JOJO
26f31a09ec
根因：state.jsonl 采用只追加日志，track_edit 的中间半成品快照与 make_snapshot 的完整快照各自成行；加载时每行都被回放为独立快照， _find_snapshot_pair 简单取下标-1 作为上一快照，导致 diff 基准落在 同一条消息自己的半成品行上——半成品中缺失的已跟踪文件被全部判为 added 并按全文件计新增（如 +1928 -0）。 彻底修复（非补丁）： - 持久化改为原子全量重写（temp + os.replace），结构性保证磁盘上 一条 message_id 永远只有一行 - _load_state 幂等重载并在加载时折叠历史重复行（保留每消息最后一行）， 旧脏数据无需迁移即可透明愈合 - track_edit / make_snapshot 在按 state 文件加锁的临界区内执行 重载->变更->保存，避免短生命周期实例间丢行 - _find_snapshot_pair 防御性跳过同 message_id 行 - 新增 6 个回归测试（test/test_shallow_versioning.py） 验证：新测试 6/6 通过；test_server_refactor_smoke 6/6 通过； 用 conv_20260721_175016_796 真实数据只读复算，seq8 由 +1295/-0 修正为 +796/-7（3 文件），seq10 由 +1928/-0 修正为 +592/-3（4 文件）， seq31 与历史正确记录 +482/-1 完全一致。
602 lines
25 KiB
Python
602 lines
25 KiB
Python
"""Conversation-scoped shallow file versioning for workspace edits.
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Mirrors Claude Code's file-history approach:
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- Only files touched by write_file / edit_file are tracked.
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- Before each edit the current content is backed up.
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- A snapshot is taken per user message, referencing the latest backup version
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of every tracked file at that point in time.
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- Rewind restores the tracked files to the state recorded for a target message.
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Persistence model (state.jsonl)
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--------------------------------
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INVARIANT: the on-disk state file holds **exactly one row per message_id** —
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the most complete snapshot known for that message. While a message is being
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processed, its single row grows as new files get tracked (track_edit rewrites
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it); when the message finishes, make_snapshot replaces it with the final full
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snapshot. Every mutation rewrites the whole file atomically (temp + replace),
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so the invariant holds at rest, not only in memory.
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Legacy append-only logs may contain multiple rows per message_id (intermediate
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track_edit journals plus the final snapshot). _load_state collapses those
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duplicates keeping the last row, which heals old state files transparently;
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the next mutation rewrites the file clean permanently.
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Concurrency: mutations (track_edit / make_snapshot) run inside a per-state-file
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process lock as reload -> mutate -> save critical sections, so short-lived
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manager instances (one per edit / per task end) can never lose each other's
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rows. Readers only see whole files because writes go through os.replace.
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"""
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from __future__ import annotations
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import hashlib
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import json
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import os
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import shutil
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import threading
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from dataclasses import dataclass, field
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from datetime import datetime
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from pathlib import Path
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from typing import Any, Dict, List, Optional, Set
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class ShallowVersioningError(RuntimeError):
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"""Raised when shallow versioning fails."""
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@dataclass
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class FileBackup:
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backup_file_name: Optional[str] # null means the file did not exist at that version
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version: int
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backup_time: str
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@dataclass
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class ShallowSnapshot:
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message_id: str
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tracked_file_backups: Dict[str, FileBackup]
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timestamp: str
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# Process-level locks keyed by state file path, so that separate manager
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# instances targeting the same conversation serialize their mutations.
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_STATE_LOCKS: Dict[str, threading.Lock] = {}
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_STATE_LOCKS_GUARD = threading.Lock()
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def _state_lock_for(state_file: Path) -> threading.Lock:
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key = str(state_file)
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with _STATE_LOCKS_GUARD:
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lock = _STATE_LOCKS.get(key)
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if lock is None:
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lock = threading.Lock()
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_STATE_LOCKS[key] = lock
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return lock
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class ShallowVersioningManager:
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"""Lightweight per-conversation backup for files edited by AI tools."""
