package org.infinispan.transaction.impl;
import org.infinispan.commands.tx.VersionedPrepareCommand;
import org.infinispan.commands.write.WriteCommand;
import org.infinispan.container.DataContainer;
import org.infinispan.container.entries.ClusteredRepeatableReadEntry;
import org.infinispan.container.versioning.EntryVersionsMap;
import org.infinispan.container.versioning.IncrementableEntryVersion;
import org.infinispan.container.versioning.VersionGenerator;
import org.infinispan.context.impl.TxInvocationContext;
import org.infinispan.persistence.manager.PersistenceManager;
import org.infinispan.remoting.responses.Response;
import org.infinispan.remoting.responses.SuccessfulResponse;
import org.infinispan.transaction.WriteSkewException;
import org.infinispan.transaction.xa.CacheTransaction;
import org.infinispan.util.TimeService;
/**
* Encapsulates write skew logic in maintaining version maps, etc.
*
* @author Manik Surtani
* @since 5.1
*/
public class WriteSkewHelper {
public static void readVersionsFromResponse(Response r, CacheTransaction ct) {
if (r != null && r.isSuccessful()) {
SuccessfulResponse sr = (SuccessfulResponse) r;
EntryVersionsMap uv = (EntryVersionsMap) sr.getResponseValue();
if (uv != null) ct.setUpdatedEntryVersions(uv.merge(ct.getUpdatedEntryVersions()));
}
}
public static EntryVersionsMap performWriteSkewCheckAndReturnNewVersions(VersionedPrepareCommand prepareCommand,
DataContainer dataContainer,
PersistenceManager persistenceManager,
VersionGenerator versionGenerator,
TxInvocationContext context,
KeySpecificLogic ksl, TimeService timeService) {
EntryVersionsMap uv = new EntryVersionsMap();
for (WriteCommand c : prepareCommand.getModifications()) {
for (Object k : c.getAffectedKeys()) {
if (ksl.performCheckOnKey(k)) {
ClusteredRepeatableReadEntry entry = (ClusteredRepeatableReadEntry) context.lookupEntry(k);
if (entry.performWriteSkewCheck(dataContainer, persistenceManager, context,
prepareCommand.getVersionsSeen().get(k), versionGenerator, timeService)) {
IncrementableEntryVersion newVersion = entry.isCreated()
? versionGenerator.generateNew()
: versionGenerator.increment((IncrementableEntryVersion) entry.getMetadata().version());
uv.put(k, newVersion);
} else {
// Write skew check detected!
throw new WriteSkewException("Write skew detected on key " + k + " for transaction " +
context.getTransaction(), k);
}
}
}
}
return uv;
}
public static EntryVersionsMap performTotalOrderWriteSkewCheckAndReturnNewVersions(VersionedPrepareCommand prepareCommand,
DataContainer dataContainer,
PersistenceManager persistenceManager,
VersionGenerator versionGenerator,
TxInvocationContext context,
KeySpecificLogic ksl,
TimeService timeService) {
EntryVersionsMap uv = new EntryVersionsMap();
for (WriteCommand c : prepareCommand.getModifications()) {
for (Object k : c.getAffectedKeys()) {
if (ksl.performCheckOnKey(k)) {
ClusteredRepeatableReadEntry entry = (ClusteredRepeatableReadEntry) context.lookupEntry(k);
if (entry.performWriteSkewCheck(dataContainer, persistenceManager, context,
prepareCommand.getVersionsSeen().get(k), versionGenerator, timeService)) {
//in total order, it does not care about the version returned. It just need the keys validated
uv.put(k, null);
} else {
// Write skew check detected!
throw new WriteSkewException("Write skew detected on key " + k + " for transaction " +
context.getTransaction(), k);
}
}
}
}
return uv;
}
public static interface KeySpecificLogic {
boolean performCheckOnKey(Object key);
}
}