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GH-117586: Speed up `pathlib.Path.glob()` by working with strings (#117589) 

Move pathlib globbing implementation into a new private class: `glob._Globber`. This class implements fast string-based globbing. It's called by `pathlib.Path.glob()`, which then converts strings back to path objects.

In the private pathlib ABCs, add a `pathlib._abc.Globber` subclass that works with `PathBase` objects rather than strings, and calls user-defined path methods like `PathBase.stat()` rather than `os.stat()`.

This sets the stage for two more improvements:

- GH-115060: Query non-wildcard segments with `lstat()`
- GH-116380: Unify `pathlib` and `glob` implementations of globbing.

No change to the implementations of `glob.glob()` and `glob.iglob()`.
This commit is contained in:
Barney Gale 2024-04-10 20:43:07 +01:00 committed by GitHub
parent 689ada7915
commit 6258844c27
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GPG Key ID: B5690EEEBB952194
4 changed files with 269 additions and 195 deletions
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186
Lib/glob.py
View File

@ -4,7 +4,9 @@ import contextlib
import os
import re
import fnmatch
import functools
import itertools
import operator
import stat
import sys
@ -256,7 +258,9 @@ def escape(pathname):
return drive + pathname
_special_parts = ('', '.', '..')
_dir_open_flags = os.O_RDONLY | getattr(os, 'O_DIRECTORY', 0)
_no_recurse_symlinks = object()
def translate(pat, *, recursive=False, include_hidden=False, seps=None):
@ -312,3 +316,185 @@ def translate(pat, *, recursive=False, include_hidden=False, seps=None):
results.append(any_sep)
res = ''.join(results)
return fr'(?s:{res})\Z'
@functools.lru_cache(maxsize=512)
def _compile_pattern(pat, sep, case_sensitive, recursive=True):
"""Compile given glob pattern to a re.Pattern object (observing case
sensitivity)."""
flags = re.NOFLAG if case_sensitive else re.IGNORECASE
regex = translate(pat, recursive=recursive, include_hidden=True, seps=sep)
return re.compile(regex, flags=flags).match
class _Globber:
"""Class providing shell-style pattern matching and globbing.
"""
def __init__(self, sep, case_sensitive, recursive=False):
self.sep = sep
self.case_sensitive = case_sensitive
self.recursive = recursive
# Low-level methods
lstat = staticmethod(os.lstat)
scandir = staticmethod(os.scandir)
parse_entry = operator.attrgetter('path')
concat_path = operator.add
if os.name == 'nt':
@staticmethod
def add_slash(pathname):
tail = os.path.splitroot(pathname)[2]
if not tail or tail[-1] in '\\/':
return pathname
return f'{pathname}\\'
else:
@staticmethod
def add_slash(pathname):
if not pathname or pathname[-1] == '/':
return pathname
return f'{pathname}/'
# High-level methods
def compile(self, pat):
return _compile_pattern(pat, self.sep, self.case_sensitive, self.recursive)
def selector(self, parts):
"""Returns a function that selects from a given path, walking and
filtering according to the glob-style pattern parts in *parts*.
"""
if not parts:
return self.select_exists
part = parts.pop()
if self.recursive and part == '**':
selector = self.recursive_selector
elif part in _special_parts:
selector = self.special_selector
else:
selector = self.wildcard_selector
return selector(part, parts)