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MAX_SNAPSHOTS = 100
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def __init__(self, project_path: Path | str, data_dir: Path | str, conversation_id: str):
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self.project_path = Path(project_path).expanduser().resolve()
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self.conversation_id = str(conversation_id or "").strip()
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if not self.conversation_id:
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raise ShallowVersioningError("缺少 conversation_id")
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self.save_root = (Path(data_dir).expanduser().resolve() / "save" / self.conversation_id).resolve()
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self.backup_dir = self.save_root / "shallow_backups"
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self.state_file = self.backup_dir / "state.jsonl"
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self._state_lock = _state_lock_for(self.state_file)
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self._tracked_files: Set[str] = set()
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self._snapshots: List[ShallowSnapshot] = []
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self._snapshot_sequence = 0
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self._load_state()
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# ----------------------------
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# persistence
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# ----------------------------
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def _load_state(self) -> None:
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"""(Re)load snapshots from disk, collapsing duplicate rows per message_id.
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Idempotent: resets in-memory state first, so it can be called inside
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mutation critical sections to pick up rows written by other instances.
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Legacy logs with multiple rows for the same message_id keep only the
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last (most complete) row, ordered by last occurrence.
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"""
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self._tracked_files = set()
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self._snapshots = []
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self._snapshot_sequence = 0
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if not self.state_file.exists():
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return
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try:
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raw_lines = self.state_file.read_text(encoding="utf-8", errors="ignore").splitlines()
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except OSError:
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return
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parsed: List[ShallowSnapshot] = []
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for raw in raw_lines:
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line = raw.strip()
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if not line:
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continue
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try:
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row = json.loads(line)
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except Exception:
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continue
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if not isinstance(row, dict):
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continue
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snapshot = self._deserialize_snapshot(row)
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if snapshot:
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parsed.append(snapshot)
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# Collapse duplicates: keep the last row per message_id.
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last_index: Dict[str, int] = {}
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for idx, snapshot in enumerate(parsed):
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last_index[str(snapshot.message_id or "")] = idx
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self._snapshots = [
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snapshot for idx, snapshot in enumerate(parsed) if last_index[str(snapshot.message_id or "")] == idx
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]
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self._snapshot_sequence = len(self._snapshots)
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for snapshot in self._snapshots:
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self._tracked_files.update(snapshot.tracked_file_backups.keys())
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def _save_state(self) -> None:
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"""Persist the full snapshot list atomically (temp file + os.replace).
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Must be called with self._state_lock held. Rewriting the whole file is
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what enforces the one-row-per-message invariant on disk.
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"""
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self.backup_dir.mkdir(parents=True, exist_ok=True)
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tmp_path = self.state_file.parent / (self.state_file.name + ".tmp")
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payload = "".join(
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json.dumps(self._serialize_snapshot(snapshot), ensure_ascii=False) + "\n"
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for snapshot in self._snapshots
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)
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tmp_path.write_text(payload, encoding="utf-8")
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os.replace(tmp_path, self.state_file)
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def _upsert_snapshot(self, snapshot: ShallowSnapshot) -> None:
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"""Insert or replace the snapshot for its message_id in memory.
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Removes every existing entry with the same message_id and places the
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new snapshot at the position of the first removed entry (appends when
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no entry existed), preserving chronological order.
