diff options
Diffstat (limited to 'oslo_messaging/rpc/client.py')
| -rw-r--r-- | oslo_messaging/rpc/client.py | 39 |
1 files changed, 35 insertions, 4 deletions
diff --git a/oslo_messaging/rpc/client.py b/oslo_messaging/rpc/client.py index cbec525..8e997e9 100644 --- a/oslo_messaging/rpc/client.py +++ b/oslo_messaging/rpc/client.py @@ -32,6 +32,7 @@ __all__ = [ 'RPCClient', 'RPCVersionCapError', 'RemoteError', + 'get_rpc_client', ] LOG = logging.getLogger(__name__) @@ -263,6 +264,9 @@ class RPCClient(_BaseCallContext): The RPCClient class is responsible for sending method invocations to and receiving return values from remote RPC servers via a messaging transport. + The class should always be instantiated by using the get_rpc_client + function and not constructing the class directly. + Two RPC patterns are supported: RPC calls and RPC casts. An RPC cast is used when an RPC method does *not* return a value to @@ -295,7 +299,7 @@ class RPCClient(_BaseCallContext): def __init__(self, transport): target = messaging.Target(topic='test', version='2.0') - self._client = messaging.RPCClient(transport, target) + self._client = messaging.get_rpc_client(transport, target) def test(self, ctxt, arg): return self._client.call(ctxt, 'test', arg=arg) @@ -320,7 +324,7 @@ class RPCClient(_BaseCallContext): transport = messaging.get_rpc_transport(cfg.CONF) target = messaging.Target(topic='test', version='2.0') - client = messaging.RPCClient(transport, target) + client = messaging.get_rpc_client(transport, target) client.call(ctxt, 'test', arg=arg) but this is probably only useful in limited circumstances as a wrapper @@ -334,7 +338,7 @@ class RPCClient(_BaseCallContext): have the RPC request fail with a MessageDeliveryFailure after the given number of retries. For example:: - client = messaging.RPCClient(transport, target, retry=None) + client = messaging.get_rpc_client(transport, target, retry=None) client.call(ctxt, 'sync') try: client.prepare(retry=0).cast(ctxt, 'ping') @@ -346,9 +350,13 @@ class RPCClient(_BaseCallContext): def __init__(self, transport, target, timeout=None, version_cap=None, serializer=None, retry=None, - call_monitor_timeout=None, transport_options=None): + call_monitor_timeout=None, transport_options=None, + _manual_load=True): """Construct an RPC client. + This should not be called directly, use the get_rpc_client function + to instantiate this class. + :param transport: a messaging transport handle :type transport: Transport :param target: the default target for invocations @@ -371,7 +379,17 @@ class RPCClient(_BaseCallContext): (less than the overall timeout parameter). :type call_monitor_timeout: int + :param transport_options: Transport options passed to client. + :type transport_options: TransportOptions + :param _manual_load: Internal use only to check if class was + manually instantiated or not. + :type _manual_load: bool """ + if _manual_load: + LOG.warning("Using RPCClient manually to instantiate client. " + "Please use get_rpc_client to obtain an RPC client " + "instance.") + if serializer is None: serializer = msg_serializer.NoOpSerializer() @@ -530,3 +548,16 @@ class RPCClient(_BaseCallContext): def can_send_version(self, version=_marker): """Check to see if a version is compatible with the version cap.""" return self.prepare(version=version).can_send_version() + + +def get_rpc_client(transport, target, **kwargs): + """Construct an RPC client. + + :param transport: the messaging transport + :type transport: Transport + :param target: the exchange, topic and server to listen on + :type target: Target + :param **kwargs: The kwargs will be passed down to the + RPCClient constructor + """ + return RPCClient(transport, target, _manual_load=False, **kwargs) |