def _interpolate_references(self, path, value, inventory):
all_refs = False
while not all_refs:
for ref in value.get_references():
path_from_ref = DictPath(self._delimiter, ref)
if path_from_ref in self._unrendered:
if self._unrendered[path_from_ref] is False:
# every call to _interpolate_inner replaces the value of
# self._unrendered[path] with False
# Therefore, if we encounter False instead of True,
# it means that we have already processed it and are now
# faced with a cyclical reference.
raise InfiniteRecursionError(path, ref)
else:
self._interpolate_inner(path_from_ref, inventory)
else:
# ensure ancestor keys are already dereferenced
ancestor = DictPath(self._delimiter)
for k in path_from_ref.key_parts():
ancestor = ancestor.new_subpath(k)
if ancestor in self._unrendered:
self._interpolate_inner(ancestor, inventory)
if value.allRefs():
all_refs = True
else:
# not all references in the value could be calculated previously so
# try recalculating references with current context and recursively
# call _interpolate_inner if the number of references has increased
# Otherwise raise an error
old = len(value.get_references())
value.assembleRefs(self._base)
if old == len(value.get_references()):
raise InterpolationError('Bad reference count, path:' +
repr(path))
def _interpolate_inner(self, path, refvalue):
self._occurrences[path] = True # mark as seen
for ref in refvalue.get_references():
path_from_ref = DictPath(self.delimiter, ref)
try:
refvalue_inner = self._occurrences[path_from_ref]
# If there is no reference, then this will throw a KeyError,
# look further down where this is caught and execution passed
# to the next iteration of the loop
#
# If we get here, then the ref references another parameter,
# requiring us to recurse, dereferencing first those refs that
# are most used and are thus at the leaves of the dependency
# tree.
if refvalue_inner is True:
# every call to _interpolate_inner replaces the value of
# the saved occurrences of a reference with True.
# Therefore, if we encounter True instead of a refvalue,
# it means that we have already processed it and are now
# faced with a cyclical reference.
raise InfiniteRecursionError(path, ref)
self._interpolate_inner(path_from_ref, refvalue_inner)
except KeyError as e:
# not actually an error, but we are done resolving all
# dependencies of the current ref, so move on
continue
try:
new = refvalue.render(self._base)
path.set_value(self._base, new)
# finally, remove the reference from the occurrences cache
del self._occurrences[path]
except UndefinedVariableError as e:
raise UndefinedVariableError(e.var, path)