Source code for fsspec.spec

import io
import logging
import os
import threading
import warnings
import weakref
from distutils.version import LooseVersion
from errno import ESPIPE
from glob import has_magic
from hashlib import sha256

from .callbacks import _DEFAULT_CALLBACK
from .config import apply_config, conf
from .dircache import DirCache
from .transaction import Transaction
from .utils import (
    _unstrip_protocol,
    get_package_version_without_import,
    other_paths,
    read_block,
    stringify_path,
    tokenize,
)

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.
    """

    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.
        if conf.get("weakref_instance_cache"):  # pragma: no cover
            # debug option for analysing fork/spawn conditions
            cls._cache = weakref.WeakValueDictionary()
        else:
            cls._cache = {}
        cls._pid = os.getpid()

    def __call__(cls, *args, **kwargs):
        kwargs = apply_config(cls, kwargs)
        extra_tokens = tuple(
            getattr(cls, attr, None) for attr in cls._extra_tokenize_attributes
        )
        token = tokenize(
            cls, cls._pid, threading.get_ident(), *args, *extra_tokens, **kwargs
        )
        skip = kwargs.pop("skip_instance_cache", False)
        if os.getpid() != cls._pid:
            cls._cache.clear()
            cls._pid = os.getpid()
        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:
                from .asyn import mirror_sync_methods

                mirror_sync_methods(obj)

            if cls.cachable and not skip:
                cls._cache[token] = obj
            return obj


pa_version = get_package_version_without_import("pyarrow")
if pa_version and LooseVersion(pa_version) < LooseVersion("2.0"):
    try:
        import pyarrow as pa

        up = pa.filesystem.DaskFileSystem
    except ImportError:  # pragma: no cover
        # pyarrow exists but doesn't import for some reason
        up = object
else:  # pragma: no cover
    up = object


