from __future__ import annotations
import contextlib
import logging
import math
import os
import pathlib
import re
import sys
import tempfile
from functools import partial
from hashlib import md5
from importlib.metadata import version
from typing import (
IO,
TYPE_CHECKING,
Any,
Callable,
Iterable,
Iterator,
Sequence,
TypeVar,
)
from urllib.parse import urlsplit
if TYPE_CHECKING:
from typing_extensions import TypeGuard
from fsspec.spec import AbstractFileSystem
DEFAULT_BLOCK_SIZE = 5 * 2**20
T = TypeVar("T")
def infer_storage_options(
urlpath: str, inherit_storage_options: dict[str, Any] | None = None
) -> dict[str, Any]:
"""Infer storage options from URL path and merge it with existing storage
options.
Parameters
----------
urlpath: str or unicode
Either local absolute file path or URL (hdfs://namenode:8020/file.csv)
inherit_storage_options: dict (optional)
Its contents will get merged with the inferred information from the
given path
Returns
-------
Storage options dict.
Examples
--------
>>> infer_storage_options('/mnt/datasets/test.csv') # doctest: +SKIP
{"protocol": "file", "path", "/mnt/datasets/test.csv"}
>>> infer_storage_options(
... 'hdfs://username:pwd@node:123/mnt/datasets/test.csv?q=1',
... inherit_storage_options={'extra': 'value'},
... ) # doctest: +SKIP
{"protocol": "hdfs", "username": "username", "password": "pwd",
"host": "node", "port": 123, "path": "/mnt/datasets/test.csv",
"url_query": "q=1", "extra": "value"}
"""
# Handle Windows paths including disk name in this special case
if (
re.match(r"^[a-zA-Z]:[\\/]", urlpath)
or re.match(r"^[a-zA-Z0-9]+://", urlpath) is None
):
return {"protocol": "file", "path": urlpath}
parsed_path = urlsplit(urlpath)
protocol = parsed_path.scheme or "file"
if parsed_path.fragment:
path = "#".join([parsed_path.path, parsed_path.fragment])
else:
path = parsed_path.path
if protocol == "file":
# Special case parsing file protocol URL on Windows according to:
# https://msdn.microsoft.com/en-us/library/jj710207.aspx
windows_path = re.match(r"^/([a-zA-Z])[:|]([\\/].*)$", path)
if windows_path:
path = "%s:%s" % windows_path.groups()
if protocol in ["http", "https"]:
# for HTTP, we don't want to parse, as requests will anyway
return {"protocol": protocol, "path": urlpath}
options: dict[str, Any] = {"protocol": protocol, "path": path}
if parsed_path.netloc:
# Parse `hostname` from netloc manually because `parsed_path.hostname`
# lowercases the hostname which is not always desirable (e.g. in S3):
# https://github.com/dask/dask/issues/1417
options["host"] = parsed_path.netloc.rsplit("@", 1)[-1].rsplit(":", 1)[0]
if protocol in ("s3", "s3a", "gcs", "gs"):
options["path"] = options["host"] + options["path"]
else:
options["host"] = options["host"]
if parsed_path.port:
options["port"] = parsed_path.port
if parsed_path.username:
options["username"] = parsed_path.username
if parsed_path.password:
options["password"] = parsed_path.password
if parsed_path.query:
options["url_query"] = parsed_path.query
if parsed_path.fragment:
options["url_fragment"] = parsed_path.fragment
if inherit_storage_options:
update_storage_options(options, inherit_storage_options)
return options
def update_storage_options(
options: dict[str, Any], inherited: dict[str, Any] | None = None
) -> None:
if not inherited:
inherited = {}
collisions = set(options) & set(inherited)
if collisions:
for collision in collisions:
if options.get(collision) != inherited.get(collision):
raise KeyError(
f"Collision between inferred and specified storage "
f"option:\n{collision}"
)
options.update(inherited)
# Compression extensions registered via fsspec.compression.register_compression
compressions: dict[str, str] = {}
def infer_compression(filename: str) -> str | None:
"""Infer compression, if available, from filename.
