import io
import logging
import os
import warnings
from hashlib import md5
from glob import has_magic
from .asyn import get_loop, mirror_sync_methods
from .dircache import DirCache
from .transaction import Transaction
from .utils import read_block, tokenize, stringify_path, other_paths
logger = logging.getLogger("fsspec")
def make_instance(cls, args, kwargs):
return cls(*args, **kwargs)
class _Cached(type):
"""
Metaclass for caching file system instances.
Notes
-----
Instances are cached according to
* The values of the class attributes listed in `_extra_tokenize_attributes`
* The arguments passed to ``__init__``.
This creates an additional reference to the filesystem, which prevents the
filesystem from being garbage collected when all *user* references go away.
A call to the :meth:`AbstractFileSystem.clear_instance_cache` must *also*
be made for a filesystem instance to be garbage collected.
"""
cachable = True
_extra_tokenize_attributes = ()
def __init__(cls, *args, **kwargs):
super().__init__(*args, **kwargs)
# Note: we intentionally create a reference here, to avoid garbage
# collecting instances when all other references are gone. To really
# delete a FileSystem, the cache must be cleared.
cls._cache = {}
def __call__(cls, *args, **kwargs):
extra_tokens = tuple(
getattr(cls, attr, None) for attr in cls._extra_tokenize_attributes
)
token = tokenize(cls, *args, *extra_tokens, **kwargs)
skip = kwargs.pop("skip_instance_cache", False)
if not skip and cls.cachable and token in cls._cache:
return cls._cache[token]
else:
obj = super().__call__(*args, **kwargs)
# Setting _fs_token here causes some static linters to complain.
obj._fs_token_ = token
obj.storage_args = args
obj.storage_options = kwargs
if obj.async_impl:
mirror_sync_methods(obj)
if cls.cachable and not skip:
cls._cache[token] = obj
return obj
try: # optionally derive from pyarrow's FileSystem, if available
import pyarrow as pa
up = pa.filesystem.DaskFileSystem
except ImportError:
up = object
class AbstractFileSystem(up, metaclass=_Cached):
"""
An abstract super-class for pythonic file-systems
Implementations are expected to be compatible with or, better, subclass
from here.
"""
cachable = True # this class can be cached, instances reused
_cached = False
blocksize = 2 ** 22
sep = "/"
protocol = "abstract"
async_impl = False
root_marker = "" # For some FSs, may require leading '/' or other character
#: Extra *class attributes* that should be considered when hashing.
_extra_tokenize_attributes = ()
def __init__(self, *args, **storage_options):
"""Create and configure file-system instance
Instances may be cachable, so if similar enough arguments are seen
a new instance is not required. The token attribute exists to allow
implementations to cache instances if they wish.
A reasonable default should be provided if there are no arguments.
Subclasses should call this method.
Parameters
----------
use_listings_cache, listings_expiry_time, max_paths:
passed to ``DirCache``, if the implementation supports
directory listing caching. Pass use_listings_cache=False
to disable such caching.
skip_instance_cache: bool
If this is a cachable implementation, pass True here to force
creating a new instance even if a matching instance exists, and prevent
storing this instance.
asynchronous: bool
loop: asyncio-compatible IOLoop or None
"""
if self._cached:
# reusing instance, don't change
return
self._cached = True
self._intrans = False
self._transaction = None
if self.async_impl:
self.asynchronous = storage_options.get("asynchronous", False)
self.loop = storage_options.get("loop", None) or get_loop()
self.dircache = DirCache(**storage_options)
if storage_options.pop("add_docs", None):
warnings.warn("add_docs is no longer supported.", FutureWarning)
if storage_options.pop("add_aliases", None):
warnings.warn("add_aliases has been removed.", FutureWarning)
# This is set in _Cached
self._fs_token_ = None
@property
def _fs_token(self):
return self._fs_token_
def __dask_tokenize__(self):
return self._fs_token
def __hash__(self):
return int(self._fs_token, 16)
def __eq__(self, other):
return isinstance(other, type(self)) and self._fs_token == other._fs_token
def __reduce__(self):
return make_instance, (type(self), self.storage_args, self.storage_options)
@classmethod
def _strip_protocol(cls, path):
""" Turn path from fully-qualified to file-system-specific
May require FS-specific handling, e.g., for relative paths or links.