[docs]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 self._invalidated_caches_in_transaction = [] 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. """ if isinstance(path, list): return [cls._strip_protocol(p) for p in path] path = stringify_path(path) protos = (cls.protocol,) if isinstance(cls.protocol, str) else cls.protocol for protocol in protos: if path.startswith(protocol + "://"): path = path[len(protocol) + 3 :] elif path.startswith(protocol + "::"): path = path[len(protocol) + 2 :] path = path.rstrip("/") # 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 {}
[docs] @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
[docs] def start_transaction(self): """Begin write transaction for deferring files, non-context version""" self._intrans = True self._transaction = Transaction(self) return self.transaction
[docs] def end_transaction(self): """Finish write transaction, non-context version""" self.transaction.complete() self._transaction = None # The invalid cache must be cleared after the transcation is completed. for path in self._invalidated_caches_in_transaction: self.invalidate_cache(path) self._invalidated_caches_in_transaction.clear()
[docs] 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. """ # Not necessary to implement invalidation mechanism, may have no cache. # But if have, you should call this method of parent class from your # subclass to ensure expiring caches after transacations correctly. # See the implementation of FTPFileSystem in ftp.py if self._intrans: self._invalidated_caches_in_transaction.append(path)
[docs] 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
[docs] 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
[docs] def rmdir(self, path): """Remove a directory, if empty""" pass # not necessary to implement, may not have directories
[docs] 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) if path.rstrip("/") in self.dircache: return self.dircache[path.rstrip("/")] try: files = [ f for f in self.dircache[parent] if f["name"] == path or (f["name"] == path.rstrip("/") and f["type"] == "directory") ] if len(files) == 0: # parent dir was listed but did not contain this file raise FileNotFoundError(path) return files except KeyError: pass
[docs] 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): if detail: return path, {}, {} return path, [], [] 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)
[docs] 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 _, 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 not out and self.isfile(path): # 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}
[docs] 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
[docs] 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 ``"[..]"``. We do not support ^ for pattern negation. Search path names that contain embedded characters special to this implementation of glob may not produce expected results; e.g., 'foo/bar/*starredfilename*'. 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 = None if "**" in path else path[ind2 + 1 :].count("/") + 1 else: root = "" depth = None if "**" in path else path[ind + 1 :].count("/") + 1 allpaths = self.find(root, maxdepth=depth, withdirs=True, detail=True, **kwargs) # Escape characters special to python regex, leaving our supported # special characters in place. # See https://www.gnu.org/software/bash/manual/html_node/Pattern-Matching.html # for shell globbing details. pattern = ( "^" + ( path.replace("\\", r"\\") .replace(".", r"\.") .replace("+", r"\+") .replace("//", "/") .replace("(", r"\(") .replace(")", r"\)") .replace("|", r"\|") .replace("^", r"\^") .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)
[docs] def exists(self, path, **kwargs): """Is there a file at the given path""" try: self.info(path, **kwargs) return True except: # noqa: E722 # any exception allowed bar FileNotFoundError? return False
[docs] def lexists(self, path, **kwargs): """If there is a file at the given path (including broken links)""" return self.exists(path)
[docs] 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)
[docs] 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)
[docs] def size(self, path): """Size in bytes of file""" return self.info(path).get("size", None)
[docs] def isdir(self, path): """Is this entry directory-like?""" try: return self.info(path)["type"] == "directory" except IOError: return False
[docs] def isfile(self, path): """Is this entry file-like?""" try: return self.info(path)["type"] == "file" except: # noqa: E722 return False
[docs] def cat_file(self, path, start=None, end=None, **kwargs): """Get the content of a file Parameters ---------- path: URL of file on this filesystems start, end: int Bytes limits of the read. If negative, backwards from end, like usual python slices. Either can be None for start or end of file, respectively kwargs: passed to ``open()``. """ # explicitly set buffering off? with self.open(path, "rb", **kwargs) as f: if start is not None: if start >= 0: f.seek(start) else: f.seek(max(0, f.size + start)) if end is not None: if end < 0: end = f.size + end return f.read(end - f.tell()) return f.read()
[docs] def pipe_file(self, path, value, **kwargs): """Set the bytes of given file""" with self.open(path, "wb") as f: f.write(value)
[docs] 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(self._strip_protocol(path), value, **kwargs) elif isinstance(path, dict): for k, v in path.items(): self.pipe_file(self._strip_protocol(k), v, **kwargs) else: raise ValueError("path must be str or dict")
def cat_ranges(self, paths, starts, ends, max_gap=None, **kwargs): if max_gap is not None: raise NotImplementedError if not isinstance(paths, list): raise TypeError if not isinstance(starts, list): starts = [starts] * len(paths) if not isinstance(ends, list): ends = [starts] * len(paths) if len(starts) != len(paths) or len(ends) != len(paths): raise ValueError return [self.cat_file(p, s, e) for p, s, e in zip(paths, starts, ends)]
