def data_provider_server(lock, conn):
"""The PyGRASS data provider server designed to be a target for
multiprocessing.Process
:param lock: A multiprocessing.Lock
:param conn: A multiprocessing.Pipe
"""
def error_handler(data):
"""This function will be called in case of a fatal error in libgis"""
# sys.stderr.write("Error handler was called\n")
# We send an exception that will be handled in
# the parent process, then close the pipe
# and release any possible lock
conn.send(
FatalError("G_fatal_error() was called in the server process"))
conn.close()
lock.release()
CALLBACK = CFUNCTYPE(c_void_p, c_void_p)
CALLBACK.restype = c_void_p
CALLBACK.argtypes = c_void_p
cerror_handler = CALLBACK(error_handler)
libgis.G_add_error_handler(cerror_handler, None)
# Crerate the function array
functions = [0] * 15
functions[RPCDefs.GET_VECTOR_TABLE_AS_DICT] = _get_vector_table_as_dict
functions[
RPCDefs.GET_VECTOR_FEATURES_AS_WKB] = _get_vector_features_as_wkb_list
functions[RPCDefs.GET_RASTER_IMAGE_AS_NP] = _get_raster_image_as_np
functions[RPCDefs.STOP] = _stop
functions[RPCDefs.G_FATAL_ERROR] = _fatal_error
while True:
# Avoid busy waiting
conn.poll(None)
data = conn.recv()
lock.acquire()
functions[data[0]](lock, conn, data)
lock.release()
