Java tutorial
/* This file is part of VoltDB. * Copyright (C) 2008-2013 VoltDB Inc. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with VoltDB. If not, see <http://www.gnu.org/licenses/>. */ package org.voltcore.messaging; import static com.google.common.base.Predicates.in; import static com.google.common.base.Predicates.not; import java.io.IOException; import java.nio.ByteBuffer; import java.util.List; import java.util.Map; import java.util.Set; import org.voltcore.utils.CoreUtils; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMap; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Sets; public class SiteFailureMessage extends VoltMessage { /** Site survivor set */ public Set<Long> m_survivors = ImmutableSet.of(); /** Greatest 2PC transaction id at source m_sourceSiteId seen from failed initiator */ public Map<Long, Long> m_safeTxnIds = ImmutableMap.of(); /** indicates that this is a site decision */ public Set<Long> m_decision = ImmutableSet.of(); public Set<Long> m_failed = ImmutableSet.of(); /** * For VoltMessage factory. */ SiteFailureMessage() { } protected SiteFailureMessage(final Set<Long> survivors, final Set<Long> decision, final Set<Long> failed, final Map<Long, Long> safeTxnIds) { m_failed = failed; m_survivors = survivors; m_safeTxnIds = safeTxnIds; m_decision = decision; m_failed = failed; } @Override protected void initFromBuffer(ByteBuffer buf) { int srvrcnt = buf.getInt(); int safecnt = buf.getInt(); int dcncnt = buf.getInt(); int fldcnt = buf.getInt(); Builder bldr = new Builder(); for (int i = 0; i < srvrcnt; ++i) { bldr.survivor(buf.getLong()); } for (int i = 0; i < safecnt; ++i) { bldr.safeTxnId(buf.getLong(), buf.getLong()); } for (int i = 0; i < dcncnt; ++i) { bldr.decision(buf.getLong()); } for (int i = 0; i < fldcnt; ++i) { bldr.failed(buf.getLong()); } bldr.initialize(this); assert (m_subject != Subject.SITE_FAILURE_UPDATE.getId() || buf.capacity() == buf.position()); } @Override public void flattenToBuffer(ByteBuffer buf) throws IOException { flattenToBuffer(buf, VoltMessageFactory.SITE_FAILURE_UPDATE_ID); buf.limit(buf.position()); assert (buf.capacity() == buf.position()); } protected void flattenToBuffer(ByteBuffer buf, byte msgId) { buf.put(msgId); buf.putInt(m_survivors.size()); buf.putInt(m_safeTxnIds.size()); buf.putInt(m_decision.size()); buf.putInt(m_failed.size()); for (long h : m_survivors) { buf.putLong(h); } for (Map.Entry<Long, Long> e : m_safeTxnIds.entrySet()) { buf.putLong(e.getKey()); buf.putLong(e.getValue()); } for (long d : m_decision) { buf.putLong(d); } for (long d : m_failed) { buf.putLong(d); } } public Set<Long> getFailedSites() { return m_failed; } @Override public int getSerializedSize() { int msgsize = 4 + // survivor host count int 4 + // safe transactions ids count 4 + // decision hosts count 4 + // failed hosts count 8 * m_survivors.size() + 8 * m_decision.size() + 8 * m_failed.size() + (8 + 8) * m_safeTxnIds.size(); msgsize += super.getSerializedSize(); return msgsize; } @Override public byte getSubject() { return Subject.SITE_FAILURE_UPDATE.getId(); } public boolean hasDirectlyWitnessed(long hSid) { return !m_survivors.contains(hSid); } public List<FaultMessage> asFaultMessages() { ImmutableList.Builder<FaultMessage> lb = ImmutableList.builder(); if (!m_decision.isEmpty()) { for (long decided : m_decision) { lb.add(new FaultMessage(m_sourceHSId, decided, m_survivors, true)); } } else { for (long failed : m_failed) { if (hasDirectlyWitnessed(failed)) { lb.add(new FaultMessage(m_sourceHSId, failed, m_survivors)); } } } return lb.build(); } public Set<Long> getObservedFailedSites() { return Sets.filter(m_failed, not(in(m_survivors))); } @Override public String toString() { StringBuilder sb = new StringBuilder(); sb.append(Subject.values()[getSubject()]); if (!m_decision.isEmpty()) { sb.append(" final decision: ["); sb.append(CoreUtils.hsIdCollectionToString(m_decision)); sb.append("]"); } sb.append(" from site: "); sb.append(CoreUtils.hsIdToString(m_sourceHSId)); sb.append(" survivors: ["); sb.append(CoreUtils.hsIdCollectionToString(m_survivors)); sb.append("] failed: ["); sb.append(CoreUtils.hsIdCollectionToString(m_failed)); sb.append("]"); return sb.toString(); } public static class Builder { ImmutableSet.Builder<Long> srvrb = ImmutableSet.builder(); ImmutableSet.Builder<Long> dcsnb = ImmutableSet.builder(); ImmutableSet.Builder<Long> failb = ImmutableSet.builder(); ImmutableMap.Builder<Long, Long> safeb = ImmutableMap.builder(); public Builder failures(Set<Long> failedSites) { failb.addAll(failedSites); return this; } public Builder failed(long failedSite) { failb.add(failedSite); return this; } public Builder decisions(Set<Long> decision) { dcsnb.addAll(decision); return this; } public Builder decision(long decisionSite) { dcsnb.add(decisionSite); return this; } public Builder survivor(long survivor) { srvrb.add(survivor); return this; } public Builder survivors(Set<Long> survivors) { for (long survivor : survivors) { survivor(survivor); } return this; } public Builder safeTxnId(long failedHsid, long safeTxnId) { safeb.put(failedHsid, safeTxnId); return this; } public Builder safeTxnIds(Map<Long, Long> safe) { safeb.putAll(safe); return this; } public SiteFailureMessage build() { return new SiteFailureMessage(srvrb.build(), dcsnb.build(), failb.build(), safeb.build()); } protected void initialize(SiteFailureMessage m) { m.m_decision = dcsnb.build(); m.m_survivors = srvrb.build(); m.m_safeTxnIds = safeb.build(); m.m_failed = failb.build(); } } static final public Builder builder() { return new Builder(); } }