/*
* WorldEdit, a Minecraft world manipulation toolkit
* Copyright (C) sk89q <http://www.sk89q.com>
* Copyright (C) WorldEdit team and contributors
*
* This program 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 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 Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.sk89q.worldedit.session;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.common.util.concurrent.MoreExecutors;
import com.sk89q.worldedit.LocalConfiguration;
import com.sk89q.worldedit.LocalSession;
import com.sk89q.worldedit.WorldEdit;
import com.sk89q.worldedit.entity.Player;
import com.sk89q.worldedit.event.platform.ConfigurationLoadEvent;
import com.sk89q.worldedit.session.storage.JsonFileSessionStore;
import com.sk89q.worldedit.session.storage.SessionStore;
import com.sk89q.worldedit.session.storage.VoidStore;
import com.sk89q.worldedit.util.concurrency.EvenMoreExecutors;
import com.sk89q.worldedit.util.eventbus.Subscribe;
import javax.annotation.Nullable;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Timer;
import java.util.TimerTask;
import java.util.UUID;
import java.util.concurrent.Callable;
import java.util.logging.Level;
import java.util.logging.Logger;
import static com.google.common.base.Preconditions.checkNotNull;
/**
* Session manager for WorldEdit.
*
* <p>Get a reference to one from {@link WorldEdit}.</p>
*
* <p>While this class is thread-safe, the returned session may not be.</p>
*/
public class SessionManager {
public static int EXPIRATION_GRACE = 600000;
private static final int FLUSH_PERIOD = 1000 * 30;
private static final ListeningExecutorService executorService = MoreExecutors.listeningDecorator(EvenMoreExecutors.newBoundedCachedThreadPool(0, 1, 5));
private static final Logger log = Logger.getLogger(SessionManager.class.getCanonicalName());
private final Timer timer = new Timer();
private final WorldEdit worldEdit;
private final Map<UUID, SessionHolder> sessions = new HashMap<UUID, SessionHolder>();
private SessionStore store = new VoidStore();
/**
* Create a new session manager.
*
* @param worldEdit a WorldEdit instance
*/
public SessionManager(WorldEdit worldEdit) {
checkNotNull(worldEdit);
this.worldEdit = worldEdit;
worldEdit.getEventBus().register(this);
timer.schedule(new SessionTracker(), FLUSH_PERIOD, FLUSH_PERIOD);
}
/**
* Get whether a session exists for the given owner.
*
* @param owner the owner
* @return true if a session exists
*/
public synchronized boolean contains(SessionOwner owner) {
checkNotNull(owner);
return sessions.containsKey(getKey(owner));
}
/**
* Find a session by its name specified by {@link SessionKey#getName()}.
*
* @param name the name
* @return the session, if found, otherwise {@code null}
*/
@Nullable
public synchronized LocalSession findByName(String name) {
checkNotNull(name);
for (SessionHolder holder : sessions.values()) {
String test = holder.key.getName();
if (test != null && name.equals(test)) {
return holder.session;
}
}
return null;
}
/**
* Gets the session for an owner and return it if it exists, otherwise
* return {@code null}.
*
* @param owner the owner
* @return the session for the owner, if it exists
*/
@Nullable
public synchronized LocalSession getIfPresent(SessionOwner owner) {
checkNotNull(owner);
SessionHolder stored = sessions.get(getKey(owner));
if (stored != null) {
return stored.session;
} else {
return null;
}
}
/**
* Get the session for an owner and create one if one doesn't exist.
