package org.infinispan.container.entries;
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.container.InternalEntryFactory;
import org.infinispan.metadata.Metadata;
import org.infinispan.util.logging.Log;
import org.infinispan.util.logging.LogFactory;
import java.util.LinkedList;
import java.util.List;
import static org.infinispan.container.entries.DeltaAwareCacheEntry.Flags.*;
/**
* 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
*/
public class DeltaAwareCacheEntry implements CacheEntry, StateChangingEntry {
private static final Log log = LogFactory.getLog(DeltaAwareCacheEntry.class);
private static final boolean trace = log.isTraceEnabled();
protected Object key;
protected CacheEntry wrappedEntry;
protected DeltaAware value, oldValue;
protected final List<Delta> deltas;
protected byte flags = 0;
// add Map representing uncommitted changes
protected AtomicHashMap<?, ?> uncommittedChanges;
public DeltaAwareCacheEntry(Object key, DeltaAware value, CacheEntry wrappedEntry) {
setValid(true);
this.key = key;
this.value = value;
this.wrappedEntry = wrappedEntry;
if (value instanceof AtomicHashMap) {
this.uncommittedChanges = ((AtomicHashMap) value).copy();
}
this.deltas = new LinkedList<Delta>();
}
@Override
public byte getStateFlags() {
if (wrappedEntry instanceof StateChangingEntry) {
return ((StateChangingEntry)wrappedEntry).getStateFlags();
}
return flags;
}
@Override
public void copyStateFlagsFrom(StateChangingEntry other) {
this.flags = other.getStateFlags();
}
public void appendDelta(Delta d) {
deltas.add(d);
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),
LOADED(1 << 5),
SKIP_LOOKUP(1 << 6);
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 Object getKey() {
return key;
}
@Override
public final Object getValue() {
return value;
}
@Override
public final Object setValue(Object value) {
Object oldValue = this.value;
this.value = (DeltaAware) value;
return oldValue;
}
@Override
public boolean isNull() {
return false;
}
@Override
public final void commit(final DataContainer 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.
container.compute(key, new DataContainer.ComputeAction() {
@Override
public InternalCacheEntry compute(Object key, InternalCacheEntry oldEntry, InternalEntryFactory factory) {
InternalCacheEntry newEntry = oldEntry;
DeltaAware containerValue = oldEntry == null ? null : (DeltaAware) oldEntry.getValue();
if (containerValue != null && containerValue != value) {
value = containerValue;
}
if (value != null && !deltas.isEmpty()) {
final boolean makeCopy = value instanceof CopyableDeltaAware;
if (makeCopy) {
value = ((CopyableDeltaAware) value).copy();
}
for (Delta delta : deltas) {
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();
if (wrappedEntry != null) {
wrappedEntry.setChanged(!makeCopy);
}
}
reset();
// only do stuff if there are changes.
if (wrappedEntry != null) {
wrappedEntry.commit(container, metadata);
}
return newEntry;
}
});
}
private Metadata extractMetadata(CacheEntry entry, Metadata provided) {
if (provided != null) {
return provided;
} else if (wrappedEntry != null) {
return wrappedEntry.getMetadata();
}
return entry == null ? null : entry.getMetadata();
}
private void reset() {
oldValue = null;
deltas.clear();
flags = 0;
if (uncommittedChanges != null) {
uncommittedChanges.clear();
}
setValid(true);
}
@Override
public final void rollback() {
if (isChanged()) {
value = oldValue;
reset();
}
}
@Override
public final boolean isChanged() {
return isFlagSet(CHANGED);
}
@Override
public final void setChanged(boolean changed) {
setFlag(changed, CHANGED);
}
@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 isFlagSet(LOADED);
}
@Override
public void setLoaded(boolean loaded) {
setFlag(loaded, 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 boolean undelete(boolean doUndelete) {
if (isRemoved() && doUndelete) {
if (trace)
log.trace("Entry is deleted in current scope. Un-deleting.");
setRemoved(false);
setValid(true);
return true;
}
return false;
}
@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 clone() {
try {
return (DeltaAwareCacheEntry) super.clone();
} catch (CloneNotSupportedException e) {
throw new AssertionError();
}
}
}