Source code for fsspec.utils

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) :]


[docs] 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]]: for attr in ["read", "close", "tell"]: if not hasattr(f, attr): return False return True 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"