twisted.web.client.FileBodyProducer

class documentation

class FileBodyProducer: (source)

Constructor: FileBodyProducer(inputFile, cooperator, readSize)

Implements interfaces: twisted.web.iweb.IBodyProducer

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FileBodyProducer produces bytes from an input file object incrementally and writes them to a consumer.

Since file-like objects cannot be read from in an event-driven manner, FileBodyProducer uses a Cooperator instance to schedule reads from the file. This process is also paused and resumed based on notifications from the IConsumer provider being written to.

The file is closed after it has been read, or if the producer is stopped early.

Method __init__ Undocumented
Method pauseProducing Temporarily suspend copying bytes from the input file to the consumer by pausing the CooperativeTask which drives that activity.
Method resumeProducing Undo the effects of a previous pauseProducing and resume copying bytes to the consumer by resuming the CooperativeTask which drives the write activity.
Method startProducing Start a cooperative task which will read bytes from the input file and write them to consumer. Return a Deferred which fires after all bytes have been written. If this Deferred is cancelled before it is fired, stop reading and writing bytes.
Method stopProducing Permanently stop writing bytes from the file to the consumer by stopping the underlying CooperativeTask.
Instance Variable length length is a int indicating how many bytes in total this IBodyProducer will write to the consumer or UNKNOWN_LENGTH if this is not known in advance.
Method _determineLength Determine how many bytes can be read out of fObj (assuming it is not modified from this point on). If the determination cannot be made, return UNKNOWN_LENGTH.
Method _writeloop Return an iterator which reads one chunk of bytes from the input file and writes them to the consumer for each time it is iterated.
Instance Variable _cooperate A method like Cooperator.cooperate which is used to schedule all reads.
Instance Variable _inputFile Any file-like object, bytes read from which will be written to a consumer.
Instance Variable _readSize The number of bytes to read from _inputFile at a time.
Instance Variable _task Undocumented
def __init__(self, inputFile, cooperator=task, readSize=2**16): (source)

Undocumented

def pauseProducing(self): (source)
from twisted.internet.interfaces.IPushProducer

Temporarily suspend copying bytes from the input file to the consumer by pausing the CooperativeTask which drives that activity.

def resumeProducing(self): (source)
from twisted.internet.interfaces.IPushProducer

Undo the effects of a previous pauseProducing and resume copying bytes to the consumer by resuming the CooperativeTask which drives the write activity.

def startProducing(self, consumer): (source)
from twisted.web.iweb.IBodyProducer

Start a cooperative task which will read bytes from the input file and write them to consumer. Return a Deferred which fires after all bytes have been written. If this Deferred is cancelled before it is fired, stop reading and writing bytes.

Parameters
consumerAny IConsumer provider
def stopProducing(self): (source)
from twisted.web.iweb.IBodyProducer

Permanently stop writing bytes from the file to the consumer by stopping the underlying CooperativeTask.

length = (source)
from twisted.web.iweb.IBodyProducer

length is a int indicating how many bytes in total this IBodyProducer will write to the consumer or UNKNOWN_LENGTH if this is not known in advance.

def _determineLength(self, fObj): (source)

Determine how many bytes can be read out of fObj (assuming it is not modified from this point on). If the determination cannot be made, return UNKNOWN_LENGTH.

def _writeloop(self, consumer): (source)

Return an iterator which reads one chunk of bytes from the input file and writes them to the consumer for each time it is iterated.

_cooperate = (source)

A method like Cooperator.cooperate which is used to schedule all reads.

_inputFile = (source)

Any file-like object, bytes read from which will be written to a consumer.

_readSize = (source)

The number of bytes to read from _inputFile at a time.

_task = (source)

Undocumented