requirements/openstack_requirements/requirement.py
Tony Breeds 4bb92e041c Integrate normalize as part of the requirements tools
Rather than have this as an external tool that open codes some of the logic
we have in the existing codebase we should integrate it.

Change-Id: I979dcefeec4ae28705088d4fac1e41b4d33e40e0
2016-06-23 10:16:23 +02:00

206 lines
7.3 KiB
Python

# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Requirements handling."""
# This module has no IO at all, and none should be added.
import collections
import distutils.version
import packaging.specifiers
import pkg_resources
import re
# A header for the requirements file(s).
# TODO(lifeless): Remove this once constraints are in use.
_REQS_HEADER = [
'# The order of packages is significant, because pip processes '
'them in the order\n',
'# of appearance. Changing the order has an impact on the overall '
'integration\n',
'# process, which may cause wedges in the gate later.\n',
]
def cmp_specifier(a, b):
weight = {'>=': 0, '>': 0,
'==': 1, '~=': 1, '!=': 1,
'<': 2, '<=': 2}
a = a._spec
b = b._spec
wa, wb = weight[a[0]], weight[b[0]]
res = cmp(wa, wb)
if res != 0:
return res
else:
return cmp(distutils.version.LooseVersion(a[1]),
distutils.version.LooseVersion(b[1]))
class Requirement(collections.namedtuple('Requirement',
['package', 'location', 'specifiers',
'markers', 'comment', 'extras'])):
def __new__(cls, package, location, specifiers, markers, comment,
extras=None):
return super(Requirement, cls).__new__(
cls, package, location, specifiers, markers, comment,
frozenset(extras or ()))
def to_line(self, marker_sep=';', line_prefix='', comment_prefix=' ',
sort_specifiers=False):
comment_p = comment_prefix if self.package else ''
comment = (comment_p + self.comment if self.comment else '')
marker = marker_sep + self.markers if self.markers else ''
package = line_prefix + self.package if self.package else ''
location = self.location + '#egg=' if self.location else ''
extras = '[%s]' % ",".join(sorted(self.extras)) if self.extras else ''
specifiers = self.specifiers
if sort_specifiers:
_specifiers = packaging.specifiers.SpecifierSet(specifiers)
_specifiers = ['%s' % s for s in sorted(_specifiers,
cmp=cmp_specifier)]
specifiers = ','.join(_specifiers)
return '%s%s%s%s%s%s\n' % (location,
package,
extras,
specifiers,
marker,
comment)
Requirements = collections.namedtuple('Requirements', ['reqs'])
url_re = re.compile(
'^(?P<url>\s*(?:-e\s)?\s*(?:(?:git+)?https|http|file)://[^#]*)'
'#egg=(?P<name>[-\.\w]+)')
def canonical_name(req_name):
"""Return the canonical form of req_name."""
return pkg_resources.safe_name(req_name).lower()
def parse(content, permit_urls=False):
return to_dict(to_reqs(content, permit_urls=permit_urls))
def parse_line(req_line, permit_urls=False):
"""Parse a single line of a requirements file.
requirements files here are a subset of pip requirements files: we don't
try to parse URL entries, or pip options like -f and -e. Those are not
permitted in global-requirements.txt. If encountered in a synchronised
file such as requirements.txt or test-requirements.txt, they are illegal
but currently preserved as-is.
They may of course be used by local test configurations, just not
committed into the OpenStack reference branches.
:param permit_urls: If True, urls are parsed into Requirement tuples.
By default they are not, because they cannot be reflected into
setuptools kwargs, and thus the default is conservative. When
urls are permitted, -e *may* be supplied at the start of the line.
"""
end = len(req_line)
hash_pos = req_line.find('#')
if hash_pos < 0:
hash_pos = end
# Don't find urls that are in comments.
if '://' in req_line[:hash_pos]:
if permit_urls:
# We accept only a subset of urls here - they have to have an egg
# name so that we can tell what project its for without doing
# network access. Egg markers use a fragment, so we need to pull
# out url from the entire line.
m = url_re.match(req_line)
name = m.group('name')
location = m.group('url')
parse_start = m.end('name')
hash_pos = req_line[parse_start:].find('#')
if hash_pos < 0:
hash_pos = end
else:
hash_pos = hash_pos + parse_start
else:
# Trigger an early failure before we look for ':'
pkg_resources.Requirement.parse(req_line)
else:
parse_start = 0
location = ''
semi_pos = req_line.find(';', parse_start, hash_pos)
colon_pos = req_line.find(':', parse_start, hash_pos)
marker_pos = max(semi_pos, colon_pos)
if marker_pos < 0:
marker_pos = hash_pos
markers = req_line[marker_pos + 1:hash_pos].strip()
if hash_pos != end:
comment = req_line[hash_pos:]
else:
comment = ''
req_line = req_line[parse_start:marker_pos]
extras = ()
if parse_start:
# We parsed a url before
specifier = ''
elif req_line:
# Pulled out a requirement
parsed = pkg_resources.Requirement.parse(req_line)
name = parsed.project_name
extras = parsed.extras
specifier = str(parsed.specifier)
else:
# Comments / blank lines etc.
name = ''
specifier = ''
return Requirement(name, location, specifier, markers, comment, extras)
def to_content(reqs, marker_sep=';', line_prefix='', prefix=True):
lines = []
if prefix:
lines += _REQS_HEADER
for req in reqs.reqs:
lines.append(req.to_line(marker_sep, line_prefix))
return u''.join(lines)
def to_dict(req_sequence):
reqs = dict()
for req, req_line in req_sequence:
if req is not None:
key = canonical_name(req.package)
reqs.setdefault(key, []).append((req, req_line))
return reqs
def _pass_through(req_line, permit_urls=False):
"""Identify unparsable lines."""
if permit_urls:
return (req_line.startswith('http://tarballs.openstack.org/') or
req_line.startswith('-f'))
else:
return (req_line.startswith('http://tarballs.openstack.org/') or
req_line.startswith('-e') or
req_line.startswith('-f'))
def to_reqs(content, permit_urls=False):
for content_line in content.splitlines(True):
req_line = content_line.strip()
if _pass_through(req_line, permit_urls=permit_urls):
yield None, content_line
else:
yield parse_line(req_line, permit_urls=permit_urls), content_line