+++ /dev/null
-/*
- * Sonitus - PredicateFilter.java - Copyright © 2013 David Roden
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-package net.pterodactylus.sonitus.data.filter;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import java.io.IOException;
-import java.util.concurrent.atomic.AtomicBoolean;
-
-import net.pterodactylus.sonitus.data.AbstractFilter;
-import net.pterodactylus.sonitus.data.Filter;
-import net.pterodactylus.sonitus.data.Metadata;
-
-import com.google.common.base.Predicate;
-
-/**
- * {@link Filter} implementation that uses a {@link Predicate} to determine
- * whether a filter will be used or the data will only be passed through.
- *
- * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
- */
-public class PredicateFilter extends AbstractFilter implements Filter {
-
- /** The predicate. */
- private final Predicate<Metadata> metadataPredicate;
-
- /** The filter to use if the predicate matches. */
- private final Filter filter;
-
- /** Whether the predicate currently matches. */
- private final AtomicBoolean metadataMatches = new AtomicBoolean(false);
-
- /**
- * Creates a new predicate filter.
- *
- * @param metadataPredicate
- * The predicate to evaluate every time the metadata changes
- * @param filter
- */
- public PredicateFilter(Predicate<Metadata> metadataPredicate, Filter filter) {
- super(String.format("%s (maybe)", filter.name()));
- this.metadataPredicate = metadataPredicate;
- this.filter = filter;
- }
-
- //
- // FILTER METHODS
- //
-
- @Override
- public void open(Metadata metadata) throws IOException {
- checkNotNull(metadata, "metadata must not be null");
-
- metadataMatches.set(metadataPredicate.apply(metadata));
- if (metadataMatches.get()) {
- filter.open(metadata);
- } else {
- super.open(metadata);
- }
- }
-
- @Override
- public void close() {
- if (metadataMatches.get()) {
- filter.close();
- } else {
- super.close();
- }
- }
-
- @Override
- public Metadata metadata() {
- if (metadataMatches.get()) {
- return filter.metadata();
- }
- return super.metadata();
- }
-
- @Override
- public void metadataUpdated(Metadata metadata) {
- metadataMatches.set(metadataPredicate.apply(metadata));
- if (metadataMatches.get()) {
- filter.metadataUpdated(metadata);
- } else {
- super.metadataUpdated(metadata);
- }
- }
-
- @Override
- public void process(byte[] buffer) throws IOException {
- if (metadataMatches.get()) {
- filter.process(buffer);
- } else {
- super.process(buffer);
- }
- }
-
- @Override
- public byte[] get(int bufferSize) throws IOException {
- if (metadataMatches.get()) {
- return filter.get(bufferSize);
- } else {
- return super.get(bufferSize);
- }
- }
-
-}