fix(parser): 修复 bufio.Scanner token too long 错误 (#64)

## 问题
- 执行 rg 等命令时，如果匹配到 minified 文件，单行输出可能超过 10MB
- 旧实现使用 bufio.Scanner，遇到超长行会报错并中止整个解析
- 导致后续的 agent_message 无法读取，任务失败

## 修复
1. **parser.go**:
   - 移除 bufio.Scanner，改用 bufio.Reader + readLineWithLimit
   - 超长行（>10MB）会被跳过但继续处理后续事件
   - 添加 codexHeader 轻量级解析，只在 agent_message 时完整解析

2. **utils.go**:
   - 修复 logWriter 内存膨胀问题
   - 添加 writeLimited 方法限制缓冲区大小

3. **测试**:
   - parser_token_too_long_test.go: 验证超长行处理
   - log_writer_limit_test.go: 验证日志缓冲限制

## 测试结果
- ✅ TestParseJSONStream_SkipsOverlongLineAndContinues
- ✅ TestLogWriterWriteLimitsBuffer
- ✅ 完整测试套件通过

Fixes #64

Generated with swe-agent-bot

Co-Authored-By: swe-agent-bot <agent@swe-agent.ai>

codeagent-wrapper/log_writer_limit_test.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"os"
+	"strings"
+	"testing"
+)
+
+func TestLogWriterWriteLimitsBuffer(t *testing.T) {
+	defer resetTestHooks()
+
+	logger, err := NewLogger()
+	if err != nil {
+		t.Fatalf("NewLogger error: %v", err)
+	}
+	setLogger(logger)
+	defer closeLogger()
+
+	lw := newLogWriter("P:", 10)
+	_, _ = lw.Write([]byte(strings.Repeat("a", 100)))
+
+	if lw.buf.Len() != 10 {
+		t.Fatalf("logWriter buffer len=%d, want %d", lw.buf.Len(), 10)
+	}
+	if !lw.dropped {
+		t.Fatalf("expected logWriter to drop overlong line bytes")
+	}
+
+	lw.Flush()
+	logger.Flush()
+	data, err := os.ReadFile(logger.Path())
+	if err != nil {
+		t.Fatalf("ReadFile error: %v", err)
+	}
+	if !strings.Contains(string(data), "P:aaaaaaa...") {
+		t.Fatalf("log output missing truncated entry, got %q", string(data))
+	}
+}
+

codeagent-wrapper/parser.go

@@ -53,9 +53,22 @@ func parseJSONStreamWithLog(r io.Reader, warnFn func(string), infoFn func(string
 	return parseJSONStreamInternal(r, warnFn, infoFn, nil)
 }
 
+const (
+	jsonLineReaderSize   = 64 * 1024
+	jsonLineMaxBytes     = 10 * 1024 * 1024
+	jsonLinePreviewBytes = 256
+)
+
+type codexHeader struct {
+	Type     string `json:"type"`
+	ThreadID string `json:"thread_id,omitempty"`
+	Item     *struct {
+		Type string `json:"type"`
+	} `json:"item,omitempty"`
+}
+
 func parseJSONStreamInternal(r io.Reader, warnFn func(string), infoFn func(string), onMessage func()) (message, threadID string) {
-	scanner := bufio.NewScanner(r)
+	reader := bufio.NewReaderSize(r, jsonLineReaderSize)
-	scanner.Buffer(make([]byte, 64*1024), 10*1024*1024)
 
 	if warnFn == nil {
 		warnFn = func(string) {}
@@ -78,79 +91,89 @@ func parseJSONStreamInternal(r io.Reader, warnFn func(string), infoFn func(strin
 		geminiBuffer  strings.Builder
 	)
 
-	for scanner.Scan() {
+	for {
-		line := strings.TrimSpace(scanner.Text())
+		line, tooLong, err := readLineWithLimit(reader, jsonLineMaxBytes, jsonLinePreviewBytes)
-		if line == "" {
+		if err != nil {
+			if errors.Is(err, io.EOF) {
+				break
+			}
+			warnFn("Read stdout error: " + err.Error())
+			break
+		}
+
+		line = bytes.TrimSpace(line)
+		if len(line) == 0 {
 			continue
 		}
 		totalEvents++
 
