Files
tono/backend/usage_tracker.py
2026-04-04 00:38:11 -07:00

134 lines
4.3 KiB
Python

"""
Lightweight node usage tracker.
Persists per-node execution counts and total execution time to a JSON file
in the app data directory. Thread-safe for concurrent prompt execution.
"""
from __future__ import annotations
import json
import logging
import threading
import time
from pathlib import Path
from typing import Any
from backend.runtime_paths import app_data_dir
log = logging.getLogger(__name__)
_FLUSH_INTERVAL = 30 # seconds between disk writes
_STATS_FILENAME = "usage_stats.json"
class UsageTracker:
"""Accumulates node execution counts and periodically flushes to disk."""
def __init__(self) -> None:
self._lock = threading.Lock()
self._path = app_data_dir() / _STATS_FILENAME
self._dirty = False
self._last_flush = 0.0
self._data: dict[str, dict[str, Any]] = {}
self._load()
# ------------------------------------------------------------------
# Public API
# ------------------------------------------------------------------
def record(self, class_name: str, elapsed_ms: float) -> None:
"""Record one execution of *class_name*."""
with self._lock:
entry = self._data.get(class_name)
if entry is None:
entry = {"count": 0, "total_ms": 0.0}
self._data[class_name] = entry
entry["count"] += 1
entry["total_ms"] += elapsed_ms
self._dirty = True
# Flush periodically (non-blocking — skip if another thread is writing)
now = time.monotonic()
if now - self._last_flush >= _FLUSH_INTERVAL:
self._try_flush()
def snapshot(self) -> dict[str, dict[str, Any]]:
"""Return a copy of the current stats."""
with self._lock:
return {k: dict(v) for k, v in self._data.items()}
def flush(self) -> None:
"""Force write to disk."""
self._try_flush(force=True)
# ------------------------------------------------------------------
# Internals
# ------------------------------------------------------------------
def _load(self) -> None:
if not self._path.exists():
return
try:
raw = json.loads(self._path.read_text(encoding="utf-8"))
if isinstance(raw, dict):
for key, value in raw.items():
if isinstance(value, dict) and "count" in value:
self._data[key] = {
"count": int(value["count"]),
"total_ms": float(value.get("total_ms", 0.0)),
}
log.info("Loaded usage stats: %d nodes tracked", len(self._data))
except Exception:
log.warning("Could not load usage stats from %s — starting fresh", self._path)
def _try_flush(self, *, force: bool = False) -> None:
with self._lock:
if not self._dirty and not force:
return
snapshot = {k: dict(v) for k, v in self._data.items()}
self._dirty = False
self._last_flush = time.monotonic()
try:
self._path.parent.mkdir(parents=True, exist_ok=True)
tmp = self._path.with_suffix(".tmp")
tmp.write_text(
json.dumps(snapshot, indent=2, sort_keys=True),
encoding="utf-8",
)
tmp.replace(self._path)
except Exception:
log.warning("Failed to write usage stats", exc_info=True)
# Module-level singleton — lazily created on first import via init().
_tracker: UsageTracker | None = None
def init() -> UsageTracker:
"""Create (or return existing) global tracker."""
global _tracker
if _tracker is None:
_tracker = UsageTracker()
return _tracker
def record(class_name: str, elapsed_ms: float) -> None:
"""Record one execution. No-op if tracker not initialised."""
if _tracker is not None:
_tracker.record(class_name, elapsed_ms)
def snapshot() -> dict[str, dict[str, Any]]:
"""Return current stats snapshot. Empty dict if not initialised."""
if _tracker is not None:
return _tracker.snapshot()
return {}
def flush() -> None:
"""Flush to disk. No-op if tracker not initialised."""
if _tracker is not None:
_tracker.flush()