org.apache.activemq.artemis.shaded.org.jgroups.protocols.EXAMPLE Maven / Gradle / Ivy
package org.apache.activemq.artemis.shaded.org.jgroups.protocols;
import org.apache.activemq.artemis.shaded.org.jgroups.*;
import org.apache.activemq.artemis.shaded.org.jgroups.annotations.MBean;
import org.apache.activemq.artemis.shaded.org.jgroups.annotations.Unsupported;
import org.apache.activemq.artemis.shaded.org.jgroups.stack.Protocol;
import org.apache.activemq.artemis.shaded.org.jgroups.util.MessageBatch;
import java.io.DataInput;
import java.io.DataOutput;
import java.util.ArrayList;
import java.util.List;
/**
* Example of a protocol layer. Contains no real functionality, can be used as a template.
*/
@Unsupported
@MBean(description="Sample protocol")
public class EXAMPLE extends Protocol {
final List members=new ArrayList<>();
/**
* Just remove if you don't need to reset any state
*/
public static void reset() {
}
public Object up(Event evt) {
switch(evt.getType()) {
case Event.MSG:
Message msg=(Message)evt.getArg();
// Do something with the event, e.g. extract the message and remove a header.
// Optionally pass up
break;
}
return up_prot.up(evt); // Pass up to the layer above us
}
public void up(MessageBatch batch) {
for(Message msg: batch) {
// do something; perhaps check for the presence of a header
}
if(!batch.isEmpty())
up_prot.up(batch);
}
public Object down(Event evt) {
switch(evt.getType()) {
case Event.TMP_VIEW:
case Event.VIEW_CHANGE:
List new_members=((View)evt.getArg()).getMembers();
synchronized(members) {
members.clear();
if(new_members != null && !new_members.isEmpty())
members.addAll(new_members);
}
return down_prot.down(evt);
case Event.MSG:
Message msg=(Message)evt.getArg();
// Do something with the event, e.g. add a header to the message
// Optionally pass down
break;
}
return down_prot.down(evt); // Pass on to the layer below us
}
public static class ExampleHeader extends Header {
// your variables
public int size() {
return 0; // return serialized size of all variables sent across the wire
}
public String toString() {
return "[EXAMPLE: ]";
}
public void writeTo(DataOutput out) throws Exception {
// write variables to stream
}
public void readFrom(DataInput in) throws Exception {
// initialize variables from stream
}
}
}