package org.infinispan.container.entries;
import static org.infinispan.container.entries.DeltaAwareCacheEntry.Flags.CHANGED;
import static org.infinispan.container.entries.DeltaAwareCacheEntry.Flags.CREATED;
import static org.infinispan.container.entries.DeltaAwareCacheEntry.Flags.EVICTED;
import static org.infinispan.container.entries.DeltaAwareCacheEntry.Flags.EXPIRED;
import static org.infinispan.container.entries.DeltaAwareCacheEntry.Flags.REMOVED;
import static org.infinispan.container.entries.DeltaAwareCacheEntry.Flags.SKIP_LOOKUP;
import static org.infinispan.container.entries.DeltaAwareCacheEntry.Flags.VALID;
import java.util.LinkedList;
import java.util.List;
import org.infinispan.atomic.CopyableDeltaAware;
import org.infinispan.atomic.Delta;
import org.infinispan.atomic.DeltaAware;
import org.infinispan.atomic.impl.AtomicHashMap;
import org.infinispan.commons.util.Util;
import org.infinispan.container.DataContainer;
import org.infinispan.context.InvocationContext;
import org.infinispan.metadata.Metadata;
import org.infinispan.persistence.PersistenceUtil;
import org.infinispan.persistence.manager.PersistenceManager;
import org.infinispan.util.TimeService;
import org.infinispan.util.logging.Log;
import org.infinispan.util.logging.LogFactory;
/**
* A wrapper around a cached entry that encapsulates DeltaAware and Delta semantics when writes are
* initiated, committed or rolled back.
*
* @author Manik Surtani (<a href="mailto:manik@jboss.org">manik@jboss.org</a>)
* @since 5.1
*/
// TODO: this class is going to work only for atomic hash maps as it has special handling for them
public class DeltaAwareCacheEntry<K> implements CacheEntry<K, DeltaAware>, MVCCEntry<K, DeltaAware> {
private static final Log log = LogFactory.getLog(DeltaAwareCacheEntry.class);
private static final boolean trace = log.isTraceEnabled();
// TODO: this is hack!
private InvocationContext ctx;
private PersistenceManager persistenceManager;
private TimeService timeService;
protected K key;
protected CacheEntry<K, DeltaAware> wrappedEntry;
protected DeltaAware value;
protected DeltaAware initialValue;
protected final List<Delta> deltas;
protected byte flags = 0;
protected AtomicHashMap<K, ?> uncommittedChanges;
public DeltaAwareCacheEntry(K key, DeltaAware value, CacheEntry<K, DeltaAware> wrappedEntry,
InvocationContext ctx, PersistenceManager persistenceManager, TimeService timeService) {
setValid(true);
this.key = key;
this.value = value;
this.initialValue = value;
this.wrappedEntry = wrappedEntry;
this.ctx = ctx;
this.persistenceManager = persistenceManager;
this.timeService = timeService;
if (value instanceof AtomicHashMap) {
this.uncommittedChanges = ((AtomicHashMap) value).copy();
}
this.deltas = new LinkedList<Delta>();
}
public void appendDelta(Delta d) {
deltas.add(d);
if (uncommittedChanges != null) {
uncommittedChanges = (AtomicHashMap<K, ?>) d.merge(uncommittedChanges);
}
setChanged(true);
}
public AtomicHashMap<?, ?> getUncommittedChages() {
return uncommittedChanges;
}
protected static enum Flags {
CHANGED(1), // same as 1 << 0
CREATED(1 << 1),
REMOVED(1 << 2),
VALID(1 << 3),
EVICTED(1 << 4),
SKIP_LOOKUP(1 << 6),
EXPIRED(1 << 7);
final byte mask;
Flags(int mask) {
this.mask = (byte) mask;
}
}
/**
* Tests whether a flag is set.
*
* @param flag
* flag to test
* @return true if set, false otherwise.
*/
protected final boolean isFlagSet(Flags flag) {
return (flags & flag.mask) != 0;
}
/**
* Utility method that sets the value of the given flag to true.
*
* @param flag
* flag to set
*/
protected final void setFlag(Flags flag) {
flags |= flag.mask;
}
/**
* Utility method that sets the value of the flag to false.
*
* @param flag
* flag to unset
*/
protected final void unsetFlag(Flags flag) {
flags &= ~flag.mask;
}
@Override
public final long getLifespan() {
return -1; // forever
}
@Override
public final long getMaxIdle() {
return -1; // forever
}
@Override
public boolean skipLookup() {
return isFlagSet(SKIP_LOOKUP);
}
@Override
public final K getKey() {
return key;
}
@Override
public final DeltaAware getValue() {
// TODO: it's not possible to return the actually modified (but uncommitted) value
// when this is not a copyable entry
return uncommittedChanges;
}
@Override
public final DeltaAware setValue(DeltaAware value) {
DeltaAware oldValue = getValue();
this.value = value;
// TODO: it is not possible to remove the special handling for AtomicHashmaps without copy() in normal deltas
DeltaAware newValueCopy;
if (value instanceof AtomicHashMap) {
newValueCopy = this.uncommittedChanges = ((AtomicHashMap<K, ?>) value).copy();
} else {
this.uncommittedChanges = null;
newValueCopy = value;
}
this.deltas.clear();
// add a delta setting the value without caring about previous one
this.deltas.add(d -> newValueCopy);
return oldValue;
}
@Override
public boolean isNull() {
return false;
}
@Override
public final void commit(final DataContainer<K, DeltaAware> container, final Metadata metadata) {
//If possible, we now ensure copy-on-write semantics. This way, it can ensure the correct transaction isolation.
