edu.berkeley.cs186.database.index

Class LeafNode

java.lang.Object

edu.berkeley.cs186.database.index.BPlusNode

edu.berkeley.cs186.database.index.LeafNode

public class LeafNode
extends BPlusNode

A leaf node of a B+ tree. A LeafNode header contains an `isLeaf` flag set to 1. A LeafNode contains LeafEntries. Inherits all the properties of a BPlusNode.

Field Summary

Fields

Modifier and Type	Field and Description
static int	headerSize

Fields inherited from class edu.berkeley.cs186.database.index.BPlusNode

numEntries

Constructor Summary

Constructors

Constructor and Description
LeafNode(BPlusTree tree)
LeafNode(BPlusTree tree, int pageNum)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	containsKey(DataBox key)
InnerEntry	insertBEntry(LeafEntry ent) Inserts a LeafEntry into this LeafNode.
boolean	isLeaf()
Iterator<RecordID>	scan() Creates an iterator of RecordIDs for all entries in this node.
Iterator<RecordID>	scanForKey(DataBox key) Creates an iterator of RecordIDs that correspond to the given key in the current leafNode Page.
Iterator<RecordID>	scanFrom(DataBox startValue) Creates an iterator of RecordIDs whose keys are greater than or equal to the given start value key.
InnerEntry	splitNode(BEntry newEntry) Splits this LeafNode and returns the resulting InnerEntry to be pushed/copied up to this LeafNode's parent as a result of the split.

Methods inherited from class edu.berkeley.cs186.database.index.BPlusNode

getAllValidEntries, getBPlusNode, getPage, getPageNum, getTree, hasSpace, locateLeaf, overwriteBNodeEntries

Methods inherited from class java.lang.Object

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

Field Detail

headerSize

public static int headerSize

Constructor Detail

LeafNode

public LeafNode(BPlusTree tree)

LeafNode

public LeafNode(BPlusTree tree,
        int pageNum)

Method Detail

isLeaf

public boolean isLeaf()

Overrides:

isLeaf in class BPlusNode

insertBEntry

public InnerEntry insertBEntry(LeafEntry ent)

Inserts a LeafEntry into this LeafNode.

Overrides:

insertBEntry in class BPlusNode

Parameters:

ent - the LeafEntry to be inserted

Returns:

the InnerEntry to be pushed/copied up to this LeafNode's parent as a result of this LeafNode being split, null otherwise

splitNode

public InnerEntry splitNode(BEntry newEntry)

Splits this LeafNode and returns the resulting InnerEntry to be pushed/copied up to this LeafNode's parent as a result of the split. The left node should contain d entries and the right node should contain d+1 entries.

Overrides:

splitNode in class BPlusNode

Parameters:

newEntry - the BEntry that is being added to this LeafNode

Returns:

the resulting InnerEntry to be pushed/copied up to this LeafNode's parent as a result of this LeafNode being split

scan

public Iterator<RecordID> scan()

Creates an iterator of RecordIDs for all entries in this node.

Returns:

an iterator of RecordIDs

scanFrom

public Iterator<RecordID> scanFrom(DataBox startValue)

Creates an iterator of RecordIDs whose keys are greater than or equal to the given start value key.

Parameters:

startValue - the start value key

Returns:

an iterator of RecordIDs

scanForKey

public Iterator<RecordID> scanForKey(DataBox key)

Creates an iterator of RecordIDs that correspond to the given key in the current leafNode Page.

Parameters:

key - the search key

Returns:

an iterator of RecordIDs

containsKey

public boolean containsKey(DataBox key)