Add google-endpoints to third_party/.

third_party/google-endpoints/cachetools/__init__.py

+"""Extensible memoizing collections and decorators."""
+
+import functools
+import warnings
+
+from .cache import Cache
+from .func import lfu_cache, lru_cache, rr_cache, ttl_cache
+from .keys import hashkey, typedkey
+from .lfu import LFUCache
+from .lru import LRUCache
+from .rr import RRCache
+from .ttl import TTLCache
+
+__all__ = (
+    'Cache', 'LFUCache', 'LRUCache', 'RRCache', 'TTLCache',
+    'cached', 'cachedmethod', 'hashkey', 'typedkey',
+    # make cachetools.func.* available for backwards compatibility
+    'lfu_cache', 'lru_cache', 'rr_cache', 'ttl_cache',
+)
+
+__version__ = '1.1.6'
+
+_default = []  # evaluates to False
+
+if hasattr(functools.update_wrapper(lambda f: f(), lambda: 42), '__wrapped__'):
+    _update_wrapper = functools.update_wrapper
+else:
+    def _update_wrapper(wrapper, wrapped):
+        functools.update_wrapper(wrapper, wrapped)
+        wrapper.__wrapped__ = wrapped
+        return wrapper
+
+
+def cached(cache, key=hashkey, lock=None):
+    """Decorator to wrap a function with a memoizing callable that saves
+    results in a cache.
+
+    """
+    def decorator(func):
+        if cache is None:
+            def wrapper(*args, **kwargs):
+                return func(*args, **kwargs)
+        elif lock is None:
+            def wrapper(*args, **kwargs):
+                k = key(*args, **kwargs)
+                try:
+                    return cache[k]
+                except KeyError:
+                    pass  # key not found
+                v = func(*args, **kwargs)
+                try:
+                    cache[k] = v
+                except ValueError:
+                    pass  # value too large
+                return v
+        else:
+            def wrapper(*args, **kwargs):
+                k = key(*args, **kwargs)
+                try:
+                    with lock:
+                        return cache[k]
+                except KeyError:
+                    pass  # key not found
+                v = func(*args, **kwargs)
+                try:
+                    with lock:
+                        cache[k] = v
+                except ValueError:
+                    pass  # value too large
+                return v
+        return _update_wrapper(wrapper, func)
+    return decorator
+
+
+def cachedmethod(cache, key=_default, lock=None, typed=_default):
+    """Decorator to wrap a class or instance method with a memoizing
+    callable that saves results in a cache.
+
+    """
+    if key is not _default and not callable(key):
+        key, typed = _default, key
+    if typed is not _default:
+        warnings.warn("Passing 'typed' to cachedmethod() is deprecated, "
+                      "use 'key=typedkey' instead", DeprecationWarning, 2)
+
+    def decorator(method):
+        # pass method to default key function for backwards compatibilty
+        if key is _default:
+            makekey = functools.partial(typedkey if typed else hashkey, method)
+        else:
+            makekey = key  # custom key function always receive method args
+        if lock is None:
+            def wrapper(self, *args, **kwargs):
+                c = cache(self)
+                if c is None:
+                    return method(self, *args, **kwargs)
+                k = makekey(self, *args, **kwargs)
+                try:
+                    return c[k]
+                except KeyError:
+                    pass  # key not found
+                v = method(self, *args, **kwargs)
+                try:
+                    c[k] = v
+                except ValueError:
+                    pass  # value too large
+                return v
+        else:
+            def wrapper(self, *args, **kwargs):
+                c = cache(self)
+                if c is None:
+                    return method(self, *args, **kwargs)
+                k = makekey(self, *args, **kwargs)
+                try:
+                    with lock(self):
+                        return c[k]
+                except KeyError:
+                    pass  # key not found
+                v = method(self, *args, **kwargs)
+                try:
+                    with lock(self):
+                        c[k] = v
+                except ValueError:
+                    pass  # value too large
+                return v
+        _update_wrapper(wrapper, method)
+
+        # deprecated wrapper attribute
+        def getter(self):
+            warnings.warn('%s.cache is deprecated' % method.__name__,
+                          DeprecationWarning, 2)
+            return cache(self)
+        wrapper.cache = getter
+        return wrapper
+    return decorator