2 * Rhynodge - TorrentMerger.java - Copyright © 2013–2021 David Roden
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 package net.pterodactylus.rhynodge.mergers;
20 import java.util.HashSet;
22 import javax.annotation.Nonnull;
24 import net.pterodactylus.rhynodge.Merger;
25 import net.pterodactylus.rhynodge.State;
26 import net.pterodactylus.rhynodge.states.TorrentState;
27 import net.pterodactylus.rhynodge.states.TorrentState.TorrentFile;
29 import static com.google.common.base.Preconditions.checkState;
32 * {@link Merger} implementation that merges two {@link TorrentState}s, taking
33 * careful note of which {@link TorrentFile}s appear in the current
34 * {@link TorrentState} but not in the previous one.
36 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
38 public class TorrentMerger implements Merger {
45 public State mergeStates(@Nonnull State previousState, @Nonnull State currentState) {
46 checkState(currentState instanceof TorrentState, "currentState is not a TorrentState but a %s", currentState.getClass().getName());
47 checkState(previousState instanceof TorrentState, "previousState is not a TorrentState but a %s", currentState.getClass().getName());
49 Set<TorrentFile> allTorrentFiles = new HashSet<>(((TorrentState) previousState).torrentFiles());
50 Set<TorrentFile> newTorrentFiles = new HashSet<>();
51 for (TorrentFile torrentFile : (TorrentState) currentState) {
52 if (allTorrentFiles.add(torrentFile)) {
53 newTorrentFiles.add(torrentFile);
57 return new TorrentState(allTorrentFiles, newTorrentFiles);