cpython/Lib/packaging/database.py

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"""PEP 376 implementation."""
import io
import os
import re
import csv
import sys
import zipimport
from hashlib import md5
from packaging import logger
from packaging.errors import PackagingError
from packaging.version import suggest_normalized_version, VersionPredicate
from packaging.metadata import Metadata
__all__ = [
'Distribution', 'EggInfoDistribution', 'distinfo_dirname',
'get_distributions', 'get_distribution', 'get_file_users',
'provides_distribution', 'obsoletes_distribution',
'enable_cache', 'disable_cache', 'clear_cache',
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'get_file_path', 'get_file']
# TODO update docs
DIST_FILES = ('INSTALLER', 'METADATA', 'RECORD', 'REQUESTED', 'RESOURCES')
# Cache
_cache_name = {} # maps names to Distribution instances
_cache_name_egg = {} # maps names to EggInfoDistribution instances
_cache_path = {} # maps paths to Distribution instances
_cache_path_egg = {} # maps paths to EggInfoDistribution instances
_cache_generated = False # indicates if .dist-info distributions are cached
_cache_generated_egg = False # indicates if .dist-info and .egg are cached
_cache_enabled = True
def enable_cache():
"""
Enables the internal cache.
Note that this function will not clear the cache in any case, for that
functionality see :func:`clear_cache`.
"""
global _cache_enabled
_cache_enabled = True
def disable_cache():
"""
Disables the internal cache.
Note that this function will not clear the cache in any case, for that
functionality see :func:`clear_cache`.
"""
global _cache_enabled
_cache_enabled = False
def clear_cache():
""" Clears the internal cache. """
global _cache_generated, _cache_generated_egg
_cache_name.clear()
_cache_name_egg.clear()
_cache_path.clear()
_cache_path_egg.clear()
_cache_generated = False
_cache_generated_egg = False
def _yield_distributions(include_dist, include_egg, paths):
"""
Yield .dist-info and .egg(-info) distributions, based on the arguments
:parameter include_dist: yield .dist-info distributions
:parameter include_egg: yield .egg(-info) distributions
"""
for path in paths:
realpath = os.path.realpath(path)
if not os.path.isdir(realpath):
continue
for dir in os.listdir(realpath):
dist_path = os.path.join(realpath, dir)
if include_dist and dir.endswith('.dist-info'):
yield Distribution(dist_path)
elif include_egg and (dir.endswith('.egg-info') or
dir.endswith('.egg')):
yield EggInfoDistribution(dist_path)
def _generate_cache(use_egg_info, paths):
global _cache_generated, _cache_generated_egg
if _cache_generated_egg or (_cache_generated and not use_egg_info):
return
else:
gen_dist = not _cache_generated
gen_egg = use_egg_info
for dist in _yield_distributions(gen_dist, gen_egg, paths):
if isinstance(dist, Distribution):
_cache_path[dist.path] = dist
if dist.name not in _cache_name:
_cache_name[dist.name] = []
_cache_name[dist.name].append(dist)
else:
_cache_path_egg[dist.path] = dist
if dist.name not in _cache_name_egg:
_cache_name_egg[dist.name] = []
_cache_name_egg[dist.name].append(dist)
if gen_dist:
_cache_generated = True
if gen_egg:
_cache_generated_egg = True
class Distribution:
"""Created with the *path* of the ``.dist-info`` directory provided to the
constructor. It reads the metadata contained in ``METADATA`` when it is
instantiated."""
name = ''
"""The name of the distribution."""
version = ''
"""The version of the distribution."""
metadata = None
"""A :class:`packaging.metadata.Metadata` instance loaded with
the distribution's ``METADATA`` file."""
requested = False
"""A boolean that indicates whether the ``REQUESTED`` metadata file is
present (in other words, whether the package was installed by user
request or it was installed as a dependency)."""
def __init__(self, path):
if _cache_enabled and path in _cache_path:
self.metadata = _cache_path[path].metadata
else:
metadata_path = os.path.join(path, 'METADATA')
self.metadata = Metadata(path=metadata_path)
self.name = self.metadata['Name']
self.version = self.metadata['Version']
self.path = path
if _cache_enabled and path not in _cache_path:
_cache_path[path] = self
def __repr__(self):
return '<Distribution %r %s at %r>' % (
self.name, self.version, self.path)
def _get_records(self, local=False):
results = []
with self.get_distinfo_file('RECORD') as record:
record_reader = csv.reader(record, delimiter=',',
lineterminator='\n')
for row in record_reader:
missing = [None for i in range(len(row), 3)]
path, checksum, size = row + missing
if local:
path = path.replace('/', os.sep)
path = os.path.join(sys.prefix, path)
results.append((path, checksum, size))
return results
def get_resource_path(self, relative_path):
with self.get_distinfo_file('RESOURCES') as resources_file:
resources_reader = csv.reader(resources_file, delimiter=',',
lineterminator='\n')
for relative, destination in resources_reader:
if relative == relative_path:
return destination
raise KeyError(
'no resource file with relative path %r is installed' %
relative_path)
def list_installed_files(self, local=False):
"""
Iterates over the ``RECORD`` entries and returns a tuple
``(path, md5, size)`` for each line. If *local* is ``True``,
the returned path is transformed into a local absolute path.
