package org.infinispan.commands.read;
import org.infinispan.commands.VisitableCommand;
import org.infinispan.commands.Visitor;
import org.infinispan.container.DataContainer;
import org.infinispan.container.entries.CacheEntry;
import org.infinispan.container.entries.InternalCacheEntry;
import org.infinispan.context.Flag;
import org.infinispan.context.InvocationContext;
import org.infinispan.util.TimeService;
import java.util.AbstractCollection;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
/**
* Command implementation for {@link java.util.Map#values()} functionality.
*
* @author Galder Zamarreño
* @author Mircea.Markus@jboss.com
* @author <a href="http://gleamynode.net/">Trustin Lee</a>
* @since 4.0
*/
public class ValuesCommand extends AbstractLocalCommand implements VisitableCommand {
private final DataContainer container;
private final TimeService timeService;
public ValuesCommand(DataContainer container, TimeService timeService, Set<Flag> flags) {
setFlags(flags);
this.container = container;
this.timeService = timeService;
}
@Override
public Object acceptVisitor(InvocationContext ctx, Visitor visitor) throws Throwable {
return visitor.visitValuesCommand(ctx, this);
}
@Override
public Collection<Object> perform(InvocationContext ctx) throws Throwable {
if (ctx.getLookedUpEntries().isEmpty()) {
return new ExpiredFilteredValues(container.entrySet(), timeService);
}
return new FilteredValues(container, ctx.getLookedUpEntries(), timeService);
}
@Override
public String toString() {
return "ValuesCommand{" +
"values=" + container.size() + " elements" +
'}';
}
private static class FilteredValues extends AbstractCollection<Object> {
final DataContainer<Object, Object> container;
final Set<InternalCacheEntry> entrySet;
final Map<Object, CacheEntry> lookedUpEntries;
final TimeService timeService;
FilteredValues(DataContainer container, Map<Object, CacheEntry> lookedUpEntries, TimeService timeService) {
this.container = container;
entrySet = container.entrySet();
this.lookedUpEntries = lookedUpEntries;
this.timeService = timeService;
}
@Override
public int size() {
long currentTimeMillis = 0;
Set<Object> validKeys = new HashSet<Object>();
// First, removed any expired ones
for (InternalCacheEntry e: entrySet) {
if (e.canExpire()) {
if (currentTimeMillis == 0)
currentTimeMillis = timeService.wallClockTime();
if (!e.isExpired(currentTimeMillis)) {
validKeys.add(e.getKey());
}
} else {
validKeys.add(e.getKey());
}
}
int size = validKeys.size();
// Update according to entries added or removed in tx
for (CacheEntry e: lookedUpEntries.values()) {
if (validKeys.contains(e.getKey())) {
if (e.isRemoved()) {
size --;
}
} else if (!e.isRemoved()) {
size ++;
}
}
return Math.max(size, 0);
}
@Override
public boolean contains(Object o) {
for (CacheEntry e: lookedUpEntries.values()) {
// A value can repeat, so only return true if we find one, not just whether or not it was removed
if (o.equals(e.getValue()) && !e.isRemoved()) {
return true;
}
}
for (Map.Entry<Object, Object> entry : container) {
Object value = entry.getValue();
// If we find the key looked up in the lookedUpEntries at this point it means that entry was removed
// however the value could be on another key so keep looking
if (o.equals(value) && !lookedUpEntries.containsKey(entry.getKey())) {
return true;
}
}
return false;
}
@Override
public Iterator<Object> iterator() {
return new Itr();
}
@Override
public boolean add(Object e) {
throw new UnsupportedOperationException();
}
@Override
public boolean remove(Object o) {
throw new UnsupportedOperationException();
}
@Override
public boolean addAll(Collection<?> 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<Object> {
private final Iterator<CacheEntry> it1 = lookedUpEntries.values().iterator();
private final Iterator<InternalCacheEntry> it2 = entrySet.iterator();
private boolean atIt1 = true;
private Object next;
Itr() {
fetchNext();
}
private void fetchNext() {
if (atIt1) {
boolean found = false;
while (it1.hasNext()) {
CacheEntry e = it1.next();
if (!e.isRemoved()) {
next = e.getValue();
found = true;
break;
}
}
if (!found) {
atIt1 = false;
}
}
if (!atIt1) {
boolean found = false;
long currentTimeMillis = 0;
while (it2.hasNext()) {
InternalCacheEntry ice = it2.next();
Object key = ice.getKey();
if (ice.canExpire()) {
if (currentTimeMillis == 0)
currentTimeMillis = timeService.wallClockTime();
if (ice.isExpired(currentTimeMillis))
continue;
}
if (!lookedUpEntries.containsKey(key)) {
next = ice.getValue();
found = true;
break;
}
}
if (!found) {
next = null;
}
}
}
@Override
public boolean hasNext() {
if (next == null) {
fetchNext();
}
return next != null;
}
@Override
public Object next() {
if (next == null) {
fetchNext();
}
if (next == null) {
throw new NoSuchElementException();
}
Object ret = next;
next = null;
return ret;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}
}
public static class ExpiredFilteredValues extends AbstractCollection<Object> {
final Set<InternalCacheEntry> entrySet;
final TimeService timeService;
public ExpiredFilteredValues(Set<InternalCacheEntry> entrySet, TimeService timeService) {
this.entrySet = entrySet;
this.timeService = timeService;
}
@Override
public Iterator<Object> iterator() {
return new Itr();
}
@Override
public boolean add(Object e) {
throw new UnsupportedOperationException();
}
@Override
public boolean remove(Object o) {
throw new UnsupportedOperationException();
}
@Override
public boolean addAll(Collection<?> 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();
}
@Override
public int size() {
// Use entry set as a way to calculate the number of values.
int s = entrySet.size();
long currentTimeMillis = 0;
for (InternalCacheEntry e: entrySet) {
if (e.canExpire()) {
if (currentTimeMillis==0)
currentTimeMillis = timeService.wallClockTime();
if (e.isExpired(currentTimeMillis))
s--;
}
}
return s;
}
private class Itr implements Iterator<Object> {
private final Iterator<InternalCacheEntry> it = entrySet.iterator();
private Object next;
private Itr() {
fetchNext();
}
private void fetchNext() {
long currentTimeMillis = 0;
while (it.hasNext()) {
InternalCacheEntry e = it.next();
final boolean canExpire = e.canExpire();
if (canExpire && currentTimeMillis == 0) {
currentTimeMillis = timeService.wallClockTime();
}
if (!canExpire) {
next = e.getValue();
break;
} else if (!e.isExpired(currentTimeMillis)) {
next = e.getValue();
break;
}
}
}
@Override
public boolean hasNext() {
if (next == null)
fetchNext();
return next != null;
}
@Override
public Object next() {
if (next == null)
fetchNext();
if (next == null)
throw new NoSuchElementException();
Object ret = next;
next = null;
return ret;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}
}
}