diff options
Diffstat (limited to '.venv/lib/python3.12/site-packages/fsspec/dircache.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/fsspec/dircache.py | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/fsspec/dircache.py b/.venv/lib/python3.12/site-packages/fsspec/dircache.py new file mode 100644 index 00000000..eca19566 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/fsspec/dircache.py @@ -0,0 +1,98 @@ +import time +from collections.abc import MutableMapping +from functools import lru_cache + + +class DirCache(MutableMapping): + """ + Caching of directory listings, in a structure like:: + + {"path0": [ + {"name": "path0/file0", + "size": 123, + "type": "file", + ... + }, + {"name": "path0/file1", + }, + ... + ], + "path1": [...] + } + + Parameters to this class control listing expiry or indeed turn + caching off + """ + + def __init__( + self, + use_listings_cache=True, + listings_expiry_time=None, + max_paths=None, + **kwargs, + ): + """ + + Parameters + ---------- + use_listings_cache: bool + If False, this cache never returns items, but always reports KeyError, + and setting items has no effect + listings_expiry_time: int or float (optional) + Time in seconds that a listing is considered valid. If None, + listings do not expire. + max_paths: int (optional) + The number of most recent listings that are considered valid; 'recent' + refers to when the entry was set. + """ + self._cache = {} + self._times = {} + if max_paths: + self._q = lru_cache(max_paths + 1)(lambda key: self._cache.pop(key, None)) + self.use_listings_cache = use_listings_cache + self.listings_expiry_time = listings_expiry_time + self.max_paths = max_paths + + def __getitem__(self, item): + if self.listings_expiry_time is not None: + if self._times.get(item, 0) - time.time() < -self.listings_expiry_time: + del self._cache[item] + if self.max_paths: + self._q(item) + return self._cache[item] # maybe raises KeyError + + def clear(self): + self._cache.clear() + + def __len__(self): + return len(self._cache) + + def __contains__(self, item): + try: + self[item] + return True + except KeyError: + return False + + def __setitem__(self, key, value): + if not self.use_listings_cache: + return + if self.max_paths: + self._q(key) + self._cache[key] = value + if self.listings_expiry_time is not None: + self._times[key] = time.time() + + def __delitem__(self, key): + del self._cache[key] + + def __iter__(self): + entries = list(self._cache) + + return (k for k in entries if k in self) + + def __reduce__(self): + return ( + DirCache, + (self.use_listings_cache, self.listings_expiry_time, self.max_paths), + ) |