org.h2.dev.store.btree
Class Cursor<K,V>

java.lang.Object
  org.h2.dev.store.btree.Cursor<K,V>

Type Parameters:

K - the key type

V - the value type

All Implemented Interfaces:

java.util.Iterator<K>

Direct Known Subclasses:

ChangeCursor

public class Cursor<K,V>
extends java.lang.Object
implements java.util.Iterator<K>

A cursor to iterate over elements in ascending order.

Field Summary

protected K	current
protected CursorPos	currentPos
protected MVMap<K,V>	map
protected java.util.ArrayList<CursorPos>	parents

Method Summary

protected void	fetchNext() Fetch the next key.
boolean	hasNext()
CursorPos	min(Page p, K from) Visit the first key that is greater or equal the given key.
K	next()
CursorPos	pop() Remove the latest cursor position from the stack and return it.
void	push(CursorPos p) Add a cursor position to the stack.
void	remove()
CursorPos	visitChild(Page p, int childIndex) Visit the first key within this child page.

Methods inherited from class java.lang.Object

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

Field Detail

map

protected final MVMap<K,V> map

parents

protected final java.util.ArrayList<CursorPos> parents

currentPos

protected CursorPos currentPos

current

protected K current

Method Detail

next

public K next()

Specified by:

next in interface java.util.Iterator<K>

fetchNext

protected void fetchNext()

Fetch the next key.

hasNext

public boolean hasNext()

Specified by:

hasNext in interface java.util.Iterator<K>

remove

public void remove()

Specified by:

remove in interface java.util.Iterator<K>

push

public void push(CursorPos p)

Add a cursor position to the stack.

Parameters:

p - the cursor position

pop

public CursorPos pop()

Remove the latest cursor position from the stack and return it.

Returns:

the cursor position, or null if none

min

public CursorPos min(Page p,
                     K from)

Visit the first key that is greater or equal the given key.

Parameters:

p - the page

from - the key, or null

Returns:

the cursor position

visitChild

public CursorPos visitChild(Page p,
                            int childIndex)

Visit the first key within this child page.

Parameters:

p - the page

childIndex - the child index

Returns:

the cursor position