-		var raw map[string]json.RawMessage
+		if tooLong {
-		if err := json.Unmarshal([]byte(line), &raw); err != nil {
+			warnFn(fmt.Sprintf("Skipped overlong JSON line (> %d bytes): %s", jsonLineMaxBytes, truncateBytes(line, 100)))
-			warnFn(fmt.Sprintf("Failed to parse line: %s", truncate(line, 100)))
 			continue
 		}
 
-		hasItemType := false
+		var codex codexHeader
-		if rawItem, ok := raw["item"]; ok {
+		if err := json.Unmarshal(line, &codex); err == nil {
-			var itemMap map[string]json.RawMessage
+			isCodex := codex.ThreadID != "" || (codex.Item != nil && codex.Item.Type != "")
-			if err := json.Unmarshal(rawItem, &itemMap); err == nil {
+			if isCodex {
-				if _, ok := itemMap["type"]; ok {
+				var details []string
-					hasItemType = true
+				if codex.ThreadID != "" {
+					details = append(details, fmt.Sprintf("thread_id=%s", codex.ThreadID))
 				}
+				if codex.Item != nil && codex.Item.Type != "" {
+					details = append(details, fmt.Sprintf("item_type=%s", codex.Item.Type))
+				}
+				if len(details) > 0 {
+					infoFn(fmt.Sprintf("Parsed event #%d type=%s (%s)", totalEvents, codex.Type, strings.Join(details, ", ")))
+				} else {
+					infoFn(fmt.Sprintf("Parsed event #%d type=%s", totalEvents, codex.Type))
+				}
+
+				switch codex.Type {
+				case "thread.started":
+					threadID = codex.ThreadID
+					infoFn(fmt.Sprintf("thread.started event thread_id=%s", threadID))
+				case "item.completed":
+					itemType := ""
+					if codex.Item != nil {
+						itemType = codex.Item.Type
+					}
+
+					if itemType == "agent_message" {
+						var event JSONEvent
+						if err := json.Unmarshal(line, &event); err != nil {
+							warnFn(fmt.Sprintf("Failed to parse Codex event: %s", truncateBytes(line, 100)))
+							continue
+						}
+
+						normalized := ""
+						if event.Item != nil {
+							normalized = normalizeText(event.Item.Text)
+						}
+						infoFn(fmt.Sprintf("item.completed event item_type=%s message_len=%d", itemType, len(normalized)))
+						if normalized != "" {
+							codexMessage = normalized
+							notifyMessage()
+						}
+					} else {
+						infoFn(fmt.Sprintf("item.completed event item_type=%s", itemType))
+					}
+				}
+				continue
 			}
 		}
 
-		isCodex := hasItemType
+		var raw map[string]json.RawMessage
-		if !isCodex {
+		if err := json.Unmarshal(line, &raw); err != nil {
-			if _, ok := raw["thread_id"]; ok {
+			warnFn(fmt.Sprintf("Failed to parse line: %s", truncateBytes(line, 100)))
-				isCodex = true
+			continue
-			}
 		}
 
 		switch {
-		case isCodex:
-			var event JSONEvent
-			if err := json.Unmarshal([]byte(line), &event); err != nil {
-				warnFn(fmt.Sprintf("Failed to parse Codex event: %s", truncate(line, 100)))
-				continue
-			}
-
-			var details []string
-			if event.ThreadID != "" {
-				details = append(details, fmt.Sprintf("thread_id=%s", event.ThreadID))
-			}
-			if event.Item != nil && event.Item.Type != "" {
-				details = append(details, fmt.Sprintf("item_type=%s", event.Item.Type))
-			}
-			if len(details) > 0 {
-				infoFn(fmt.Sprintf("Parsed event #%d type=%s (%s)", totalEvents, event.Type, strings.Join(details, ", ")))
-			} else {
-				infoFn(fmt.Sprintf("Parsed event #%d type=%s", totalEvents, event.Type))
-			}
-
-			switch event.Type {
-			case "thread.started":
-				threadID = event.ThreadID
-				infoFn(fmt.Sprintf("thread.started event thread_id=%s", threadID))
-			case "item.completed":
-				var itemType string
-				var normalized string
-				if event.Item != nil {
-					itemType = event.Item.Type
-					normalized = normalizeText(event.Item.Text)
-				}
-				infoFn(fmt.Sprintf("item.completed event item_type=%s message_len=%d", itemType, len(normalized)))
-				if event.Item != nil && event.Item.Type == "agent_message" && normalized != "" {
-					codexMessage = normalized
-					notifyMessage()
-				}
-			}
-
 		case hasKey(raw, "subtype") || hasKey(raw, "result"):
 			var event ClaudeEvent
-			if err := json.Unmarshal([]byte(line), &event); err != nil {
+			if err := json.Unmarshal(line, &event); err != nil {
-				warnFn(fmt.Sprintf("Failed to parse Claude event: %s", truncate(line, 100)))
+				warnFn(fmt.Sprintf("Failed to parse Claude event: %s", truncateBytes(line, 100)))
 				continue
 			}
 