"""
path = stringify_path(path)
protos = (cls.protocol,) if isinstance(cls.protocol, str) else cls.protocol
for protocol in protos:
path = path.rstrip("/")
if path.startswith(protocol + "://"):
path = path[len(protocol) + 3 :]
elif path.startswith(protocol + ":"):
path = path[len(protocol) + 1 :]
# use of root_marker to make minimum required path, e.g., "/"
return path or cls.root_marker
@staticmethod
def _get_kwargs_from_urls(path):
"""If kwargs can be encoded in the paths, extract them here
This should happen before instantiation of the class; incoming paths
then should be amended to strip the options in methods.
Examples may look like an sftp path "sftp://user@host:/my/path", where
the user and host should become kwargs and later get stripped.
"""
# by default, nothing happens
return {}
@classmethod
def current(cls):
""" Return the most recently created FileSystem
If no instance has been created, then create one with defaults
"""
if not len(cls._cache):
return cls()
else:
return list(cls._cache.values())[-1]
@property
def transaction(self):
"""A context within which files are committed together upon exit
Requires the file class to implement `.commit()` and `.discard()`
for the normal and exception cases.
"""
if self._transaction is None:
self._transaction = Transaction(self)
return self._transaction
def start_transaction(self):
"""Begin write transaction for deferring files, non-context version"""
self._intrans = True
self._transaction = Transaction(self)
return self.transaction
def end_transaction(self):
"""Finish write transaction, non-context version"""
self.transaction.complete()
self._transaction = None
def invalidate_cache(self, path=None):
"""
Discard any cached directory information
Parameters
----------
path: string or None
If None, clear all listings cached else listings at or under given
path.
"""
pass # not necessary to implement, may have no cache
def mkdir(self, path, create_parents=True, **kwargs):
"""
Create directory entry at path
For systems that don't have true directories, may create an for
this instance only and not touch the real filesystem
Parameters
----------
path: str
location
create_parents: bool
if True, this is equivalent to ``makedirs``
kwargs:
may be permissions, etc.
"""
pass # not necessary to implement, may not have directories
def makedirs(self, path, exist_ok=False):
"""Recursively make directories
Creates directory at path and any intervening required directories.
Raises exception if, for instance, the path already exists but is a
file.
Parameters
----------
path: str
leaf directory name
exist_ok: bool (False)
If True, will error if the target already exists
"""
pass # not necessary to implement, may not have directories
def rmdir(self, path):
"""Remove a directory, if empty"""
pass # not necessary to implement, may not have directories
def ls(self, path, detail=True, **kwargs):
"""List objects at path.
This should include subdirectories and files at that location. The
difference between a file and a directory must be clear when details
are requested.
The specific keys, or perhaps a FileInfo class, or similar, is TBD,
but must be consistent across implementations.
Must include:
- full path to the entry (without protocol)
- size of the entry, in bytes. If the value cannot be determined, will
be ``None``.
- type of entry, "file", "directory" or other
Additional information
may be present, aproriate to the file-system, e.g., generation,
checksum, etc.
May use refresh=True|False to allow use of self._ls_from_cache to
check for a saved listing and avoid calling the backend. This would be
common where listing may be expensive.
Parameters
----------
path: str
detail: bool
if True, gives a list of dictionaries, where each is the same as
the result of ``info(path)``. If False, gives a list of paths
(str).
kwargs: may have additional backend-specific options, such as version
information
Returns
-------
List of strings if detail is False, or list of directory information
dicts if detail is True.
"""
raise NotImplementedError
def _ls_from_cache(self, path):
"""Check cache for listing
Returns listing, if found (may me empty list for a directly that exists
but contains nothing), None if not in cache.
"""
parent = self._parent(path)
try:
return self.dircache[path]
except KeyError:
pass
try:
files = [f for f in self.dircache[parent] if f["name"] == path]
if len(files) == 0:
# parent dir was listed but did not contain this file
raise FileNotFoundError(path)
return files
except KeyError:
pass
def walk(self, path, maxdepth=None, **kwargs):
""" Return all files belows path
List all files, recursing into subdirectories; output is iterator-style,
like ``os.walk()``. For a simple list of files, ``find()`` is available.
Note that the "files" outputted will include anything that is not
a directory, such as links.
Parameters
----------
path: str
Root to recurse into
maxdepth: int
Maximum recursion depth. None means limitless, but not recommended
on link-based file-systems.
kwargs: passed to ``ls``
"""
path = self._strip_protocol(path)
full_dirs = {}
dirs = {}
files = {}
detail = kwargs.pop("detail", False)
try:
listing = self.ls(path, detail=True, **kwargs)
except (FileNotFoundError, IOError):
return [], [], []
for info in listing:
# each info name must be at least [path]/part , but here
# we check also for names like [path]/part/
pathname = info["name"].rstrip("/")
name = pathname.rsplit("/", 1)[-1]
if info["type"] == "directory" and pathname != path:
# do not include "self" path
full_dirs[pathname] = info
dirs[name] = info
elif pathname == path:
# file-like with same name as give path
files[""] = info
else:
files[name] = info
if detail:
yield path, dirs, files
else:
yield path, list(dirs), list(files)
if maxdepth is not None:
maxdepth -= 1
if maxdepth < 1:
return
for d in full_dirs:
yield from self.walk(d, maxdepth=maxdepth, detail=detail, **kwargs)
def find(self, path, maxdepth=None, withdirs=False, **kwargs):
"""List all files below path.
