Package org.apache.iotdb.db.mpp.execution.schedule.queue

Class L1PriorityQueue<E extends IDIndexedAccessible>

java.lang.Object

org.apache.iotdb.db.mpp.execution.schedule.queue.IndexedBlockingQueue<E>

org.apache.iotdb.db.mpp.execution.schedule.queue.L1PriorityQueue<E>

public class L1PriorityQueue<E extends IDIndexedAccessible>
extends IndexedBlockingQueue<E>

An efficient subclass of IndexedBlockingQueue with 1-level priority groups.

The time complexity of operations are:

• remove(IDIndexedAccessible) ()}: O(logN).
• IndexedBlockingQueue.push(IDIndexedAccessible): O(logN).
• IndexedBlockingQueue.poll(): O(logN).
• IndexedBlockingQueue.get(ID)}: O(1).

Constructor Summary

Constructors

Constructor	Description
L1PriorityQueue(int maxCapacity, java.util.Comparator<E> comparator, E queryHolder)	Init the queue with max capacity and specified comparator.

Method Summary

Modifier and Type	Method	Description
protected void	clearAllElements()	Clear all elements in this queue.
protected boolean	contains(E element)	Check whether an element with the same ID exists.
protected E	get(E element)	Return the element with the same id of the input, null if it doesn't exist.
protected boolean	isEmpty()	Whether the queue is empty.
protected E	pollFirst()	Get and remove the first element.
protected void	pushToQueue(E element)	Push the element into the queue.
protected E	remove(E element)	Remove and return the element by its ID.

Methods inherited from class org.apache.iotdb.db.mpp.execution.schedule.queue.IndexedBlockingQueue

clear, get, poll, push, remove, size

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

L1PriorityQueue

public L1PriorityQueue(int maxCapacity,
                       java.util.Comparator<E> comparator,
                       E queryHolder)

Init the queue with max capacity and specified comparator.

Parameters:

maxCapacity - the max capacity of the queue.

comparator - the comparator for comparing the elements.

queryHolder - the query holder instance.

Throws:

java.lang.IllegalArgumentException - if maxCapacity <= 0.

See Also:

IndexedBlockingQueue

Method Detail

isEmpty

protected boolean isEmpty()

Description copied from class: IndexedBlockingQueue

Whether the queue is empty.

This implementation needn't be thread-safe.

Specified by:

isEmpty in class IndexedBlockingQueue<E extends IDIndexedAccessible>

Returns:

true if the queue is empty, otherwise false.

pollFirst

protected E pollFirst()

Description copied from class: IndexedBlockingQueue

Get and remove the first element.

This implementation needn't be thread-safe.

Specified by:

pollFirst in class IndexedBlockingQueue<E extends IDIndexedAccessible>

Returns:

The first element.

pushToQueue

protected void pushToQueue(E element)

Description copied from class: IndexedBlockingQueue

Push the element into the queue.

This implementation needn't be thread-safe.

Specified by:

pushToQueue in class IndexedBlockingQueue<E extends IDIndexedAccessible>

Parameters:

element - the element to be pushed.

remove

protected E remove(E element)

Description copied from class: IndexedBlockingQueue

Remove and return the element by its ID. It returns null if it doesn't exist.

This implementation needn't be thread-safe.

Specified by:

remove in class IndexedBlockingQueue<E extends IDIndexedAccessible>

Parameters:

element - the element to be removed.

Returns:

the removed element.

contains

protected boolean contains(E element)

Description copied from class: IndexedBlockingQueue

Check whether an element with the same ID exists.

This implementation needn't be thread-safe.

Specified by:

contains in class IndexedBlockingQueue<E extends IDIndexedAccessible>

Parameters:

element - the element to be checked.

Returns:

true if an element with the same ID exists, otherwise false.

get

protected E get(E element)

Description copied from class: IndexedBlockingQueue

Return the element with the same id of the input, null if it doesn't exist.

This implementation needn't be thread-safe.

Specified by:

get in class IndexedBlockingQueue<E extends IDIndexedAccessible>

Parameters:

element - the element to be queried.

Returns:

the element with the same id in the queue. Null if it doesn't exist.

clearAllElements

protected void clearAllElements()

Description copied from class: IndexedBlockingQueue

Clear all elements in this queue.

This implementation needn't be thread-safe.

Specified by:

clearAllElements in class IndexedBlockingQueue<E extends IDIndexedAccessible>