@@ -167,8 +190,8 @@ func parseJSONStreamInternal(r io.Reader, warnFn func(string), infoFn func(strin
 
 		case hasKey(raw, "role") || hasKey(raw, "delta"):
 			var event GeminiEvent
-			if err := json.Unmarshal([]byte(line), &event); err != nil {
+			if err := json.Unmarshal(line, &event); err != nil {
-				warnFn(fmt.Sprintf("Failed to parse Gemini event: %s", truncate(line, 100)))
+				warnFn(fmt.Sprintf("Failed to parse Gemini event: %s", truncateBytes(line, 100)))
 				continue
 			}
 
@@ -184,14 +207,10 @@ func parseJSONStreamInternal(r io.Reader, warnFn func(string), infoFn func(strin
 			infoFn(fmt.Sprintf("Parsed Gemini event #%d type=%s role=%s delta=%t status=%s content_len=%d", totalEvents, event.Type, event.Role, event.Delta, event.Status, len(event.Content)))
 
 		default:
-			warnFn(fmt.Sprintf("Unknown event format: %s", truncate(line, 100)))
+			warnFn(fmt.Sprintf("Unknown event format: %s", truncateBytes(line, 100)))
 		}
 	}
 
-	if err := scanner.Err(); err != nil && !errors.Is(err, io.EOF) {
-		warnFn("Read stdout error: " + err.Error())
-	}
-
 	switch {
 	case geminiBuffer.Len() > 0:
 		message = geminiBuffer.String()
@@ -236,6 +255,79 @@ func discardInvalidJSON(decoder *json.Decoder, reader *bufio.Reader) (*bufio.Rea
 	return bufio.NewReader(io.MultiReader(bytes.NewReader(remaining), reader)), err
 }
 
+func readLineWithLimit(r *bufio.Reader, maxBytes int, previewBytes int) (line []byte, tooLong bool, err error) {
+	if r == nil {
+		return nil, false, errors.New("reader is nil")
+	}
+	if maxBytes <= 0 {
+		return nil, false, errors.New("maxBytes must be > 0")
+	}
+	if previewBytes < 0 {
+		previewBytes = 0
+	}
+
+	part, isPrefix, err := r.ReadLine()
+	if err != nil {
+		return nil, false, err
+	}
+
+	if !isPrefix {
+		if len(part) > maxBytes {
+			return part[:min(len(part), previewBytes)], true, nil
+		}
+		return part, false, nil
+	}
+
+	preview := make([]byte, 0, min(previewBytes, len(part)))
+	if previewBytes > 0 {
+		preview = append(preview, part[:min(previewBytes, len(part))]...)
+	}
+
+	buf := make([]byte, 0, min(maxBytes, len(part)*2))
+	total := 0
+	if len(part) > maxBytes {
+		tooLong = true
+	} else {
+		buf = append(buf, part...)
+		total = len(part)
+	}
+
+	for isPrefix {
+		part, isPrefix, err = r.ReadLine()
+		if err != nil {
+			return nil, tooLong, err
+		}
+
+		if previewBytes > 0 && len(preview) < previewBytes {
+			preview = append(preview, part[:min(previewBytes-len(preview), len(part))]...)
+		}
+
+		if !tooLong {
+			if total+len(part) > maxBytes {
+				tooLong = true
+				continue
+			}
+			buf = append(buf, part...)
+			total += len(part)
+		}
+	}
+
+	if tooLong {
+		return preview, true, nil
+	}
+	return buf, false, nil
+}
+
+func truncateBytes(b []byte, maxLen int) string {
+	if len(b) <= maxLen {
+		return string(b)
+	}
+	if maxLen < 0 {
+		return ""
+	}
+	return string(b[:maxLen]) + "..."
+}
+
 func normalizeText(text interface{}) string {
 	switch v := text.(type) {
 	case string:

codeagent-wrapper/parser_token_too_long_test.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestParseJSONStream_SkipsOverlongLineAndContinues(t *testing.T) {
+	// Exceed the 10MB bufio.Scanner limit in parseJSONStreamInternal.
+	tooLong := strings.Repeat("a", 11*1024*1024)
+
+	input := strings.Join([]string{
+		`{"type":"item.completed","item":{"type":"other_type","text":"` + tooLong + `"}}`,
+		`{"type":"thread.started","thread_id":"t-1"}`,
+		`{"type":"item.completed","item":{"type":"agent_message","text":"ok"}}`,
+	}, "\n")
+
+	var warns []string
+	warnFn := func(msg string) { warns = append(warns, msg) }
+
+	gotMessage, gotThreadID := parseJSONStreamInternal(strings.NewReader(input), warnFn, nil, nil)
+	if gotMessage != "ok" {
+		t.Fatalf("message=%q, want %q (warns=%v)", gotMessage, "ok", warns)
+	}
+	if gotThreadID != "t-1" {
+		t.Fatalf("threadID=%q, want %q (warns=%v)", gotThreadID, "t-1", warns)
+	}
+	if len(warns) == 0 || !strings.Contains(warns[0], "Skipped overlong JSON line") {
+		t.Fatalf("expected warning about overlong JSON line, got %v", warns)
+	}
+}

codeagent-wrapper/utils.go

@@ -78,6 +78,7 @@ type logWriter struct {
 	prefix string
 	maxLen int
 	buf    bytes.Buffer
+	dropped bool
 }
 
 func newLogWriter(prefix string, maxLen int) *logWriter {
@@ -94,12 +95,12 @@ func (lw *logWriter) Write(p []byte) (int, error) {
 	total := len(p)
 	for len(p) > 0 {
 		if idx := bytes.IndexByte(p, '\n'); idx >= 0 {
-			lw.buf.Write(p[:idx])
+			lw.writeLimited(p[:idx])
 			lw.logLine(true)
 			p = p[idx+1:]
 			continue
 		}
-		lw.buf.Write(p)
+		lw.writeLimited(p)
 		break
 	}
 	return total, nil
@@ -117,21 +118,53 @@ func (lw *logWriter) logLine(force bool) {
 		return
 	}
 	line := lw.buf.String()
+	dropped := lw.dropped
+	lw.dropped = false
 	lw.buf.Reset()
 	if line == "" && !force {
 		return
 	}
-	if lw.maxLen > 0 && len(line) > lw.maxLen {
+	if lw.maxLen > 0 {
-		cutoff := lw.maxLen
+		if dropped {
-		if cutoff > 3 {
+			if lw.maxLen > 3 {
-			line = line[:cutoff-3] + "..."
+				line = line[:min(len(line), lw.maxLen-3)] + "..."
-		} else {
+			} else {
-			line = line[:cutoff]
+				line = line[:min(len(line), lw.maxLen)]
+			}
+		} else if len(line) > lw.maxLen {
+			cutoff := lw.maxLen
+			if cutoff > 3 {
+				line = line[:cutoff-3] + "..."
+			} else {
+				line = line[:cutoff]
+			}
 		}
 	}
 	logInfo(lw.prefix + line)
 }
 
+func (lw *logWriter) writeLimited(p []byte) {
+	if lw == nil || len(p) == 0 {
+		return
+	}
+	if lw.maxLen <= 0 {
+		lw.buf.Write(p)
+		return
+	}
+
+	remaining := lw.maxLen - lw.buf.Len()
+	if remaining <= 0 {
+		lw.dropped = true
+		return
+	}
+	if len(p) <= remaining {
+		lw.buf.Write(p)
+		return
+	}
+	lw.buf.Write(p[:remaining])
+	lw.dropped = true
+}
+
 type tailBuffer struct {
 	limit int
 	data  []byte