def special_selector(self, part, parts):
"""Returns a function that selects special children of the given path.
"""
select_next = self.selector(parts)
def select_special(path, exists=False):
path = self.concat_path(self.add_slash(path), part)
return select_next(path, exists)
return select_special
def wildcard_selector(self, part, parts):
"""Returns a function that selects direct children of a given path,
filtering by pattern.
"""
match = None if part == '*' else self.compile(part)
dir_only = bool(parts)
if dir_only:
select_next = self.selector(parts)
def select_wildcard(path, exists=False):
try:
# We must close the scandir() object before proceeding to
# avoid exhausting file descriptors when globbing deep trees.
with self.scandir(path) as scandir_it:
entries = list(scandir_it)
except OSError:
pass
else:
for entry in entries:
if match is None or match(entry.name):
if dir_only:
try:
if not entry.is_dir():
continue
except OSError:
continue
entry_path = self.parse_entry(entry)
if dir_only:
yield from select_next(entry_path, exists=True)
else:
yield entry_path
return select_wildcard
def recursive_selector(self, part, parts):
"""Returns a function that selects a given path and all its children,
recursively, filtering by pattern.
"""
# Optimization: consume following '**' parts, which have no effect.
while parts and parts[-1] == '**':
parts.pop()
# Optimization: consume and join any following non-special parts here,
# rather than leaving them for the next selector. They're used to
# build a regular expression, which we use to filter the results of
# the recursive walk. As a result, non-special pattern segments
# following a '**' wildcard don't require additional filesystem access
# to expand.
follow_symlinks = self.recursive is not _no_recurse_symlinks
if follow_symlinks:
while parts and parts[-1] not in _special_parts:
part += self.sep + parts.pop()
match = None if part == '**' else self.compile(part)
dir_only = bool(parts)
select_next = self.selector(parts)
def select_recursive(path, exists=False):
path = self.add_slash(path)
match_pos = len(str(path))
if match is None or match(str(path), match_pos):
yield from select_next(path, exists)
stack = [path]
while stack:
yield from select_recursive_step(stack, match_pos)
def select_recursive_step(stack, match_pos):
path = stack.pop()
try:
# We must close the scandir() object before proceeding to
# avoid exhausting file descriptors when globbing deep trees.
with self.scandir(path) as scandir_it:
entries = list(scandir_it)
except OSError:
pass
else:
for entry in entries:
is_dir = False
try:
if entry.is_dir(follow_symlinks=follow_symlinks):
is_dir = True
except OSError:
pass
if is_dir or not dir_only:
entry_path = self.parse_entry(entry)
if match is None or match(str(entry_path), match_pos):
if dir_only:
yield from select_next(entry_path, exists=True)
else:
# Optimization: directly yield the path if this is
# last pattern part.
yield entry_path
if is_dir:
stack.append(entry_path)
return select_recursive
def select_exists(self, path, exists=False):
"""Yields the given path, if it exists.
"""
if exists:
# Optimization: this path is already known to exist, e.g. because
# it was returned from os.scandir(), so we skip calling lstat().
yield path
else:
try:
self.lstat(path)
yield path
except OSError:
pass