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"""
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target_id = str(snapshot.message_id or "")
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first_match = -1
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for idx, existing in enumerate(self._snapshots):
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if str(existing.message_id or "") == target_id:
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first_match = idx
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break
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self._snapshots = [
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existing for existing in self._snapshots if str(existing.message_id or "") != target_id
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]
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if first_match < 0:
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self._snapshots.append(snapshot)
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self._snapshot_sequence += 1
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else:
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insert_at = min(first_match, len(self._snapshots))
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self._snapshots.insert(insert_at, snapshot)
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def _serialize_snapshot(self, snapshot: ShallowSnapshot) -> Dict[str, Any]:
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return {
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"message_id": snapshot.message_id,
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"timestamp": snapshot.timestamp,
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"tracked_file_backups": {
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path: {
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"backup_file_name": backup.backup_file_name,
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"version": backup.version,
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"backup_time": backup.backup_time,
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}
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for path, backup in snapshot.tracked_file_backups.items()
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},
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}
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def _deserialize_snapshot(self, row: Dict[str, Any]) -> Optional[ShallowSnapshot]:
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if not isinstance(row.get("message_id"), str):
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return None
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backups: Dict[str, FileBackup] = {}
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for path, backup_raw in (row.get("tracked_file_backups") or {}).items():
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if not isinstance(backup_raw, dict):
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continue
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backups[str(path)] = FileBackup(
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backup_file_name=backup_raw.get("backup_file_name"),
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version=int(backup_raw.get("version") or 1),
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backup_time=str(backup_raw.get("backup_time") or datetime.now().isoformat()),
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)
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return ShallowSnapshot(
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message_id=row["message_id"],
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tracked_file_backups=backups,
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timestamp=str(row.get("timestamp") or datetime.now().isoformat()),
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)
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# ----------------------------
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# path helpers
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# ----------------------------
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def _normalize_path(self, file_path: Path | str) -> str:
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path = Path(file_path).expanduser()
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if not path.is_absolute():
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path = self.project_path / path
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try:
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rel = path.resolve().relative_to(self.project_path)
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return str(rel).replace("\\", "/")
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except ValueError:
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return str(path).replace("\\", "/")
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def _resolve_file_path(self, tracking_path: str) -> Path:
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if Path(tracking_path).is_absolute():
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return Path(tracking_path).expanduser().resolve()
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return (self.project_path / tracking_path).resolve()
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def _backup_file_name(self, tracking_path: str, version: int) -> str:
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file_name_hash = hashlib.sha256(tracking_path.encode("utf-8")).hexdigest()[:16]
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return f"{file_name_hash}@v{version}"
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def _backup_path(self, backup_file_name: str) -> Path:
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return (self.backup_dir / backup_file_name).resolve()
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# ----------------------------
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# backup operations
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# ----------------------------
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def _create_backup(self, file_path: Path, version: int) -> FileBackup:
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backup_file_name = self._backup_file_name(str(file_path), version)
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backup_path = self._backup_path(backup_file_name)
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backup_path.parent.mkdir(parents=True, exist_ok=True)
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if not file_path.exists():
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return FileBackup(backup_file_name=None, version=version, backup_time=datetime.now().isoformat())
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shutil.copy2(file_path, backup_path)
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return FileBackup(
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backup_file_name=backup_file_name,
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version=version,
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backup_time=datetime.now().isoformat(),
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)
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def _get_latest_backup_version(self, tracking_path: str) -> Optional[FileBackup]:
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latest: Optional[FileBackup] = None
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for snapshot in self._snapshots:
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backup = snapshot.tracked_file_backups.get(tracking_path)
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if backup and (latest is None or backup.version > latest.version):
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latest = backup
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return latest
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def _file_changed_since_backup(self, file_path: Path, backup: FileBackup) -> bool:
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if backup.backup_file_name is None:
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return file_path.exists()
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backup_path = self._backup_path(backup.backup_file_name)
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if not file_path.exists():
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return True
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if not backup_path.exists():
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return True
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try:
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if file_path.stat().st_size != backup_path.stat().st_size:
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return True
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current = file_path.read_text(encoding="utf-8", errors="ignore")
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saved = backup_path.read_text(encoding="utf-8", errors="ignore")
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return current != saved
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except Exception:
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return True
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# ----------------------------
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# public API
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# ----------------------------
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def _find_latest_snapshot_by_message_id(self, message_id: str) -> Optional[ShallowSnapshot]:
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"""Return the most recent snapshot whose message_id matches."""
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target = str(message_id or "")
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for snapshot in reversed(self._snapshots):
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if str(snapshot.message_id or "") == target:
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return snapshot
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return None
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def track_edit(self, file_path: Path | str, message_id: str) -> None:
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"""Track a file before it is edited; backup its current content if not already tracked."""
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tracking_path = self._normalize_path(file_path)
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from utils.perf_log import perf_log
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perf_log("[ShallowVersioning] track_edit called", extra={
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"tracking_path": tracking_path,
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"message_id": message_id,
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})
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# Critical section: reload so rows written by other (short-lived)
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# instances are visible, then mutate and save atomically.