Like posix ``find`` command without conditions
Parameters
----------
path : str
maxdepth: int or None
If not None, the maximum number of levels to descend
withdirs: bool
Whether to include directory paths in the output. This is True
when used by glob, but users usually only want files.
kwargs are passed to ``ls``.
"""
# TODO: allow equivalent of -name parameter
path = self._strip_protocol(path)
out = dict()
detail = kwargs.pop("detail", False)
for path, dirs, files in self.walk(path, maxdepth, detail=True, **kwargs):
if withdirs:
files.update(dirs)
out.update({info["name"]: info for name, info in files.items()})
if self.isfile(path) and path not in out:
# walk works on directories, but find should also return [path]
# when path happens to be a file
out[path] = {}
names = sorted(out)
if not detail:
return names
else:
return {name: out[name] for name in names}
def du(self, path, total=True, maxdepth=None, **kwargs):
"""Space used by files within a path
Parameters
----------
path: str
total: bool
whether to sum all the file sizes
maxdepth: int or None
maximum number of directory levels to descend, None for unlimited.
kwargs: passed to ``ls``
Returns
-------
Dict of {fn: size} if total=False, or int otherwise, where numbers
refer to bytes used.
"""
sizes = {}
for f in self.find(path, maxdepth=maxdepth, **kwargs):
info = self.info(f)
sizes[info["name"]] = info["size"]
if total:
return sum(sizes.values())
else:
return sizes
def glob(self, path, **kwargs):
"""
Find files by glob-matching.
If the path ends with '/' and does not contain "*", it is essentially
the same as ``ls(path)``, returning only files.
We support ``"**"``,
``"?"`` and ``"[..]"``.
kwargs are passed to ``ls``.
"""
import re
ends = path.endswith("/")
path = self._strip_protocol(path)
indstar = path.find("*") if path.find("*") >= 0 else len(path)
indques = path.find("?") if path.find("?") >= 0 else len(path)
indbrace = path.find("[") if path.find("[") >= 0 else len(path)
ind = min(indstar, indques, indbrace)
detail = kwargs.pop("detail", False)
if not has_magic(path):
root = path
depth = 1
if ends:
path += "/*"
elif self.exists(path):
if not detail:
return [path]
else:
return {path: self.info(path)}
else:
if not detail:
return [] # glob of non-existent returns empty
else:
return {}
elif "/" in path[:ind]:
ind2 = path[:ind].rindex("/")
root = path[: ind2 + 1]
depth = 20 if "**" in path else path[ind2 + 1 :].count("/") + 1
else:
root = ""
depth = 20 if "**" in path else 1
allpaths = self.find(root, maxdepth=depth, withdirs=True, detail=True, **kwargs)
pattern = (
"^"
+ (
path.replace("\\", r"\\")
.replace(".", r"\.")
.replace("+", r"\+")
.replace("//", "/")
.replace("(", r"\(")
.replace(")", r"\)")
.replace("|", r"\|")
.rstrip("/")
.replace("?", ".")
)
+ "$"
)
pattern = re.sub("[*]{2}", "=PLACEHOLDER=", pattern)
pattern = re.sub("[*]", "[^/]*", pattern)
pattern = re.compile(pattern.replace("=PLACEHOLDER=", ".*"))
out = {
p: allpaths[p]
for p in sorted(allpaths)
if pattern.match(p.replace("//", "/").rstrip("/"))
}
if detail:
return out
else:
return list(out)
def exists(self, path):
"""Is there a file at the given path"""
try:
self.info(path)
return True
except: # noqa: E722
# any exception allowed bar FileNotFoundError?
return False
def info(self, path, **kwargs):
"""Give details of entry at path
Returns a single dictionary, with exactly the same information as ``ls``
would with ``detail=True``.
The default implementation should calls ls and could be overridden by a
shortcut. kwargs are passed on to ```ls()``.
Some file systems might not be able to measure the file's size, in
which case, the returned dict will include ``'size': None``.