77
Lib/pathlib/__init__.py
View File

@ -5,8 +5,10 @@ paths with operations that have semantics appropriate for different
operating systems.
"""
import glob
import io
import ntpath
import operator
import os
import posixpath
import sys
@ -111,6 +113,7 @@ class PurePath(_abc.PurePathBase):
'_hash',
)
parser = os.path
_globber = glob._Globber
def __new__(cls, *args, **kwargs):
"""Construct a PurePath from one or several strings and or existing
@ -253,14 +256,17 @@ class PurePath(_abc.PurePathBase):
return cls.parser.sep.join(tail)
def _from_parsed_parts(self, drv, root, tail):
path_str = self._format_parsed_parts(drv, root, tail)
path = self.with_segments(path_str)
path._str = path_str or '.'
path = self._from_parsed_string(self._format_parsed_parts(drv, root, tail))
path._drv = drv
path._root = root
path._tail_cached = tail
return path
def _from_parsed_string(self, path_str):
path = self.with_segments(path_str)
path._str = path_str or '.'
return path
@classmethod
def _parse_path(cls, path):
if not path:
@ -453,21 +459,6 @@ class PurePath(_abc.PurePathBase):
from urllib.parse import quote_from_bytes
return prefix + quote_from_bytes(os.fsencode(path))
@property
def _pattern_stack(self):
"""Stack of path components, to be used with patterns in glob()."""
parts = self._tail.copy()
pattern = self._raw_path
if self.anchor:
raise NotImplementedError("Non-relative patterns are unsupported")
elif not parts:
raise ValueError("Unacceptable pattern: {!r}".format(pattern))
elif pattern[-1] in (self.parser.sep, self.parser.altsep):
# GH-65238: pathlib doesn't preserve trailing slash. Add it back.
parts.append('')
parts.reverse()
return parts
@property
def _pattern_str(self):
"""The path expressed as a string, for use in pattern-matching."""
@ -576,6 +567,17 @@ class Path(_abc.PathBase, PurePath):
encoding = io.text_encoding(encoding)
return _abc.PathBase.write_text(self, data, encoding, errors, newline)
_remove_leading_dot = operator.itemgetter(slice(2, None))
_remove_trailing_slash = operator.itemgetter(slice(-1))
def _filter_trailing_slash(self, paths):
sep = self.parser.sep
anchor_len = len(self.anchor)
for path_str in paths:
if len(path_str) > anchor_len and path_str[-1] == sep:
path_str = path_str[:-1]
yield path_str
def iterdir(self):
"""Yield path objects of the directory contents.
@ -587,13 +589,9 @@ class Path(_abc.PathBase, PurePath):
def _scandir(self):
return os.scandir(self)
def _direntry_str(self, entry):
# Transform an entry yielded from _scandir() into a path string.
return entry.name if str(self) == '.' else entry.path
def _make_child_direntry(self, entry):
# Transform an entry yielded from _scandir() into a path object.
path_str = self._direntry_str(entry)
path_str = entry.name if str(self) == '.' else entry.path
path = self.with_segments(path_str)
path._str = path_str
path._drv = self.drive
@ -626,8 +624,30 @@ class Path(_abc.PathBase, PurePath):
sys.audit("pathlib.Path.glob", self, pattern)
if not isinstance(pattern, PurePath):
pattern = self.with_segments(pattern)
return _abc.PathBase.glob(
self, pattern, case_sensitive=case_sensitive, recurse_symlinks=recurse_symlinks)
if pattern.anchor:
raise NotImplementedError("Non-relative patterns are unsupported")
parts = pattern._tail.copy()
if not parts:
raise ValueError("Unacceptable pattern: {!r}".format(pattern))
raw = pattern._raw_path
if raw[-1] in (self.parser.sep, self.parser.altsep):
# GH-65238: pathlib doesn't preserve trailing slash. Add it back.
parts.append('')
if not self.is_dir():
return iter([])
select = self._glob_selector(parts[::-1], case_sensitive, recurse_symlinks)
root = str(self)
paths = select(root, exists=True)
# Normalize results
if root == '.':
paths = map(self._remove_leading_dot, paths)
if parts[-1] == '':
paths = map(self._remove_trailing_slash, paths)
elif parts[-1] == '**':
paths = self._filter_trailing_slash(paths)
paths = map(self._from_parsed_string, paths)
return paths
def rglob(self, pattern, *, case_sensitive=None, recurse_symlinks=False):
"""Recursively yield all existing files (of any kind, including
@ -638,8 +658,7 @@ class Path(_abc.PathBase, PurePath):
if not isinstance(pattern, PurePath):
pattern = self.with_segments(pattern)
pattern = '**' / pattern
return _abc.PathBase.glob(
self, pattern, case_sensitive=case_sensitive, recurse_symlinks=recurse_symlinks)
return self.glob(pattern, case_sensitive=case_sensitive, recurse_symlinks=recurse_symlinks)
def walk(self, top_down=True, on_error=None, follow_symlinks=False):
"""Walk the directory tree from this directory, similar to os.walk()."""
@ -669,9 +688,7 @@ class Path(_abc.PathBase, PurePath):
# of joining, and we exploit the fact that getcwd() returns a
# fully-normalized string by storing it in _str. This is used to
# implement Path.cwd().
result = self.with_segments(cwd)
result._str = cwd
return result
return self._from_parsed_string(cwd)
drive, root, rel = os.path.splitroot(cwd)
if not rel:
return self._from_parsed_parts(drive, root, self._tail)

