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author | Donald Stufft <donald@stufft.io> | 2017-08-31 11:48:18 -0400 |
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committer | Donald Stufft <donald@stufft.io> | 2017-08-31 14:53:00 -0400 |
commit | 95bcf8c5f6394298035a7332c441868f3b0169f4 (patch) | |
tree | 3af031ebaaaa3616e9e7eebc68f654ddcfcdecc6 /pip/resolve.py | |
parent | c58a4ccf1d4028d0991044fa24849c2ae44ce802 (diff) | |
download | pip-95bcf8c5f6394298035a7332c441868f3b0169f4.tar.gz |
Move all internal APIs to pip._internal
Diffstat (limited to 'pip/resolve.py')
-rw-r--r-- | pip/resolve.py | 253 |
1 files changed, 0 insertions, 253 deletions
diff --git a/pip/resolve.py b/pip/resolve.py deleted file mode 100644 index f794a8511..000000000 --- a/pip/resolve.py +++ /dev/null @@ -1,253 +0,0 @@ -"""Dependency Resolution - -The dependency resolution in pip is performed as follows: - -for top-level requirements: - a. only one spec allowed per project, regardless of conflicts or not. - otherwise a "double requirement" exception is raised - b. they override sub-dependency requirements. -for sub-dependencies - a. "first found, wins" (where the order is breadth first) -""" - -import logging -from itertools import chain - -from pip.exceptions import ( - BestVersionAlreadyInstalled, - DistributionNotFound, HashError, HashErrors, UnsupportedPythonVersion -) -from pip.req.req_install import InstallRequirement -from pip.utils import dist_in_usersite, ensure_dir -from pip.utils.logging import indent_log -from pip.utils.packaging import check_dist_requires_python - -logger = logging.getLogger(__name__) - - -class Resolver(object): - """Resolves which packages need to be installed/uninstalled to perform \ - the requested operation without breaking the requirements of any package. - """ - - _allowed_strategies = {"eager", "only-if-needed", "to-satisfy-only"} - - def __init__(self, preparer, session, finder, wheel_cache, use_user_site, - ignore_dependencies, ignore_installed, ignore_requires_python, - force_reinstall, isolated, upgrade_strategy): - super(Resolver, self).__init__() - assert upgrade_strategy in self._allowed_strategies - - self.preparer = preparer - self.finder = finder - self.session = session - - # NOTE: This would eventually be replaced with a cache that can give - # information about both sdist and wheels transparently. - self.wheel_cache = wheel_cache - - self.require_hashes = None # This is set in resolve - - self.upgrade_strategy = upgrade_strategy - self.force_reinstall = force_reinstall - self.isolated = isolated - self.ignore_dependencies = ignore_dependencies - self.ignore_installed = ignore_installed - self.ignore_requires_python = ignore_requires_python - self.use_user_site = use_user_site - - def resolve(self, requirement_set): - """Resolve what operations need to be done - - As a side-effect of this method, the packages (and their dependencies) - are downloaded, unpacked and prepared for installation. This - preparation is done by ``pip.operations.prepare``. - - Once PyPI has static dependency metadata available, it would be - possible to move the preparation to become a step separated from - dependency resolution. - """ - # make the wheelhouse - if self.preparer.wheel_download_dir: - ensure_dir(self.preparer.wheel_download_dir) - - # If any top-level requirement has a hash specified, enter - # hash-checking mode, which requires hashes from all. - root_reqs = ( - requirement_set.unnamed_requirements + - list(requirement_set.requirements.values()) - ) - self.require_hashes = ( - requirement_set.require_hashes or - any(req.has_hash_options for req in root_reqs) - ) - - # Display where finder is looking for packages - locations = self.finder.get_formatted_locations() - if locations: - logger.info(locations) - - # Actually prepare the files, and collect any exceptions. Most hash - # exceptions cannot be checked ahead of time, because - # req.populate_link() needs to be called before we can make decisions - # based on link type. - discovered_reqs = [] - hash_errors = HashErrors() - for req in chain(root_reqs, discovered_reqs): - try: - discovered_reqs.extend( - self._resolve_one(requirement_set, req) - ) - except HashError as exc: - exc.req = req - hash_errors.append(exc) - - if hash_errors: - raise hash_errors - - def _is_upgrade_allowed(self, req): - if self.upgrade_strategy == "to-satisfy-only": - return False - elif self.upgrade_strategy == "eager": - return True - else: - assert self.upgrade_strategy == "only-if-needed" - return req.is_direct - - def _set_req_to_reinstall(self, req): - """ - Set a requirement to be installed. - """ - # Don't uninstall the conflict if doing a user install and the - # conflict is not a user install. - if not self.use_user_site or dist_in_usersite(req.satisfied_by): - req.conflicts_with = req.satisfied_by - req.satisfied_by = None - - # XXX: Stop passing requirement_set for options - def _check_skip_installed(self, req_to_install): - """Check if req_to_install should be skipped. - - This will check if the req is installed, and whether we should upgrade - or reinstall it, taking into account all the relevant user options. - - After calling this req_to_install will only have satisfied_by set to - None if the req_to_install is to be upgraded/reinstalled etc. Any - other value will be a dist recording the current thing installed that - satisfies the requirement. - - Note that for vcs urls and the like we can't assess skipping in this - routine - we simply identify that we need to pull the thing down, - then later on it is pulled down and introspected to assess upgrade/ - reinstalls etc. - - :return: A text reason for why it was skipped, or None. - """ - if self.ignore_installed: - return None - - req_to_install.check_if_exists() - if not req_to_install.satisfied_by: - return None - - if not self._is_upgrade_allowed(req_to_install): - if self.upgrade_strategy == "only-if-needed": - return 'not upgraded as not directly required' - return 'already satisfied' - - # Check for the possibility of an upgrade. For link-based - # requirements we have to pull the tree down and inspect to assess - # the version #, so it's handled way down. - if not (self.force_reinstall or req_to_install.link): - try: - self.finder.find_requirement(req_to_install, upgrade=True) - except BestVersionAlreadyInstalled: - # Then the best version is installed. - return 'already up-to-date' - except DistributionNotFound: - # No distribution found, so we squash the error. It will - # be raised later when we re-try later to do the install. - # Why don't we just raise here? - pass - - self._set_req_to_reinstall(req_to_install) - return None - - def _resolve_one(self, requirement_set, req_to_install): - """Prepare a single requirements file. - - :return: A list of additional InstallRequirements to also install. - """ - # Tell user what we are doing for this requirement: - # obtain (editable), skipping, processing (local url), collecting - # (remote url or package name) - if req_to_install.constraint or req_to_install.prepared: - return [] - - req_to_install.prepared = True - abstract_dist = self.preparer.prepare_requirement(req_to_install, self) - - # register tmp src for cleanup in case something goes wrong - requirement_set.reqs_to_cleanup.append(req_to_install) - - # Parse and return dependencies - dist = abstract_dist.dist(self.finder) - try: - check_dist_requires_python(dist) - except UnsupportedPythonVersion as err: - if self.ignore_requires_python: - logger.warning(err.args[0]) - else: - raise - - more_reqs = [] - - def add_req(subreq, extras_requested): - sub_install_req = InstallRequirement.from_req( - str(subreq), - req_to_install, - isolated=self.isolated, - wheel_cache=self.wheel_cache, - ) - more_reqs.extend( - requirement_set.add_requirement( - sub_install_req, req_to_install.name, - extras_requested=extras_requested - ) - ) - - with indent_log(): - # We add req_to_install before its dependencies, so that we - # can refer to it when adding dependencies. - if not requirement_set.has_requirement(req_to_install.name): - # 'unnamed' requirements will get added here - requirement_set.add_requirement(req_to_install, None) - - if not self.ignore_dependencies: - if req_to_install.extras: - logger.debug( - "Installing extra requirements: %r", - ','.join(req_to_install.extras), - ) - missing_requested = sorted( - set(req_to_install.extras) - set(dist.extras) - ) - for missing in missing_requested: - logger.warning( - '%s does not provide the extra \'%s\'', - dist, missing - ) - - available_requested = sorted( - set(dist.extras) & set(req_to_install.extras) - ) - for subreq in dist.requires(available_requested): - add_req(subreq, extras_requested=available_requested) - - if not req_to_install.editable and not req_to_install.satisfied_by: - # XXX: --no-install leads this to report 'Successfully - # downloaded' for only non-editable reqs, even though we took - # action on them. - requirement_set.successfully_downloaded.append(req_to_install) - - return more_reqs |