class AsyncFunction(ForkProcess):
"""
Execute a function call in a fork, and retrieve the function
return value via pickling/unpickling, accessible as the
"result" attribute after the forked process has exited.
"""
# NOTE: This class overrides the meaning of the SpawnProcess 'args'
# attribute, and uses it to hold the positional arguments for the
# 'target' function.
__slots__ = ('kwargs', 'result', 'target', '_async_func_reader',
'_async_func_reader_pw')
def _start(self):
pr, pw = os.pipe()
self.fd_pipes = {}
self.fd_pipes[pw] = pw
self._async_func_reader_pw = pw
self._async_func_reader = PipeReader(input_files={"input": pr},
scheduler=self.scheduler)
self._async_func_reader.addExitListener(self._async_func_reader_exit)
self._async_func_reader.start()
ForkProcess._start(self)
os.close(pw)
def _run(self):
try:
result = self.target(*(self.args or []), **(self.kwargs or {}))
os.write(self._async_func_reader_pw, pickle.dumps(result))
except Exception:
traceback.print_exc()
return 1
return os.EX_OK
def _pipe_logger_exit(self, pipe_logger):
# Ignore this event, since we want to ensure that we exit
# only after _async_func_reader_exit has reached EOF.
self._pipe_logger = None
def _async_func_reader_exit(self, pipe_reader):
try:
self.result = pickle.loads(pipe_reader.getvalue())
except Exception:
# The child process will have printed a traceback in this case,
# and returned an unsuccessful returncode.
pass
self._async_func_reader = None
self._unregister()
self.wait()
def _unregister(self):
ForkProcess._unregister(self)
pipe_reader = self._async_func_reader
if pipe_reader is not None:
self._async_func_reader = None
pipe_reader.removeExitListener(self._async_func_reader_exit)
pipe_reader.cancel()
class _Reader(object):
def __init__(self, future, input_file, loop):
self._future = future
self._pipe_reader = PipeReader(input_files={'input_file': input_file},
scheduler=loop)
self._future.add_done_callback(self._cancel_callback)
self._pipe_reader.addExitListener(self._eof)
self._pipe_reader.start()
def _cancel_callback(self, future):
if future.cancelled():
self._cancel()
def _eof(self, pipe_reader):
self._pipe_reader = None
self._future.set_result(pipe_reader.getvalue())
def _cancel(self):
if self._pipe_reader is not None and self._pipe_reader.poll() is None:
self._pipe_reader.removeExitListener(self._eof)
self._pipe_reader.cancel()
self._pipe_reader = None
class FileDigester(ForkProcess):
"""
Asynchronously generate file digests. Pass in file_path and
hash_names, and after successful execution, the digests
attribute will be a dict containing all of the requested
digests.
"""
__slots__ = ('file_path', 'digests', 'hash_names', '_digest_pipe_reader',
'_digest_pw')
def _start(self):
pr, pw = os.pipe()
self.fd_pipes = {}
self.fd_pipes[pw] = pw
self._digest_pw = pw
self._digest_pipe_reader = PipeReader(input_files={"input": pr},
scheduler=self.scheduler)
self._digest_pipe_reader.addExitListener(self._digest_pipe_reader_exit)
self._digest_pipe_reader.start()
ForkProcess._start(self)
os.close(pw)
def _run(self):
digests = perform_multiple_checksums(self.file_path,
hashes=self.hash_names)
buf = "".join("%s=%s\n" % item
for item in digests.items()).encode('utf_8')
while buf:
buf = buf[os.write(self._digest_pw, buf):]
return os.EX_OK
def _parse_digests(self, data):
digests = {}
for line in data.decode('utf_8').splitlines():
parts = line.split('=', 1)
if len(parts) == 2:
digests[parts[0]] = parts[1]
self.digests = digests
def _pipe_logger_exit(self, pipe_logger):
# Ignore this event, since we want to ensure that we
# exit only after _digest_pipe_reader has reached EOF.
self._pipe_logger = None
def _digest_pipe_reader_exit(self, pipe_reader):
self._parse_digests(pipe_reader.getvalue())
self._digest_pipe_reader = None
self._unregister()
self.wait()
def _unregister(self):
ForkProcess._unregister(self)
pipe_reader = self._digest_pipe_reader
if pipe_reader is not None:
self._digest_pipe_reader = None
pipe_reader.removeExitListener(self._digest_pipe_reader_exit)
pipe_reader.cancel()
class FileDigester(ForkProcess):
"""
Asynchronously generate file digests. Pass in file_path and
hash_names, and after successful execution, the digests
attribute will be a dict containing all of the requested
digests.
