Class Pump
source code
object --+
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Pump
Pumps data from a ReadStream to a WriteStream and performs flow
control where necessary to prevent the write stream from getting
overloaded.
Instances of this class read bytes from a ReadStream and write them to
a WriteStream. If data can be read faster than it can be written this
could result in the write queue of the WriteStream growing without bound,
eventually causing it to exhaust all available RAM. To prevent this,
after each write, instances of this class check whether the write queue
of the WriteStream is full, and if so, the ReadStream is paused, and a
WriteStreamdrain_handler is set on the WriteStream. When the WriteStream
has processed half of its backlog, the drain_handler will be called,
which results in the pump resuming the ReadStream.
This class can be used to pump from any ReadStream to any
WriteStream, e.g. from an HttpServerRequest to an AsyncFile, or from
NetSocket to a WebSocket.
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write_queue_max_size = property(fset= set_write_queue_max_size)
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__init__(self,
read_stream,
write_stream)
(Constructor)
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- Overrides:
object.__init__
- (inherited documentation)
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Set the write queue max size
Keyword arguments:
- Parameters:
val - The write queue max size
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Start the Pump. The Pump can be started and stopped multiple
times.
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Stop the Pump. The Pump can be started and stopped multiple times.
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return the total number of bytes pumped by this pump.
- Decorators:
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