76 lines
2.1 KiB
Python
76 lines
2.1 KiB
Python
import logging
|
|
from twisted.internet import interfaces, defer
|
|
from zope.interface import implements
|
|
|
|
|
|
log = logging.getLogger(__name__)
|
|
|
|
|
|
class StreamCreator(object):
|
|
"""Classes which derive from this class create a 'stream', which can be any
|
|
collection of associated blobs and associated metadata. These classes
|
|
use the IConsumer interface to get data from an IProducer and transform
|
|
the data into a 'stream'"""
|
|
|
|
implements(interfaces.IConsumer)
|
|
|
|
def __init__(self, name):
|
|
"""
|
|
@param name: the name of the stream
|
|
"""
|
|
self.name = name
|
|
self.stopped = True
|
|
self.producer = None
|
|
self.streaming = None
|
|
self.blob_count = -1
|
|
self.current_blob = None
|
|
self.finished_deferreds = []
|
|
|
|
def _blob_finished(self, blob_info):
|
|
pass
|
|
|
|
def registerProducer(self, producer, streaming):
|
|
|
|
from twisted.internet import reactor
|
|
|
|
self.producer = producer
|
|
self.streaming = streaming
|
|
self.stopped = False
|
|
if streaming is False:
|
|
reactor.callLater(0, self.producer.resumeProducing)
|
|
|
|
def unregisterProducer(self):
|
|
self.stopped = True
|
|
self.producer = None
|
|
|
|
def stop(self):
|
|
"""Stop creating the stream. Create the terminating zero-length blob."""
|
|
log.debug("stop has been called for StreamCreator")
|
|
self.stopped = True
|
|
if self.current_blob is not None:
|
|
current_blob = self.current_blob
|
|
d = current_blob.close()
|
|
d.addCallback(self._blob_finished)
|
|
self.finished_deferreds.append(d)
|
|
self.current_blob = None
|
|
self._finalize()
|
|
dl = defer.DeferredList(self.finished_deferreds)
|
|
dl.addCallback(lambda _: self._finished())
|
|
return dl
|
|
|
|
def _finalize(self):
|
|
pass
|
|
|
|
def _finished(self):
|
|
pass
|
|
|
|
def write(self, data):
|
|
|
|
from twisted.internet import reactor
|
|
|
|
self._write(data)
|
|
if self.stopped is False and self.streaming is False:
|
|
reactor.callLater(0, self.producer.resumeProducing)
|
|
|
|
def _write(self, data):
|
|
pass |