org.netbeans.mdr.persistence.btreeimpl.btreeindex

Class ShrinkablePage

java.lang.Object

org.netbeans.mdr.persistence.btreeimpl.btreeindex.BtreePage

org.netbeans.mdr.persistence.btreeimpl.btreeindex.ShrinkablePage

All Implemented Interfaces:

Streamable

public class ShrinkablePage
extends BtreePage

Implementation of a BtreePage with fixed key length and fixed data length that are stored in compressed form if all the stored keys or data prefixes are strings of zeros (these prefixes are excluded then).

Field Summary

Fields inherited from class org.netbeans.mdr.persistence.btreeimpl.btreeindex.BtreePage

pageBuffer, pageId

Constructor Summary

Constructors

Constructor and Description
ShrinkablePage()

Method Summary

Methods

Modifier and Type	Method and Description
protected byte	compare(byte[] key, int entryNum) Compares the key with that of the specified entry.
protected byte	compareData(byte[] data, int entryNum)
void	dump()
void	dumpBuffer()
void	init(Btree btree, byte[] pageId, byte[] pageBuffer, boolean isNew) Initialize a newly-instantiated or recycled ShrinkablePage.
void	store() Write BtreePage header data to the page buffer.

Methods inherited from class org.netbeans.mdr.persistence.btreeimpl.btreeindex.BtreePage

consistencyCheck, dumpPage, dumpPageBuffer, dumpPageEntries, dumpPageHeader, dumpTree, get, getLocation, makeRoot, put, put, read, remove, remove, remove, split, uninit, write

Methods inherited from class java.lang.Object

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

Constructor Detail

ShrinkablePage

public ShrinkablePage()

Method Detail

init

public void init(Btree btree,
        byte[] pageId,
        byte[] pageBuffer,
        boolean isNew)
          throws StorageException

Initialize a newly-instantiated or recycled ShrinkablePage. Note that the isNew parameter pertains to whether a new page is being added to the btree, not to whether this BtreePage object is new or recycled.

Overrides:

init in class BtreePage

Parameters:

btree - btree to which this page belongs

pageId - page ID in byte array

pageBuffer - page buffer

isNew - is this page new to the btree

Throws:

StorageException

compare

protected byte compare(byte[] key,
           int entryNum)

Description copied from class: BtreePage

Compares the key with that of the specified entry. Just handles one special case and then calls btree.keyInfo.compare().

Overrides:

compare in class BtreePage

Parameters:

key - search key

entryNum - entry number of target entry

Returns:

EntryTypeInfo.EQUAL if the two keys are equal EntryTypeInfo.GREATER if search key is greater than entry's key EntryTypeInfo.LESS if search key is less than entry's key

compareData

protected byte compareData(byte[] data,
               int entryNum)

Overrides:

compareData in class BtreePage

store

public void store()

Description copied from class: BtreePage

Write BtreePage header data to the page buffer.

Overrides:

store in class BtreePage

dump

public void dump()

dumpBuffer

public void dumpBuffer()