#
# Handle depend propigation.
#
# Propigation occurs when a layer A depends on layer B, and
# layer C depends on layer D, but Layer A also depends on Layer
# C, which means layer D must now also depend on layer B.
#
# Currently this creates a depend-all (LayerOnLayer) between
# the propigated depends.
#
for depend in on_layer.get_depends():
if depend.is_propigated():
for my_depend in self.get_depends():
dependant = my_depend.get_depend_on_layer()
logger.info("propigating dependency %s -> %s" %
(dependant, depend.get_depend_on_layer()))
dependant.depend_all(depend.get_depend_on_layer(),
propigate=False)
def undepend(self, depend):
"""
Remove the given dependency. If the dependency does not exist
no exception is thrown.
"""
try:
self.__depends.remove(depend)
except Exception, e:
logger.warn("failed to remove dependency %s, %s" % (depend, e))
def get_depends(self):
"""Return a tuple of dependencies this layer depends on."""