//note: we want to merge/copy to/from the data container value.
PersistenceUtil.loadAndComputeInDataContainer(container, persistenceManager, key, ctx, timeService, (key, oldEntry, factory) -> {
InternalCacheEntry<K, DeltaAware> newEntry = oldEntry;
DeltaAware containerValue = oldEntry == null ? null : (DeltaAware) oldEntry.getValue();
if (containerValue != null && containerValue != value) {
value = containerValue;
}
// If we were removed then only apply the deltas
if (!deltas.isEmpty()) {
// If we were created don't use the original value
if (isCreated()) {
value = null;
for (Delta delta : deltas) {
value = delta.merge(value);
}
value.commit();
newEntry = factory.create(key, value, extractMetadata(null, metadata));
} else if (value != null) {
final boolean makeCopy = value instanceof CopyableDeltaAware;
if (makeCopy) {
value = ((CopyableDeltaAware) value).copy();
}
for (Delta delta : deltas) {
value = delta.merge(value);
}
if (makeCopy) {
//create or update existing entry.
newEntry = oldEntry == null ?
factory.create(key, value, extractMetadata(null, metadata)) :
factory.update(oldEntry, value, extractMetadata(oldEntry, metadata));
}
value.commit();
}
}
return newEntry;
});
}
private Metadata extractMetadata(CacheEntry<K, DeltaAware> entry, Metadata provided) {
if (provided != null) {
return provided;
} else if (wrappedEntry != null) {
return wrappedEntry.getMetadata();
}
return entry == null ? null : entry.getMetadata();
}
@Override
public void resetCurrentValue() {
deltas.clear();
flags = 0;
if (uncommittedChanges != null) {
uncommittedChanges.clear();
}
setValid(true);
}
@Override
public void updatePreviousValue() {
// noop
}
@Override
public final boolean isChanged() {
return isFlagSet(CHANGED);
}
@Override
public final void setChanged(boolean changed) {
setFlag(changed, CHANGED);
}
@Override
public void setExpired(boolean expired) {
setFlag(expired, EXPIRED);
}
@Override
public boolean isExpired() {
return isFlagSet(EXPIRED);
}
@Override
public boolean isValid() {
if (wrappedEntry != null) {
return wrappedEntry.isValid();
} else {
return isFlagSet(VALID);
}
}
@Override
public final void setValid(boolean valid) {
setFlag(valid, VALID);
}
@Override
public final boolean isCreated() {
if (wrappedEntry != null) {
return wrappedEntry.isCreated();
} else {
return isFlagSet(CREATED);
}
}
@Override
public final void setCreated(boolean created) {
setFlag(created, CREATED);
}
@Override
public boolean isRemoved() {
if (wrappedEntry != null) {
return wrappedEntry.isRemoved();
} else {
return isFlagSet(REMOVED);
}
}
@Override
public boolean isEvicted() {
if (wrappedEntry != null) {
return wrappedEntry.isEvicted();
} else {
return isFlagSet(EVICTED);
}
}
@Override
public final void setRemoved(boolean removed) {
setFlag(removed, REMOVED);
}
@Override
public void setEvicted(boolean evicted) {
setFlag(evicted, EVICTED);
}
@Override
public boolean isLoaded() {
return false;
}
@Override
public void setLoaded(boolean loaded) {
}
@Override
public void setSkipLookup(boolean skipLookup) {
setFlag(skipLookup, SKIP_LOOKUP);
}
private void setFlag(boolean enable, Flags flag) {
if (enable)
setFlag(flag);
else
unsetFlag(flag);
}
@Override
public String toString() {
return getClass().getSimpleName() + "(" + Util.hexIdHashCode(this) + "){" + "key=" + key
+ ", value=" + value + ", oldValue=" + uncommittedChanges + ", isCreated="
+ isCreated() + ", isChanged=" + isChanged() + ", isRemoved=" + isRemoved()
+ ", isValid=" + isValid() + '}';
}
@Override
public Metadata getMetadata() {
return null; // DeltaAware are always metadata unaware
}
@Override
public void setMetadata(Metadata metadata) {
// DeltaAware are always metadata unaware
}
@Override
public DeltaAwareCacheEntry<K> clone() {
try {
return (DeltaAwareCacheEntry) super.clone();
} catch (CloneNotSupportedException e) {
throw new AssertionError();
}
}
}