org.apache.directory.mavibot.btree

Class ValueArrayCursor<V>

java.lang.Object

org.apache.directory.mavibot.btree.ValueArrayCursor<V>

All Implemented Interfaces:

Cursor<V>, ValueCursor<V>

class ValueArrayCursor<V>
extends java.lang.Object
implements ValueCursor<V>

A class that encapsulate the values into an array

Field Summary

Fields

Modifier and Type	Field and Description
private int	currentPos Store the current position in the array or in the BTree
private V[]	valueArray The array storing values (1 to N)

Fields inherited from interface org.apache.directory.mavibot.btree.Cursor

AFTER_LAST, BEFORE_FIRST

Constructor Summary

Constructors

Constructor and Description
ValueArrayCursor(V[] valueArray) Create an instance

Method Summary

Modifier and Type	Method and Description
void	afterLast() Places the cursor at the end of the last position
void	beforeFirst() moves the cursor to the same position that was given at the time of instantiating the cursor.
void	close() Closes the cursor, thus releases the associated transaction
boolean	hasNext() Tells if the cursor can return a next element
boolean	hasPrev() Tells if the cursor can return a previous element
V	next() Find the next key/value
V	prev() Find the previous key/value
int	size()

Methods inherited from class java.lang.Object

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

Field Detail

currentPos

private int currentPos

Store the current position in the array or in the BTree

valueArray

private V[] valueArray

The array storing values (1 to N)

Constructor Detail

ValueArrayCursor

public ValueArrayCursor(V[] valueArray)

Create an instance

Method Detail

hasNext

public boolean hasNext()

Tells if the cursor can return a next element

Specified by:

hasNext in interface Cursor<V>

Returns:

true if there are some more elements

next

public V next()

Find the next key/value

Specified by:

next in interface ValueCursor<V>

Returns:

A Tuple containing the found key and value

hasPrev

public boolean hasPrev()
                throws EndOfFileExceededException,
                       java.io.IOException

Tells if the cursor can return a previous element

Specified by:

hasPrev in interface Cursor<V>

Returns:

true if there are some more elements

Throws:

EndOfFileExceededException

java.io.IOException

close

public void close()

Closes the cursor, thus releases the associated transaction

Specified by:

close in interface Cursor<V>

beforeFirst

public void beforeFirst()
                 throws java.io.IOException

moves the cursor to the same position that was given at the time of instantiating the cursor. For example, if the cursor was created using browse() method, then beforeFirst() will place the cursor before the 0th position. If the cursor was created using browseFrom(K), then calling beforeFirst() will reset the position to the just before the position where K is present.

Specified by:

beforeFirst in interface Cursor<V>

Throws:

java.io.IOException

afterLast

public void afterLast()
               throws java.io.IOException

Places the cursor at the end of the last position

Specified by:

afterLast in interface Cursor<V>

Throws:

java.io.IOException

prev

public V prev()
       throws EndOfFileExceededException,
              java.io.IOException

Find the previous key/value

Specified by:

prev in interface ValueCursor<V>

Returns:

A Tuple containing the found key and value

Throws:

EndOfFileExceededException

java.io.IOException

size

public int size()

Specified by:

size in interface ValueCursor<V>

Returns:

The number of elements stored in the cursor