org.jgroups.MergeView Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
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package org.jgroups;
import org.jgroups.annotations.Immutable;
import org.jgroups.util.Util;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.function.Supplier;
/**
* A view that is sent as a result of a cluster merge. Whenever a group splits into subgroups, e.g., due to
* a network partition, and later the subgroups merge back together, a MergeView instead of a View
* will be received by the application. The MergeView class is a subclass of View and contains as
* additional instance variable: the list of views that were merged. For example, if the group
* denoted by view V1:(p,q,r,s,t) splits into subgroups V2:(p,q,r) and V2:(s,t), the merged view
* might be V3:(p,q,r,s,t). In this case the MergeView would contain a list of 2 views: V2:(p,q,r)
* and V2:(s,t).
*
* @since 2.0
* @author Bela Ban
*/
@Immutable
public class MergeView extends View {
protected View[] subgroups; // subgroups that merged into this single view (a list of Views)
public MergeView() { // Used by externalization
}
/**
* Creates a new merge view
*
* @param view_id The view id of this view (can not be null)
* @param members Contains a list of all the members in the view, can be empty but not null.
* @param subgroups A list of Views representing the former subgroups
*/
public MergeView(ViewId view_id, List members, List subgroups) {
super(view_id, members);
this.subgroups=listToArray(subgroups);
}
public MergeView(ViewId view_id, Address[] members, List subgroups) {
super(view_id, members);
this.subgroups=listToArray(subgroups);
}
/**
* Creates a new view
*
* @param creator The creator of this view (can not be null)
* @param id The lamport timestamp of this view
* @param members Contains a list of all the members in the view, can be empty but not null.
* @param subgroups A list of Views representing the former subgroups
*/
public MergeView(Address creator, long id, List members, List subgroups) {
super(creator, id, members);
this.subgroups=listToArray(subgroups);
}
public Supplier create() {
return MergeView::new;
}
public List getSubgroups() {
return Collections.unmodifiableList(Arrays.asList(subgroups));
}
public MergeView copy() {
return this;
}
public boolean deepEquals(View other) {
if(!super.deepEquals(other)) return false;
if(!(other instanceof MergeView))
return true;
MergeView other_view=(MergeView)other;
if(subgroups == null && other_view.subgroups == null) return true;
if(subgroups.length != other_view.subgroups.length) return false;
for(int i=0; i < subgroups.length; i++) {
View my_view=subgroups[i], oth_view=other_view.subgroups[i];
if(!my_view.deepEquals(oth_view))
return false;
}
return true;
}
public String toString() {
StringBuilder sb=new StringBuilder("MergeView::").append(super.toString());
if(subgroups != null && subgroups.length > 0) {
sb.append(", ").append(subgroups.length).append(" subgroups: ");
sb.append(Util.printListWithDelimiter(subgroups, ", ", Util.MAX_LIST_PRINT_SIZE));
}
return sb.toString();
}
@Override
public void writeTo(DataOutput out) throws IOException {
super.writeTo(out);
// write subgroups
int len=subgroups != null? subgroups.length : 0;
out.writeShort(len);
if(len == 0)
return;
for(View v: subgroups) {
int index=get(v.getCreator());
out.writeShort(index);
// if we don't find the member, write the addres (https://issues.redhat.com/browse/JGRP-1707)
if(index < 0)
Util.writeAddress(v.getCreator(), out);
out.writeLong(v.getViewId().getId());
int num_mbrs=v.size();
out.writeShort(num_mbrs);
for(Address mbr: v) {
index=get(mbr);
out.writeShort(index);
if(index < 0)
Util.writeAddress(mbr, out);
}
}
}
@Override
public void readFrom(DataInput in) throws IOException, ClassNotFoundException {
super.readFrom(in);
short len=in.readShort();
if(len > 0) {
subgroups=new View[len];
for(int i=0; i < len; i++) {
int index=in.readShort();
Address creator=index >= 0 ? get(index) : Util.readAddress(in);
long id=in.readLong();
Address[] mbrs=new Address[in.readShort()];
for(int j=0; j < mbrs.length; j++) {
index=in.readShort();
mbrs[j]=index >= 0? get(index) : Util.readAddress(in);
}
try {
View view=View.create(creator, id, mbrs);
subgroups[i]=view;
}
catch(Throwable t) {
}
}
}
}
@Override
public int serializedSize() {
int retval=super.serializedSize();
retval+=Global.SHORT_SIZE; // for size of subgroups vector
if(subgroups == null)
return retval;
for(View v: subgroups) {
retval+=Global.SHORT_SIZE + Global.LONG_SIZE // creator and ID (ViewId)
+ Global.SHORT_SIZE; // number of members in the subview
Address creator=v.getCreator();
if(get(creator) < 0)
retval+=Util.size(creator);
retval+=v.size() * Global.SHORT_SIZE; // a short (index) for each member
for(Address sub_mbr: v) {
int index=get(sub_mbr);
if(index < 0)
retval+=Util.size(sub_mbr);
}
}
return retval;
}
protected static View[] listToArray(List list) {
if(list == null)
return null;
View[] retval=new View[list.size()];
int index=0;
for(View view: list)
retval[index++]=view;
return retval;
}
protected int get(Address member) {
if(member == null)
return -1;
for(int i=0; i < members.length; i++)
if(member.equals(members[i]))
return i;
return -1;
}
protected Address get(int index) {
return members != null && index >= 0 && index < members.length? members[index] : null;
}
}