Returns
-------
dict with keys: name (full path in the FS), size (in bytes), type (file,
directory, or something else) and other FS-specific keys.
"""
path = self._strip_protocol(path)
out = self.ls(self._parent(path), detail=True, **kwargs)
out = [o for o in out if o["name"].rstrip("/") == path]
if out:
return out[0]
out = self.ls(path, detail=True, **kwargs)
path = path.rstrip("/")
out1 = [o for o in out if o["name"].rstrip("/") == path]
if len(out1) == 1:
if "size" not in out1[0]:
out1[0]["size"] = None
return out1[0]
elif len(out1) > 1 or out:
return {"name": path, "size": 0, "type": "directory"}
else:
raise FileNotFoundError(path)
def checksum(self, path):
"""Unique value for current version of file
If the checksum is the same from one moment to another, the contents
are guaranteed to be the same. If the checksum changes, the contents
*might* have changed.
This should normally be overridden; default will probably capture
creation/modification timestamp (which would be good) or maybe
access timestamp (which would be bad)
"""
return int(tokenize(self.info(path)), 16)
def size(self, path):
"""Size in bytes of file"""
return self.info(path).get("size", None)
def isdir(self, path):
"""Is this entry directory-like?"""
try:
return self.info(path)["type"] == "directory"
except IOError:
return False
def isfile(self, path):
"""Is this entry file-like?"""
try:
return self.info(path)["type"] == "file"
except: # noqa: E722
return False
def cat_file(self, path):
""" Get the content of a file """
return self.open(path, "rb").read()
def pipe_file(self, path, value, **kwargs):
"""Set the bytes of given file"""
with self.open(path, "wb") as f:
f.write(value)
def pipe(self, path, value=None, **kwargs):
"""Put value into path
(counterpart to ``cat``)
Parameters
----------
path: string or dict(str, bytes)
If a string, a single remote location to put ``value`` bytes; if a dict,
a mapping of {path: bytesvalue}.
value: bytes, optional
If using a single path, these are the bytes to put there. Ignored if
``path`` is a dict
"""
if isinstance(path, str):
self.pipe_file(path, value, **kwargs)
elif isinstance(path, dict):
for k, v in path.items():
self.pipe_file(k, v, **kwargs)
else:
raise ValueError("path must be str or dict")
def cat(self, path, recursive=False, **kwargs):
"""Fetch (potentially multiple) paths' contents
Returns a dict of {path: contents} if there are multiple paths
or the path has been otherwise expanded
"""
paths = self.expand_path(path, recursive=recursive)
if len(paths) > 1 or isinstance(path, list) or paths[0] != path:
return {path: self.cat_file(path, **kwargs) for path in paths}
else:
return self.cat_file(paths[0])
def get_file(self, rpath, lpath, **kwargs):
"""Copy single remote file to local"""
if self.isdir(rpath):
os.makedirs(lpath, exist_ok=True)
else:
with self.open(rpath, "rb", **kwargs) as f1:
with open(lpath, "wb") as f2:
data = True
while data:
data = f1.read(self.blocksize)
f2.write(data)
def get(self, rpath, lpath, recursive=False, **kwargs):
"""Copy file(s) to local.
Copies a specific file or tree of files (if recursive=True). If lpath
ends with a "/", it will be assumed to be a directory, and target files
will go within.
Calls get_file for each source.
"""
from .implementations.local import make_path_posix
rpath = self._strip_protocol(rpath)
if isinstance(lpath, str):
lpath = make_path_posix(lpath)
rpaths = self.expand_path(rpath, recursive=recursive)
lpaths = other_paths(rpaths, lpath)
for lpath, rpath in zip(lpaths, rpaths):
self.get_file(rpath, lpath, **kwargs)
def put_file(self, lpath, rpath, **kwargs):
"""Copy single file to remote"""
if os.path.isdir(lpath):
self.makedirs(rpath, exist_ok=True)
else:
with open(lpath, "rb") as f1:
self.mkdirs(os.path.dirname(rpath), exist_ok=True)
with self.open(rpath, "wb", **kwargs) as f2:
data = True
while data:
data = f1.read(self.blocksize)
f2.write(data)
def put(self, lpath, rpath, recursive=False, **kwargs):
"""Copy file(s) from local.
Copies a specific file or tree of files (if recursive=True). If rpath
ends with a "/", it will be assumed to be a directory, and target files
will go within.
Calls put_file for each source.