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with self._state_lock:
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self._load_state()
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if tracking_path in self._tracked_files:
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return
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resolved = self._resolve_file_path(tracking_path)
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backup = self._create_backup(resolved, 1)
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self._tracked_files.add(tracking_path)
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# 归属到当前 message_id 对应的 snapshot；不存在则新建。
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# 避免把本次输入的修改追加到上一个输入的 snapshot。
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now = datetime.now().isoformat()
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target_snapshot = self._find_latest_snapshot_by_message_id(message_id)
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if target_snapshot is not None:
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target_snapshot.tracked_file_backups[tracking_path] = backup
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else:
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target_snapshot = ShallowSnapshot(
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message_id=message_id,
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tracked_file_backups={tracking_path: backup},
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timestamp=now,
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)
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self._upsert_snapshot(target_snapshot)
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self._save_state()
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def make_snapshot(self, message_id: str) -> Dict[str, Any]:
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"""Create a snapshot for the given message, backing up changed tracked files."""
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from utils.perf_log import perf_log
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perf_log("[ShallowVersioning] make_snapshot called", extra={
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"message_id": message_id,
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})
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# Critical section: reload so track_edit rows from other instances are
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# visible before deciding what changed and which version comes next.
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with self._state_lock:
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self._load_state()
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tracked_file_backups: Dict[str, FileBackup] = {}
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now = datetime.now().isoformat()
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for tracking_path in self._tracked_files:
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resolved = self._resolve_file_path(tracking_path)
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latest_backup = self._get_latest_backup_version(tracking_path)
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next_version = (latest_backup.version + 1) if latest_backup else 1
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if latest_backup and not self._file_changed_since_backup(resolved, latest_backup):
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tracked_file_backups[tracking_path] = latest_backup
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continue
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tracked_file_backups[tracking_path] = self._create_backup(resolved, next_version)
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snapshot = ShallowSnapshot(
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message_id=message_id,
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tracked_file_backups=tracked_file_backups,
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timestamp=now,
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)
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# 一条消息只保留一个快照：替换 track_edit 阶段留下的进行中的行。
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self._upsert_snapshot(snapshot)
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# Evict old snapshots while keeping the most recent MAX_SNAPSHOTS.
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if len(self._snapshots) > self.MAX_SNAPSHOTS:
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self._snapshots = self._snapshots[-self.MAX_SNAPSHOTS :]
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self._save_state()
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perf_log("[ShallowVersioning] make_snapshot done", extra={
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"message_id": message_id,
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"tracked_files_count": len(tracked_file_backups),
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"backups": {k: v.backup_file_name for k, v in tracked_file_backups.items()},
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})
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return {
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"message_id": message_id,
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"tracked_files_count": len(tracked_file_backups),
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"timestamp": now,
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}
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def can_restore(self, message_id: str) -> bool:
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return any(snapshot.message_id == message_id for snapshot in self._snapshots)
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def rewind(self, message_id: str) -> Dict[str, Any]:
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"""Restore tracked files to the state recorded for the target message."""
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target_snapshot: Optional[ShallowSnapshot] = None
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for snapshot in reversed(self._snapshots):
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if snapshot.message_id == message_id:
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target_snapshot = snapshot
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break
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if not target_snapshot:
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raise ShallowVersioningError(f"未找到消息 {message_id} 对应的快照")
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files_changed: List[str] = []
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for tracking_path in self._tracked_files:
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target_backup = target_snapshot.tracked_file_backups.get(tracking_path)
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if not target_backup:
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# File was not tracked at the target snapshot; leave it unchanged.
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continue
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resolved = self._resolve_file_path(tracking_path)
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if target_backup.backup_file_name is None:
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if resolved.exists():
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resolved.unlink()
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files_changed.append(tracking_path)
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continue
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backup_path = self._backup_path(target_backup.backup_file_name)
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if not backup_path.exists():
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continue
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if self._file_changed_since_backup(resolved, target_backup):
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resolved.parent.mkdir(parents=True, exist_ok=True)
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shutil.copy2(backup_path, resolved)
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files_changed.append(tracking_path)
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return {
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"success": True,
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"message_id": message_id,
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"files_changed": files_changed,
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}
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def _read_backup_lines(self, backup: Optional[FileBackup]) -> List[str]:
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"""Read lines from a backup entry; empty list for missing/deleted files."""
