def request_chunk(self, x, z):
"""
Request a ``Chunk`` to be delivered later.
:returns: ``Deferred`` that will be called with the ``Chunk``
"""
# First, try the cache.
cached = self._cache.get((x, z))
if cached is not None:
returnValue(cached)
# Is it pending?
if (x, z) in self._pending_chunks:
# Rig up another Deferred and wrap it up in a to-go box.
retval = yield self._pending_chunks[x, z].deferred()
returnValue(retval)
# Create a new chunk object, since the cache turned up empty.
try:
chunk = yield maybeDeferred(self.serializer.load_chunk, x, z)
except SerializerReadException:
# Looks like the chunk wasn't already on disk. Guess we're gonna
# need to keep going.
chunk = Chunk(x, z)
# Add in our magic dirtiness hook so that the cache can be aware of
# chunks who have been...naughty.
chunk.dirtied = self._cache.dirtied
if chunk.dirty:
# The chunk was already dirty!? Oh, naughty indeed!
self._cache.dirtied(chunk)
if chunk.populated:
self._cache.put(chunk)
self.postprocess_chunk(chunk)
if self.factory:
self.factory.scan_chunk(chunk)
returnValue(chunk)
if self. async:
from ampoule import deferToAMPProcess
from bravo.remote import MakeChunk
generators = [plugin.name for plugin in self.pipeline]
d = deferToAMPProcess(MakeChunk,
x=x,
z=z,
seed=self.level.seed,
generators=generators)
# Get chunk data into our chunk object.
def fill_chunk(kwargs):
chunk.blocks = array("B")
chunk.blocks.fromstring(kwargs["blocks"])
chunk.heightmap = array("B")
chunk.heightmap.fromstring(kwargs["heightmap"])
chunk.metadata = array("B")
chunk.metadata.fromstring(kwargs["metadata"])
chunk.skylight = array("B")
chunk.skylight.fromstring(kwargs["skylight"])
chunk.blocklight = array("B")
chunk.blocklight.fromstring(kwargs["blocklight"])
return chunk
d.addCallback(fill_chunk)
else:
# Populate the chunk the slow way. :c
for stage in self.pipeline:
stage.populate(chunk, self.level.seed)
chunk.regenerate()
d = succeed(chunk)
# Set up our event and generate our return-value Deferred. It has to
# be done early becaues PendingEvents only fire exactly once and it
# might fire immediately in certain cases.
pe = PendingEvent()
# This one is for our return value.
retval = pe.deferred()
# This one is for scanning the chunk for automatons.
if self.factory:
pe.deferred().addCallback(self.factory.scan_chunk)
self._pending_chunks[x, z] = pe
def pp(chunk):
chunk.populated = True
chunk.dirty = True
self.postprocess_chunk(chunk)
self._cache.dirtied(chunk)
del self._pending_chunks[x, z]
return chunk
# Set up callbacks.
d.addCallback(pp)
d.chainDeferred(pe)
# Because multiple people might be attached to this callback, we're
# going to do something magical here. We will yield a forked version
# of our Deferred. This means that we will wait right here, for a
# long, long time, before actually returning with the chunk, *but*,
# when we actually finish, we'll be ready to return the chunk
# immediately. Our caller cannot possibly care because they only see a
# Deferred either way.
retval = yield retval
returnValue(retval)
