"""Simple in-memory cache with TTL support for node type information."""
from __future__ import annotations
import time
from typing import Any, Dict, Optional, TypeVar
T = TypeVar("T")
class CacheEntry:
"""A cache entry with expiration time."""
def __init__(self, value: Any, ttl: float):
self.value = value
self.expiry = time.time() + ttl
def is_expired(self) -> bool:
"""Check if this cache entry has expired."""
return time.time() > self.expiry
class SimpleCache:
"""Simple in-memory cache with TTL support."""
def __init__(self, default_ttl: float = 3600.0):
"""
Initialize the cache.
Args:
default_ttl: Default time-to-live for cache entries in seconds (default: 1 hour)
"""
self.default_ttl = default_ttl
self._cache: Dict[str, CacheEntry] = {}
def get(self, key: str) -> Optional[Any]:
"""
Get a value from the cache.
Args:
key: The cache key
Returns:
The cached value if it exists and hasn't expired, None otherwise
"""
entry = self._cache.get(key)
if entry is None:
return None
if entry.is_expired():
# Clean up expired entry
del self._cache[key]
return None
return entry.value
def set(self, key: str, value: Any, ttl: Optional[float] = None) -> None:
"""
Set a value in the cache.
Args:
key: The cache key
value: The value to cache
ttl: Time-to-live in seconds (uses default_ttl if not specified)
"""
if ttl is None:
ttl = self.default_ttl
self._cache[key] = CacheEntry(value, ttl)
def delete(self, key: str) -> None:
"""
Delete a value from the cache.
Args:
key: The cache key to delete
"""
self._cache.pop(key, None)
def clear(self) -> None:
"""Clear all entries from the cache."""
self._cache.clear()
def cleanup_expired(self) -> int:
"""
Remove all expired entries from the cache.
Returns:
Number of entries removed
"""
expired_keys = [
key for key, entry in self._cache.items() if entry.is_expired()
]
for key in expired_keys:
del self._cache[key]
return len(expired_keys)
def size(self) -> int:
"""Get the number of entries in the cache."""
return len(self._cache)
# Global cache instance for node types
# Cache for 1 hour (3600 seconds) - node types rarely change
node_type_cache = SimpleCache(default_ttl=3600.0)