"""
from .implementations.local import make_path_posix, LocalFileSystem
rpath = self._strip_protocol(rpath)
if isinstance(lpath, str):
lpath = make_path_posix(lpath)
fs = LocalFileSystem()
lpaths = fs.expand_path(lpath, recursive=recursive)
rpaths = other_paths(lpaths, rpath)
for lpath, rpath in zip(lpaths, rpaths):
self.put_file(lpath, rpath, **kwargs)
def head(self, path, size=1024):
""" Get the first ``size`` bytes from file """
with self.open(path, "rb") as f:
return f.read(size)
def tail(self, path, size=1024):
""" Get the last ``size`` bytes from file """
with self.open(path, "rb") as f:
f.seek(max(-size, -f.size), 2)
return f.read()
def cp_file(self, path1, path2, **kwargs):
raise NotImplementedError
def copy(self, path1, path2, recursive=False, **kwargs):
""" Copy within two locations in the filesystem"""
paths = self.expand_path(path1, recursive=recursive)
path2 = other_paths(paths, path2)
for p1, p2 in zip(paths, path2):
self.cp_file(p1, p2, **kwargs)
def expand_path(self, path, recursive=False, maxdepth=None):
"""Turn one or more globs or directories into a list of all matching files"""
if isinstance(path, str):
out = self.expand_path([path], recursive, maxdepth)
else:
out = set()
for p in path:
if has_magic(p):
bit = set(self.glob(p))
out |= bit
if recursive:
out += self.expand_path(p)
elif recursive:
out |= set(self.find(p, withdirs=True))
out.add(p)
if not out:
raise FileNotFoundError(path)
return list(sorted(out))
def mv(self, path1, path2, recursive=False, maxdepth=None, **kwargs):
""" Move file(s) from one location to another """
self.copy(path1, path2, recursive=recursive, maxdepth=maxdepth)
self.rm(path1, recursive=recursive)
def rm_file(self, path):
"""Delete a file"""
raise NotImplementedError
def rm(self, path, recursive=False, maxdepth=None):
"""Delete files.
Parameters
----------
path: str or list of str
File(s) to delete.
recursive: bool
If file(s) are directories, recursively delete contents and then
also remove the directory
maxdepth: int or None
Depth to pass to walk for finding files to delete, if recursive.
If None, there will be no limit and infinite recursion may be
possible.
"""
path = self.expand_path(path, recursive=recursive, maxdepth=maxdepth)
for p in reversed(path):
self._rm(p)
@classmethod
def _parent(cls, path):
path = cls._strip_protocol(path.rstrip("/"))
if "/" in path:
return cls.root_marker + path.rsplit("/", 1)[0]
else:
return cls.root_marker
def _open(
self,
path,
mode="rb",
block_size=None,
autocommit=True,
cache_options=None,
**kwargs
):
"""Return raw bytes-mode file-like from the file-system"""
return AbstractBufferedFile(
self,
path,
mode,
block_size,
autocommit,
cache_options=cache_options,
**kwargs
)
def open(self, path, mode="rb", block_size=None, cache_options=None, **kwargs):
"""
Return a file-like object from the filesystem
The resultant instance must function correctly in a context ``with``
block.
Parameters
----------
path: str
Target file
mode: str like 'rb', 'w'
See builtin ``open()``
block_size: int
Some indication of buffering - this is a value in bytes
cache_options : dict, optional
Extra arguments to pass through to the cache.
encoding, errors, newline: passed on to TextIOWrapper for text mode
"""
import io
path = self._strip_protocol(path)
if "b" not in mode:
mode = mode.replace("t", "") + "b"
text_kwargs = {
k: kwargs.pop(k)
for k in ["encoding", "errors", "newline"]
if k in kwargs
}
return io.TextIOWrapper(
self.open(path, mode, block_size, **kwargs), **text_kwargs
)
else:
ac = kwargs.pop("autocommit", not self._intrans)
f = self._open(
path,
mode=mode,
block_size=block_size,
autocommit=ac,
cache_options=cache_options,
**kwargs
)
if not ac:
self.transaction.files.append(f)
return f
def touch(self, path, truncate=True, **kwargs):
""" Create empty file, or update timestamp
Parameters
----------
path: str
file location
truncate: bool
If True, always set file size to 0; if False, update timestamp and
leave file unchanged, if backend allows this
"""
if truncate or not self.exists(path):
with self.open(path, "wb", **kwargs):
pass
else:
raise NotImplementedError # update timestamp, if possible
def ukey(self, path):
"""Hash of file properties, to tell if it has changed"""
return md5(str(self.info(path)).encode()).hexdigest()
def read_block(self, fn, offset, length, delimiter=None):
""" Read a block of bytes from
Starting at ``offset`` of the file, read ``length`` bytes. If
``delimiter`` is set then we ensure that the read starts and stops at
delimiter boundaries that follow the locations ``offset`` and ``offset
+ length``. If ``offset`` is zero then we start at zero. The
bytestring returned WILL include the end delimiter string.
