org.h2.store
Class PageStreamTrunk

java.lang.Object
  org.h2.util.CacheObject
      org.h2.store.Record
          org.h2.store.Page
              org.h2.store.PageStreamTrunk

public class PageStreamTrunk
extends Page

A trunk page of a stream. It contains the page numbers of the stream, and the page number of the next trunk. The format is:

• page type: byte (0)
• checksum: short (1-2)
• previous trunk page, or 0 if none: int (3-6)
• log key: int (7-10)
• next trunk page: int (11-14)
• number of pages: short (15-16)
• page ids (17-)

Field Summary

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

boolean	canRemove() Check if the object can be removed from the cache.
int	getByteCount(DataPage dummy) Get the number of bytes required for the data if the given data page would be used.
int	getMemorySize() Get the estimated memory size.
int	getNextTrunk()
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.
void	write(DataPage buff) Write the record to the data page.

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, toString, wait, wait, wait

Method Detail

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

getMemorySize

public int getMemorySize()

Get the estimated memory size.

Overrides:

getMemorySize in class CacheObject

Returns:

number of double words (4 bytes)

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

getNextTrunk

public int getNextTrunk()

canRemove

public boolean canRemove()

Description copied from class: CacheObject

Check if the object can be removed from the cache. For example pinned objects can not be removed.

Overrides:

canRemove in class Record

Returns:

true if it can be removed