def app_on_receive_event(rcv, msg, app_state):
'Application receiver event callback.'
if msg.type == lib.LBM_MSG_DATA:
data = ffi.string(ffi.cast('char *', msg.data))
topic_name = ffi.string(ffi.cast('char *', msg.topic_name))
src = ffi.string(ffi.cast('char *', msg.source))
print('Msg:' + data.decode('utf-8') + '[' + topic_name.decode('utf-8') +
':' + src.decode('utf-8') + ':' + str(msg.sequence_number) +
'], state=' + str(app_state))
def pylbm_src_cb_proc(src, event, event_data, clientd):
'UM source event application callback.'
if event == lib.LBM_SRC_EVENT_CONNECT:
clientname = ffi.string(ffi.cast('const char *', event_data))
print('Receiver connect ['+clientname.decode('utf-8')+']')
elif event == lib.LBM_SRC_EVENT_DISCONNECT:
clientname = ffi.string(ffi.cast('const char *', event_data))
print('Receiver disconnect ['+clientname.decode('utf-8')+']')
return 0
def main():
'Put "main" program in a function to allow callable.'
# Setup logging callback.
lbmerr(lib.lbm_log(lib.pylbm_log_cb_proc, ffi.NULL))
# Read the config file.
err = lib.lbm_config(b'um.cfg')
if err == lib.LBM_FAILURE:
print("Warning, lbm_config 'um.cfg' error: " +
str(ffi.string(lib.lbm_errmsg())))
# Create the context attribute.
p_cattr = ffi.new('lbm_context_attr_t **')
lbmerr(lib.lbm_context_attr_create(p_cattr))
# Get the attribute pointer.
cattr = p_cattr[0]
# This test program uses the "new source notification" callback to
# demonstrate setting up a callback via a configuration option.
# See python function pylbm_src_notify_function_cb() above.
lbm_src_notify_func = ffi.new('lbm_src_notify_func_t *')
lbm_src_notify_func.notifyfunc = lib.pylbm_src_notify_function_cb
lbmerr(
lib.lbm_context_attr_setopt(cattr,
b'resolver_source_notification_function',
lbm_src_notify_func,
ffi.sizeof('lbm_src_notify_func_t')))
# Create the context.
p_ctx = ffi.new('lbm_context_t **')
lbmerr(lib.lbm_context_create(p_ctx, cattr, ffi.NULL, ffi.NULL))
#get the context pointer
ctx = p_ctx[0]
# Delete the context attribute.
lib.lbm_context_attr_delete(cattr)
# Create the receiver topic attribute.
p_rcv_tattr = ffi.new('lbm_rcv_topic_attr_t **')
lbmerr(lib.lbm_rcv_topic_attr_create(p_rcv_tattr))
# Get the attribute pointer.
rcv_tattr = p_rcv_tattr[0]
# Lookup for the receiver topic.
p_topic = ffi.new('lbm_topic_t **')
lbmerr(lib.lbm_rcv_topic_lookup(p_topic, ctx, b'lbmtst.py', rcv_tattr))
# Get the topic object.
topic = p_topic[0]
# Set some application state.
app_state = {'abc':123}
main.app_state_handle = ffi.new_handle(app_state)
# Create the callback object.
lbm_rcv_callback = LbmRcvCallback(app_on_receive_event, app_state)
callback_handle = ffi.new_handle(lbm_rcv_callback)
# Create the receiver.
p_rcv = ffi.new('lbm_rcv_t **')
lbmerr(lib.lbm_rcv_create(p_rcv, ctx, topic, lib.pylbm_rcv_cb_proc,
callback_handle, ffi.NULL))
# Get the receiver object.
rcv = p_rcv[0]
print('Receiver created for lbmtst.py topic')
# Delete the topic attribute.
lib.lbm_rcv_topic_attr_delete(rcv_tattr)
# Create the source topic attribute.
p_src_tattr = ffi.new('lbm_src_topic_attr_t **')
lbmerr(lib.lbm_src_topic_attr_create(p_src_tattr))
# Get the attribute pointer.
src_tattr = p_src_tattr[0]
print('source topic created')
# Allocate the desired source topic.
p_topic = ffi.new('lbm_topic_t **')
lbmerr(lib.lbm_src_topic_alloc(p_topic, ctx, b'lbmtst.py', src_tattr))
# Get the topic object.
topic = p_topic[0]
# Create the source.
p_src = ffi.new('lbm_src_t **')
lbmerr(lib.lbm_src_create(p_src, ctx, topic, lib.pylbm_src_cb_proc,
ffi.NULL, ffi.NULL))
# Get the source object.
src = p_src[0]
print('source created')
# Delete the topic attribute.
lib.lbm_src_topic_attr_delete(src_tattr)
# Let topic res complete.
time.sleep(1)
print('TR complete')
# Publish 50 messages.
for i in range(50):
message = ('message%d' % i).encode('utf-8')
lbmerr(lib.lbm_src_send(src, message, len(message), lib.LBM_SRC_BLOCK))
# Let messages be delivered.
time.sleep(1)
# Cleanup.
print('Deleting receiver')
lbmerr(lib.lbm_rcv_delete(rcv))
print('Deleting source')
lbmerr(lib.lbm_src_delete(src))
print('Deleting context')
lbmerr(lib.lbm_context_delete(ctx))
def lbmerr(err):
'Very simple, programmer-friendly (user-hostile) error checker.'
assert err != lib.LBM_FAILURE, ffi.string(lib.lbm_errmsg())
def pylbm_log_cb_proc(level, message, clientd):
'UM logger application callback.'
print(ffi.string(message).decode('utf-8'))
return 0
def pylbm_src_notify_function_cb(topic_str, src_str, clientd):
'New source notification callback.'
topic = ffi.string(topic_str).decode('utf-8')
source = ffi.string(src_str).decode('utf-8')
print('new source: topic=' + topic + ', source_string=' + source)
return 0
def pylbm_log_cb_proc(_unused_level, message, _unused_clientd):
"""UM logger application callback."""
print(ffi.string(message).decode('utf-8'))
return 0
def lbmerr(err):
"""Very simple, programmer-friendly (user-hostile) error checker."""
assert err != lib.LBM_FAILURE, ffi.string(lib.lbm_errmsg().decode('utf-8'))
