refactor(memory): 提取 JSON 工具函数到共享模块

将 thread_summary.py 中的 _strip_code_fence、_extract_json_object、
_escape_inner_quotes_in_json_strings 三个函数提取到新建的
json_utils.py 共享模块，thread_updater.py 同步使用统一接口。

backend/packages/harness/deerflow/agents/memory/json_utils.py

@@ -0,0 +1,95 @@
+"""JSON extraction helpers for LLM-generated memory payloads."""
+
+from __future__ import annotations
+
+import json
+import re
+from typing import Any
+
+
+def strip_code_fence(text: str) -> str:
+    cleaned = text.strip()
+    if not cleaned.startswith("```"):
+        return cleaned
+    lines = cleaned.split("\n")
+    return "\n".join(lines[1:-1] if lines[-1].strip() == "```" else lines[1:]).strip()
+
+
+def escape_inner_quotes_in_json_strings(text: str) -> str:
+    """Heuristically repair unescaped inner double quotes inside JSON strings."""
+    out: list[str] = []
+    in_string = False
+    escape = False
+    n = len(text)
+    i = 0
+    while i < n:
+        ch = text[i]
+        if not in_string:
+            out.append(ch)
+            if ch == '"':
+                in_string = True
+            i += 1
+            continue
+
+        if escape:
+            out.append(ch)
+            escape = False
+            i += 1
+            continue
+
+        if ch == "\\":
+            out.append(ch)
+            escape = True
+            i += 1
+            continue
+
+        if ch == '"':
+            j = i + 1
+            while j < n and text[j].isspace():
+                j += 1
+            next_char = text[j] if j < n else ""
+            if next_char in {":", ",", "}", "]", ""}:
+                out.append(ch)
+                in_string = False
+            else:
+                out.append('\\"')
+            i += 1
+            continue
+
+        out.append(ch)
+        i += 1
+
+    return "".join(out)
+
+
+def extract_json_object(text: str) -> dict[str, Any] | None:
+    cleaned = strip_code_fence(text)
+    try:
+        parsed = json.loads(cleaned)
+        return parsed if isinstance(parsed, dict) else None
+    except json.JSONDecodeError:
+        repaired = escape_inner_quotes_in_json_strings(cleaned)
+        if repaired != cleaned:
+            try:
+                parsed = json.loads(repaired)
+                return parsed if isinstance(parsed, dict) else None
+            except json.JSONDecodeError:
+                pass
+
+    match = re.search(r"\{.*\}", cleaned, flags=re.DOTALL)
+    if not match:
+        return None
+
+    candidate = match.group(0)
+    try:
+        parsed = json.loads(candidate)
+        return parsed if isinstance(parsed, dict) else None
+    except json.JSONDecodeError:
+        repaired = escape_inner_quotes_in_json_strings(candidate)
+        if repaired != candidate:
+            try:
+                parsed = json.loads(repaired)
+                return parsed if isinstance(parsed, dict) else None
+            except json.JSONDecodeError:
+                return None
+        return None

backend/packages/harness/deerflow/agents/memory/thread_summary.py

@@ -4,10 +4,14 @@ from __future__ import annotations
 
 import json
 import logging
-import re
 import hashlib
 from typing import Any
 
+from deerflow.agents.memory.json_utils import (
+    escape_inner_quotes_in_json_strings as _escape_inner_quotes_in_json_strings,
+)
+from deerflow.agents.memory.json_utils import extract_json_object as _extract_json_object
+from deerflow.agents.memory.json_utils import strip_code_fence as _strip_code_fence
 from deerflow.agents.memory.thread_prompt import create_empty_thread_memory
 from deerflow.agents.memory.thread_storage import get_thread_memory_storage
 from deerflow.agents.memory.thread_updater import ThreadMemoryUpdater
@@ -74,106 +78,6 @@ def _get_summary_model():
     config = get_thread_memory_config()
     return create_chat_model(name=config.model_name, thinking_enabled=False, stream_usage=False)
 
