org.h2.index
Class PageBtreeNode

java.lang.Object
  org.h2.util.CacheObject
      org.h2.store.Record
          org.h2.store.Page
              org.h2.index.PageBtree
                  org.h2.index.PageBtreeNode

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, 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

blockCount, cacheQueue, chained, next, previous

Method Summary

int	getByteCount(DataPage dummy) Get the number of bytes required for the data if the given data page would be used.
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.
java.lang.String	toString()
void	write(DataPage buff) Write the record to the data page.

Methods inherited from class org.h2.index.PageBtree

canRemove, getMemorySize, readAllRows

Methods inherited from class org.h2.store.Record

commit, getSessionId, getStorageId, isDeleted, isEmpty, isLogWritten, prepareWrite, setDeleted, setLastLog, setLogWritten, setSessionId, setStorageId

Methods inherited from class org.h2.util.CacheObject

getBlockCount, getPos, isChanged, isPinned, setBlockCount, setChanged, setPos, sort

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)
                 throws java.sql.SQLException

Read a b-tree node page.

Parameters:

index - the index

data - the data

pageId - the page id

Returns:

the page

Throws:

java.sql.SQLException

remapChildren

protected void remapChildren()
                      throws java.sql.SQLException

Description copied from class: PageBtree

Update the parent id of all children.

Throws:

java.sql.SQLException

getByteCount

public int getByteCount(DataPage dummy)

Description copied from class: Record

Get the number of bytes required for the data if the given data page would be used.

Specified by:

getByteCount in class Record

Parameters:

dummy - the template data page

Returns:

the number of bytes

write

public void write(DataPage buff)
           throws java.sql.SQLException

Description copied from class: Record

Write the record to the data page.

Specified by:

write in class Record

Parameters:

buff - the data page

Throws:

java.sql.SQLException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

moveTo

public void moveTo(Session session,
                   int newPos)
            throws java.sql.SQLException

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

Throws:

java.sql.SQLException