shz.core.queue.l.ConcurrentDLinkedQueue Maven / Gradle / Ivy
package shz.core.queue.l;
import shz.core.constant.ArrayConstant;
import shz.core.node.DSNode;
/**
* 元素类型为double基于链表的队列
*
* 20+16*(n+1)(n为元素个数)
*
* B=8+16*(n+3)
*/
public class ConcurrentDLinkedQueue extends ConcurrentLinkedQueue {
protected ConcurrentDLinkedQueue() {
}
public static ConcurrentDLinkedQueue of() {
return new ConcurrentDLinkedQueue();
}
@Override
protected final Double get(DSNode node) {
return node.val;
}
public final void offer(double e) {
writeLock.lock();
try {
DSNode temp = tail;
tail = DSNode.of(e);
if (head == null) head = tail;
else temp.next(tail);
++size;
} finally {
writeLock.unlock();
}
}
public final double poll() {
writeLock.lock();
try {
double val = head();
head = head.next();
if (head == null) tail = null;
--size;
return val;
} finally {
writeLock.unlock();
}
}
public final double head() {
readLock.lock();
try {
return head.val;
} finally {
readLock.unlock();
}
}
public final double tail() {
readLock.lock();
try {
return tail.val;
} finally {
readLock.unlock();
}
}
public final double[] toArray() {
if (size == 0) return ArrayConstant.EMPTY_DOUBLE_ARRAY;
double[] array = new double[size];
int idx = 0;
DSNode current = head;
while (current != null) {
array[idx++] = current.val;
current = current.next();
}
return array;
}
}