brain_server/memory/short_term.py

"""Short-term in-memory store with TTL."""
import time
import logging
from typing import Any, Dict

logger = logging.getLogger("kapo.memory.short_term")


class ShortTermMemory:
    def __init__(self, ttl_sec: int = 1800, max_items: int = 500):
        self.ttl_sec = ttl_sec
        self.max_items = max_items
        self._store: Dict[str, Any] = {}
        self._ts: Dict[str, float] = {}

    def _cleanup(self):
        try:
            now = time.time()
            expired = [k for k, t in self._ts.items() if now - t > self.ttl_sec]
            for k in expired:
                self._store.pop(k, None)
                self._ts.pop(k, None)
            if len(self._store) > self.max_items:
                for k in list(self._store.keys())[: len(self._store) - self.max_items]:
                    self._store.pop(k, None)
                    self._ts.pop(k, None)
        except Exception:
            logger.exception("Cleanup failed")

    def set(self, key: str, value: Any):
        self._store[key] = value
        self._ts[key] = time.time()
        self._cleanup()

    def get(self, key: str):
        self._cleanup()
        return self._store.get(key)