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ColossalAI/examples/tutorial/opt/inference/cache.py

65 lines
2.3 KiB

from collections import OrderedDict
from contextlib import contextmanager
from threading import Lock
from typing import Any, Dict, Hashable, List
class MissCacheError(Exception):
pass
class ListCache:
def __init__(self, cache_size: int, list_size: int, fixed_keys: List[Hashable] = []) -> None:
"""Cache a list of values. The fixed keys won't be removed. For other keys, LRU is applied.
When the value list is not full, a cache miss occurs. Otherwise, a cache hit occurs. Redundant values will be removed.
Args:
cache_size (int): Max size for LRU cache.
list_size (int): Value list size.
fixed_keys (List[Hashable], optional): The keys which won't be removed. Defaults to [].
"""
self.cache_size = cache_size
self.list_size = list_size
self.cache: OrderedDict[Hashable, List[Any]] = OrderedDict()
self.fixed_cache: Dict[Hashable, List[Any]] = {}
for key in fixed_keys:
self.fixed_cache[key] = []
self._lock = Lock()
def get(self, key: Hashable) -> List[Any]:
with self.lock():
if key in self.fixed_cache:
l = self.fixed_cache[key]
if len(l) >= self.list_size:
return l
elif key in self.cache:
self.cache.move_to_end(key)
l = self.cache[key]
if len(l) >= self.list_size:
return l
raise MissCacheError()
def add(self, key: Hashable, value: Any) -> None:
with self.lock():
if key in self.fixed_cache:
l = self.fixed_cache[key]
if len(l) < self.list_size and value not in l:
l.append(value)
elif key in self.cache:
self.cache.move_to_end(key)
l = self.cache[key]
if len(l) < self.list_size and value not in l:
l.append(value)
else:
if len(self.cache) >= self.cache_size:
self.cache.popitem(last=False)
self.cache[key] = [value]
@contextmanager
def lock(self):
try:
self._lock.acquire()
yield
finally:
self._lock.release()