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if not backup or backup.backup_file_name is None:
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return []
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backup_path = self._backup_path(backup.backup_file_name)
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if not backup_path.exists():
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return []
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try:
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return backup_path.read_text(encoding="utf-8", errors="ignore").splitlines()
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except Exception:
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return []
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def _count_line_changes(self, previous_lines: List[str], target_lines: List[str]) -> tuple[int, int]:
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"""Count real insertions/deletions between two line lists using SequenceMatcher."""
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if previous_lines == target_lines:
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return 0, 0
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try:
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import difflib
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sm = difflib.SequenceMatcher(None, previous_lines, target_lines)
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except Exception:
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# Fallback to naive delta if difflib fails.
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if len(previous_lines) > len(target_lines):
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return 0, len(previous_lines) - len(target_lines)
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return len(target_lines) - len(previous_lines), 0
|
||
|
||
insertions = 0
|
||
deletions = 0
|
||
for tag, i1, i2, j1, j2 in sm.get_opcodes():
|
||
if tag == "insert":
|
||
insertions += j2 - j1
|
||
elif tag == "delete":
|
||
deletions += i2 - i1
|
||
elif tag == "replace":
|
||
insertions += j2 - j1
|
||
deletions += i2 - i1
|
||
return insertions, deletions
|
||
|
||
def _find_snapshot_pair(self, message_id: str):
|
||
"""Return (target_snapshot, previous_snapshot) for the given message_id.
|
||
|
||
The previous snapshot is the nearest preceding snapshot belonging to a
|
||
*different* message_id, so duplicate rows of the same message can never
|
||
be mistaken for the diff base.
|
||
"""
|
||
target_snapshot: Optional[ShallowSnapshot] = None
|
||
target_index = -1
|
||
target_id = str(message_id or "")
|
||
for idx, snapshot in enumerate(self._snapshots):
|
||
if str(snapshot.message_id or "") == target_id:
|
||
target_snapshot = snapshot
|
||
target_index = idx
|
||
if not target_snapshot or target_index < 0:
|
||
return None, None
|
||
previous_snapshot: Optional[ShallowSnapshot] = None
|
||
for idx in range(target_index - 1, -1, -1):
|
||
if str(self._snapshots[idx].message_id or "") != target_id:
|
||
previous_snapshot = self._snapshots[idx]
|
||
break
|
||
return target_snapshot, previous_snapshot
|
||
|
||
def get_diff_stats(self, message_id: str) -> Optional[Dict[str, Any]]:
|
||
"""Compute insertions/deletions/files_changed between the target snapshot and the previous snapshot."""
|
||
target_snapshot, previous_snapshot = self._find_snapshot_pair(message_id)
|
||
if not target_snapshot:
|
||
return None
|
||
|
||
files_changed: List[str] = []
|
||
insertions = 0
|
||
deletions = 0
|
||
|
||
for tracking_path in self._tracked_files:
|
||
target_backup = target_snapshot.tracked_file_backups.get(tracking_path)
|
||
if not target_backup:
|
||
continue
|
||
|
||
previous_backup = previous_snapshot.tracked_file_backups.get(tracking_path) if previous_snapshot else None
|
||
previous_lines = self._read_backup_lines(previous_backup)
|
||
target_lines = self._read_backup_lines(target_backup)
|
||
|
||
if previous_lines == target_lines:
|
||
continue
|
||
|
||
files_changed.append(tracking_path)
|
||
ins, dels = self._count_line_changes(previous_lines, target_lines)
|
||
insertions += ins
|
||
deletions += dels
|
||
|
||
return {
|
||
"filesChanged": files_changed,
|
||
"insertions": insertions,
|
||
"deletions": deletions,
|
||
}
|
||
|
||
def has_any_changes(self, message_id: str) -> bool:
|
||
stats = self.get_diff_stats(message_id)
|
||
if not stats:
|
||
return False
|
||
return bool(stats.get("filesChanged"))
|
||
|
||
def get_file_diff_stats(self, message_id: str) -> List[Dict[str, Any]]:
|
||
"""Return per-file insertions/deletions/status for a target snapshot vs previous snapshot."""
