123 lines
3.2 KiB
Python
123 lines
3.2 KiB
Python
|
import os
|
||
|
|
import select
|
||
|
|
import time
|
||
|
|
import threading
|
||
|
|
|
||
|
|
import logging
|
||
|
|
|
||
|
|
logger = logging.getLogger(__name__)
|
||
|
|
|
||
|
|
|
||
|
|
class Pipe(object):
|
||
|
|
READ = "r"
|
||
|
|
WRITE = "w"
|
||
|
|
NONE = None
|
||
|
|
|
||
|
|
@staticmethod
|
||
|
|
def create(path, t, encoding=None):
|
||
|
|
if t == Pipe.READ:
|
||
|
|
return ReadingPipe(path, encoding=encoding)
|
||
|
|
elif t == Pipe.WRITE:
|
||
|
|
return WritingPipe(path, encoding=encoding)
|
||
|
|
elif t == Pipe.NONE:
|
||
|
|
return Pipe(path, None, encoding=encoding)
|
||
|
|
|
||
|
|
def __init__(self, path, direction, encoding=None):
|
||
|
|
self.doOpen = True
|
||
|
|
self.path = "{base}_{myid}".format(base=path, myid=id(self))
|
||
|
|
self.direction = direction
|
||
|
|
self.encoding = encoding
|
||
|
|
self.file = None
|
||
|
|
os.mkfifo(self.path)
|
||
|
|
|
||
|
|
def open(self):
|
||
|
|
retries = 0
|
||
|
|
|
||
|
|
def opener(path, flags):
|
||
|
|
fd = os.open(path, flags | os.O_NONBLOCK)
|
||
|
|
os.set_blocking(fd, True)
|
||
|
|
return fd
|
||
|
|
|
||
|
|
while self.file is None and self.doOpen and retries < 10:
|
||
|
|
try:
|
||
|
|
self.file = open(self.path, self.direction, encoding=self.encoding, opener=opener)
|
||
|
|
except OSError as error:
|
||
|
|
# ENXIO = FIFO has not been opened for reading
|
||
|
|
if error.errno == 6:
|
||
|
|
time.sleep(.1)
|
||
|
|
retries += 1
|
||
|
|
else:
|
||
|
|
raise
|
||
|
|
|
||
|
|
# if doOpen is false, opening has been canceled, so no warning in that case.
|
||
|
|
if self.file is None and self.doOpen:
|
||
|
|
logger.warning("could not open FIFO %s", self.path)
|
||
|
|
|
||
|
|
def close(self):
|
||
|
|
self.doOpen = False
|
||
|
|
try:
|
||
|
|
if self.file is not None:
|
||
|
|
self.file.close()
|
||
|
|
os.unlink(self.path)
|
||
|
|
except FileNotFoundError:
|
||
|
|
# it seems like we keep calling this twice. no idea why, but we don't need the resulting error.
|
||
|
|
pass
|
||
|
|
except Exception:
|
||
|
|
logger.exception("Pipe.close()")
|
||
|
|
|
||
|
|
def __str__(self):
|
||
|
|
return self.path
|
||
|
|
|
||
|
|
|
||
|
|
class WritingPipe(Pipe):
|
||
|
|
def __init__(self, path, encoding=None):
|
||
|
|
self.queue = []
|
||
|
|
self.queueLock = threading.Lock()
|
||
|
|
super().__init__(path, "w", encoding=encoding)
|
||
|
|
self.open()
|
||
|
|
|
||
|
|
def open_and_dequeue(self):
|
||
|
|
super().open()
|
||
|
|
|
||
|
|
if self.file is None:
|
||
|
|
return
|
||
|
|
|
||
|
|
with self.queueLock:
|
||
|
|
for i in self.queue:
|
||
|
|
self.file.write(i)
|
||
|
|
self.file.flush()
|
||
|
|
self.queue = None
|
||
|
|
|
||
|
|
def open(self):
|
||
|
|
threading.Thread(target=self.open_and_dequeue).start()
|
||
|
|
|
||
|
|
def write(self, data):
|
||
|
|
if self.file is None:
|
||
|
|
with self.queueLock:
|
||
|
|
self.queue.append(data)
|
||
|
|
return
|
||
|
|
r = self.file.write(data)
|
||
|
|
self.file.flush()
|
||
|
|
return r
|
||
|
|
|
||
|
|
|
||
|
|
class ReadingPipe(Pipe):
|
||
|
|
def __init__(self, path, encoding=None):
|
||
|
|
super().__init__(path, "r", encoding=encoding)
|
||
|
|
|
||
|
|
def open(self):
|
||
|
|
if not self.doOpen:
|
||
|
|
return
|
||
|
|
super().open()
|
||
|
|
select.select([self.file], [], [], 10)
|
||
|
|
|
||
|
|
def read(self):
|
||
|
|
if self.file is None:
|
||
|
|
self.open()
|
||
|
|
return self.file.read()
|
||
|
|
|
||
|
|
def readline(self):
|
||
|
|
if self.file is None:
|
||
|
|
self.open()
|
||
|
|
return self.file.readline()
|