If offset+length is beyond the eof, reads to eof.
Parameters
----------
fn: string
Path to filename
offset: int
Byte offset to start read
length: int
Number of bytes to read
delimiter: bytes (optional)
Ensure reading starts and stops at delimiter bytestring
Examples
--------
>>> fs.read_block('data/file.csv', 0, 13) # doctest: +SKIP
b'Alice, 100\\nBo'
>>> fs.read_block('data/file.csv', 0, 13, delimiter=b'\\n') # doctest: +SKIP
b'Alice, 100\\nBob, 200\\n'
Use ``length=None`` to read to the end of the file.
>>> fs.read_block('data/file.csv', 0, None, delimiter=b'\\n') # doctest: +SKIP
b'Alice, 100\\nBob, 200\\nCharlie, 300'
See Also
--------
utils.read_block
"""
with self.open(fn, "rb") as f:
size = f.size
if length is None:
length = size
if size is not None and offset + length > size:
length = size - offset
return read_block(f, offset, length, delimiter)
def to_json(self):
"""
JSON representation of this filesystem instance
Returns
-------
str: JSON structure with keys cls (the python location of this class),
protocol (text name of this class's protocol, first one in case of
multiple), args (positional args, usually empty), and all other
kwargs as their own keys.
"""
import json
cls = type(self)
cls = ".".join((cls.__module__, cls.__name__))
proto = (
self.protocol[0]
if isinstance(self.protocol, (tuple, list))
else self.protocol
)
return json.dumps(
dict(
**{"cls": cls, "protocol": proto, "args": self.storage_args},
**self.storage_options
)
)
@staticmethod
def from_json(blob):
"""
Recreate a filesystem instance from JSON representation
See ``.to_json()`` for the expected structure of the input
Parameters
----------
blob: str
Returns
-------
file system instance, not necessarily of this particular class.
"""
from .registry import _import_class, get_filesystem_class
import json
dic = json.loads(blob)
protocol = dic.pop("protocol")
try:
cls = _import_class(dic.pop("cls"))
except (ImportError, ValueError, RuntimeError, KeyError):
cls = get_filesystem_class(protocol)
return cls(*dic.pop("args", ()), **dic)
def _get_pyarrow_filesystem(self):
"""
Make a version of the FS instance which will be acceptable to pyarrow
"""
# all instances already also derive from pyarrow
return self
def get_mapper(self, root, check=False, create=False):
"""Create key/value store based on this file-system
Makes a MutibleMapping interface to the FS at the given root path.
See ``fsspec.mapping.FSMap`` for further details.
"""
from .mapping import FSMap
return FSMap(root, self, check, create)
@classmethod
def clear_instance_cache(cls):
"""
Clear the cache of filesystem instances.
Notes
-----
Unless overridden by setting the ``cachable`` class attribute to False,
the filesystem class stores a reference to newly created instances. This
prevents Python's normal rules around garbage collection from working,
since the instances refcount will not drop to zero until
``clear_instance_cache`` is called.
"""
cls._cache.clear()
# ------------------------------------------------------------------------
# Aliases
def makedir(self, path, create_parents=True, **kwargs):
"""Alias of :ref:`FilesystemSpec.mkdir`."""
return self.mkdir(path, create_parents=create_parents, **kwargs)
def mkdirs(self, path, exist_ok=False):
"""Alias of :ref:`FilesystemSpec.makedirs`."""
return self.makedirs(path, exist_ok=exist_ok)
def listdir(self, path, detail=True, **kwargs):
"""Alias of :ref:`FilesystemSpec.ls`."""
return self.ls(path, detail=detail, **kwargs)
def cp(self, path1, path2, **kwargs):
"""Alias of :ref:`FilesystemSpec.copy`."""
return self.copy(path1, path2, **kwargs)
def move(self, path1, path2, **kwargs):
"""Alias of :ref:`FilesystemSpec.mv`."""
return self.mv(path1, path2, **kwargs)
def stat(self, path, **kwargs):
"""Alias of :ref:`FilesystemSpec.info`."""
return self.info(path, **kwargs)
def disk_usage(self, path, total=True, maxdepth=None, **kwargs):
"""Alias of :ref:`FilesystemSpec.du`."""
return self.du(path, total=total, maxdepth=maxdepth, **kwargs)
def rename(self, path1, path2, **kwargs):
"""Alias of :ref:`FilesystemSpec.mv`."""
