public class PRIO extends Protocol
When a message is received (up/down), it is added to the up/downMessageQueue. The up/downMessageThread will block on the queue until new message is added. Messages with the highest priority (0=highest) will bubble to the top of the queue and those be processed before other messages received at the same time.
Example of setting a message priority:
// Create a message to send to everyone
Message message = new Message( null, null, messagePayload );
// Add the priority protocol header
PrioHeader header = new PrioHeader( 1 );
short protocolId = ClassConfigurator.getProtocolId(PRIO.class);
message.putHeader( protocolId, header);
| 限定符和类型 | 类和说明 |
|---|---|
protected static class |
PRIO.PriorityMessage
This class is a simple wrapper to contain the Event, timestamp and priority of the message.
|
| 构造器和说明 |
|---|
PRIO() |
| 限定符和类型 | 方法和说明 |
|---|---|
java.lang.Object |
down(Event evt)
An event is to be sent down the stack.
|
void |
start()
This method is called on a
Channel.connect(String). |
void |
stop()
This method is called on a
Channel.disconnect(). |
java.lang.Object |
up(Event evt)
An event was received from the layer below.
|
void |
up(MessageBatch batch)
Sends up a multiple messages in a
MessageBatch. |
accept, destroy, dumpStats, enableStats, getConfigurableObjects, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getName, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, getUpServices, getValue, init, isErgonomics, level, parse, printStats, providedDownServices, providedUpServices, requiredDownServices, requiredUpServices, resetStatistics, resetStats, setDownProtocol, setErgonomics, setId, setLevel, setProtocolStack, setSocketFactory, setUpProtocol, setValue, setValues, statsEnabledpublic void start()
throws java.lang.Exception
Channel.connect(String). Starts work.
Protocols are connected and queues are ready to receive events.
Will be called from bottom to top. This call will replace
the START and START_OK events.start 在类中 Protocoljava.lang.Exception - Thrown if protocol cannot be started successfully. This will cause the ProtocolStack
to fail, so Channel.connect(String) will throw an exceptionpublic void stop()
Channel.disconnect(). Stops work (e.g. by closing multicast socket).
Will be called from top to bottom. This means that at the time of the method invocation the
neighbor protocol below is still working. This method will replace the
STOP, STOP_OK, CLEANUP and CLEANUP_OK events. The ProtocolStack guarantees that
when this method is called all messages in the down queue will have been flushedpublic java.lang.Object up(Event evt)
down_prot.down() or c) the event (or another event) is sent up
the stack using up_prot.up().public void up(MessageBatch batch)
ProtocolMessageBatch. The sender of the batch is always the same, and so is the
destination (null == multicast messages). Messages in a batch can be OOB messages, regular messages, or mixed
messages, although the transport itself will create initial MessageBatches that contain only either OOB or
regular messages.
The default processing below sends messages up the stack individually, based on a matching criteria
(calling Protocol.accept(Message)), and - if true - calls Protocol.up(Event)
for that message and removes the message. If the batch is not empty, it is passed up, or else it is dropped.
Subclasses should check if there are any messages destined for them (e.g. using
MessageBatch.getMatchingMessages(short, boolean)), then possibly remove and process them and finally pass
the batch up to the next protocol. Protocols can also modify messages in place, e.g. ENCRYPT could decrypt all
encrypted messages in the batch, not remove them, and pass the batch up when done.public java.lang.Object down(Event evt)
down_prot.down(). In case of a GET_ADDRESS event (which tries to
retrieve the stack's address from one of the bottom layers), the layer may need to send
a new response event back up the stack using up_prot.up().