Otherwise the raw value from RECORD is returned.
A local absolute path is an absolute path in which occurrences of
``'/'`` have been replaced by the system separator given by ``os.sep``.
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:parameter local: flag to say if the path should be returned as a local
absolute path
:type local: boolean
:returns: iterator of (path, md5, size)
"""
for result in self._get_records(local):
yield result
def uses(self, path):
"""
Returns ``True`` if path is listed in ``RECORD``. *path* can be a local
absolute path or a relative ``'/'``-separated path.
:rtype: boolean
"""
for p, checksum, size in self._get_records():
local_absolute = os.path.join(sys.prefix, p)
if path == p or path == local_absolute:
return True
return False
def get_distinfo_file(self, path, binary=False):
"""
Returns a file located under the ``.dist-info`` directory. Returns a
``file`` instance for the file pointed by *path*.
:parameter path: a ``'/'``-separated path relative to the
``.dist-info`` directory or an absolute path;
If *path* is an absolute path and doesn't start
with the ``.dist-info`` directory path,
a :class:`PackagingError` is raised
:type path: string
:parameter binary: If *binary* is ``True``, opens the file in read-only
binary mode (``rb``), otherwise opens it in
read-only mode (``r``).
:rtype: file object
"""
open_flags = 'r'
if binary:
open_flags += 'b'
# Check if it is an absolute path # XXX use relpath, add tests
if path.find(os.sep) >= 0:
# it's an absolute path?
distinfo_dirname, path = path.split(os.sep)[-2:]
if distinfo_dirname != self.path.split(os.sep)[-1]:
raise PackagingError(
'dist-info file %r does not belong to the %r %s '
'distribution' % (path, self.name, self.version))
# The file must be relative
if path not in DIST_FILES:
raise PackagingError('invalid path for a dist-info file: %r' %
path)
path = os.path.join(self.path, path)
return open(path, open_flags)
def list_distinfo_files(self, local=False):
"""
Iterates over the ``RECORD`` entries and returns paths for each line if
the path is pointing to a file located in the ``.dist-info`` directory
or one of its subdirectories.
:parameter local: If *local* is ``True``, each returned path is
transformed into a local absolute path. Otherwise the
raw value from ``RECORD`` is returned.
:type local: boolean
:returns: iterator of paths
"""
for path, checksum, size in self._get_records(local):
yield path
def __eq__(self, other):
return isinstance(other, Distribution) and self.path == other.path
# See http://docs.python.org/reference/datamodel#object.__hash__
__hash__ = object.__hash__
class EggInfoDistribution:
"""Created with the *path* of the ``.egg-info`` directory or file provided
to the constructor. It reads the metadata contained in the file itself, or
if the given path happens to be a directory, the metadata is read from the
file ``PKG-INFO`` under that directory."""
name = ''
"""The name of the distribution."""
version = ''
"""The version of the distribution."""
metadata = None
"""A :class:`packaging.metadata.Metadata` instance loaded with
the distribution's ``METADATA`` file."""
_REQUIREMENT = re.compile(
r'(?P<name>[-A-Za-z0-9_.]+)\s*'
r'(?P<first>(?:<|<=|!=|==|>=|>)[-A-Za-z0-9_.]+)?\s*'
r'(?P<rest>(?:\s*,\s*(?:<|<=|!=|==|>=|>)[-A-Za-z0-9_.]+)*)\s*'
r'(?P<extras>\[.*\])?')
