org.apache.derby.impl.store.access.btree

Class LeafControlRow

java.lang.Object

org.apache.derby.impl.store.access.btree.ControlRow

org.apache.derby.impl.store.access.btree.LeafControlRow

All Implemented Interfaces:

TypedFormat, AuxObject

public class LeafControlRow
extends ControlRow

Field Summary

Fields inherited from class org.apache.derby.impl.store.access.btree.ControlRow

SPLIT_FLAG_FIRST_IN_TABLE, SPLIT_FLAG_FIRST_ON_PAGE, SPLIT_FLAG_LAST_IN_TABLE, SPLIT_FLAG_LAST_ON_PAGE

Constructor Summary

Constructors

Constructor and Description
LeafControlRow() No arg constructor.

Method Summary

Modifier and Type	Method and Description
int	checkConsistency(OpenBTree btree, ControlRow parent, boolean check_other_pages) Perform consistency checks on a leaf page.
int	getTypeFormatId() Return my format identifier.
static void	initEmptyBtree(OpenBTree open_btree) Initialize conglomerate with one page, to be a 1 page btree.
boolean	isLeftmostLeaf() Is the current page the leftmost leaf of tree?
boolean	isRightmostLeaf() Is the current page the rightmost leaf of tree?
void	printTree(OpenBTree btree) Recursively print the tree starting at current node in tree.
ControlRow	search(SearchParameters sp) Perform a search of this leaf page, ultimately returning the latched leaf page and row slot after which the given key belongs.

Methods inherited from class org.apache.derby.impl.store.access.btree.ControlRow

auxObjectInvalidated, compareIndexRowFromPageToKey, compareIndexRowToKey, debugPage, get, get, getConglom, getLeftSibling, getleftSiblingPageNumber, getNoWait, getPage, getRowTemplate, release, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

LeafControlRow

public LeafControlRow()

No arg constructor.

Public no arg constructor is for the monitor to call for format id implemenation, it should not be called for any other reason.

Method Detail

initEmptyBtree

public static void initEmptyBtree(OpenBTree open_btree)
                           throws StandardException

Initialize conglomerate with one page, to be a 1 page btree. Given a conglomerate which already has one page allocated to it, initialize the page to be a leaf-root page with no entries. Allocate the control row and store it on the page.

Parameters:

open_btree - The open btree to initialize (container is open).

Throws:

StandardException - Standard exception policy.

isLeftmostLeaf

public boolean isLeftmostLeaf()
                       throws StandardException

Is the current page the leftmost leaf of tree?

Specified by:

isLeftmostLeaf in class ControlRow

Returns:

true if the current page is the leftmost leaf of the tree, else return false.

Throws:

StandardException - Standard exception policy.

isRightmostLeaf

public boolean isRightmostLeaf()
                        throws StandardException

Is the current page the rightmost leaf of tree?

Specified by:

isRightmostLeaf in class ControlRow

Returns:

true if the current page is the rightmost leaf of the tree, else return false.

Throws:

StandardException - Standard exception policy.

search

public ControlRow search(SearchParameters sp)
                  throws StandardException

Perform a search of this leaf page, ultimately returning the latched leaf page and row slot after which the given key belongs. The slot is returned in the result structure. If the key exists on the page, the result.exact will be true. Otherwise, result.exact will be false, and the row slot returned will be the one immediately preceding the position at which the key belongs.

Specified by:

search in class ControlRow

Throws:

StandardException - Standard exception policy.

checkConsistency

public int checkConsistency(OpenBTree btree,
                            ControlRow parent,
                            boolean check_other_pages)
                     throws StandardException

Perform consistency checks on a leaf page. Check consistency of the page and its children, returning the number of pages seen, and throwing errors if inconsistencies are found. The checks specific to a leaf page are:

Page is at level 0.

Version is a valid leaf page version.

Control row has right number of columns for leaf.

This method also performs the consistency checks that are common to both leaf and branch pages.

Parameters:

btree - The open btree to associate latches/locks with.

parent - The parent page of this page, "null" if this page is root or if not maintaining parent links.

check_other_pages - Should the consistency check go to other pages (this option breaks the latch protocol).

Returns:

The identifier to be used to open the conglomerate later.

Throws:

StandardException - Standard exception policy.

See Also:

ControlRow.checkGeneric(org.apache.derby.impl.store.access.btree.OpenBTree, org.apache.derby.impl.store.access.btree.ControlRow, boolean)

printTree

public void printTree(OpenBTree btree)
               throws StandardException

Recursively print the tree starting at current node in tree. This is a leaf so return.

Specified by:

printTree in class ControlRow

Throws:

StandardException - Standard exception policy.

getTypeFormatId

public int getTypeFormatId()

Return my format identifier.

Returns:

The identifier. (A UUID stuffed in an array of 16 bytes).

See Also:

TypedFormat.getTypeFormatId()