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Diffstat (limited to 'src/buildstream/_loader/loadelement.pyx')
| -rw-r--r-- | src/buildstream/_loader/loadelement.pyx | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/src/buildstream/_loader/loadelement.pyx b/src/buildstream/_loader/loadelement.pyx new file mode 100644 index 000000000..867de6f29 --- /dev/null +++ b/src/buildstream/_loader/loadelement.pyx @@ -0,0 +1,228 @@ +# +# Copyright (C) 2016 Codethink Limited +# +# This program is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2 of the License, or (at your option) any later version. +# +# This library 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 +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library. If not, see <http://www.gnu.org/licenses/>. +# +# Authors: +# Tristan Van Berkom <tristan.vanberkom@codethink.co.uk> + +from functools import cmp_to_key + +from pyroaring import BitMap, FrozenBitMap # pylint: disable=no-name-in-module + +from ..node cimport MappingNode +from .types import Symbol + + +# Counter to get ids to LoadElements +cdef int _counter = 0 + +cdef int _next_synthetic_counter(): + global _counter + _counter += 1 + return _counter + + +# Dependency(): +# +# A link from a LoadElement to its dependencies. +# +# Keeps a link to one of the current Element's dependencies, together with +# its dependency type. +# +# Args: +# element (LoadElement): a LoadElement on which there is a dependency +# dep_type (str): the type of dependency this dependency link is +cdef class Dependency: + cdef readonly LoadElement element + cdef readonly str dep_type + + def __cinit__(self, LoadElement element, str dep_type): + self.element = element + self.dep_type = dep_type + + +# LoadElement(): +# +# A transient object breaking down what is loaded allowing us to +# do complex operations in multiple passes. +# +# Args: +# node (dict): A YAML loaded dictionary +# name (str): The element name +# loader (Loader): The Loader object for this element +# +cdef class LoadElement: + + cdef readonly MappingNode node + cdef readonly str name + cdef readonly full_name + cdef public bint meta_done + cdef int node_id + cdef readonly object _loader + # TODO: if/when pyroaring exports symbols, we could type this statically + cdef object _dep_cache + cdef readonly list dependencies + + def __cinit__(self, MappingNode node, str filename, object loader): + + # + # Public members + # + self.node = node # The YAML node + self.name = filename # The element name + self.full_name = None # The element full name (with associated junction) + self.meta_done = False # If the MetaElement for this LoadElement is done + self.node_id = _next_synthetic_counter() + + # + # Private members + # + self._loader = loader # The Loader object + self._dep_cache = None # The dependency cache, to speed up depends() + + # + # Initialization + # + if loader.project.junction: + # dependency is in subproject, qualify name + self.full_name = '{}:{}'.format(loader.project.junction.name, self.name) + else: + # dependency is in top-level project + self.full_name = self.name + + # Ensure the root node is valid + self.node.validate_keys([ + 'kind', 'depends', 'sources', 'sandbox', + 'variables', 'environment', 'environment-nocache', + 'config', 'public', 'description', + 'build-depends', 'runtime-depends', + ]) + + self.dependencies = [] + + @property + def junction(self): + return self._loader.project.junction + + # depends(): + # + # Checks if this element depends on another element, directly + # or indirectly. + # + # Args: + # other (LoadElement): Another LoadElement + # + # Returns: + # (bool): True if this LoadElement depends on 'other' + # + def depends(self, LoadElement other not None): + self._ensure_depends_cache() + return other.node_id in self._dep_cache + + ########################################### + # Private Methods # + ########################################### + cdef void _ensure_depends_cache(self): + cdef Dependency dep + + if self._dep_cache: + return + + self._dep_cache = BitMap() + + for dep in self.dependencies: + elt = dep.element + + # Ensure the cache of the element we depend on + elt._ensure_depends_cache() + + # We depend on this element + self._dep_cache.add(elt.node_id) + + # And we depend on everything this element depends on + self._dep_cache.update(elt._dep_cache) + + self._dep_cache = FrozenBitMap(self._dep_cache) + + +def _dependency_cmp(Dependency dep_a, Dependency dep_b): + cdef LoadElement element_a = dep_a.element + cdef LoadElement element_b = dep_b.element + + # Sort on inter element dependency first + if element_a.depends(element_b): + return 1 + elif element_b.depends(element_a): + return -1 + + # If there are no inter element dependencies, place + # runtime only dependencies last + if dep_a.dep_type != dep_b.dep_type: + if dep_a.dep_type == Symbol.RUNTIME: + return 1 + elif dep_b.dep_type == Symbol.RUNTIME: + return -1 + + # All things being equal, string comparison. + if element_a.name > element_b.name: + return 1 + elif element_a.name < element_b.name: + return -1 + + # Sort local elements before junction elements + # and use string comparison between junction elements + if element_a.junction and element_b.junction: + if element_a.junction > element_b.junction: + return 1 + elif element_a.junction < element_b.junction: + return -1 + elif element_a.junction: + return -1 + elif element_b.junction: + return 1 + + # This wont ever happen + return 0 + + +# sort_dependencies(): +# +# Sort dependencies of each element by their dependencies, +# so that direct dependencies which depend on other direct +# dependencies (directly or indirectly) appear later in the +# list. +# +# This avoids the need for performing multiple topological +# sorts throughout the build process. +# +# Args: +# element (LoadElement): The element to sort +# +def sort_dependencies(LoadElement element): + cdef list working_elements = [element] + cdef set visited = set(working_elements) + cdef Dependency dep + + # Now dependency sort, we ensure that if any direct dependency + # directly or indirectly depends on another direct dependency, + # it is found later in the list. + while working_elements: + element = working_elements.pop() + for dep in element.dependencies: + if dep.element not in visited: + visited.add(dep.element) + working_elements.append(dep.element) + + element.dependencies.sort(key=cmp_to_key(_dependency_cmp)) |