
 // AddKeyValue add the received key and values to the decoder,
-func (d *decoder) AddKeyValue(key, value []byte) error {
-	// TODO implement me
-	panic("implement me")
+func (d *decoder) AddKeyValue(_, value []byte) error {
+	if d.value != nil {
+		return cerror.ErrDecodeFailed.GenWithStack(
+			"decoder value already exists, not consumed yet")
+	}
+	d.value = value
+	return nil
 }
 
 // HasNext returns whether there is any event need to be consumed
 func (d *decoder) HasNext() (model.MessageType, bool, error) {
-	// TODO implement me
-	panic("implement me")
+	if d.value == nil {
+		return model.MessageTypeUnknown, false, nil
+	}
+
+	var m message
+	if err := json.Unmarshal(d.value, &m); err != nil {
+		return model.MessageTypeUnknown, false, cerror.WrapError(cerror.ErrDecodeFailed, err)
+	}
+	d.msg = &m
+	d.value = nil
+
+	if d.msg.Type == WatermarkType {
+		return model.MessageTypeResolved, true, nil
+	}
+	if d.msg.Data != nil || d.msg.Old != nil {
+		return model.MessageTypeRow, true, nil
+	}
+	return model.MessageTypeDDL, true, nil
 }
 
 // NextResolvedEvent returns the next resolved event if exists
 func (d *decoder) NextResolvedEvent() (uint64, error) {
-	// TODO implement me
-	panic("implement me")
+	if d.msg.Type != WatermarkType {
+		return 0, cerror.ErrCodecDecode.GenWithStack(
+			"not found resolved event message")
+	}
+
+	ts := d.msg.CommitTs
+	d.msg = nil
+
+	return ts, nil
 }
 
 // NextRowChangedEvent returns the next row changed event if exists

pkg/sink/codec/simple/encoder.go

@@ -15,8 +15,12 @@ package simple
 
 import (
 	"context"
+	"encoding/json"
 
 	"github.com/pingcap/tiflow/cdc/model"
+	"github.com/pingcap/tiflow/pkg/config"
+	cerror "github.com/pingcap/tiflow/pkg/errors"
+	"github.com/pingcap/tiflow/pkg/sink/codec"
 	"github.com/pingcap/tiflow/pkg/sink/codec/common"
 )
 
@@ -27,8 +31,12 @@ type builder struct{}
 
 // NewBuilder returns a new builder
 func NewBuilder() *builder {
-	// TODO implement me
-	panic("implement me")
+	return &builder{}
+}
+
+// Build implement the RowEventEncoderBuilder interface
+func (b *builder) Build() codec.RowEventEncoder {
+	return &encoder{}
 }
 
 // AppendRowChangedEvent implement the RowEventEncoder interface
@@ -53,8 +61,12 @@ func (e *encoder) Build() []*common.Message {
 //
 //nolint:unused
 func (e *encoder) EncodeCheckpointEvent(ts uint64) (*common.Message, error) {
-	// TODO implement me
-	panic("implement me")
+	message := newResolvedMessage(ts)
+	value, err := json.Marshal(message)
+	if err != nil {
+		return nil, cerror.WrapError(cerror.ErrEncodeFailed, err)
+	}
+	return common.NewResolvedMsg(config.ProtocolSimple, nil, value, ts), nil
 }
 
 // EncodeDDLEvent implement the DDLEventBatchEncoder interface

pkg/sink/codec/simple/encoder_test.go

@@ -0,0 +1,44 @@
+// Copyright 2023 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package simple
+
+import (
+	"testing"
+
+	"github.com/pingcap/tiflow/cdc/model"
+	"github.com/stretchr/testify/require"
+)
+
+func TestEncodeCheckpoint(t *testing.T) {
+	t.Parallel()
+
+	enc := NewBuilder().Build()
+
+	checkpoint := 23
+	m, err := enc.EncodeCheckpointEvent(uint64(checkpoint))
+	require.NoError(t, err)
+
+	dec := NewDecoder()
+	err = dec.AddKeyValue(m.Key, m.Value)
+	require.NoError(t, err)
+
+	messageType, hasNext, err := dec.HasNext()
+	require.NoError(t, err)
+	require.True(t, hasNext)
+	require.Equal(t, model.MessageTypeResolved, messageType)
+
+	ts, err := dec.NextResolvedEvent()
+	require.NoError(t, err)
+	require.Equal(t, uint64(checkpoint), ts)
+}

pkg/sink/codec/simple/message.go

@@ -0,0 +1,46 @@
+// Copyright 2023 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package simple
+
+const (
+	defaultVersion = 0
+)
+
+// EventType describes the type of the event.
+type EventType string
+
+const (
+	// WatermarkType is the type of the watermark event.
+	WatermarkType EventType = "WATERMARK"
+)
+
+type message struct {
+	Version int `json:"version"`
+	// Scheme and Table is empty for the resolved ts event.
+	Schema   string    `json:"schema,omitempty"`
+	Table    string    `json:"table,omitempty"`
+	Type     EventType `json:"type"`
+	CommitTs uint64    `json:"commitTs"`
+	// Data is available for the row changed event.
+	Data map[string]interface{} `json:"data,omitempty"`
+	Old  map[string]interface{} `json:"old,omitempty"`
+}
+
+func newResolvedMessage(ts uint64) *message {
+	return &message{
+		Version:  defaultVersion,
+		Type:     WatermarkType,
+		CommitTs: ts,
+	}
+}