return self.mv(path1, path2, **kwargs)
def delete(self, path, recursive=False, maxdepth=None):
"""Alias of :ref:`FilesystemSpec.rm`."""
return self.rm(path, recursive=recursive, maxdepth=maxdepth)
def upload(self, lpath, rpath, recursive=False, **kwargs):
"""Alias of :ref:`FilesystemSpec.put`."""
return self.put(lpath, rpath, recursive=recursive, **kwargs)
def download(self, rpath, lpath, recursive=False, **kwargs):
"""Alias of :ref:`FilesystemSpec.get`."""
return self.get(rpath, lpath, recursive=recursive, **kwargs)
def created(self, path):
"""Return the created timestamp of a file as a datetime.datetime"""
raise NotImplementedError
def modified(self, path):
"""Return the modified timestamp of a file as a datetime.datetime"""
raise NotImplementedError
class AbstractBufferedFile(io.IOBase):
"""Convenient class to derive from to provide buffering
In the case that the backend does not provide a pythonic file-like object
already, this class contains much of the logic to build one. The only
methods that need to be overridden are ``_upload_chunk``,
``_initate_upload`` and ``_fetch_range``.
"""
DEFAULT_BLOCK_SIZE = 5 * 2 ** 20
def __init__(
self,
fs,
path,
mode="rb",
block_size="default",
autocommit=True,
cache_type="readahead",
cache_options=None,
**kwargs
):
"""
Template for files with buffered reading and writing
Parameters
----------
fs: instance of FileSystem
path: str
location in file-system
mode: str
Normal file modes. Currently only 'wb', 'ab' or 'rb'. Some file
systems may be read-only, and some may not support append.
block_size: int
Buffer size for reading or writing, 'default' for class default
autocommit: bool
Whether to write to final destination; may only impact what
happens when file is being closed.
cache_type: {"readahead", "none", "mmap", "bytes"}, default "readahead"
Caching policy in read mode. See the definitions in ``core``.
cache_options : dict
Additional options passed to the constructor for the cache specified
by `cache_type`.
kwargs:
Gets stored as self.kwargs
"""
from .core import caches
self.path = path
self.fs = fs
self.mode = mode
self.blocksize = (
self.DEFAULT_BLOCK_SIZE if block_size in ["default", None] else block_size
)
self.loc = 0
self.autocommit = autocommit
self.end = None
self.start = None
self.closed = False
if cache_options is None:
cache_options = {}
if "trim" in kwargs:
warnings.warn(
"Passing 'trim' to control the cache behavior has been deprecated. "
"Specify it within the 'cache_options' argument instead.",
FutureWarning,
)
cache_options["trim"] = kwargs.pop("trim")
self.kwargs = kwargs
if mode not in {"ab", "rb", "wb"}:
raise NotImplementedError("File mode not supported")
if mode == "rb":
if not hasattr(self, "details"):
self.details = fs.info(path)
self.size = self.details["size"]
self.cache = caches[cache_type](
self.blocksize, self._fetch_range, self.size, **cache_options
)
else:
self.buffer = io.BytesIO()
self.offset = None
self.forced = False
self.location = None
@property
def closed(self):
# get around this attr being read-only in IOBase
# use getattr here, since this can be called during del
return getattr(self, "_closed", True)
@closed.setter
def closed(self, c):
self._closed = c
def __hash__(self):
if "w" in self.mode:
return id(self)
else:
return int(tokenize(self.details), 16)
def __eq__(self, other):
"""Files are equal if they have the same checksum, only in read mode"""
return self.mode == "rb" and other.mode == "rb" and hash(self) == hash(other)
def commit(self):
"""Move from temp to final destination"""
def discard(self):
"""Throw away temporary file"""
def info(self):
""" File information about this path """
if "r" in self.mode:
return self.details
else:
raise ValueError("Info not available while writing")
def tell(self):
""" Current file location """
return self.loc
def seek(self, loc, whence=0):
""" Set current file location
Parameters
----------
loc: int
byte location
whence: {0, 1, 2}
from start of file, current location or end of file, resp.
"""
loc = int(loc)
if not self.mode == "rb":
raise OSError("Seek only available in read mode")
if whence == 0:
nloc = loc
elif whence == 1:
nloc = self.loc + loc
elif whence == 2:
nloc = self.size + loc
else:
raise ValueError("invalid whence (%s, should be 0, 1 or 2)" % whence)
if nloc < 0:
raise ValueError("Seek before start of file")
self.loc = nloc
return self.loc
def write(self, data):
"""
Write data to buffer.
Buffer only sent on flush() or if buffer is greater than
or equal to blocksize.