*
* @param owner the owner
* @return a session
*/
public synchronized LocalSession get(SessionOwner owner) {
checkNotNull(owner);
LocalSession session = getIfPresent(owner);
LocalConfiguration config = worldEdit.getConfiguration();
SessionKey sessionKey = owner.getSessionKey();
// No session exists yet -- create one
if (session == null) {
try {
session = store.load(getKey(sessionKey));
session.postLoad();
} catch (IOException e) {
log.log(Level.WARNING, "Failed to load saved session", e);
session = new LocalSession();
}
session.setConfiguration(config);
session.setBlockChangeLimit(config.defaultChangeLimit);
// Remember the session if the session is still active
if (sessionKey.isActive()) {
sessions.put(getKey(owner), new SessionHolder(sessionKey, session));
}
}
// Set the limit on the number of blocks that an operation can
// change at once, or don't if the owner has an override or there
// is no limit. There is also a default limit
int currentChangeLimit = session.getBlockChangeLimit();
if (!owner.hasPermission("worldedit.limit.unrestricted") && config.maxChangeLimit > -1) {
// If the default limit is infinite but there is a maximum
// limit, make sure to not have it be overridden
if (config.defaultChangeLimit < 0) {
if (currentChangeLimit < 0 || currentChangeLimit > config.maxChangeLimit) {
session.setBlockChangeLimit(config.maxChangeLimit);
}
} else {
// Bound the change limit
int maxChangeLimit = config.maxChangeLimit;
if (currentChangeLimit == -1 || currentChangeLimit > maxChangeLimit) {
session.setBlockChangeLimit(maxChangeLimit);
}
}
}
// Have the session use inventory if it's enabled and the owner
// doesn't have an override
session.setUseInventory(config.useInventory
&& !(config.useInventoryOverride
&& (owner.hasPermission("worldedit.inventory.unrestricted")
|| (config.useInventoryCreativeOverride && (!(owner instanceof Player) || ((Player) owner).hasCreativeMode())))));
return session;
}
/**
* Save a map of sessions to disk.
*
* @param sessions a map of sessions to save
* @return a future that completes on save or error
*/
private ListenableFuture<?> commit(final Map<SessionKey, LocalSession> sessions) {
checkNotNull(sessions);
if (sessions.isEmpty()) {
return Futures.immediateFuture(sessions);
}
return executorService.submit(new Callable<Object>() {
@Override
public Object call() throws Exception {
Exception exception = null;
for (Map.Entry<SessionKey, LocalSession> entry : sessions.entrySet()) {
SessionKey key = entry.getKey();
if (key.isPersistent()) {
try {
store.save(getKey(key), entry.getValue());
} catch (IOException e) {
log.log(Level.WARNING, "Failed to write session for UUID " + getKey(key), e);
exception = e;
}
}
}
if (exception != null) {
throw exception;
}
return sessions;
}
});
}
/**
* Get the key to use in the map for an owner.
*
* @param owner the owner
* @return the key object
*/
protected UUID getKey(SessionOwner owner) {
return getKey(owner.getSessionKey());
}
/**
* Get the key to use in the map for a {@code SessionKey}.
*
* @param key the session key object
* @return the key object
*/
protected UUID getKey(SessionKey key) {
String forcedKey = System.getProperty("worldedit.session.uuidOverride");
if (forcedKey != null) {
return UUID.fromString(forcedKey);
} else {
return key.getUniqueId();
}
}
/**
* Remove the session for the given owner if one exists.
*
* @param owner the owner
*/
public synchronized void remove(SessionOwner owner) {
checkNotNull(owner);
sessions.remove(getKey(owner));
}
/**
* Remove all sessions.
*/
public synchronized void clear() {
sessions.clear();
}
@Subscribe
public void onConfigurationLoad(ConfigurationLoadEvent event) {
LocalConfiguration config = event.getConfiguration();
File dir = new File(config.getWorkingDirectory(), "sessions");
store = new JsonFileSessionStore(dir);
}
/**
* Stores the owner of a session, the session, and the last active time.
*/
private static class SessionHolder {
private final SessionKey key;
private final LocalSession session;
private long lastActive = System.currentTimeMillis();
private SessionHolder(SessionKey key, LocalSession session) {
this.key = key;
this.session = session;
}
}
/**
* Removes inactive sessions after they have been inactive for a period
* of time. Commits them as well.
*/
private class SessionTracker extends TimerTask {
@Override
public void run() {
synchronized (SessionManager.this) {
long now = System.currentTimeMillis();
Iterator<SessionHolder> it = sessions.values().iterator();
Map<SessionKey, LocalSession> saveQueue = new HashMap<SessionKey, LocalSession>();
while (it.hasNext()) {
SessionHolder stored = it.next();
if (stored.key.isActive()) {
stored.lastActive = now;
if (stored.session.compareAndResetDirty()) {
saveQueue.put(stored.key, stored.session);
}
} else {
if (now - stored.lastActive > EXPIRATION_GRACE) {
if (stored.session.compareAndResetDirty()) {
saveQueue.put(stored.key, stored.session);
}
it.remove();
}
}
}
if (!saveQueue.isEmpty()) {
commit(saveQueue);
}
}
}
}
}