68 lines
2.2 KiB
Python
68 lines
2.2 KiB
Python
from typing import Any, Callable
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from functools import wraps
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import hashlib
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import pickle
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import logging
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from core.config import CoreConfig
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cfg: CoreConfig = None # type: ignore
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# Make memcache optional
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try:
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import pylibmc # type: ignore
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has_mc = True
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except ModuleNotFoundError:
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has_mc = False
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def cached(lifetime: int = 10, extra_key: Any = None) -> Callable:
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def _cached(func: Callable) -> Callable:
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if has_mc:
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hostname = "127.0.0.1"
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if cfg:
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hostname = cfg.database.memcached_host
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memcache = pylibmc.Client([hostname], binary=True)
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memcache.behaviors = {"tcp_nodelay": True, "ketama": True}
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@wraps(func)
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def wrapper(*args: Any, **kwargs: Any) -> Any:
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if lifetime is not None:
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# Hash function args
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items = kwargs.items()
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hashable_args = (args[1:], sorted(list(items)))
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args_key = hashlib.md5(pickle.dumps(hashable_args)).hexdigest()
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# Generate unique cache key
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cache_key = f'{func.__module__}-{func.__name__}-{args_key}-{extra_key() if hasattr(extra_key, "__call__") else extra_key}'
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# Return cached version if allowed and available
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try:
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result = memcache.get(cache_key)
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except pylibmc.Error as e:
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logging.getLogger("database").error(f"Memcache failed: {e}")
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result = None
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if result is not None:
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logging.getLogger("database").debug(f"Cache hit: {result}")
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return result
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# Generate output
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result = func(*args, **kwargs)
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# Cache output if allowed
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if lifetime is not None and result is not None:
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logging.getLogger("database").debug(f"Setting cache: {result}")
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memcache.set(cache_key, result, lifetime)
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return result
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else:
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@wraps(func)
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def wrapper(*args: Any, **kwargs: Any) -> Any:
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return func(*args, **kwargs)
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return wrapper
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return _cached
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