/*
* JBoss, Home of Professional Open Source
* Copyright 2009 Red Hat Inc. and/or its affiliates and other
* contributors as indicated by the @author tags. All rights reserved.
* See the copyright.txt in the distribution for a full listing of
* individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.infinispan.commands.read;
import org.infinispan.commands.VisitableCommand;
import org.infinispan.commands.Visitor;
import org.infinispan.container.DataContainer;
import org.infinispan.container.InternalEntryFactory;
import org.infinispan.container.entries.CacheEntry;
import org.infinispan.container.entries.InternalCacheEntry;
import org.infinispan.context.InvocationContext;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import static org.infinispan.util.Immutables.immutableInternalCacheEntry;
/**
* Command implementation for {@link java.util.Map#entrySet()} functionality.
*
* @author Galder Zamarreño
* @author <a href="http://gleamynode.net/">Trustin Lee</a>
* @since 4.0
*/
public class EntrySetCommand extends AbstractLocalCommand implements VisitableCommand {
private final DataContainer container;
private final InternalEntryFactory entryFactory;
public EntrySetCommand(DataContainer container, InternalEntryFactory internalEntryFactory) {
this.container = container;
this.entryFactory = internalEntryFactory;
}
@Override
public Object acceptVisitor(InvocationContext ctx, Visitor visitor) throws Throwable {
return visitor.visitEntrySetCommand(ctx, this);
}
@Override
public Set<InternalCacheEntry> perform(InvocationContext ctx) throws Throwable {
Set<InternalCacheEntry> entries = container.entrySet(null);
if (noTxModifications(ctx)) {
return new ExpiredFilteredEntrySet(entries);
}
return new FilteredEntrySet(entries, ctx.getLookedUpEntries());
}
@Override
public String toString() {
return "EntrySetCommand{" +
"set=" + container.size(null) + " elements" +
'}';
}
private class FilteredEntrySet extends AbstractSet<InternalCacheEntry> {
final Set<InternalCacheEntry> entrySet;
final Map<Object, CacheEntry> lookedUpEntries;
FilteredEntrySet(Set<InternalCacheEntry> entrySet, Map<Object, CacheEntry> lookedUpEntries) {
this.entrySet = entrySet;
this.lookedUpEntries = lookedUpEntries;
}
@Override
public int size() {
long currentTimeMillis = 0;
int size = entrySet.size();
// First, removed any expired ones
for (InternalCacheEntry e: entrySet) {
if (e.canExpire()) {
if (currentTimeMillis == 0)
currentTimeMillis = System.currentTimeMillis();
if (e.isExpired(currentTimeMillis))
size--;
}
}
// Update according to entries added or removed in tx
for (CacheEntry e: lookedUpEntries.values()) {
if (e.isCreated()) {
size ++;
} else if (e.isRemoved()) {
size --;
}
}
return Math.max(size, 0);
}
@Override
public boolean contains(Object o) {
if (!(o instanceof Map.Entry)) {
return false;
}
@SuppressWarnings("rawtypes")
Map.Entry e = (Map.Entry) o;
CacheEntry ce = lookedUpEntries.get(e.getKey());
if (ce == null || ce.isRemoved()) {
return false;
}
if (ce.isChanged() || ce.isCreated()) {
return ce.getValue().equals(e.getValue());
}
return entrySet.contains(o);
}
@Override
public Iterator<InternalCacheEntry> iterator() {
return new Itr();
}
@Override
public boolean add(InternalCacheEntry e) {
throw new UnsupportedOperationException();
}
@Override
public boolean remove(Object o) {
throw new UnsupportedOperationException();
}
@Override
public boolean addAll(Collection<? extends InternalCacheEntry> c) {
throw new UnsupportedOperationException();
}
@Override
public boolean retainAll(Collection<?> c) {
throw new UnsupportedOperationException();
}
@Override
public boolean removeAll(Collection<?> c) {
throw new UnsupportedOperationException();
}
@Override
public void clear() {
throw new UnsupportedOperationException();
