Spaces:
Runtime error
Runtime error
File size: 8,165 Bytes
9cddcfd |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 |
import array
import posixpath
import warnings
from collections.abc import MutableMapping
from functools import cached_property
from .core import url_to_fs
class FSMap(MutableMapping):
"""Wrap a FileSystem instance as a mutable wrapping.
The keys of the mapping become files under the given root, and the
values (which must be bytes) the contents of those files.
Parameters
----------
root: string
prefix for all the files
fs: FileSystem instance
check: bool (=True)
performs a touch at the location, to check for write access.
Examples
--------
>>> fs = FileSystem(**parameters) # doctest: +SKIP
>>> d = FSMap('my-data/path/', fs) # doctest: +SKIP
or, more likely
>>> d = fs.get_mapper('my-data/path/')
>>> d['loc1'] = b'Hello World' # doctest: +SKIP
>>> list(d.keys()) # doctest: +SKIP
['loc1']
>>> d['loc1'] # doctest: +SKIP
b'Hello World'
"""
def __init__(self, root, fs, check=False, create=False, missing_exceptions=None):
self.fs = fs
self.root = fs._strip_protocol(root).rstrip("/")
self._root_key_to_str = fs._strip_protocol(posixpath.join(root, "x"))[:-1]
if missing_exceptions is None:
missing_exceptions = (
FileNotFoundError,
IsADirectoryError,
NotADirectoryError,
)
self.missing_exceptions = missing_exceptions
self.check = check
self.create = create
if create:
if not self.fs.exists(root):
self.fs.mkdir(root)
if check:
if not self.fs.exists(root):
raise ValueError(
f"Path {root} does not exist. Create "
f" with the ``create=True`` keyword"
)
self.fs.touch(root + "/a")
self.fs.rm(root + "/a")
@cached_property
def dirfs(self):
"""dirfs instance that can be used with the same keys as the mapper"""
from .implementations.dirfs import DirFileSystem
return DirFileSystem(path=self._root_key_to_str, fs=self.fs)
def clear(self):
"""Remove all keys below root - empties out mapping"""
try:
self.fs.rm(self.root, True)
self.fs.mkdir(self.root)
except: # noqa: E722
pass
def getitems(self, keys, on_error="raise"):
"""Fetch multiple items from the store
If the backend is async-able, this might proceed concurrently
Parameters
----------
keys: list(str)
They keys to be fetched
on_error : "raise", "omit", "return"
If raise, an underlying exception will be raised (converted to KeyError
if the type is in self.missing_exceptions); if omit, keys with exception
will simply not be included in the output; if "return", all keys are
included in the output, but the value will be bytes or an exception
instance.
Returns
-------
dict(key, bytes|exception)
"""
keys2 = [self._key_to_str(k) for k in keys]
oe = on_error if on_error == "raise" else "return"
try:
out = self.fs.cat(keys2, on_error=oe)
if isinstance(out, bytes):
out = {keys2[0]: out}
except self.missing_exceptions as e:
raise KeyError from e
out = {
k: (KeyError() if isinstance(v, self.missing_exceptions) else v)
for k, v in out.items()
}
return {
key: out[k2]
for key, k2 in zip(keys, keys2)
if on_error == "return" or not isinstance(out[k2], BaseException)
}
def setitems(self, values_dict):
"""Set the values of multiple items in the store
Parameters
----------
values_dict: dict(str, bytes)
"""
values = {self._key_to_str(k): maybe_convert(v) for k, v in values_dict.items()}
self.fs.pipe(values)
def delitems(self, keys):
"""Remove multiple keys from the store"""
self.fs.rm([self._key_to_str(k) for k in keys])
def _key_to_str(self, key):
"""Generate full path for the key"""
if not isinstance(key, str):
# raise TypeError("key must be of type `str`, got `{type(key).__name__}`"
warnings.warn(
"from fsspec 2023.5 onward FSMap non-str keys will raise TypeError",
DeprecationWarning,
)
if isinstance(key, list):
key = tuple(key)
key = str(key)
return f"{self._root_key_to_str}{key}"
def _str_to_key(self, s):
"""Strip path of to leave key name"""
return s[len(self.root) :].lstrip("/")
def __getitem__(self, key, default=None):
"""Retrieve data"""
k = self._key_to_str(key)
try:
result = self.fs.cat(k)
except self.missing_exceptions:
if default is not None:
return default
raise KeyError(key)
return result
def pop(self, key, default=None):
"""Pop data"""
result = self.__getitem__(key, default)
try:
del self[key]
except KeyError:
pass
return result
def __setitem__(self, key, value):
"""Store value in key"""
key = self._key_to_str(key)
self.fs.mkdirs(self.fs._parent(key), exist_ok=True)
self.fs.pipe_file(key, maybe_convert(value))
def __iter__(self):
return (self._str_to_key(x) for x in self.fs.find(self.root))
def __len__(self):
return len(self.fs.find(self.root))
def __delitem__(self, key):
"""Remove key"""
try:
self.fs.rm(self._key_to_str(key))
except: # noqa: E722
raise KeyError
def __contains__(self, key):
"""Does key exist in mapping?"""
path = self._key_to_str(key)
return self.fs.exists(path) and self.fs.isfile(path)
def __reduce__(self):
return FSMap, (self.root, self.fs, False, False, self.missing_exceptions)
def maybe_convert(value):
if isinstance(value, array.array) or hasattr(value, "__array__"):
# bytes-like things
if hasattr(value, "dtype") and value.dtype.kind in "Mm":
# The buffer interface doesn't support datetime64/timdelta64 numpy
# arrays
value = value.view("int64")
value = bytes(memoryview(value))
return value
def get_mapper(
url="",
check=False,
create=False,
missing_exceptions=None,
alternate_root=None,
**kwargs,
):
"""Create key-value interface for given URL and options
The URL will be of the form "protocol://location" and point to the root
of the mapper required. All keys will be file-names below this location,
and their values the contents of each key.
Also accepts compound URLs like zip::s3://bucket/file.zip , see ``fsspec.open``.
Parameters
----------
url: str
Root URL of mapping
check: bool
Whether to attempt to read from the location before instantiation, to
check that the mapping does exist
create: bool
Whether to make the directory corresponding to the root before
instantiating
missing_exceptions: None or tuple
If given, these exception types will be regarded as missing keys and
return KeyError when trying to read data. By default, you get
(FileNotFoundError, IsADirectoryError, NotADirectoryError)
alternate_root: None or str
In cases of complex URLs, the parser may fail to pick the correct part
for the mapper root, so this arg can override
Returns
-------
``FSMap`` instance, the dict-like key-value store.
"""
# Removing protocol here - could defer to each open() on the backend
fs, urlpath = url_to_fs(url, **kwargs)
root = alternate_root if alternate_root is not None else urlpath
return FSMap(root, fs, check, create, missing_exceptions=missing_exceptions)
|