def __init__(self, path):
self.path = path
if _cache_enabled and path in _cache_path_egg:
self.metadata = _cache_path_egg[path].metadata
self.name = self.metadata['Name']
self.version = self.metadata['Version']
return
# reused from Distribute's pkg_resources
def yield_lines(strs):
"""Yield non-empty/non-comment lines of a ``basestring``
or sequence"""
if isinstance(strs, str):
for s in strs.splitlines():
s = s.strip()
# skip blank lines/comments
if s and not s.startswith('#'):
yield s
else:
for ss in strs:
for s in yield_lines(ss):
yield s
requires = None
if path.endswith('.egg'):
if os.path.isdir(path):
meta_path = os.path.join(path, 'EGG-INFO', 'PKG-INFO')
self.metadata = Metadata(path=meta_path)
try:
req_path = os.path.join(path, 'EGG-INFO', 'requires.txt')
with open(req_path, 'r') as fp:
requires = fp.read()
except IOError:
requires = None
else:
# FIXME handle the case where zipfile is not available
zipf = zipimport.zipimporter(path)
fileobj = io.StringIO(
zipf.get_data('EGG-INFO/PKG-INFO').decode('utf8'))
self.metadata = Metadata(fileobj=fileobj)
try:
requires = zipf.get_data('EGG-INFO/requires.txt')
except IOError:
requires = None
self.name = self.metadata['Name']
self.version = self.metadata['Version']
elif path.endswith('.egg-info'):
if os.path.isdir(path):
path = os.path.join(path, 'PKG-INFO')
try:
with open(os.path.join(path, 'requires.txt'), 'r') as fp:
requires = fp.read()
except IOError:
requires = None
self.metadata = Metadata(path=path)
self.name = self.metadata['Name']
self.version = self.metadata['Version']
else:
raise ValueError('path must end with .egg-info or .egg, got %r' %
path)
if requires is not None:
if self.metadata['Metadata-Version'] == '1.1':
# we can't have 1.1 metadata *and* Setuptools requires
for field in ('Obsoletes', 'Requires', 'Provides'):
del self.metadata[field]
reqs = []
if requires is not None:
for line in yield_lines(requires):
if line.startswith('['):
logger.warning(
'extensions in requires.txt are not supported '
'(used by %r %s)', self.name, self.version)
break
else:
match = self._REQUIREMENT.match(line.strip())
if not match:
# this happens when we encounter extras; since they
# are written at the end of the file we just exit
break
else:
if match.group('extras'):
msg = ('extra requirements are not supported '
'(used by %r %s)', self.name, self.version)
logger.warning(msg, self.name)
name = match.group('name')
version = None
if match.group('first'):
version = match.group('first')
if match.group('rest'):
version += match.group('rest')
version = version.replace(' ', '') # trim spaces
if version is None:
reqs.append(name)
else:
reqs.append('%s (%s)' % (name, version))
if len(reqs) > 0:
self.metadata['Requires-Dist'] += reqs
if _cache_enabled:
_cache_path_egg[self.path] = self
def __repr__(self):
return '<EggInfoDistribution %r %s at %r>' % (
self.name, self.version, self.path)
def list_installed_files(self, local=False):
def _md5(path):
with open(path, 'rb') as f:
content = f.read()
return md5(content).hexdigest()
def _size(path):
return os.stat(path).st_size
path = self.path
if local:
path = path.replace('/', os.sep)
# XXX What about scripts and data files ?
if os.path.isfile(path):
return [(path, _md5(path), _size(path))]
else:
files = []
for root, dir, files_ in os.walk(path):
for item in files_:
item = os.path.join(root, item)
files.append((item, _md5(item), _size(item)))
return files
return []
def uses(self, path):
return False
def __eq__(self, other):
return (isinstance(other, EggInfoDistribution) and
self.path == other.path)
# See http://docs.python.org/reference/datamodel#object.__hash__
__hash__ = object.__hash__
def distinfo_dirname(name, version):
"""
The *name* and *version* parameters are converted into their
filename-escaped form, i.e. any ``'-'`` characters are replaced
with ``'_'`` other than the one in ``'dist-info'`` and the one
separating the name from the version number.
:parameter name: is converted to a standard distribution name by replacing
any runs of non- alphanumeric characters with a single
``'-'``.
:type name: string
:parameter version: is converted to a standard version string. Spaces
become dots, and all other non-alphanumeric characters
(except dots) become dashes, with runs of multiple
dashes condensed to a single dash.
:type version: string
:returns: directory name
:rtype: string"""
file_extension = '.dist-info'
name = name.replace('-', '_')
normalized_version = suggest_normalized_version(version)
# Because this is a lookup procedure, something will be returned even if
# it is a version that cannot be normalized
if normalized_version is None:
# Unable to achieve normality?
normalized_version = version
return '-'.join([name, normalized_version]) + file_extension
def get_distributions(use_egg_info=False, paths=None):
"""
Provides an iterator that looks for ``.dist-info`` directories in
``sys.path`` and returns :class:`Distribution` instances for each one of
them. If the parameters *use_egg_info* is ``True``, then the ``.egg-info``
files and directores are iterated as well.
