com.db4o.internal.btree

Class BTreeNode

java.lang.Object

com.db4o.internal.Identifiable

com.db4o.internal.PersistentBase

com.db4o.internal.LocalPersistentBase

com.db4o.internal.btree.BTreeNode

All Implemented Interfaces:

LinkLengthAware, Persistent

public final class BTreeNode
extends LocalPersistentBase

We work with BTreeNode in two states: - deactivated: never read, no valid members, ID correct or 0 if new - write: real representation of keys, values and children in arrays The write state can be detected with canWrite(). States can be changed as needed with prepareRead() and prepareWrite().

Field Summary

Fields inherited from class com.db4o.internal.Identifiable

_id, _state

Constructor Summary

Constructors

Constructor and Description
BTreeNode(BTree btree, int count, boolean isLeaf, int parentID, int previousID, int nextID)
BTreeNode(int id, BTree btree)
BTreeNode(Transaction trans, BTreeNode firstChild, BTreeNode secondChild)

Method Summary

Methods

Modifier and Type	Method and Description
BTreeNode	add(Transaction trans, PreparedComparison preparedComparison, java.lang.Object obj)
BTree	btree()
boolean	canWrite()
void	commit(Transaction trans)
int	count()
void	debugLoadFully(Transaction trans)
static void	defragIndex(DefragmentContextImpl context, Indexable4 keyHandler)
boolean	equals(java.lang.Object obj)
int	firstKeyIndex(Transaction trans)
void	free(LocalTransaction trans)
byte	getIdentifier()
int	hashCode()
TransactionalIdSystem	idSystem(Transaction trans)
boolean	indexIsValid(Transaction trans, int index)
boolean	isLeaf()
java.lang.Object	key(Transaction trans, int index)
int	lastKeyIndex(Transaction trans)
BTreePointer	lastPointer(Transaction trans)
BTreeNode	nextNode()
int	ownLength()
BTreeNode	previousNode()
void	purge()
void	readThis(Transaction trans, ByteArrayBuffer reader)
void	remove(Transaction trans, int index)
boolean	remove(Transaction trans, java.lang.Object obj, int index)
void	remove(Transaction trans, PreparedComparison preparedComparison, java.lang.Object obj, int index)
int	size(Transaction trans)
SlotChangeFactory	slotChangeFactory()
void	toReadMode()
java.lang.String	toString()
void	traverseKeys(Transaction trans, Visitor4 visitor)
boolean	writeObjectBegin()
void	writeThis(Transaction trans, ByteArrayBuffer buffer)

Methods inherited from class com.db4o.internal.LocalPersistentBase

readBufferById

Methods inherited from class com.db4o.internal.PersistentBase

linkLength, newWriteBuffer, produceReadBuffer, produceWriteBuffer, read, read, write, writeOwnID

Methods inherited from class com.db4o.internal.Identifiable

beginProcessing, endProcessing, getID, isActive, isDirty, isNew, setID, setStateClean, setStateDeactivated, setStateDirty

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BTreeNode

public BTreeNode(BTree btree,
         int count,
         boolean isLeaf,
         int parentID,
         int previousID,
         int nextID)

BTreeNode

public BTreeNode(int id,
         BTree btree)

BTreeNode

public BTreeNode(Transaction trans,
         BTreeNode firstChild,
         BTreeNode secondChild)

Method Detail

btree

public BTree btree()

add

public BTreeNode add(Transaction trans,
            PreparedComparison preparedComparison,
            java.lang.Object obj)

Returns:

the split node if this node is split or this if the first key has changed

canWrite

public boolean canWrite()

commit

public void commit(Transaction trans)

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class Identifiable

free

public void free(LocalTransaction trans)

Overrides:

free in class PersistentBase

count

public int count()

firstKeyIndex

public int firstKeyIndex(Transaction trans)

lastKeyIndex

public int lastKeyIndex(Transaction trans)

indexIsValid

public boolean indexIsValid(Transaction trans,
                   int index)

getIdentifier

public byte getIdentifier()

key

public java.lang.Object key(Transaction trans,
                   int index)

ownLength

public int ownLength()

readThis

public void readThis(Transaction trans,
            ByteArrayBuffer reader)

remove

public void remove(Transaction trans,
          int index)

remove

public boolean remove(Transaction trans,
             java.lang.Object obj,
             int index)

remove

public void remove(Transaction trans,
          PreparedComparison preparedComparison,
          java.lang.Object obj,
          int index)

previousNode

public BTreeNode previousNode()

nextNode

public BTreeNode nextNode()

lastPointer

public BTreePointer lastPointer(Transaction trans)

purge

public void purge()

traverseKeys

public void traverseKeys(Transaction trans,
                Visitor4 visitor)

writeObjectBegin

public boolean writeObjectBegin()

Overrides:

writeObjectBegin in class PersistentBase

writeThis

public void writeThis(Transaction trans,
             ByteArrayBuffer buffer)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

debugLoadFully

public void debugLoadFully(Transaction trans)

defragIndex

public static void defragIndex(DefragmentContextImpl context,
               Indexable4 keyHandler)

isLeaf

public boolean isLeaf()

size

public int size(Transaction trans)

slotChangeFactory

public SlotChangeFactory slotChangeFactory()

Overrides:

slotChangeFactory in class PersistentBase

idSystem

public TransactionalIdSystem idSystem(Transaction trans)

Overrides:

idSystem in class LocalPersistentBase

toReadMode

public void toReadMode()