package org.infinispan.counter.impl.function;
import static org.infinispan.counter.impl.entries.CounterValue.newCounterValue;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.Collections;
import java.util.Optional;
import java.util.Set;
import java.util.function.Function;
import org.infinispan.commons.api.functional.EntryView;
import org.infinispan.commons.marshall.AdvancedExternalizer;
import org.infinispan.counter.api.CounterConfiguration;
import org.infinispan.counter.impl.entries.CounterKey;
import org.infinispan.counter.impl.entries.CounterValue;
import org.infinispan.counter.impl.externalizers.ExternalizerIds;
import org.infinispan.counter.impl.metadata.ConfigurationMetadata;
/**
* Function that initializes the {@link CounterValue} and {@link ConfigurationMetadata} if they don't exists.
*
* @author Pedro Ruivo
* @since 9.0
*/
public class InitializeCounterFunction<K extends CounterKey> implements
Function<EntryView.ReadWriteEntryView<K, CounterValue>, CounterValue> {
public static final AdvancedExternalizer<InitializeCounterFunction> EXTERNALIZER = new Externalizer();
private final CounterConfiguration counterConfiguration;
public InitializeCounterFunction(CounterConfiguration counterConfiguration) {
this.counterConfiguration = counterConfiguration;
}
@Override
public CounterValue apply(EntryView.ReadWriteEntryView<K, CounterValue> entryView) {
Optional<CounterValue> currentValue = entryView.find();
if (currentValue.isPresent()) {
return currentValue.get();
}
CounterValue newValue = newCounterValue(counterConfiguration);
entryView.set(newValue, new ConfigurationMetadata(counterConfiguration));
return newValue;
}
@Override
public String toString() {
return "InitializeCounterFunction{" +
"counterConfiguration=" + counterConfiguration +
'}';
}
private static class Externalizer implements AdvancedExternalizer<InitializeCounterFunction> {
@Override
public void writeObject(ObjectOutput output, InitializeCounterFunction object) throws IOException {
CounterConfiguration.EXTERNALIZER.writeObject(output, object.counterConfiguration);
}
@Override
public InitializeCounterFunction readObject(ObjectInput input) throws IOException, ClassNotFoundException {
return new InitializeCounterFunction<>(CounterConfiguration.EXTERNALIZER.readObject(input));
}
@Override
public Set<Class<? extends InitializeCounterFunction>> getTypeClasses() {
return Collections.singleton(InitializeCounterFunction.class);
}
@Override
public Integer getId() {
return ExternalizerIds.INITIALIZE_FUNCTION;
}
}
}