def get_macro_obj_from_id(macro_id, macro=None):
'''Get a processed macro from the macro id. Raises an exception
on error. Assumes valid input. Incrments the view counter
for this macro.'''
# First check memcache for a processed macro object:
macro_obj = memcache.get(MACRO_PROC_KEY % macro_id)
if not macro_obj:
# Nothing from memcache, load from data store.
if not macro:
saved_macro_entity = SavedMacroOps.get_macro_entity(macro_id)
# If saved_macro_entity is still none, we failed
# in the datastore.
if saved_macro_entity is None:
raise NoInputError("Macro id '%s' not found." % macro_id)
macro = saved_macro_entity.macro
# Process the macro, lazily importing.
from macro.interpret.interpreter import MacroInterpreter
macro_obj = MacroInterpreter().interpret_macro(macro)
# Save macro in memcached.
memcache.add(MACRO_PROC_KEY % macro_id,
macro_obj,
MEMCACHED_MACRO_PROC)
return macro_obj
