Python BuildInvalidator.existing_hash方法代碼示例

# 需要導入模塊: from pants.base.build_invalidator import BuildInvalidator [as 別名]
# 或者: from pants.base.build_invalidator.BuildInvalidator import existing_hash [as 別名]
class CacheManager(object):
  """Manages cache checks, updates and invalidation keeping track of basic change
  and invalidation statistics.
  Note that this is distinct from the ArtifactCache concept, and should probably be renamed.
  """
  def __init__(self, cache_key_generator, build_invalidator_dir,
               invalidate_dependents, extra_data, only_externaldeps):
    self._cache_key_generator = cache_key_generator
    self._invalidate_dependents = invalidate_dependents
    self._extra_data = pickle.dumps(extra_data)  # extra_data may be None.
    self._sources = NO_SOURCES if only_externaldeps else TARGET_SOURCES

    self._invalidator = BuildInvalidator(build_invalidator_dir)

  def update(self, vts):
    """Mark a changed or invalidated VersionedTargetSet as successfully processed."""
    for vt in vts.versioned_targets:
      self._invalidator.update(vt.cache_key)
      vt.valid = True
    self._invalidator.update(vts.cache_key)
    vts.valid = True

  def force_invalidate(self, vts):
    """Force invalidation of a VersionedTargetSet."""
    for vt in vts.versioned_targets:
      self._invalidator.force_invalidate(vt.cache_key)
      vt.valid = False
    self._invalidator.force_invalidate(vts.cache_key)
    vts.valid = False

  def check(self, targets, partition_size_hint=None):
    """Checks whether each of the targets has changed and invalidates it if so.

    Returns a list of VersionedTargetSet objects (either valid or invalid). The returned sets
    'cover' the input targets, possibly partitioning them, and are in topological order.
    The caller can inspect these in order and, e.g., rebuild the invalid ones.
    """
    all_vts = self._sort_and_validate_targets(targets)
    invalid_vts = filter(lambda vt: not vt.valid, all_vts)
    return InvalidationCheck(all_vts, invalid_vts, partition_size_hint)

  def _sort_and_validate_targets(self, targets):
    """Validate each target.

    Returns a topologically ordered set of VersionedTargets, each representing one input target.
    """
    # We must check the targets in this order, to ensure correctness if invalidate_dependents=True,
    # since we use earlier cache keys to compute later cache keys in this case.
    ordered_targets = self._order_target_list(targets)

    # This will be a list of VersionedTargets that correspond to @targets.
    versioned_targets = []

    # This will be a mapping from each target to its corresponding VersionedTarget.
    versioned_targets_by_target = {}

    # Map from id to current fingerprint of the target with that id. We update this as we iterate,
    # in topological order, so when handling a target, this will already contain all its deps (in
    # this round).
    id_to_hash = {}

    for target in ordered_targets:
      dependency_keys = set()
      if self._invalidate_dependents and hasattr(target, 'dependencies'):
        # Note that we only need to do this for the immediate deps, because those will already
        # reflect changes in their own deps.
        for dep in target.dependencies:
          # We rely on the fact that any deps have already been processed, either in an earlier
          # round or because they came first in ordered_targets.
          # Note that only external deps (e.g., JarDependency) or targets with sources can
          # affect invalidation. Other targets (JarLibrary, Pants) are just dependency scaffolding.
          if isinstance(dep, ExternalDependency):
            dependency_keys.add(dep.cache_key())
          elif isinstance(dep, TargetWithSources):
            fprint = id_to_hash.get(dep.id, None)
            if fprint is None:
              # It may have been processed in a prior round, and therefore the fprint should
              # have been written out by the invalidator.
              fprint = self._invalidator.existing_hash(dep.id)
              # Note that fprint may still be None here. E.g., a codegen target is in the list
              # of deps, but its fprint is not visible to our self._invalidator (that of the
              # target synthesized from it is visible, so invalidation will still be correct.)
              #
              # Another case where this can happen is a dep of a codegen target on, say,
              # a java target that hasn't been built yet (again, the synthesized target will
              # depend on that same java target, so invalidation will still be correct.)
              # TODO(benjy): Make this simpler and more obviously correct.
            if fprint is not None:
              dependency_keys.add(fprint)
          elif isinstance(dep, JarLibrary) or isinstance(dep, Pants):
            pass
          else:
            raise ValueError('Cannot calculate a cache_key for a dependency: %s' % dep)
      cache_key = self._key_for(target, dependency_keys)
      id_to_hash[target.id] = cache_key.hash

      # Create a VersionedTarget corresponding to @target.
      versioned_target = VersionedTarget(self, target, cache_key)

      # Add the new VersionedTarget to the list of computed VersionedTargets.
#.........這裏部分代碼省略.........