org.h2.index

Class PageBtreeNode

java.lang.Object

org.h2.util.CacheObject

org.h2.store.Page

org.h2.index.PageBtree

org.h2.index.PageBtreeNode

All Implemented Interfaces:

Comparable<CacheObject>

public class PageBtreeNode
extends PageBtree

A b-tree node page that contains index data. Format:

• page type: byte
• checksum: short
• parent page id (0 for root): int
• index id: varInt
• count of all children (-1 if not known): int
• entry count: short
• rightmost child page id: int
• entries (child page id: int, offset: short)

The row contains the largest key of the respective child, meaning row[0] contains the largest key of child[0].

Field Summary

Fields inherited from class org.h2.index.PageBtree

data, entryCount, index, memoryEstimated, offsets, onlyPosition, parentPageId, rows, start, written

Fields inherited from class org.h2.store.Page

changeCount, FLAG_LAST, TYPE_BTREE_LEAF, TYPE_BTREE_NODE, TYPE_DATA_LEAF, TYPE_DATA_NODE, TYPE_DATA_OVERFLOW, TYPE_EMPTY, TYPE_FREE_LIST, TYPE_STREAM_DATA, TYPE_STREAM_TRUNK

Fields inherited from class org.h2.util.CacheObject

cacheChained, cacheNext, cachePrevious

Method Summary

Methods

Modifier and Type	Method and Description
void	moveTo(Session session, int newPos) Copy the data to a new location, change the parent to point to the new location, and free up the current page.
static Page	read(PageBtreeIndex index, Data data, int pageId) Read a b-tree node page.
protected void	remapChildren() Update the parent id of all children.
String	toString()
void	write() Write the page.

Methods inherited from class org.h2.index.PageBtree

canRemove, getMemory, memoryChange, readAllRows

Methods inherited from class org.h2.store.Page

add, canMove, insert, insert, insert, remove, remove, remove

Methods inherited from class org.h2.util.CacheObject

compareTo, getPos, isChanged, isStream, setChanged, setPos

Methods inherited from class java.lang.Object

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

Method Detail

read

public static Page read(PageBtreeIndex index,
        Data data,
        int pageId)

Read a b-tree node page.

Parameters:

index - the index

data - the data

pageId - the page id

Returns:

the page

remapChildren

protected void remapChildren()

Description copied from class: PageBtree

Update the parent id of all children.

write

public void write()

Description copied from class: Page

Write the page.

Specified by:

write in class Page

toString

public String toString()

Overrides:

toString in class Object

moveTo

public void moveTo(Session session,
          int newPos)

Description copied from class: Page

Copy the data to a new location, change the parent to point to the new location, and free up the current page.

Specified by:

moveTo in class Page

Parameters:

session - the session

newPos - the new position