/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hazelcast.partition.membergroup;
import com.hazelcast.core.Member;
import java.util.Collection;
import java.util.Iterator;
import java.util.Set;
abstract class BackupSafeMemberGroupFactory implements MemberGroupFactory {
@Override
public final Collection<MemberGroup> createMemberGroups(Collection<? extends Member> members) {
Collection<MemberGroup> groups = createInternalMemberGroups(members);
if (groups.size() == 1 && members.size() > 1) {
// If there are more than one members and just one group
// then split members into two groups to guarantee at least the first backup.
MemberGroup group1 = groups.iterator().next();
MemberGroup group2 = new DefaultMemberGroup();
int sizePerGroup = group1.size() / 2;
Iterator<Member> iter = group1.iterator();
while (group2.size() < sizePerGroup && iter.hasNext()) {
group2.addMember(iter.next());
iter.remove();
}
groups.add(group2);
}
return groups;
}
protected abstract Set<MemberGroup> createInternalMemberGroups(Collection<? extends Member> allMembers);
}