twisted.internet.interfaces.IConsumer.registerProducer(producer, streaming) method documentation

Register to receive data from a producer.

This sets self to be a consumer for a producer. When this object runs out of data (as when a send(2) call on a socket succeeds in moving the last data from a userspace buffer into a kernelspace buffer), it will ask the producer to resumeProducing().

For IPullProducer providers, resumeProducing will be called once each time data is required.

For IPushProducer providers, pauseProducing will be called whenever the write buffer fills up and resumeProducing will only be called when it empties. The consumer will only call resumeProducing to balance a previous pauseProducing call; the producer is assumed to start in an un-paused state.