org.apache.xml.utils

Class ObjectStack

java.lang.Object

org.apache.xml.utils.ObjectVector

org.apache.xml.utils.ObjectStack

All Implemented Interfaces:

Cloneable

public class ObjectStack
extends ObjectVector

Implement a stack of simple integers. %OPT% This is currently based on ObjectVector, which permits fast acess but pays a heavy recopying penalty if/when its size is increased. If we expect deep stacks, we should consider a version based on ChunkedObjectVector.

Field Summary

Fields inherited from class org.apache.xml.utils.ObjectVector

m_blocksize, m_firstFree, m_map, m_mapSize

Constructor Summary

Constructors

Constructor and Description
ObjectStack() Default constructor.
ObjectStack(int blocksize) Construct a ObjectVector, using the given block size.
ObjectStack(ObjectStack v) Copy constructor for ObjectStack

Method Summary

Modifier and Type	Method and Description
Object	clone() Returns clone of current ObjectStack
boolean	empty() Tests if this stack is empty.
Object	peek() Looks at the object at the top of this stack without removing it from the stack.
Object	peek(int n) Looks at the object at the position the stack counting down n items.
Object	pop() Removes the object at the top of this stack and returns that object as the value of this function.
Object	push(Object i) Pushes an item onto the top of this stack.
void	quickPop(int n) Quickly pops a number of items from the stack.
int	search(Object o) Returns where an object is on this stack.
void	setTop(Object val) Sets an object at a the top of the statck

Methods inherited from class org.apache.xml.utils.ObjectVector

addElement, addElements, addElements, contains, elementAt, indexOf, indexOf, insertElementAt, lastIndexOf, removeAllElements, removeElement, removeElementAt, setElementAt, setSize, setToSize, size

Methods inherited from class java.lang.Object

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

Constructor Detail

ObjectStack

public ObjectStack()

Default constructor. Note that the default block size is very small, for small lists.

ObjectStack

public ObjectStack(int blocksize)

Construct a ObjectVector, using the given block size.

Parameters:

blocksize - Size of block to allocate

ObjectStack

public ObjectStack(ObjectStack v)

Copy constructor for ObjectStack

Parameters:

v - ObjectStack to copy

Method Detail

push

public Object push(Object i)

Pushes an item onto the top of this stack.

Parameters:

i - the int to be pushed onto this stack.

Returns:

the item argument.

pop

public Object pop()

Removes the object at the top of this stack and returns that object as the value of this function.

Returns:

The object at the top of this stack.

quickPop

public void quickPop(int n)

Quickly pops a number of items from the stack.

peek

public Object peek()

Looks at the object at the top of this stack without removing it from the stack.

Returns:

the object at the top of this stack.

Throws:

EmptyStackException - if this stack is empty.

peek

public Object peek(int n)

Looks at the object at the position the stack counting down n items.

Parameters:

n - The number of items down, indexed from zero.

Returns:

the object at n items down.

Throws:

EmptyStackException - if this stack is empty.

setTop

public void setTop(Object val)

Sets an object at a the top of the statck

Parameters:

val - object to set at the top

Throws:

EmptyStackException - if this stack is empty.

empty

public boolean empty()

Tests if this stack is empty.

Returns:

true if this stack is empty; false otherwise.

Since:

JDK1.0

search

public int search(Object o)

Returns where an object is on this stack.

Parameters:

o - the desired object.

Returns:

the distance from the top of the stack where the object is] located; the return value -1 indicates that the object is not on the stack.

Since:

JDK1.0

clone

public Object clone()
             throws CloneNotSupportedException

Returns clone of current ObjectStack

Overrides:

clone in class ObjectVector

Returns:

clone of current ObjectStack

Throws:

CloneNotSupportedException