Parameters
----------
data: bytes
Set of bytes to be written.
"""
if self.mode not in {"wb", "ab"}:
raise ValueError("File not in write mode")
if self.closed:
raise ValueError("I/O operation on closed file.")
if self.forced:
raise ValueError("This file has been force-flushed, can only close")
out = self.buffer.write(data)
self.loc += out
if self.buffer.tell() >= self.blocksize:
self.flush()
return out
def flush(self, force=False):
"""
Write buffered data to backend store.
Writes the current buffer, if it is larger than the block-size, or if
the file is being closed.
Parameters
----------
force: bool
When closing, write the last block even if it is smaller than
blocks are allowed to be. Disallows further writing to this file.
"""
if self.closed:
raise ValueError("Flush on closed file")
if force and self.forced:
raise ValueError("Force flush cannot be called more than once")
if force:
self.forced = True
if self.mode not in {"wb", "ab"}:
# no-op to flush on read-mode
return
if not force and self.buffer.tell() < self.blocksize:
# Defer write on small block
return
if self.offset is None:
# Initialize a multipart upload
self.offset = 0
self._initiate_upload()
if self._upload_chunk(final=force) is not False:
self.offset += self.buffer.seek(0, 2)
self.buffer = io.BytesIO()
def _upload_chunk(self, final=False):
""" Write one part of a multi-block file upload
Parameters
==========
final: bool
This is the last block, so should complete file, if
self.autocommit is True.
"""
# may not yet have been initialized, may neet to call _initialize_upload
def _initiate_upload(self):
""" Create remote file/upload """
pass
def _fetch_range(self, start, end):
"""Get the specified set of bytes from remote"""
raise NotImplementedError
def read(self, length=-1):
"""
Return data from cache, or fetch pieces as necessary
Parameters
----------
length: int (-1)
Number of bytes to read; if <0, all remaining bytes.
"""
length = -1 if length is None else int(length)
if self.mode != "rb":
raise ValueError("File not in read mode")
if length < 0:
length = self.size - self.loc
if self.closed:
raise ValueError("I/O operation on closed file.")
logger.debug("%s read: %i - %i" % (self, self.loc, self.loc + length))
if length == 0:
# don't even bother calling fetch
return b""
out = self.cache._fetch(self.loc, self.loc + length)
self.loc += len(out)
return out
def readinto(self, b):
"""mirrors builtin file's readinto method
https://docs.python.org/3/library/io.html#io.RawIOBase.readinto
"""
data = self.read(len(b))
memoryview(b).cast("B")[: len(data)] = data
return len(data)
def readuntil(self, char=b"\n", blocks=None):
"""Return data between current position and first occurrence of char
char is included in the output, except if the end of the tile is
encountered first.
Parameters
----------
char: bytes
Thing to find
blocks: None or int
How much to read in each go. Defaults to file blocksize - which may
mean a new read on every call.
"""
out = []
while True:
start = self.tell()
part = self.read(blocks or self.blocksize)
if len(part) == 0:
break
found = part.find(char)
if found > -1:
out.append(part[: found + len(char)])
self.seek(start + found + len(char))
break
out.append(part)
return b"".join(out)
def readline(self):
"""Read until first occurrence of newline character
Note that, because of character encoding, this is not necessarily a
true line ending.
"""
return self.readuntil(b"\n")
def __next__(self):
out = self.readline()
if out:
return out
raise StopIteration
def __iter__(self):
return self
def readlines(self):
"""Return all data, split by the newline character"""
data = self.read()
lines = data.split(b"\n")
out = [l + b"\n" for l in lines[:-1]]
if data.endswith(b"\n"):
return out
else:
return out + [lines[-1]]
# return list(self) ???
def readinto1(self, b):
return self.readinto(b)
def close(self):
""" Close file
Finalizes writes, discards cache
"""
if self.closed:
return
if self.mode == "rb":
self.cache = None
else:
if not self.forced:
self.flush(force=True)
if self.fs is not None:
self.fs.invalidate_cache(self.path)
self.fs.invalidate_cache(self.fs._parent(self.path))
self.closed = True
def readable(self):
"""Whether opened for reading"""
return self.mode == "rb" and not self.closed
def seekable(self):
"""Whether is seekable (only in read mode)"""
return self.readable()
def writable(self):
"""Whether opened for writing"""
return self.mode in {"wb", "ab"} and not self.closed
def __del__(self):
self.close()
def __str__(self):
return "<File-like object %s, %s>" % (type(self.fs).__name__, self.path)
__repr__ = __str__
def __enter__(self):
return self
def __exit__(self, *args):
self.close()
