org.h2.index

Class PageBtree

java.lang.Object

org.h2.util.CacheObject

org.h2.store.Page

org.h2.index.PageBtree

All Implemented Interfaces:

Comparable<CacheObject>

Direct Known Subclasses:

PageBtreeLeaf, PageBtreeNode

public abstract class PageBtree
extends Page

A page that contains index data.

Field Summary

Fields

Modifier and Type	Field and Description
protected Data	data The data page.
protected int	entryCount The number of entries.
protected PageBtreeIndex	index The index.
protected int	memoryEstimated The estimated memory used by this object.
protected int[]	offsets The row offsets.
protected boolean	onlyPosition If only the position of the row is stored in the page
protected int	parentPageId The page number of the parent.
protected SearchRow[]	rows The index data
protected int	start The start of the data area.
protected boolean	written Whether the data page is up-to-date.

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
boolean	canRemove() Check if the object can be removed from the cache.
int	getMemory() Get the estimated memory size.
protected void	memoryChange() The memory usage of this page was changed.
protected void	readAllRows() Ensure all rows are read in memory.

Methods inherited from class org.h2.store.Page

add, canMove, insert, insert, insert, moveTo, remove, remove, remove, write

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, toString, wait, wait, wait

Field Detail

index

protected final PageBtreeIndex index

The index.

parentPageId

protected int parentPageId

The page number of the parent.

data

protected final Data data

The data page.

offsets

protected int[] offsets

The row offsets.

entryCount

protected int entryCount

The number of entries.

rows

protected SearchRow[] rows

The index data

start

protected int start

The start of the data area.

onlyPosition

protected boolean onlyPosition

If only the position of the row is stored in the page

written

protected boolean written

Whether the data page is up-to-date.

memoryEstimated

protected int memoryEstimated

The estimated memory used by this object.

Method Detail

memoryChange

protected void memoryChange()

The memory usage of this page was changed. Propagate the change if needed.

readAllRows

protected void readAllRows()

Ensure all rows are read in memory.

getMemory

public int getMemory()

Get the estimated memory size.

Specified by:

getMemory in class CacheObject

Returns:

number of double words (4 bytes)

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.

Specified by:

canRemove in class CacheObject

Returns:

true if it can be removed