Source code for kiwi.solver.sat

# Copyright (c) 2015 SUSE Linux GmbH.  All rights reserved.
#
# This file is part of kiwi.
#
# kiwi is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# kiwi is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with kiwi.  If not, see <http://www.gnu.org/licenses/>
#
import importlib
import logging
from collections import namedtuple
from xml.etree import ElementTree
from xml.dom import minidom

# project
from kiwi.exceptions import (
    KiwiSatSolverPluginError,
    KiwiSatSolverJobError,
    KiwiSatSolverJobProblems
)

log = logging.getLogger('kiwi')


[docs]class Sat: """ **Sat Solver class to run package solver operations** The class uses SUSE's libsolv sat plugin """ def __init__(self): """ An instance of Sat auto loads the python solv plugin which is a python binding to the libsolv C library. An exception is raised if the module failed to load. On success a new solver pool is initialized for this instance :raises KiwiSatSolverPluginError: if libsolv module can't be loaded """ try: self.solv = importlib.import_module('solv') except Exception as e: raise KiwiSatSolverPluginError( '{0}: {1}'.format(type(e).__name__, format(e)) ) self.pool = self.solv.Pool() self.pool.setarch()
[docs] def add_repository(self, solver_repository): """ Add a repository solvable to the pool. This basically add the required repository metadata which is needed to run a solver operation later. :param object solver_repository: Instance of :class:`SolverRepository` """ solvable = solver_repository.create_repository_solvable() pool_repository = self.pool.add_repo(solver_repository.uri.uri) pool_repository.add_solv(solvable) self.pool.addfileprovides() self.pool.createwhatprovides()
[docs] def solve(self, job_names, skip_missing=False, ignore_recommended=True): """ Solve dependencies for the given job list. The list is allowed to contain element names of the following format: * name describes a package name * pattern:name describes a package collection name whose metadata type is called 'pattern' and stored as such in the repository metadata. Usually SUSE repos uses that * group:name describes a package collection name whose metadata type is called 'group' and stored as such in the repository metadata. Usually RHEL/CentOS/Fedora repos uses that :param list job_names: list of strings :param bool skip_missing: skip job if not found :param bool ignore_recommended: do not include recommended packages :raises KiwiSatSolverJobProblems: if solver reports solving problems :return: Transaction result information :rtype: dict """ solver = self.pool.Solver() if ignore_recommended: solver.set_flag(self.solv.Solver.SOLVER_FLAG_IGNORE_RECOMMENDED, 1) solver_problems = solver.solve( self._setup_jobs(job_names, skip_missing) ) solver_problem_info = self._evaluate_solver_problems( solver_problems ) if solver_problem_info: raise KiwiSatSolverJobProblems(solver_problem_info) solver_transaction = solver.transaction() return self._evaluate_solver_result( solver_transaction )
def _evaluate_solver_problems(self, solver_problems): """ Iterate over solver problems and their solutions The method creates a pretty print XML information and returns that as a UTF-8 encoded string :param object solver_problems: result of :class:`Pool::Solver::solve()` :return: solver problem info and solutions :rtype: str """ if solver_problems: problems = ElementTree.Element('problems') for problem in solver_problems: problem_detail = ElementTree.SubElement( problems, 'problem', id=format(problem.id), message=problem.findproblemrule().info().problemstr() ) for solution in problem.solutions(): solution_detail = ElementTree.SubElement( problem_detail, 'solution', id=format(solution.id) ) for option in solution.elements(1): solution_option = ElementTree.SubElement( solution_detail, 'option' ) solution_option.text = option.str() xml_data_unformatted = ElementTree.tostring( problems, 'utf-8' ) xml_data_domtree = minidom.parseString(xml_data_unformatted) return xml_data_domtree.toprettyxml(indent=" ") def _evaluate_solver_result(self, solver_transaction): """ Iterate over solver result and return a data dictionary :param object solver_transaction: result of :class:`Pool::Solver::transaction()` :return: dict of packages and their details :rtype: dict """ result_type = namedtuple( 'result_type', [ 'uri', 'installsize_bytes', 'arch', 'version', 'checksum' ] ) result = {} for solvable in solver_transaction.newpackages(): name = solvable.lookup_str(self.solv.SOLVABLE_NAME) result[name] = result_type( uri=solvable.repo.name, installsize_bytes=solvable.lookup_num( self.solv.SOLVABLE_INSTALLSIZE ), arch=solvable.lookup_str( self.solv.SOLVABLE_ARCH ), version=solvable.lookup_str( self.solv.SOLVABLE_EVR ), checksum=solvable.lookup_checksum( self.solv.SOLVABLE_CHECKSUM ) ) return result def _setup_jobs(self, job_names, skip_missing): """ Create a solver job list from given list of job names :param list job_names: list of package,pattern,group names :param bool skip_missing: continue or raise if job selection failed :return: list of :class:`Pool.selection()` objects :rtype: list """ jobs = [] for job_name in job_names: selection_name = self.solv.Selection.SELECTION_NAME selection_provides = self.solv.Selection.SELECTION_PROVIDES selection = self.pool.select( job_name, selection_name | selection_provides ) if selection.flags & self.solv.Selection.SELECTION_PROVIDES: log.info('--> Using capability match for {0}'.format(job_name)) if selection.isempty(): if skip_missing: log.info( '--> Package {0} not found: skipped'.format(job_name) ) else: raise KiwiSatSolverJobError( 'Package {0} not found'.format(job_name) ) else: jobs += selection.jobs(self.solv.Job.SOLVER_INSTALL) return jobs