200
Lib/pathlib/_abc.py
View File

@ -12,6 +12,8 @@ resemble pathlib's PurePath and Path respectively.
"""
import functools
import glob
import operator
from errno import ENOENT, ENOTDIR, EBADF, ELOOP, EINVAL
from stat import S_ISDIR, S_ISLNK, S_ISREG, S_ISSOCK, S_ISBLK, S_ISCHR, S_ISFIFO
@ -40,109 +42,23 @@ def _ignore_error(exception):
def _is_case_sensitive(parser):
return parser.normcase('Aa') == 'Aa'
#
# Globbing helpers
#
re = glob = None
class Globber(glob._Globber):
lstat = operator.methodcaller('lstat')
scandir = operator.methodcaller('_scandir')
add_slash = operator.methodcaller('joinpath', '')
@staticmethod
def concat_path(path, text):
"""Appends text to the given path.
"""
return path.with_segments(path._raw_path + text)
@functools.lru_cache(maxsize=512)
def _compile_pattern(pat, sep, case_sensitive, recursive=True):
"""Compile given glob pattern to a re.Pattern object (observing case
sensitivity)."""
global re, glob
if re is None:
import re, glob
flags = re.NOFLAG if case_sensitive else re.IGNORECASE
regex = glob.translate(pat, recursive=recursive, include_hidden=True, seps=sep)
return re.compile(regex, flags=flags).match
def _select_special(paths, part):
"""Yield special literal children of the given paths."""
for path in paths:
yield path._make_child_relpath(part)
def _select_children(parent_paths, dir_only, match):
"""Yield direct children of given paths, filtering by name and type."""
for parent_path in parent_paths:
try:
# We must close the scandir() object before proceeding to
# avoid exhausting file descriptors when globbing deep trees.
with parent_path._scandir() as scandir_it:
entries = list(scandir_it)
except OSError:
pass
else:
for entry in entries:
if dir_only:
try:
if not entry.is_dir():
continue
except OSError:
continue
# Avoid cost of making a path object for non-matching paths by
# matching against the os.DirEntry.name string.
if match is None or match(entry.name):
yield parent_path._make_child_direntry(entry)
def _select_recursive(parent_paths, dir_only, follow_symlinks, match):
"""Yield given paths and all their children, recursively, filtering by
string and type.
"""
for parent_path in parent_paths:
if match is not None:
# If we're filtering paths through a regex, record the length of
# the parent path. We'll pass it to match(path, pos=...) later.
parent_len = len(str(parent_path._make_child_relpath('_'))) - 1
paths = [parent_path._make_child_relpath('')]
while paths:
path = paths.pop()
if match is None or match(str(path), parent_len):
# Yield *directory* path that matches pattern (if any).
yield path
try:
# We must close the scandir() object before proceeding to
# avoid exhausting file descriptors when globbing deep trees.
with path._scandir() as scandir_it:
entries = list(scandir_it)
except OSError:
pass
else:
for entry in entries:
# Handle directory entry.
try:
if entry.is_dir(follow_symlinks=follow_symlinks):
# Recurse into this directory.
paths.append(path._make_child_direntry(entry))
continue
except OSError:
pass
# Handle file entry.
if not dir_only:
# Avoid cost of making a path object for non-matching
# files by matching against the os.DirEntry object.
if match is None or match(path._direntry_str(entry), parent_len):
# Yield *file* path that matches pattern (if any).
yield path._make_child_direntry(entry)
def _select_unique(paths):
"""Yields the given paths, filtering out duplicates."""
yielded = set()
try:
for path in paths:
path_str = str(path)
if path_str not in yielded:
yield path
yielded.add(path_str)
finally:
yielded.clear()
@staticmethod
def parse_entry(entry):
"""Returns the path of an entry yielded from scandir().
"""
return entry
class UnsupportedOperation(NotImplementedError):
@ -218,6 +134,7 @@ class PurePathBase:
'_resolving',
)
parser = ParserBase()
_globber = Globber
def __init__(self, path, *paths):
self._raw_path = self.parser.join(path, *paths) if paths else path
@ -454,14 +371,6 @@ class PurePathBase:
a drive)."""
return self.parser.isabs(self._raw_path)
@property
def _pattern_stack(self):
"""Stack of path components, to be used with patterns in glob()."""
anchor, parts = self._stack
if anchor:
raise NotImplementedError("Non-relative patterns are unsupported")
return parts
@property
def _pattern_str(self):
"""The path expressed as a string, for use in pattern-matching."""
