chat.dim.stargate.Dock Maven / Gradle / Ivy
/* license: https://mit-license.org
*
* Star Gate: Interfaces for network connection
*
* Written in 2020 by Moky
*
* ==============================================================================
* The MIT License (MIT)
*
* Copyright (c) 2020 Albert Moky
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
* ==============================================================================
*/
package chat.dim.stargate;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
final class Dock {
// tasks for sending out
private final List priorityList = new ArrayList<>();
private final Map> shipTables = new HashMap<>();
private final ReentrantReadWriteLock shipLock = new ReentrantReadWriteLock();
void addShip(StarShip task) {
Lock writeLock = shipLock.writeLock();
writeLock.lock();
try {
int priority = task.priority;
List table = shipTables.get(priority);
if (table == null) {
// create new table for this priority
table = new ArrayList<>();
shipTables.put(priority, table);
// insert the priority in a sorted list
int index = 0;
for (; index < priorityList.size(); ++index) {
if (priority < priorityList.get(index)) {
// insert priority before the bigger one
break;
}
}
priorityList.add(index, priority);
}
// append to tail
table.add(task);
} finally {
writeLock.unlock();
}
}
StarShip getShip() {
StarShip task = null;
Lock writeLock = shipLock.writeLock();
writeLock.lock();
try {
List table;
for (int priority : priorityList) {
table = shipTables.get(priority);
if (table == null || table.size() == 0) {
continue;
}
// pop from the head
task = table.remove(0);
break;
}
} finally {
writeLock.unlock();
}
return task;
}
}