def subprocess_pickle_echo(input_data, protocol=None):
"""Echo function with a child Python process
Pickle the input data into a buffer, send it to a subprocess via
stdin, expect the subprocess to unpickle, re-pickle that data back
and send it back to the parent process via stdout for final unpickling.
>>> subprocess_pickle_echo([1, 'a', None])
[1, 'a', None]
"""
pickled_input_data = dumps(input_data, protocol=protocol)
cmd = [sys.executable, __file__] # run then pickle_echo() in __main__
cloudpickle_repo_folder = op.normpath(
op.join(op.dirname(__file__), '..', '..', '..'))
cwd = cloudpickle_repo_folder
pythonpath = "{src}/srsly/tests/pickle:{src}".format(
src=cloudpickle_repo_folder)
env = {'PYTHONPATH': pythonpath}
proc = Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=PIPE, cwd=cwd, env=env)
try:
comm_kwargs = {}
if timeout_supported:
comm_kwargs['timeout'] = 5
out, err = proc.communicate(pickled_input_data, **comm_kwargs)
if proc.returncode != 0 or len(err):
message = "Subprocess returned %d: " % proc.returncode
message += err.decode('utf-8')
raise RuntimeError(message)
return loads(out)
except TimeoutExpired:
proc.kill()
out, err = proc.communicate()
message = u"\n".join([out.decode('utf-8'), err.decode('utf-8')])
raise RuntimeError(message)
def pickle_echo(stream_in=None, stream_out=None, protocol=None):
"""Read a pickle from stdin and pickle it back to stdout"""
if stream_in is None:
stream_in = sys.stdin
if stream_out is None:
stream_out = sys.stdout
# Force the use of bytes streams under Python 3
if hasattr(stream_in, 'buffer'):
stream_in = stream_in.buffer
if hasattr(stream_out, 'buffer'):
stream_out = stream_out.buffer
input_bytes = stream_in.read()
stream_in.close()
unpickled_content = loads(input_bytes)
stream_out.write(dumps(unpickled_content, protocol=protocol))
stream_out.close()