@ -487,8 +396,9 @@ class PurePathBase:
return False
if len(path_parts) > len(pattern_parts) and path_pattern.anchor:
return False
globber = self._globber(sep, case_sensitive)
for path_part, pattern_part in zip(path_parts, pattern_parts):
match = _compile_pattern(pattern_part, sep, case_sensitive, recursive=False)
match = globber.compile(pattern_part)
if match(path_part) is None:
return False
return True
@ -502,7 +412,8 @@ class PurePathBase:
pattern = self.with_segments(pattern)
if case_sensitive is None:
case_sensitive = _is_case_sensitive(self.parser)
match = _compile_pattern(pattern._pattern_str, pattern.parser.sep, case_sensitive)
globber = self._globber(pattern.parser.sep, case_sensitive, recursive=True)
match = globber.compile(pattern._pattern_str)
return match(self._pattern_str) is not None
@ -772,11 +683,6 @@ class PathBase(PurePathBase):
from contextlib import nullcontext
return nullcontext(self.iterdir())
def _direntry_str(self, entry):
# Transform an entry yielded from _scandir() into a path string.
# PathBase._scandir() yields PathBase objects, so use str().
return str(entry)
def _make_child_direntry(self, entry):
# Transform an entry yielded from _scandir() into a path object.
# PathBase._scandir() yields PathBase objects, so this is a no-op.
@ -785,62 +691,26 @@ class PathBase(PurePathBase):
def _make_child_relpath(self, name):
return self.joinpath(name)
def _glob_selector(self, parts, case_sensitive, recurse_symlinks):
if case_sensitive is None:
case_sensitive = _is_case_sensitive(self.parser)
recursive = True if recurse_symlinks else glob._no_recurse_symlinks
globber = self._globber(self.parser.sep, case_sensitive, recursive)
return globber.selector(parts)
def glob(self, pattern, *, case_sensitive=None, recurse_symlinks=True):
"""Iterate over this subtree and yield all existing files (of any
kind, including directories) matching the given relative pattern.
"""
if not isinstance(pattern, PurePathBase):
pattern = self.with_segments(pattern)
if case_sensitive is None:
# TODO: evaluate case-sensitivity of each directory in _select_children().
case_sensitive = _is_case_sensitive(self.parser)
stack = pattern._pattern_stack
specials = ('', '.', '..')
deduplicate_paths = False
sep = self.parser.sep
paths = iter([self] if self.is_dir() else [])
while stack:
part = stack.pop()
if part in specials:
# Join special component (e.g. '..') onto paths.
paths = _select_special(paths, part)
elif part == '**':
# Consume following '**' components, which have no effect.
while stack and stack[-1] == '**':
stack.pop()
# Consume following non-special components, provided we're
# treating symlinks consistently. Each component is joined
# onto 'part', which is used to generate an re.Pattern object.
if recurse_symlinks:
while stack and stack[-1] not in specials:
part += sep + stack.pop()
# If the previous loop consumed pattern components, compile an
# re.Pattern object based on those components.
match = _compile_pattern(part, sep, case_sensitive) if part != '**' else None
# Recursively walk directories, filtering by type and regex.
paths = _select_recursive(paths, bool(stack), recurse_symlinks, match)
# De-duplicate if we've already seen a '**' component.
if deduplicate_paths:
paths = _select_unique(paths)
deduplicate_paths = True
elif '**' in part:
raise ValueError("Invalid pattern: '**' can only be an entire path component")
else:
# If the pattern component isn't '*', compile an re.Pattern
# object based on the component.
match = _compile_pattern(part, sep, case_sensitive) if part != '*' else None
# Iterate over directories' children filtering by type and regex.
paths = _select_children(paths, bool(stack), match)
return paths
anchor, parts = pattern._stack
if anchor:
raise NotImplementedError("Non-relative patterns are unsupported")
if not self.is_dir():
return iter([])
select = self._glob_selector(parts, case_sensitive, recurse_symlinks)
return select(self, exists=True)
def rglob(self, pattern, *, case_sensitive=None, recurse_symlinks=True):
"""Recursively yield all existing files (of any kind, including

1
Misc/NEWS.d/next/Library/2024-04-06-20-31-09.gh-issue-117586.UgWdRK.rst Normal file
View File

@ -0,0 +1 @@
Speed up :meth:`pathlib.Path.glob` by working with strings internally.