Infer a named compression type, if registered and available, from filename
extension. This includes builtin (gz, bz2, zip) compressions, as well as
optional compressions. See fsspec.compression.register_compression.
"""
extension = os.path.splitext(filename)[-1].strip(".").lower()
if extension in compressions:
return compressions[extension]
return None
def build_name_function(max_int: float) -> Callable[[int], str]:
"""Returns a function that receives a single integer
and returns it as a string padded by enough zero characters
to align with maximum possible integer
>>> name_f = build_name_function(57)
>>> name_f(7)
'07'
>>> name_f(31)
'31'
>>> build_name_function(1000)(42)
'0042'
>>> build_name_function(999)(42)
'042'
>>> build_name_function(0)(0)
'0'
"""
# handle corner cases max_int is 0 or exact power of 10
max_int += 1e-8
pad_length = int(math.ceil(math.log10(max_int)))
def name_function(i: int) -> str:
return str(i).zfill(pad_length)
return name_function
def seek_delimiter(file: IO[bytes], delimiter: bytes, blocksize: int) -> bool:
r"""Seek current file to file start, file end, or byte after delimiter seq.
Seeks file to next chunk delimiter, where chunks are defined on file start,
a delimiting sequence, and file end. Use file.tell() to see location afterwards.
Note that file start is a valid split, so must be at offset > 0 to seek for
delimiter.
Parameters
----------
file: a file
delimiter: bytes
a delimiter like ``b'\n'`` or message sentinel, matching file .read() type
blocksize: int
Number of bytes to read from the file at once.
Returns
-------
Returns True if a delimiter was found, False if at file start or end.
"""
if file.tell() == 0:
# beginning-of-file, return without seek
return False
# Interface is for binary IO, with delimiter as bytes, but initialize last
# with result of file.read to preserve compatibility with text IO.
last: bytes | None = None
while True:
current = file.read(blocksize)
if not current:
# end-of-file without delimiter
return False
full = last + current if last else current
try:
if delimiter in full:
i = full.index(delimiter)
file.seek(file.tell() - (len(full) - i) + len(delimiter))
return True
elif len(current) < blocksize:
# end-of-file without delimiter
return False
except (OSError, ValueError):
pass
last = full[-len(delimiter) :]
def read_block(
f: IO[bytes],
offset: int,
length: int | None,
delimiter: bytes | None = None,
split_before: bool = False,
) -> bytes:
"""Read a block of bytes from a file
Parameters
----------
f: File
Open file
offset: int
Byte offset to start read
length: int
Number of bytes to read, read through end of file if None
delimiter: bytes (optional)
Ensure reading starts and stops at delimiter bytestring
split_before: bool (optional)
Start/stop read *before* delimiter bytestring.
If using the ``delimiter=`` keyword argument 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, regardless of delimiter. The bytestring returned WILL
include the terminating delimiter string.
Examples
--------
>>> from io import BytesIO # doctest: +SKIP
>>> f = BytesIO(b'Alice, 100\\nBob, 200\\nCharlie, 300') # doctest: +SKIP
>>> read_block(f, 0, 13) # doctest: +SKIP
b'Alice, 100\\nBo'
>>> read_block(f, 0, 13, delimiter=b'\\n') # doctest: +SKIP
b'Alice, 100\\nBob, 200\\n'
>>> read_block(f, 10, 10, delimiter=b'\\n') # doctest: +SKIP
b'Bob, 200\\nCharlie, 300'
"""
if delimiter:
f.seek(offset)
found_start_delim = seek_delimiter(f, delimiter, 2**16)
if length is None:
return f.read()
start = f.tell()
length -= start - offset
f.seek(start + length)
found_end_delim = seek_delimiter(f, delimiter, 2**16)
end = f.tell()