-
-def _strip_code_fence(text: str) -> str:
-    cleaned = text.strip()
-    if not cleaned.startswith("```"):
-        return cleaned
-    lines = cleaned.split("\n")
-    return "\n".join(lines[1:-1] if lines[-1].strip() == "```" else lines[1:]).strip()
-
-
-def _extract_json_object(text: str) -> dict[str, Any] | None:
-    cleaned = _strip_code_fence(text)
-    try:
-        parsed = json.loads(cleaned)
-        return parsed if isinstance(parsed, dict) else None
-    except json.JSONDecodeError:
-        repaired = _escape_inner_quotes_in_json_strings(cleaned)
-        if repaired != cleaned:
-            try:
-                parsed = json.loads(repaired)
-                if isinstance(parsed, dict):
-                    logger.warning("THREAD_SUMMARY_DEBUG parse_repaired mode=full_text")
-                    return parsed
-            except json.JSONDecodeError:
-                pass
-
-    match = re.search(r"\{.*\}", cleaned, flags=re.DOTALL)
-    if not match:
-        return None
-    try:
-        parsed = json.loads(match.group(0))
-        return parsed if isinstance(parsed, dict) else None
-    except json.JSONDecodeError:
-        candidate = match.group(0)
-        repaired = _escape_inner_quotes_in_json_strings(candidate)
-        if repaired != candidate:
-            try:
-                parsed = json.loads(repaired)
-                if isinstance(parsed, dict):
-                    logger.warning("THREAD_SUMMARY_DEBUG parse_repaired mode=regex_object")
-                    return parsed
-            except json.JSONDecodeError:
-                return None
-        return None
-
-
-def _escape_inner_quotes_in_json_strings(text: str) -> str:
-    """Heuristically repair unescaped inner double quotes inside JSON strings.
-
-    If a quote appears while inside a string but the next non-space character is
-    not a valid string terminator (comma, object/array close, or key colon), it is
-    treated as content and escaped.
-    """
-    out: list[str] = []
-    in_string = False
-    escape = False
-    n = len(text)
-    i = 0
-    while i < n:
-        ch = text[i]
-        if not in_string:
-            out.append(ch)
-            if ch == '"':
-                in_string = True
-            i += 1
-            continue
-
-        if escape:
-            out.append(ch)
-            escape = False
-            i += 1
-            continue
-
-        if ch == "\\":
-            out.append(ch)
-            escape = True
-            i += 1
-            continue
-
-        if ch == '"':
-            j = i + 1
-            while j < n and text[j].isspace():
-                j += 1
-            next_char = text[j] if j < n else ""
-            # Valid JSON string terminators in context:
-            # - key string: :
-            # - value string: , } ]
-            if next_char in {":", ",", "}", "]", ""}:
-                out.append(ch)
-                in_string = False
-            else:
-                out.append('\\"')
-            i += 1
-            continue
-
-        out.append(ch)
-        i += 1
-
-    return "".join(out)
-
-
 def _merge_summary_patch(base: dict[str, Any], patch: dict[str, Any]) -> dict[str, Any]:
     merged = {"ownerId": base.get("ownerId"), **create_empty_thread_memory()}
     merged["user"] = dict(base.get("user", {})) if isinstance(base.get("user"), dict) else merged["user"]

backend/packages/harness/deerflow/agents/memory/thread_updater.py

@@ -9,6 +9,7 @@ import uuid
 from datetime import UTC, datetime
 from typing import Any
 
+from deerflow.agents.memory.json_utils import extract_json_object
 from deerflow.agents.memory.updater import _extract_text
 from deerflow.agents.memory.thread_prompt import build_thread_memory_prompt, create_empty_thread_memory
 from deerflow.agents.memory.thread_storage import get_thread_memory_storage
@@ -128,10 +129,9 @@ class ThreadMemoryUpdater:
         try:
             response = self._get_model().invoke(prompt)
             response_text = _extract_text(response.content).strip()
-            if response_text.startswith("```"):
+            parsed = extract_json_object(response_text)
-                lines = response_text.split("\n")
+            if not isinstance(parsed, dict):
-                response_text = "\n".join(lines[1:-1] if lines[-1] == "```" else lines[1:])
+                raise json.JSONDecodeError("No valid JSON object found", response_text, 0)
-            parsed = json.loads(response_text)
             cleaned = self._scrub_sensitive(parsed, thread_id)
 
             expected_version = 0 if current is None else int(current.get("memoryVersion", 0))