}
private class Itr implements Iterator<InternalCacheEntry> {
private final Iterator<CacheEntry> it1 = lookedUpEntries.values().iterator();
private final Iterator<InternalCacheEntry> it2 = entrySet.iterator();
private boolean atIt1 = true;
private InternalCacheEntry next;
Itr() {
fetchNext();
}
private void fetchNext() {
if (atIt1) {
boolean found = false;
while (it1.hasNext()) {
CacheEntry e = it1.next();
if (e.isCreated()) {
next = immutableInternalCacheEntry(entryFactory.create(e.getKey(), e.getValue(), e.getVersion()));
found = true;
break;
}
}
if (!found) {
atIt1 = false;
}
}
if (!atIt1) {
boolean found = false;
while (it2.hasNext()) {
InternalCacheEntry ice = it2.next();
Object key = ice.getKey();
CacheEntry e = lookedUpEntries.get(key);
if (e == null) {
next = ice;
found = true;
break;
}
if (e.isChanged()) {
next = immutableInternalCacheEntry(entryFactory.create(key, e.getValue(), e.getVersion()));
found = true;
break;
}
}
if (!found) {
next = null;
}
}
}
@Override
public boolean hasNext() {
if (next == null) {
fetchNext();
}
return next != null;
}
@Override
public InternalCacheEntry next() {
if (next == null) {
fetchNext();
}
if (next == null) {
throw new NoSuchElementException();
}
InternalCacheEntry ret = next;
next = null;
return ret;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}
}
/**
* An immutable entry set that filters out expired entries. The reason for
* making it immutable is to avoid having to do further wrapping with an
* immutable delegate.
*/
private static class ExpiredFilteredEntrySet extends AbstractSet<InternalCacheEntry> {
final Set<InternalCacheEntry> entrySet;
public ExpiredFilteredEntrySet(Set<InternalCacheEntry> entrySet) {
this.entrySet = entrySet;
}
@Override
public Iterator<InternalCacheEntry> iterator() {
return new Itr();
}
@Override
public int size() {
// Size cannot be cached because even if the set is immutable,
// over time, the expired entries could grow hence reducing the size
int s = entrySet.size();
long currentTimeMillis = 0;
for (InternalCacheEntry e: entrySet) {
if (e.canExpire()) {
if (currentTimeMillis == 0)
currentTimeMillis = System.currentTimeMillis();
if (e.isExpired(currentTimeMillis))
s--;
}
}
return s;
}
@Override
public boolean add(InternalCacheEntry e) {
throw new UnsupportedOperationException();
}
@Override
public boolean remove(Object o) {
throw new UnsupportedOperationException();
}
@Override
public boolean addAll(Collection<? extends InternalCacheEntry> c) {
throw new UnsupportedOperationException();
}
@Override
public boolean retainAll(Collection<?> c) {
throw new UnsupportedOperationException();
}
@Override
public boolean removeAll(Collection<?> c) {
throw new UnsupportedOperationException();
}
@Override
public void clear() {
throw new UnsupportedOperationException();
}
private class Itr implements Iterator<InternalCacheEntry> {
private final Iterator<InternalCacheEntry> it = entrySet.iterator();
private InternalCacheEntry next;
private Itr() {
fetchNext();
}
private void fetchNext() {
long currentTimeMillis = -1; //lazily look at the wall clock: we want to look no more than once, but not at all if all entries are immortal.
while (it.hasNext()) {
InternalCacheEntry e = it.next();
if (e.canExpire()) {
if (currentTimeMillis == -1) currentTimeMillis = System.currentTimeMillis();
if (! e.isExpired(currentTimeMillis)) {
next = e;
return;
}
}
else {
next = e;
return;
}
}
}
@Override
public boolean hasNext() {
if (next == null)
fetchNext();
return next != null;
}
@Override
public InternalCacheEntry next() {
if (next == null)
fetchNext();
if (next == null)
throw new NoSuchElementException();
InternalCacheEntry ret = next;
next = null;
return ret;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}
}
}