|
||
target_snapshot, previous_snapshot = self._find_snapshot_pair(message_id)
|
||
if not target_snapshot:
|
||
return []
|
||
|
||
result: List[Dict[str, Any]] = []
|
||
for tracking_path in self._tracked_files:
|
||
target_backup = target_snapshot.tracked_file_backups.get(tracking_path)
|
||
if not target_backup:
|
||
continue
|
||
|
||
previous_backup = previous_snapshot.tracked_file_backups.get(tracking_path) if previous_snapshot else None
|
||
previous_lines = self._read_backup_lines(previous_backup)
|
||
target_lines = self._read_backup_lines(target_backup)
|
||
|
||
if previous_lines == target_lines:
|
||
continue
|
||
|
||
insertions, deletions = self._count_line_changes(previous_lines, target_lines)
|
||
|
||
status = "deleted" if target_backup.backup_file_name is None else ("added" if previous_backup is None or previous_backup.backup_file_name is None else "modified")
|
||
result.append({
|
||
"path": tracking_path,
|
||
"status": status,
|
||
"insertions": insertions,
|
||
"deletions": deletions,
|
||
})
|
||
return result
|
||
|
||
def get_file_patch_lines(
|
||
self,
|
||
tracking_path: str,
|
||
message_id: str,
|
||
max_lines: int = 600,
|
||
) -> Dict[str, Any]:
|
||
"""Return contextual patch lines between target snapshot and previous snapshot."""
|
||
target_snapshot, previous_snapshot = self._find_snapshot_pair(message_id)
|
||
if not target_snapshot:
|
||
return {"lines": [], "truncated": False}
|
||
|
||
target_backup = target_snapshot.tracked_file_backups.get(tracking_path)
|
||
if not target_backup:
|
||
return {"lines": [], "truncated": False}
|
||
|
||
previous_backup = previous_snapshot.tracked_file_backups.get(tracking_path) if previous_snapshot else None
|
||
previous_lines = self._read_backup_lines(previous_backup)
|
||
target_lines = self._read_backup_lines(target_backup)
|
||
|
||
if previous_lines == target_lines:
|
||
return {"lines": [], "truncated": False}
|
||
|
||
try:
|
||
import difflib
|
||
sm = difflib.SequenceMatcher(None, previous_lines, target_lines)
|
||
except Exception:
|
||
return {"lines": [], "truncated": False}
|
||
|
||
lines: List[Dict[str, Any]] = []
|
||
truncated = False
|
||
for tag, i1, i2, j1, j2 in sm.get_opcodes():
|
||
if tag == "equal":
|
||
continue
|
||
if tag == "replace" or tag == "delete":
|
||
for line in previous_lines[i1:i2]:
|
||
if len(lines) >= max_lines:
|
||
truncated = True
|
||
break
|
||
lines.append({"type": "remove", "content": line})
|
||
if tag == "replace" or tag == "insert":
|
||
for line in target_lines[j1:j2]:
|
||
if len(lines) >= max_lines:
|
||
truncated = True
|
||
break
|
||
lines.append({"type": "add", "content": line})
|
||
if truncated:
|
||
break
|
||
return {"lines": lines, "truncated": truncated}
|
||
|
||
def get_snapshot_by_seq(self, seq: int) -> Optional[ShallowSnapshot]:
|
||
"""Return the user-message snapshot by 1-based index (skips the initial track_edit snapshot)."""
|
||
user_snapshots = [s for s in self._snapshots if s.message_id != self.conversation_id]
|
||
idx = int(seq) - 1
|
||
if idx < 0 or idx >= len(user_snapshots):
|
||
return None
|
||
return user_snapshots[idx]
|
||
|
||
def list_snapshots(self) -> List[Dict[str, Any]]:
|
||
return [self._serialize_snapshot(s) for s in self._snapshots]
|