Package org.web3d.util

Class SimpleStack

java.lang.Object

org.web3d.util.SimpleStack

All Implemented Interfaces:

SimpleStackInterface

Direct Known Subclasses:

SimpleStackLogged

public class SimpleStack
extends Object
implements SimpleStackInterface

A stack that has a minimal implementation and no synchronisation.

This stack is designed to be used in a high-speed, single threaded environment. It is directly backed by an array for fast access.

Version:

$Revision: 1.10 $

Author:

Justin Couch

See Also:

• Stack

Field Summary

Fields

Modifier and Type	Field	Description
protected static final int	STACK_START_SIZE	The initial size of the stack for element processing

Constructor Summary

Constructors

Constructor	Description
SimpleStack()	Constructs a new, empty hashtable with a default capacity and load factor, which is 20 respectively.
SimpleStack(int initialCapacity)	Constructs a new, empty hashtable with the specified initial capacity and default load factor, which is 0.75.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears this stack so that it contains no values.
boolean	contains(Object value)	Returns true if this stack contains an instance of the value.
boolean	isEmpty()	Tests if this stack maps no values.
Object	peek()	Peek at the value on the top of the stack without removing it.
Object	pop()	Pop the value from the top of the stack.
void	push(Object val)	Push a new value onto the top of the stack.
void	remove(Object obj)	Remove the given object from the stack if it exists.
int	size()	Returns the number of keys in this hashtable.
String	toString()	Generate a string representation of this stack object.

Methods inherited from class java.lang.Object

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

Field Details

STACK_START_SIZE

protected static final int STACK_START_SIZE

The initial size of the stack for element processing

See Also:

• Constant Field Values

Constructor Details

SimpleStack

public SimpleStack()

Constructs a new, empty hashtable with a default capacity and load factor, which is 20 respectively.

SimpleStack

public SimpleStack(int initialCapacity)

Constructs a new, empty hashtable with the specified initial capacity and default load factor, which is 0.75.

Parameters:

initialCapacity - the initial capacity of the hashtable.

Throws:

IllegalArgumentException - if the initial capacity is less than zero.

Method Details

toString

public String toString()

Generate a string representation of this stack object. Prints a string in reverse order from top to bottom.

Overrides:

toString in class Object

Returns:

A string representation of the stack

size

public int size()

Returns the number of keys in this hashtable.

Specified by:

size in interface SimpleStackInterface

Returns:

the number of keys in this hashtable.

isEmpty

public boolean isEmpty()

Tests if this stack maps no values.

Specified by:

isEmpty in interface SimpleStackInterface

Returns:

true if this stack has no values

push

public void push(Object val)

Push a new value onto the top of the stack. The value may be any legal reference to an object including null.

Specified by:

push in interface SimpleStackInterface

Parameters:

val - The new value for the stack.

peek

public Object peek()
            throws EmptyStackException

Peek at the value on the top of the stack without removing it. If the value pushed was null, then null is returned here.

Specified by:

peek in interface SimpleStackInterface

Returns:

A reference to the object on the top of the stack

Throws:

EmptyStackException - The stack is currently empty

pop

public Object pop()

Pop the value from the top of the stack. If the last value in the stack was null then this will return null.

Specified by:

pop in interface SimpleStackInterface

Returns:

The top object on the stack

contains

public boolean contains(Object value)

Returns true if this stack contains an instance of the value. The checl looks at both the reference comparison (==) and the equality using .equals(). If the stack is currently empty this will always return false. The search order is from the top of the stack towards the bottom.

Specified by:

contains in interface SimpleStackInterface

Parameters:

value - The value whose presence in this stack is to be tested.

Returns:

true if this stack contains the value.

remove

public void remove(Object obj)

Remove the given object from the stack if it exists. If it is not in the stack, then ignore it quietly.

Specified by:

remove in interface SimpleStackInterface

Parameters:

obj - The object to be removed

clear

public void clear()

Clears this stack so that it contains no values.

Specified by:

clear in interface SimpleStackInterface