class documentation

class ProcessWriter(abstract.FileDescriptor): (source)

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(Internal) Helper class to write into a Process's input pipe.

I am a helper which describes a selectable asynchronous writer to a process's input pipe, including stdin.

Method __init__ Initialize, specifying a Process instance to connect to.
Method connectionLost See abstract.FileDescriptor.connectionLost.
Method doRead The only way a write pipe can become "readable" is at EOF, because the child has closed it, and we're using a reactor which doesn't distinguish between readable and closed (such as the select reactor).
Method fileno Return the fileno() of my process's stdin.
Method write Reliably write some data.
Method writeSomeData Write some data to the open process.
Class Variable connected Undocumented
Class Variable ic Undocumented
Instance Variable enableReadHack A flag which determines how readability on this write descriptor will be handled. If True, then readability may indicate the reader for this write descriptor has been closed (ie, the connection has been lost). If False, then readability events are ignored.
Instance Variable fd Undocumented
Instance Variable name Undocumented
Instance Variable proc Undocumented

Inherited from FileDescriptor:

Method doWrite Called when data can be written.
Method getHost Similar to getPeer, but returns an address describing this side of the connection.
Method getPeer Get the remote address of this connection.
Method loseConnection Close the connection at the next available opportunity.
Method loseWriteConnection Undocumented
Method pauseProducing Pause producing data.
Method readConnectionLost Indicates read connection was lost.
Method resumeProducing Resume producing data.
Method startReading Start waiting for read availability.
Method startWriting Start waiting for write availability.
Method stopConsuming Stop consuming data.
Method stopProducing Stop producing data.
Method stopReading Stop waiting for read availability.
Method stopWriting Stop waiting for write availability.
Method writeConnectionLost Indicates write connection was lost.
Method writeSequence Reliably write a sequence of data.
Class Variable bufferSize Undocumented
Class Variable SEND_LIMIT Undocumented
Instance Variable dataBuffer Undocumented
Instance Variable disconnected Undocumented
Instance Variable disconnecting Undocumented
Instance Variable offset Undocumented
Instance Variable producer Undocumented
Instance Variable producerPaused Undocumented
Instance Variable reactor Undocumented
Method _closeWriteConnection Undocumented
Method _isSendBufferFull Determine whether the user-space send buffer for this transport is full or not.
Method _maybePauseProducer Possibly pause a producer, if there is one and the send buffer is full.
Method _postLoseConnection Called after a loseConnection(), when all data has been written.
Instance Variable _tempDataBuffer Undocumented
Instance Variable _tempDataLen Undocumented
Instance Variable _writeDisconnected Undocumented
Instance Variable _writeDisconnecting Undocumented

Inherited from _ConsumerMixin (via FileDescriptor):

Method registerProducer Register to receive data from a producer.
Method unregisterProducer Stop consuming data from a producer, without disconnecting.
Instance Variable streamingProducer bool or int

Inherited from _LogOwner (via FileDescriptor):

Method logPrefix Override this method to insert custom logging behavior. Its return value will be inserted in front of every line. It may be called more times than the number of output lines.
Method _getLogPrefix Determine the log prefix to use for messages related to applicationObject, which may or may not be an interfaces.ILoggingContext provider.
def __init__(self, reactor, proc, name, fileno, forceReadHack=False): (source)
Initialize, specifying a Process instance to connect to.
def connectionLost(self, reason): (source)
def doRead(self): (source)

The only way a write pipe can become "readable" is at EOF, because the child has closed it, and we're using a reactor which doesn't distinguish between readable and closed (such as the select reactor).

Except that's not true on linux < 2.6.11. It has the following characteristics: write pipe is completely empty => POLLOUT (writable in select), write pipe is not completely empty => POLLIN (readable in select), write pipe's reader closed => POLLIN|POLLERR (readable and writable in select)

That's what this funky code is for. If linux was not broken, this function could be simply "return CONNECTION_LOST".

def fileno(self): (source)
Return the fileno() of my process's stdin.
def write(self, data): (source)

Reliably write some data.

The data is buffered until the underlying file descriptor is ready for writing. If there is more than self.bufferSize data in the buffer and this descriptor has a registered streaming producer, its pauseProducing() method will be called.

def writeSomeData(self, data): (source)
Write some data to the open process.

Undocumented

enableReadHack: bool = (source)
A flag which determines how readability on this write descriptor will be handled. If True, then readability may indicate the reader for this write descriptor has been closed (ie, the connection has been lost). If False, then readability events are ignored.

Undocumented

name = (source)

Undocumented

proc = (source)

Undocumented