[docs] def cat(self, path, recursive=False, on_error="raise", **kwargs): """Fetch (potentially multiple) paths' contents Parameters ---------- recursive: bool If True, assume the path(s) are directories, and get all the contained files 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. kwargs: passed to cat_file Returns ------- 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] != self._strip_protocol(path) ): out = {} for path in paths: try: out[path] = self.cat_file(path, **kwargs) except Exception as e: if on_error == "raise": raise if on_error == "return": out[path] = e return out else: return self.cat_file(paths[0], **kwargs)
[docs] def get_file(self, rpath, lpath, callback=_DEFAULT_CALLBACK, **kwargs): """Copy single remote file to local""" if self.isdir(rpath): os.makedirs(lpath, exist_ok=True) return None with self.open(rpath, "rb", **kwargs) as f1: callback.set_size(getattr(f1, "size", None)) with open(lpath, "wb") as f2: data = True while data: data = f1.read(self.blocksize) segment_len = f2.write(data) callback.relative_update(segment_len)
[docs] def get(self, rpath, lpath, recursive=False, callback=_DEFAULT_CALLBACK, **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. Can submit a list of paths, which may be glob-patterns and will be expanded. Calls get_file for each source. """ from .implementations.local import make_path_posix if isinstance(lpath, str): lpath = make_path_posix(lpath) rpaths = self.expand_path(rpath, recursive=recursive) lpaths = other_paths(rpaths, lpath) callback.set_size(len(lpaths)) for lpath, rpath in callback.wrap(zip(lpaths, rpaths)): callback.branch(rpath, lpath, kwargs) self.get_file(rpath, lpath, **kwargs)
[docs] def put_file(self, lpath, rpath, callback=_DEFAULT_CALLBACK, **kwargs): """Copy single file to remote""" if os.path.isdir(lpath): self.makedirs(rpath, exist_ok=True) return None with open(lpath, "rb") as f1: callback.set_size(f1.seek(0, 2)) f1.seek(0) self.mkdirs(self._parent(os.fspath(rpath)), exist_ok=True) with self.open(rpath, "wb", **kwargs) as f2: data = True while data: data = f1.read(self.blocksize) segment_len = f2.write(data) callback.relative_update(segment_len)
[docs] def put(self, lpath, rpath, recursive=False, callback=_DEFAULT_CALLBACK, **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 LocalFileSystem, make_path_posix rpath = ( self._strip_protocol(rpath) if isinstance(rpath, str) else [self._strip_protocol(p) for p in rpath] ) if isinstance(lpath, str): lpath = make_path_posix(lpath) fs = LocalFileSystem() lpaths = fs.expand_path(lpath, recursive=recursive) rpaths = other_paths( lpaths, rpath, exists=isinstance(rpath, str) and self.isdir(rpath) ) callback.set_size(len(rpaths)) for lpath, rpath in callback.wrap(zip(lpaths, rpaths)): callback.branch(lpath, rpath, kwargs) self.put_file(lpath, rpath, **kwargs)
[docs] def head(self, path, size=1024): """ Get the first ``size`` bytes from file """ with self.open(path, "rb") as f: return f.read(size)
[docs] 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
[docs] def copy(self, path1, path2, recursive=False, on_error=None, **kwargs): """Copy within two locations in the filesystem on_error : "raise", "ignore" If raise, any not-found exceptions will be raised; if ignore any not-found exceptions will cause the path to be skipped; defaults to raise unless recursive is true, where the default is ignore """ if on_error is None and recursive: on_error = "ignore" elif on_error is None: on_error = "raise" paths = self.expand_path(path1, recursive=recursive) path2 = other_paths(paths, path2) for p1, p2 in zip(paths, path2): try: self.cp_file(p1, p2, **kwargs) except FileNotFoundError: if on_error == "raise": raise
[docs] def expand_path(self, path, recursive=False, maxdepth=None): """Turn one or more globs or directories into a list of all matching paths to files or directories.""" if isinstance(path, str): out = self.expand_path([path], recursive, maxdepth) else: # reduce depth on each recursion level unless None or 0 maxdepth = maxdepth if not maxdepth else maxdepth - 1 out = set() path = [self._strip_protocol(p) for p in path] for p in path: if has_magic(p): bit = set(self.glob(p)) out |= bit if recursive: out |= set( self.expand_path( list(bit), recursive=recursive, maxdepth=maxdepth ) ) continue elif recursive: rec = set(self.find(p, maxdepth=maxdepth, withdirs=True)) out |= rec if p not in out and (recursive is False or self.exists(p)): # should only check once, for the root out.add(p) if not out: raise FileNotFoundError(path) return list(sorted(out))
[docs] 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)
[docs] def rm_file(self, path): """Delete a file""" self._rm(path)
def _rm(self, path): """Delete one file""" # this is the old name for the method, prefer rm_file raise NotImplementedError
[docs] 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_file(p)
@classmethod def _parent(cls, path): path = cls._strip_protocol(path.rstrip("/")) if "/" in path: parent = path.rsplit("/", 1)[0].lstrip(cls.root_marker) return cls.root_marker + parent 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, )
[docs] 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 and "r" not in mode: self.transaction.files.append(f) return f
[docs] 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
[docs] def ukey(self, path): """Hash of file properties, to tell if it has changed""" return sha256(str(self.info(path)).encode()).hexdigest()
[docs] 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)
[docs] 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, ) )
[docs] @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. """ import json from .registry import _import_class, get_filesystem_class 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
