def call(self):
"""
Process the message.
Calls application callbacks and then updates the global state.
"""
thread = threading.current_thread()
logging.info('{0} invokes message: {1}'.format(
str(thread), self._message))
from_state = self._message['simpleFields']['FROM_STATE']
to_state = self._message['simpleFields']['TO_STATE']
session_id = self._participant.get_session_id()
resource_name = self._message['simpleFields']['RESOURCE_NAME']
partition_name = self._message['simpleFields']['PARTITION_NAME']
try:
parser = self._state_model_parser
method_to_invoke = parser.get_method_for_transition(
self._state_model, from_state, to_state)
logging.info('method_to_invoke: {0}'.format(str(method_to_invoke)))
method_to_invoke(self._message)
except Exception as e:
logging.error('{0}-{1} transition failed, {2}'.format(
from_state, to_state, e))
to_state = 'ERROR'
error_key = self._builder.error(
self._participant_id, session_id, resource_name,
partition_name)
error_node = znode.get_empty_znode(partition_name)
error_node['simpleFields']['ERROR'] = str(e)
self._accessor.update(error_key, error_node)
self._state_model._current_state = to_state
# update current-state, then remove message
sub = False
current_state = znode.get_empty_znode(resource_name)
current_state['mapFields'][partition_name] = {}
if to_state != 'DROPPED':
# update the current state
current_state['mapFields'][partition_name]['CURRENT_STATE'] = (
to_state)
current_state['simpleFields']['STATE_MODEL_DEF'] = (
self._message['simpleFields']['STATE_MODEL_DEF'])
current_state['simpleFields']['SESSION_ID'] = session_id
else:
# drop the partition from the current state
sub = True
self._accessor.update(self._builder.current_state(
self._participant_id, session_id,
resource_name), current_state, sub=sub)
self._accessor.remove(self._builder.message(
self._participant_id, self._message['id']))
def _ensure_participant_config(self):
"""
Ensure that ZNodes for a participant all exist, non-atomic (private)
Returns:
True if everything was persisted, False otherwise
"""
exists = self._accessor.exists(
self._builder.participant_config(self._participant_id))
if not exists and self._auto_join_allowed():
node = znode.get_empty_znode(self._participant_id)
node['simpleFields'] = {
'HELIX_HOST': self._host, 'HELIX_PORT': str(self._port),
'HELIX_ENABLED': 'true'}
self._accessor.create(
self._builder.participant_config(self._participant_id), node)
self._accessor.create(
self._builder.instance(self._participant_id), b'')
self._accessor.create(
self._builder.current_states(self._participant_id), b'')
self._accessor.create(
self._builder.errors(self._participant_id), b'')
self._accessor.create(
self._builder.health_report(self._participant_id), b'')
self._accessor.create(
self._builder.messages(self._participant_id), b'')
self._accessor.create(
self._builder.status_updates(self._participant_id), b'')
elif not exists:
return False
return True
def _ensure_participant_config(self):
"""
Ensure that ZNodes for a participant all exist, non-atomic (private)
Returns:
True if everything was persisted, False otherwise
"""
exists = self._accessor.exists(
self._builder.participant_config(self._participant_id))
if not exists and self._auto_join_allowed():
node = znode.get_empty_znode(self._participant_id)
node['simpleFields'] = {
'HELIX_HOST': self._host,
'HELIX_PORT': str(self._port),
'HELIX_ENABLED': 'true'
}
self._accessor.create(
self._builder.participant_config(self._participant_id), node)
self._accessor.create(self._builder.instance(self._participant_id),
b'')
self._accessor.create(
self._builder.current_states(self._participant_id), b'')
self._accessor.create(self._builder.errors(self._participant_id),
b'')
self._accessor.create(
self._builder.health_report(self._participant_id), b'')
self._accessor.create(self._builder.messages(self._participant_id),
b'')
self._accessor.create(
self._builder.status_updates(self._participant_id), b'')
elif not exists:
return False
return True
def _create_live_instance_node(self):
"""
Create a live instance ZNode for this participant (private)
Returns:
True if created, False otherwise
"""
node = znode.get_empty_znode(self._participant_id)
node['simpleFields'] = {
'HELIX_VERSION': 'pyhelix-{0}'.format(constants.CURRENT_VERSION),
'SESSION_ID': str(self._client.client_id[0]),
'LIVE_INSTANCE': '{0}@{1}'.format(os.getpid(), self._host)}
return self._accessor.create(
self._builder.live_instance(self._participant_id), node)
def _create_live_instance_node(self):
"""
Create a live instance ZNode for this participant (private)
Returns:
True if created, False otherwise
"""
node = znode.get_empty_znode(self._participant_id)
node['simpleFields'] = {
'HELIX_VERSION': 'pyhelix-{0}'.format(constants.CURRENT_VERSION),
'SESSION_ID': str(self._client.client_id[0]),
'LIVE_INSTANCE': '{0}@{1}'.format(os.getpid(), self._host)
}
return self._accessor.create(
self._builder.live_instance(self._participant_id), node)