:rtype: iterator of :class:`Distribution` and :class:`EggInfoDistribution`
instances
"""
if paths is None:
paths = sys.path
if not _cache_enabled:
for dist in _yield_distributions(True, use_egg_info, paths):
yield dist
else:
_generate_cache(use_egg_info, paths)
for dist in _cache_path.values():
yield dist
if use_egg_info:
for dist in _cache_path_egg.values():
yield dist
def get_distribution(name, use_egg_info=False, paths=None):
"""
Scans all elements in ``sys.path`` and looks for all directories
ending with ``.dist-info``. Returns a :class:`Distribution`
corresponding to the ``.dist-info`` directory that contains the
``METADATA`` that matches *name* for the *name* metadata field.
If no distribution exists with the given *name* and the parameter
*use_egg_info* is set to ``True``, then all files and directories ending
with ``.egg-info`` are scanned. A :class:`EggInfoDistribution` instance is
returned if one is found that has metadata that matches *name* for the
*name* metadata field.
This function only returns the first result found, as no more than one
value is expected. If the directory is not found, ``None`` is returned.
:rtype: :class:`Distribution` or :class:`EggInfoDistribution` or None
"""
if paths is None:
paths = sys.path
if not _cache_enabled:
for dist in _yield_distributions(True, use_egg_info, paths):
if dist.name == name:
return dist
else:
_generate_cache(use_egg_info, paths)
if name in _cache_name:
return _cache_name[name][0]
elif use_egg_info and name in _cache_name_egg:
return _cache_name_egg[name][0]
else:
return None
def obsoletes_distribution(name, version=None, use_egg_info=False):
"""
Iterates over all distributions to find which distributions obsolete
*name*.
If a *version* is provided, it will be used to filter the results.
If the argument *use_egg_info* is set to ``True``, then ``.egg-info``
distributions will be considered as well.
:type name: string
:type version: string
:parameter name:
"""
for dist in get_distributions(use_egg_info):
obsoleted = (dist.metadata['Obsoletes-Dist'] +
dist.metadata['Obsoletes'])
for obs in obsoleted:
o_components = obs.split(' ', 1)
if len(o_components) == 1 or version is None:
if name == o_components[0]:
yield dist
break
else:
try:
predicate = VersionPredicate(obs)
except ValueError:
raise PackagingError(
'distribution %r has ill-formed obsoletes field: '
'%r' % (dist.name, obs))
if name == o_components[0] and predicate.match(version):
yield dist
break
def provides_distribution(name, version=None, use_egg_info=False):
"""
Iterates over all distributions to find which distributions provide *name*.
If a *version* is provided, it will be used to filter the results. Scans
all elements in ``sys.path`` and looks for all directories ending with
``.dist-info``. Returns a :class:`Distribution` corresponding to the
``.dist-info`` directory that contains a ``METADATA`` that matches *name*
for the name metadata. If the argument *use_egg_info* is set to ``True``,
then all files and directories ending with ``.egg-info`` are considered
as well and returns an :class:`EggInfoDistribution` instance.
This function only returns the first result found, since no more than
one values are expected. If the directory is not found, returns ``None``.
:parameter version: a version specifier that indicates the version
required, conforming to the format in ``PEP-345``
:type name: string
:type version: string
"""
predicate = None
if not version is None:
try:
predicate = VersionPredicate(name + ' (' + version + ')')
except ValueError:
raise PackagingError('invalid name or version: %r, %r' %
(name, version))
for dist in get_distributions(use_egg_info):
provided = dist.metadata['Provides-Dist'] + dist.metadata['Provides']
for p in provided:
p_components = p.rsplit(' ', 1)
if len(p_components) == 1 or predicate is None:
if name == p_components[0]:
yield dist
break
else:
p_name, p_ver = p_components
if len(p_ver) < 2 or p_ver[0] != '(' or p_ver[-1] != ')':
raise PackagingError(
'distribution %r has invalid Provides field: %r' %
(dist.name, p))
p_ver = p_ver[1:-1] # trim off the parenthesis
if p_name == name and predicate.match(p_ver):
yield dist
break
def get_file_users(path):
"""
Iterates over all distributions to find out which distributions use
*path*.
:parameter path: can be a local absolute path or a relative
``'/'``-separated path.
:type path: string
:rtype: iterator of :class:`Distribution` instances
"""
for dist in get_distributions():
if dist.uses(path):
yield dist
def get_file_path(distribution_name, relative_path):
"""Return the path to a resource file."""
dist = get_distribution(distribution_name)
if dist is not None:
return dist.get_resource_path(relative_path)
raise LookupError('no distribution named %r found' % distribution_name)
def get_file(distribution_name, relative_path, *args, **kwargs):
"""Open and return a resource file."""
return open(get_file_path(distribution_name, relative_path),
*args, **kwargs)