perf(java): bind ipc debug log to config, use sonic for protocol json

The Java IPC protocol unconditionally enabled debug logging on the
reader and writer, causing each of the ~2.5k messages per parse to
trigger a full JSON dump to stderr. Bind SetDebug to the existing
JavaParserServer config so debug output is off by default.

Switch the protocol layer to sonic for the four Unmarshal sites and
one Marshal site. encoding/json was the dominant cost on the Go side
(38% of CPU, 2s of unmarshal time on a 2k-class repo); sonic cuts the
ReadMessage path by ~75%.

Combined effect on travel-business (2153 java files):
  wall   61.0s -> 53.4s  (-12.5%)
  user   6:37  -> 5:30
  Go CPU 8.48% -> 5.83%

Author: wzekin

lang/java/ipc/protocol.go

@@ -23,6 +23,7 @@ import (
 	"io"
 	"log"
 
+	"github.com/bytedance/sonic"
 	"github.com/cloudwego/abcoder/lang/java/pb"
 )
 
@@ -133,7 +134,7 @@ func (pr *ProtocolReader) ReadMessage() (*pb.Message, error) {
 		Payload   json.RawMessage `json:"payload,omitempty"`
 	}
 	var raw rawMessage
-	if err := json.Unmarshal(pr.buf, &raw); err != nil {
+	if err := sonic.Unmarshal(pr.buf, &raw); err != nil {
 		if pr.debug {
 			log.Printf("[Protocol] <<< Failed to unmarshal: %v", err)
 		}
@@ -156,7 +157,7 @@ func (pr *ProtocolReader) ReadMessage() (*pb.Message, error) {
 			Payload     json.RawMessage `json:"payload"`
 		}
 		var arRaw rawAnalyzeResponse
-		if err := json.Unmarshal(raw.Payload, &arRaw); err != nil {
+		if err := sonic.Unmarshal(raw.Payload, &arRaw); err != nil {
 			return nil, fmt.Errorf("failed to unmarshal analyze_response payload: %w", err)
 		}
 
@@ -183,7 +184,7 @@ func (pr *ProtocolReader) ReadMessage() (*pb.Message, error) {
 		if rm, ok := payload.(json.RawMessage); ok {
 			ar.Payload = rm
 		} else {
-			if err := json.Unmarshal(arRaw.Payload, payload); err != nil {
+			if err := sonic.Unmarshal(arRaw.Payload, payload); err != nil {
 				return nil, fmt.Errorf("failed to unmarshal analyze_response inner payload (%s): %w", arRaw.PayloadType, err)
 			}
 			ar.Payload = payload
@@ -192,21 +193,21 @@ func (pr *ProtocolReader) ReadMessage() (*pb.Message, error) {
 
 	case pb.TYPE_ANALYZE_REQUEST:
 		var req pb.AnalyzeRequest
-		if err := json.Unmarshal(raw.Payload, &req); err != nil {
+		if err := sonic.Unmarshal(raw.Payload, &req); err != nil {
 			return nil, fmt.Errorf("failed to unmarshal analyze_request payload: %w", err)
 		}
 		msg.Payload = &req
 
 	case pb.TYPE_STOP_REQUEST:
 		var stop pb.StopRequest
-		if err := json.Unmarshal(raw.Payload, &stop); err != nil {
+		if err := sonic.Unmarshal(raw.Payload, &stop); err != nil {
 			return nil, fmt.Errorf("failed to unmarshal stop_request payload: %w", err)
 		}
 		msg.Payload = &stop
 
 	case pb.TYPE_HEARTBEAT:
 		var hb pb.Heartbeat
-		if err := json.Unmarshal(raw.Payload, &hb); err != nil {
+		if err := sonic.Unmarshal(raw.Payload, &hb); err != nil {
 			return nil, fmt.Errorf("failed to unmarshal heartbeat payload: %w", err)
 		}
 		msg.Payload = &hb
@@ -247,7 +248,7 @@ func (pw *ProtocolWriter) SetDebug(enabled bool) {
 
 // WriteMessage writes a length-prefixed JSON Message.
 func (pw *ProtocolWriter) WriteMessage(msg *pb.Message) error {
-	data, err := json.Marshal(msg)
+	data, err := sonic.Marshal(msg)
 	if err != nil {
 		return fmt.Errorf("failed to marshal JSON message: %w", err)
 	}

lang/java/ipc/server.go

@@ -245,7 +245,7 @@ func (s *JavaParserServer) sendAnalyzeRequest(repoPath string, config *pb.Analyz
 	}
 
 	writer := NewProtocolWriter(s.conn)
-	writer.SetDebug(true) // Enable debug logging for sent messages
+	writer.SetDebug(s.config.Debug)
 	if err := writer.WriteRequest(request); err != nil {
 		return fmt.Errorf("failed to write analyze request: %w", err)
 	}
@@ -261,7 +261,7 @@ func (s *JavaParserServer) readResponses(ctx context.Context, responseChan chan<
 	defer s.cleanup()
 
 	reader := NewProtocolReader(s.conn)
-	reader.SetDebug(true) // Enable debug logging for received messages
+	reader.SetDebug(s.config.Debug)
 
 	for {
 		select {