# Adjust split location to before delimiter if seek found the
# delimiter sequence, not start or end of file.
if found_start_delim and split_before:
start -= len(delimiter)
if found_end_delim and split_before:
end -= len(delimiter)
offset = start
length = end - start
f.seek(offset)
# TODO: allow length to be None and read to the end of the file?
assert length is not None
b = f.read(length)
return b
def tokenize(*args: Any, **kwargs: Any) -> str:
"""Deterministic token
(modified from dask.base)
>>> tokenize([1, 2, '3'])
'9d71491b50023b06fc76928e6eddb952'
>>> tokenize('Hello') == tokenize('Hello')
True
"""
if kwargs:
args += (kwargs,)
try:
h = md5(str(args).encode())
except ValueError:
# FIPS systems: https://github.com/fsspec/filesystem_spec/issues/380
h = md5(str(args).encode(), usedforsecurity=False)
return h.hexdigest()
def stringify_path(filepath: str | os.PathLike[str] | pathlib.Path) -> str:
"""Attempt to convert a path-like object to a string.
Parameters
----------
filepath: object to be converted
Returns
-------
filepath_str: maybe a string version of the object
Notes
-----
Objects supporting the fspath protocol are coerced according to its
__fspath__ method.
For backwards compatibility with older Python version, pathlib.Path
objects are specially coerced.
Any other object is passed through unchanged, which includes bytes,
strings, buffers, or anything else that's not even path-like.
"""
if isinstance(filepath, str):
return filepath
elif hasattr(filepath, "__fspath__"):
return filepath.__fspath__()
elif hasattr(filepath, "path"):
return filepath.path
else:
return filepath # type: ignore[return-value]
def make_instance(
cls: Callable[..., T], args: Sequence[Any], kwargs: dict[str, Any]
) -> T:
inst = cls(*args, **kwargs)
inst._determine_worker() # type: ignore[attr-defined]
return inst
def common_prefix(paths: Iterable[str]) -> str:
"""For a list of paths, find the shortest prefix common to all"""
parts = [p.split("/") for p in paths]
lmax = min(len(p) for p in parts)
end = 0
for i in range(lmax):
end = all(p[i] == parts[0][i] for p in parts)
if not end:
break
i += end
return "/".join(parts[0][:i])
def other_paths(
paths: list[str],
path2: str | list[str],
exists: bool = False,
flatten: bool = False,
) -> list[str]:
"""In bulk file operations, construct a new file tree from a list of files
Parameters
----------
paths: list of str
The input file tree
path2: str or list of str
Root to construct the new list in. If this is already a list of str, we just
assert it has the right number of elements.
exists: bool (optional)
For a str destination, it is already exists (and is a dir), files should
end up inside.
flatten: bool (optional)
Whether to flatten the input directory tree structure so that the output files
are in the same directory.
Returns
-------
list of str
"""
if isinstance(path2, str):
path2 = path2.rstrip("/")
if flatten:
path2 = ["/".join((path2, p.split("/")[-1])) for p in paths]
else:
cp = common_prefix(paths)
if exists:
cp = cp.rsplit("/", 1)[0]
if not cp and all(not s.startswith("/") for s in paths):
path2 = ["/".join([path2, p]) for p in paths]
else:
path2 = [p.replace(cp, path2, 1) for p in paths]
else:
assert len(paths) == len(path2)
return path2
def is_exception(obj: Any) -> bool:
return isinstance(obj, BaseException)
def isfilelike(f: Any) -> TypeGuard[IO[bytes]]:
return all(hasattr(f, attr) for attr in ["read", "close", "tell"])
def get_protocol(url: str) -> str:
url = stringify_path(url)
parts = re.split(r"(\:\:|\://)", url, maxsplit=1)
if len(parts) > 1:
return parts[0]
return "file"
def can_be_local(path: str) -> bool:
"""Can the given URL be used with open_local?"""
from fsspec import get_filesystem_class
try:
return getattr(get_filesystem_class(get_protocol(path)), "local_file", False)
except (ValueError, ImportError):
# not in registry or import failed
return False
def get_package_version_without_import(name: str) -> str | None:
"""For given package name, try to find the version without importing it
Import and package.__version__ is still the backup here, so an import
*might* happen.
