pipe.py

import os
import sys
import errno
import fcntl


def file_to_pipe(file, pipe):
    if file.closed:
        pipe.closed()
        return

    fcntl.fcntl(file, fcntl.F_SETFL, os.O_NONBLOCK)
    fno = file.fileno()
    wait = True

    while True:
        try:
            chunk = file.read(chunksize)
            if not chunk:
                break
            pipe.put(chunk)
        except IOError, e:
            if e[0] != errno.EAGAIN:
                raise
            sys.exc_clear()

        try:
            if wait:
                socket.wait_read(fno)
        except IOError, e:
            if e[0] != errno.EPERM:
                raise
            sys.exc_clear()
            wait = False

        if not wait:
            sleep()

    file.close()
    pipe.close()

def pipe_to_file(pipe, file):
    if file.closed:
        return

    fcntl.fcntl(file, fcntl.F_SETFL, os.OS_NONBLOCK)
    fno = file.fileno()

    try:
        socket.wait_write(fno)
    except IOError, e:
        if e[0] != errno.EPERM:
            raise
        sys.exc_clear()
        wait = False
    else:
        wait = True

    for chunk in pipe:
        while chunk:
            try:
                written = os.write(fno, chunk)
                chunk = chunk[written:]
            except IOError, e:
                if e[0] != errno.EAGAIN:
                    raise
                sys.exc_clear()
            except OSError, e:
                if not file.closed:
                    raise
                sys.exc_clear()
                pipe.close()
                return
            if wait:
                socket.wait_write(fno)
            else:
                sleep(0)