org.htmlunit.cyberneko.util

Class MiniStack<E>

java.lang.Object

org.htmlunit.cyberneko.util.MiniStack<E>

public class MiniStack<E>
extends Object

Extremely light stack implementation. Perfect for inlining.

Since:

3.10.0

Author:

René Schwietzke

Constructor Summary

Constructors

Constructor and Description
MiniStack() Create a new empty stack with 8 elements capacity.

Method Summary

Modifier and Type	Method and Description
void	clear() Empties the stack.
boolean	isEmpty() Checks if we have any element at all on the stack.
E	peek() Returns the top/last element without removing it.
E	pop() Removes and returns the last element
void	push(E element) Add a new element on top of the stack.
void	reset() Resets the stack to zero but does not clean it.
int	size() Returns the current size of the stack.

Methods inherited from class java.lang.Object

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

Constructor Detail

MiniStack

public MiniStack()

Create a new empty stack with 8 elements capacity.

A reference are typically (less than 32 GB memory) 4 bytes. The overhead of any object is about 24 bytes, give or take, hence 8*4 + 24 fits a cache line of 64 bytes.

Method Detail

clear

public void clear()

Empties the stack. It will not only reset the pointer but empty out the backing array to ensure we are not holding old references.

reset

public void reset()

Resets the stack to zero but does not clean it. Use with caution to avoid holding old objects and preventing them from GC.

pop

public E pop()

Removes and returns the last element

Returns:

the last element or null of none

peek

public E peek()

Returns the top/last element without removing it. Will return null if we don't have a last element.

Returns:

the top/last element if any, null otherwise

push

public void push(E element)

Add a new element on top of the stack. You can add null but the return value of pop and peek will become ambiguous.

Parameters:

element - the element to add

isEmpty

public boolean isEmpty()

Checks if we have any element at all on the stack.

Returns:

true if the stack holds elements, false otherwise

size

public int size()

Returns the current size of the stack.

Returns:

the size of the stack, always >= 0