/**
* Get the protocol name. If the protocol class has a ProtocolAnnotation, then get the protocol
* name from the annotation; otherwise the class name is the protocol name.
*/
public static String getProtocolName(Class<?> protocol) {
if (protocol == null) {
return null;
}
ProtocolInfo anno = protocol.getAnnotation(ProtocolInfo.class);
return (anno == null) ? protocol.getName() : anno.protocolName();
}
// Register protocol and its impl for rpc calls
void registerProtocolAndImpl(RpcKind rpcKind, Class<?> protocolClass, Object protocolImpl) {
String protocolName = RPC.getProtocolName(protocolClass);
long version;
try {
version = RPC.getProtocolVersion(protocolClass);
} catch (Exception ex) {
LOG.warn("Protocol " + protocolClass + " NOT registered as cannot get protocol version ");
return;
}
getProtocolImplMap(rpcKind)
.put(
new ProtoNameVer(protocolName, version),
new ProtoClassProtoImpl(protocolClass, protocolImpl));
LOG.debug(
"RpcKind = "
+ rpcKind
+ " Protocol Name = "
+ protocolName
+ " version="
+ version
+ " ProtocolImpl="
+ protocolImpl.getClass().getName()
+ " protocolClass="
+ protocolClass.getName());
}
// return the RpcEngine configured to handle a protocol
static synchronized RpcEngine getProtocolEngine(Class<?> protocol, Configuration conf) {
RpcEngine engine = PROTOCOL_ENGINES.get(protocol);
if (engine == null) {
Class<?> impl =
conf.getClass(ENGINE_PROP + "." + protocol.getName(), WritableRpcEngine.class);
engine = (RpcEngine) ReflectionUtils.newInstance(impl, conf);
PROTOCOL_ENGINES.put(protocol, engine);
}
return engine;
}
/** Write a {@link Writable}, {@link String}, primitive type, or an array of the preceding. */
public static void writeObject(
DataOutput out, Object instance, Class declaredClass, Configuration conf) throws IOException {
if (instance == null) { // null
instance = new NullInstance(declaredClass, conf);
declaredClass = Writable.class;
}
UTF8.writeString(out, declaredClass.getName()); // always write declared
if (declaredClass.isArray()) { // array
int length = Array.getLength(instance);
out.writeInt(length);
for (int i = 0; i < length; i++) {
writeObject(out, Array.get(instance, i), declaredClass.getComponentType(), conf);
}
} else if (declaredClass == String.class) { // String
UTF8.writeString(out, (String) instance);
} else if (declaredClass.isPrimitive()) { // primitive type
if (declaredClass == Boolean.TYPE) { // boolean
out.writeBoolean(((Boolean) instance).booleanValue());
} else if (declaredClass == Character.TYPE) { // char
out.writeChar(((Character) instance).charValue());
} else if (declaredClass == Byte.TYPE) { // byte
out.writeByte(((Byte) instance).byteValue());
} else if (declaredClass == Short.TYPE) { // short
out.writeShort(((Short) instance).shortValue());
} else if (declaredClass == Integer.TYPE) { // int
out.writeInt(((Integer) instance).intValue());
} else if (declaredClass == Long.TYPE) { // long
out.writeLong(((Long) instance).longValue());
} else if (declaredClass == Float.TYPE) { // float
out.writeFloat(((Float) instance).floatValue());
} else if (declaredClass == Double.TYPE) { // double
out.writeDouble(((Double) instance).doubleValue());
} else if (declaredClass == Void.TYPE) { // void
} else {
throw new IllegalArgumentException("Not a primitive: " + declaredClass);
}
} else if (declaredClass.isEnum()) { // enum
UTF8.writeString(out, ((Enum) instance).name());
} else if (Writable.class.isAssignableFrom(declaredClass)) { // Writable
UTF8.writeString(out, instance.getClass().getName());
((Writable) instance).write(out);
} else {
throw new IOException("Can't write: " + instance + " as " + declaredClass);
}
}
/**
* Construct a client-side proxy that implements the named protocol, talking to a server at the
* named address.
*
* @param protocol protocol
* @param clientVersion client's version
* @param addr server address
* @param ticket security ticket
* @param conf configuration
* @param factory socket factory
* @param rpcTimeout max time for each rpc; 0 means no timeout
* @return the proxy
* @throws IOException if any error occurs
*/
@SuppressWarnings("unchecked")
public static <T extends VersionedProtocol> ProtocolProxy<T> getProtocolProxy(
Class<T> protocol,
long clientVersion,
InetSocketAddress addr,
UserGroupInformation ticket,
Configuration conf,
SocketFactory factory,
int rpcTimeout)
throws IOException {
T proxy =
(T)
Proxy.newProxyInstance(
protocol.getClassLoader(),
new Class[] {protocol},
new Invoker(addr, ticket, conf, factory, rpcTimeout, protocol));
String protocolName = protocol.getName();
try {
ProtocolSignature serverInfo =
proxy.getProtocolSignature(
protocolName, clientVersion, ProtocolSignature.getFingerprint(protocol.getMethods()));
return new ProtocolProxy<T>(protocol, proxy, serverInfo.getMethods());
} catch (RemoteException re) {
IOException ioe = re.unwrapRemoteException(IOException.class);
if (ioe.getMessage()
.startsWith(IOException.class.getName() + ": " + NoSuchMethodException.class.getName())) {
// Method getProtocolSignature not supported
long serverVersion = proxy.getProtocolVersion(protocol.getName(), clientVersion);
if (serverVersion == clientVersion) {
return new ProtocolProxy<T>(protocol, proxy, null);
}
throw new VersionMismatch(protocolName, clientVersion, serverVersion, proxy);
}
throw re;
}
}
/**
* Set a protocol to use a non-default RpcEngine.
*
* @param conf configuration to use
* @param protocol the protocol interface
* @param engine the RpcEngine impl
*/
public static void setProtocolEngine(Configuration conf, Class<?> protocol, Class<?> engine) {
conf.setClass(ENGINE_PROP + "." + protocol.getName(), engine, RpcEngine.class);
}
public void write(DataOutput out) throws IOException {
UTF8.writeString(out, declaredClass.getName());
}