"""
__slots__ = ('file_path', 'digests', 'hash_names',
'_digest_pipe_reader', '_digest_pw')
def _start(self):
pr, pw = os.pipe()
self.fd_pipes = {}
self.fd_pipes[pw] = pw
self._digest_pw = pw
self._digest_pipe_reader = PipeReader(
input_files={"input":pr},
scheduler=self.scheduler)
self._digest_pipe_reader.addExitListener(self._digest_pipe_reader_exit)
self._digest_pipe_reader.start()
ForkProcess._start(self)
os.close(pw)
def _run(self):
digests = perform_multiple_checksums(self.file_path,
hashes=self.hash_names)
buf = "".join("%s=%s\n" % item
for item in digests.items()).encode('utf_8')
while buf:
buf = buf[os.write(self._digest_pw, buf):]
return os.EX_OK
def _parse_digests(self, data):
digests = {}
for line in data.decode('utf_8').splitlines():
parts = line.split('=', 1)
if len(parts) == 2:
digests[parts[0]] = parts[1]
self.digests = digests
def _pipe_logger_exit(self, pipe_logger):
# Ignore this event, since we want to ensure that we
# exit only after _digest_pipe_reader has reached EOF.
self._pipe_logger = None
def _digest_pipe_reader_exit(self, pipe_reader):
self._parse_digests(pipe_reader.getvalue())
self._digest_pipe_reader = None
self._unregister()
self.wait()
def _unregister(self):
ForkProcess._unregister(self)
pipe_reader = self._digest_pipe_reader
if pipe_reader is not None:
self._digest_pipe_reader = None
pipe_reader.removeExitListener(self._digest_pipe_reader_exit)
pipe_reader.cancel()
class AsyncFunction(ForkProcess):
"""
Execute a function call in a fork, and retrieve the function
return value via pickling/unpickling, accessible as the
"result" attribute after the forked process has exited.
"""
# NOTE: This class overrides the meaning of the SpawnProcess 'args'
# attribute, and uses it to hold the positional arguments for the
# 'target' function.
__slots__ = ('kwargs', 'result', 'target',
'_async_func_reader', '_async_func_reader_pw')
def _start(self):
pr, pw = os.pipe()
self.fd_pipes = {}
self.fd_pipes[pw] = pw
self._async_func_reader_pw = pw
self._async_func_reader = PipeReader(
input_files={"input":pr},
scheduler=self.scheduler)
self._async_func_reader.addExitListener(self._async_func_reader_exit)
self._async_func_reader.start()
ForkProcess._start(self)
os.close(pw)
def _run(self):
try:
result = self.target(*(self.args or []), **(self.kwargs or {}))
os.write(self._async_func_reader_pw, pickle.dumps(result))
except Exception:
traceback.print_exc()
return 1
return os.EX_OK
def _pipe_logger_exit(self, pipe_logger):
# Ignore this event, since we want to ensure that we exit
# only after _async_func_reader_exit has reached EOF.
self._pipe_logger = None
def _async_func_reader_exit(self, pipe_reader):
try:
self.result = pickle.loads(pipe_reader.getvalue())
except Exception:
# The child process will have printed a traceback in this case,
# and returned an unsuccessful returncode.
pass
self._async_func_reader = None
if self.returncode is None:
self._async_waitpid()
else:
self._unregister()
self._async_wait()
def _unregister(self):
ForkProcess._unregister(self)
pipe_reader = self._async_func_reader
if pipe_reader is not None:
self._async_func_reader = None
pipe_reader.removeExitListener(self._async_func_reader_exit)
pipe_reader.cancel()
