syntax revamp

SYS/repl_queue.py

@@ -1,16 +1,86 @@
 from __future__ import annotations
 
 import json
+import os
 import time
 import uuid
 from pathlib import Path
 from typing import Any, Dict, List, Optional
 
 
+_REPL_STATE_FILENAME = "medeia-repl-state.json"
+
+
 def repl_queue_dir(root: Path) -> Path:
     return Path(root) / "Log" / "repl_queue"
 
 
+def repl_state_path(root: Path) -> Path:
+    return Path(root) / "Log" / _REPL_STATE_FILENAME
+
+
+def _write_json_atomic(path: Path, payload: Dict[str, Any]) -> Path:
+    path.parent.mkdir(parents=True, exist_ok=True)
+    temp_path = path.with_suffix(path.suffix + ".tmp")
+    temp_path.write_text(json.dumps(payload, ensure_ascii=False), encoding="utf-8")
+    temp_path.replace(path)
+    return path
+
+
+def touch_repl_state(
+    root: Path,
+    *,
+    session_id: Optional[str] = None,
+    pid: Optional[int] = None,
+    status: str = "running",
+) -> Path:
+    payload: Dict[str, Any] = {
+        "status": str(status or "running").strip() or "running",
+        "updated_at": time.time(),
+        "pid": int(pid) if pid is not None else int(os.getpid()),
+    }
+    if isinstance(session_id, str) and session_id.strip():
+        payload["session_id"] = session_id.strip()
+    return _write_json_atomic(repl_state_path(root), payload)
+
+
+def read_repl_state(root: Path) -> Optional[Dict[str, Any]]:
+    path = repl_state_path(root)
+    try:
+        if not path.exists() or not path.is_file():
+            return None
+        payload = json.loads(path.read_text(encoding="utf-8"))
+    except Exception:
+        return None
+    return payload if isinstance(payload, dict) else None
+
+
+def clear_repl_state(root: Path) -> None:
+    path = repl_state_path(root)
+    try:
+        path.unlink()
+    except Exception:
+        return
+
+
+def repl_state_is_alive(root: Path, *, max_age_seconds: float = 3.0) -> bool:
+    payload = read_repl_state(root)
+    if not isinstance(payload, dict):
+        return False
+    if str(payload.get("status") or "").strip().lower() != "running":
+        return False
+    try:
+        updated_at = float(payload.get("updated_at") or 0.0)
+    except Exception:
+        return False
+    if updated_at <= 0:
+        return False
+    try:
+        return (time.time() - updated_at) <= max(0.0, float(max_age_seconds))
+    except Exception:
+        return False
+
+
 def _legacy_repl_queue_glob(root: Path) -> list[Path]:
     log_dir = Path(root) / "Log"
     if not log_dir.exists():