[docs] def get_mapper(self, root, check=False, create=False): """Create key/value store based on this file-system Makes a MutableMapping 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)
[docs] @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()
[docs] def created(self, path): """Return the created timestamp of a file as a datetime.datetime""" raise NotImplementedError
[docs] def modified(self, path): """Return the modified timestamp of a file as a datetime.datetime""" raise NotImplementedError
# ------------------------------------------------------------------------ # Aliases
[docs] def makedir(self, path, create_parents=True, **kwargs): """Alias of `AbstractFileSystem.mkdir`.""" return self.mkdir(path, create_parents=create_parents, **kwargs)
[docs] def mkdirs(self, path, exist_ok=False): """Alias of `AbstractFileSystem.makedirs`.""" return self.makedirs(path, exist_ok=exist_ok)
[docs] def listdir(self, path, detail=True, **kwargs): """Alias of `AbstractFileSystem.ls`.""" return self.ls(path, detail=detail, **kwargs)
[docs] def cp(self, path1, path2, **kwargs): """Alias of `AbstractFileSystem.copy`.""" return self.copy(path1, path2, **kwargs)
[docs] def move(self, path1, path2, **kwargs): """Alias of `AbstractFileSystem.mv`.""" return self.mv(path1, path2, **kwargs)
[docs] def stat(self, path, **kwargs): """Alias of `AbstractFileSystem.info`.""" return self.info(path, **kwargs)
[docs] def disk_usage(self, path, total=True, maxdepth=None, **kwargs): """Alias of `AbstractFileSystem.du`.""" return self.du(path, total=total, maxdepth=maxdepth, **kwargs)
[docs] def rename(self, path1, path2, **kwargs): """Alias of `AbstractFileSystem.mv`.""" return self.mv(path1, path2, **kwargs)
[docs] def delete(self, path, recursive=False, maxdepth=None): """Alias of `AbstractFileSystem.rm`.""" return self.rm(path, recursive=recursive, maxdepth=maxdepth)
[docs] def upload(self, lpath, rpath, recursive=False, **kwargs): """Alias of `AbstractFileSystem.put`.""" return self.put(lpath, rpath, recursive=recursive, **kwargs)
[docs] def download(self, rpath, lpath, recursive=False, **kwargs): """Alias of `AbstractFileSystem.get`.""" return self.get(rpath, lpath, recursive=recursive, **kwargs)
[docs] def sign(self, path, expiration=100, **kwargs): """Create a signed URL representing the given path Some implementations allow temporary URLs to be generated, as a way of delegating credentials. Parameters ---------- path : str The path on the filesystem expiration : int Number of seconds to enable the URL for (if supported) Returns ------- URL : str The signed URL Raises ------ NotImplementedError : if method is not implemented for a filesystem """ raise NotImplementedError("Sign is not implemented for this filesystem")
def _isfilestore(self): # Originally inherited from pyarrow DaskFileSystem. Keeping this # here for backwards compatibility as long as pyarrow uses its # legacy fsspec-compatible filesystems and thus accepts fsspec # filesystems as well return False
[docs]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``, ``_initiate_upload`` and ``_fetch_range``. """ DEFAULT_BLOCK_SIZE = 5 * 2 ** 20 _details = None def __init__( self, fs, path, mode="rb", block_size="default", autocommit=True, cache_type="readahead", cache_options=None, size=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`. size: int If given and in read mode, suppressed having to look up the file size 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 size is not None: self.size = size else: 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 details(self): if self._details is None: self._details = self.fs.info(self.path) return self._details @details.setter def details(self, value): self._details = value self.size = value["size"] @property def full_name(self): return _unstrip_protocol(self.path, self.fs) @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)
[docs] def commit(self): """Move from temp to final destination"""
[docs] def discard(self): """Throw away temporary file"""
[docs] def info(self): """ File information about this path """ if "r" in self.mode: return self.details else: raise ValueError("Info not available while writing")
[docs] def tell(self): """ Current file location """ return self.loc
[docs] 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(ESPIPE, "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
[docs] 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
[docs] 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 try: self._initiate_upload() except: # noqa: E722 self.closed = True raise 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 need 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
[docs] 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
[docs] def readinto(self, b): """mirrors builtin file's readinto method https://docs.python.org/3/library/io.html#io.RawIOBase.readinto """ out = memoryview(b).cast("B") data = self.read(out.nbytes) out[: len(data)] = data return len(data)
[docs] 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)
[docs] 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
[docs] 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)
[docs] def close(self): """Close file Finalizes writes, discards cache """ if getattr(self, "_unclosable", False): return 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
[docs] def readable(self): """Whether opened for reading""" return self.mode == "rb" and not self.closed
[docs] def seekable(self): """Whether is seekable (only in read mode)""" return self.readable()
[docs] def writable(self): """Whether opened for writing""" return self.mode in {"wb", "ab"} and not self.closed
def __del__(self): if not self.closed: 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()