Returns either the version string, or None if the package
or the version was not readily found.
"""
if name in sys.modules:
mod = sys.modules[name]
if hasattr(mod, "__version__"):
return mod.__version__
try:
return version(name)
except: # noqa: E722
pass
try:
import importlib
mod = importlib.import_module(name)
return mod.__version__
except (ImportError, AttributeError):
return None
def setup_logging(
logger: logging.Logger | None = None,
logger_name: str | None = None,
level: str = "DEBUG",
clear: bool = True,
) -> logging.Logger:
if logger is None and logger_name is None:
raise ValueError("Provide either logger object or logger name")
logger = logger or logging.getLogger(logger_name)
handle = logging.StreamHandler()
formatter = logging.Formatter(
"%(asctime)s - %(name)s - %(levelname)s - %(funcName)s -- %(message)s"
)
handle.setFormatter(formatter)
if clear:
logger.handlers.clear()
logger.addHandler(handle)
logger.setLevel(level)
return logger
def _unstrip_protocol(name: str, fs: AbstractFileSystem) -> str:
return fs.unstrip_protocol(name)
def mirror_from(
origin_name: str, methods: Iterable[str]
) -> Callable[[type[T]], type[T]]:
"""Mirror attributes and methods from the given
origin_name attribute of the instance to the
decorated class"""
def origin_getter(method: str, self: Any) -> Any:
origin = getattr(self, origin_name)
return getattr(origin, method)
def wrapper(cls: type[T]) -> type[T]:
for method in methods:
wrapped_method = partial(origin_getter, method)
setattr(cls, method, property(wrapped_method))
return cls
return wrapper
@contextlib.contextmanager
def nullcontext(obj: T) -> Iterator[T]:
yield obj
def merge_offset_ranges(
paths: list[str],
starts: list[int] | int,
ends: list[int] | int,
max_gap: int = 0,
max_block: int | None = None,
sort: bool = True,
) -> tuple[list[str], list[int], list[int]]:
"""Merge adjacent byte-offset ranges when the inter-range
gap is <= `max_gap`, and when the merged byte range does not
exceed `max_block` (if specified). By default, this function
will re-order the input paths and byte ranges to ensure sorted
order. If the user can guarantee that the inputs are already
sorted, passing `sort=False` will skip the re-ordering.
"""
# Check input
if not isinstance(paths, list):
raise TypeError
if not isinstance(starts, list):
starts = [starts] * len(paths)
if not isinstance(ends, list):
ends = [ends] * len(paths)
if len(starts) != len(paths) or len(ends) != len(paths):
raise ValueError
# Early Return
if len(starts) <= 1:
return paths, starts, ends
starts = [s or 0 for s in starts]
# Sort by paths and then ranges if `sort=True`
if sort:
paths, starts, ends = (
list(v)
for v in zip(
*sorted(
zip(paths, starts, ends),
)
)
)
if paths:
# Loop through the coupled `paths`, `starts`, and
# `ends`, and merge adjacent blocks when appropriate
new_paths = paths[:1]
new_starts = starts[:1]
new_ends = ends[:1]
for i in range(1, len(paths)):
if paths[i] == paths[i - 1] and new_ends[-1] is None:
continue
elif (
paths[i] != paths[i - 1]
or ((starts[i] - new_ends[-1]) > max_gap)
or (max_block is not None and (ends[i] - new_starts[-1]) > max_block)
):
# Cannot merge with previous block.
# Add new `paths`, `starts`, and `ends` elements
new_paths.append(paths[i])
new_starts.append(starts[i])
new_ends.append(ends[i])
else:
# Merge with previous block by updating the
# last element of `ends`
new_ends[-1] = ends[i]
return new_paths, new_starts, new_ends
# `paths` is empty. Just return input lists
return paths, starts, ends
def file_size(filelike: IO[bytes]) -> int:
"""Find length of any open read-mode file-like"""
pos = filelike.tell()
try:
return filelike.seek(0, 2)
finally:
filelike.seek(pos)
@contextlib.contextmanager
def atomic_write(path: str, mode: str = "wb"):
"""
A context manager that opens a temporary file next to `path` and, on exit,
replaces `path` with the temporary file, thereby updating `path`
atomically.
