Buffered pipes

Attempt to generalize the “feeder” part of a Channel: an object which can be read from and closed, but is reading from a buffer fed by another thread. The read operations are blocking and can have a timeout set.

class paramiko.buffered_pipe.BufferedPipe

A buffer that obeys normal read (with timeout) & close semantics for a file or socket, but is fed data from another thread. This is used by Channel.

__init__()

Initialize self. See help(type(self)) for accurate signature.

__len__()

Return the number of bytes buffered.

Returns:number (int) of bytes buffered
__weakref__

list of weak references to the object (if defined)

close()

Close this pipe object. Future calls to read after the buffer has been emptied will return immediately with an empty string.

empty()

Clear out the buffer and return all data that was in it.

Returns:any data that was in the buffer prior to clearing it out, as a str
feed(data)

Feed new data into this pipe. This method is assumed to be called from a separate thread, so synchronization is done.

Parameters:data – the data to add, as a str or bytes
read(nbytes, timeout=None)

Read data from the pipe. The return value is a string representing the data received. The maximum amount of data to be received at once is specified by nbytes. If a string of length zero is returned, the pipe has been closed.

The optional timeout argument can be a nonnegative float expressing seconds, or None for no timeout. If a float is given, a PipeTimeout will be raised if the timeout period value has elapsed before any data arrives.

Parameters:
  • nbytes (int) – maximum number of bytes to read
  • timeout (float) – maximum seconds to wait (or None, the default, to wait forever)
Returns:

the read data, as a str or bytes
Raises:

PipeTimeout – if a timeout was specified and no data was ready before that timeout
read_ready()

Returns true if data is buffered and ready to be read from this feeder. A False result does not mean that the feeder has closed; it means you may need to wait before more data arrives.

Returns:True if a read call would immediately return at least one byte; False otherwise.
set_event(event)

Set an event on this buffer. When data is ready to be read (or the buffer has been closed), the event will be set. When no data is ready, the event will be cleared.

Parameters:event (threading.Event) – the event to set/clear

Unlink an Event object from this buffer.

exception paramiko.buffered_pipe.PipeTimeout

Indicates that a timeout was reached on a read from a BufferedPipe.

__weakref__

list of weak references to the object (if defined)