"""
fd, fn = tempfile.mkstemp(
dir=os.path.dirname(path), prefix=os.path.basename(path) + "-"
)
try:
with open(fd, mode) as fp:
yield fp
except BaseException:
with contextlib.suppress(FileNotFoundError):
os.unlink(fn)
raise
else:
os.replace(fn, path)
def _translate(pat, STAR, QUESTION_MARK):
# Copied from: https://github.com/python/cpython/pull/106703.
res: list[str] = []
add = res.append
i, n = 0, len(pat)
while i < n:
c = pat[i]
i = i + 1
if c == "*":
# compress consecutive `*` into one
if (not res) or res[-1] is not STAR:
add(STAR)
elif c == "?":
add(QUESTION_MARK)
elif c == "[":
j = i
if j < n and pat[j] == "!":
j = j + 1
if j < n and pat[j] == "]":
j = j + 1
while j < n and pat[j] != "]":
j = j + 1
if j >= n:
add("\\[")
else:
stuff = pat[i:j]
if "-" not in stuff:
stuff = stuff.replace("\\", r"\\")
else:
chunks = []
k = i + 2 if pat[i] == "!" else i + 1
while True:
k = pat.find("-", k, j)
if k < 0:
break
chunks.append(pat[i:k])
i = k + 1
k = k + 3
chunk = pat[i:j]
if chunk:
chunks.append(chunk)
else:
chunks[-1] += "-"
# Remove empty ranges -- invalid in RE.
for k in range(len(chunks) - 1, 0, -1):
if chunks[k - 1][-1] > chunks[k][0]:
chunks[k - 1] = chunks[k - 1][:-1] + chunks[k][1:]
del chunks[k]
# Escape backslashes and hyphens for set difference (--).
# Hyphens that create ranges shouldn't be escaped.
stuff = "-".join(
s.replace("\\", r"\\").replace("-", r"\-") for s in chunks
)
# Escape set operations (&&, ~~ and ||).
stuff = re.sub(r"([&~|])", r"\\\1", stuff)
i = j + 1
if not stuff:
# Empty range: never match.
add("(?!)")
elif stuff == "!":
# Negated empty range: match any character.
add(".")
else:
if stuff[0] == "!":
stuff = "^" + stuff[1:]
elif stuff[0] in ("^", "["):
stuff = "\\" + stuff
add(f"[{stuff}]")
else:
add(re.escape(c))
assert i == n
return res
def glob_translate(pat):
# Copied from: https://github.com/python/cpython/pull/106703.
# The keyword parameters' values are fixed to:
# recursive=True, include_hidden=True, seps=None
"""Translate a pathname with shell wildcards to a regular expression."""
if os.path.altsep:
seps = os.path.sep + os.path.altsep
else:
seps = os.path.sep
escaped_seps = "".join(map(re.escape, seps))
any_sep = f"[{escaped_seps}]" if len(seps) > 1 else escaped_seps
not_sep = f"[^{escaped_seps}]"
one_last_segment = f"{not_sep}+"
one_segment = f"{one_last_segment}{any_sep}"
any_segments = f"(?:.+{any_sep})?"
any_last_segments = ".*"
results = []
parts = re.split(any_sep, pat)
last_part_idx = len(parts) - 1
for idx, part in enumerate(parts):
if part == "*":
results.append(one_segment if idx < last_part_idx else one_last_segment)
continue
if part == "**":
results.append(any_segments if idx < last_part_idx else any_last_segments)
continue
elif "**" in part:
raise ValueError(
"Invalid pattern: '**' can only be an entire path component"
)
if part:
results.extend(_translate(part, f"{not_sep}*", not_sep))
if idx < last_part_idx:
results.append(any_sep)
res = "".join(results)
return rf"(?s:{res})\Z"