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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:

org.apache.derby.iapi.store.raw.AuxObject, org.apache.derby.iapi.services.io.TypedFormat

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public class LeafControlRow

extends ControlRow

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Field Summary

 

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

CR_COLID_FIRST, CR_COLID_LAST, CR_CONGLOM_BITSET, CR_CONGLOM_COLID, CR_ISROOT_BITSET, CR_ISROOT_COLID, CR_LEFTSIB_BITSET, CR_LEFTSIB_COLID, CR_LEVEL_BITSET, CR_LEVEL_COLID, CR_NCOLUMNS, CR_PARENT_BITSET, CR_PARENT_COLID, CR_RIGHTSIB_BITSET, CR_RIGHTSIB_COLID, CR_SLOT, CR_VERSION_BITSET, CR_VERSION_COLID, fetchDesc, last_search_result, page, row, scratch_row, SPLIT_FLAG_FIRST_IN_TABLE, SPLIT_FLAG_FIRST_ON_PAGE, SPLIT_FLAG_LAST_IN_TABLE, SPLIT_FLAG_LAST_ON_PAGE, use_last_search_result_hint

 

Constructor Summary
	LeafControlRow()           No arg constructor.
(package private)	LeafControlRow(OpenBTree btree, org.apache.derby.iapi.store.raw.Page page, ControlRow parent, boolean isRoot)           Constructs a leaf-page control row, for a newly allocated leaf page.

 

Method Summary
private static LeafControlRow	Allocate(OpenBTree btree, ControlRow parent)           Allocate a new leaf page to the conglomerate.
int	checkConsistency(OpenBTree btree, ControlRow parent, boolean check_other_pages)           Perform consistency checks on a leaf page.
protected  void	ControlRowInit()           Perform page specific initialization.
private  float	get_left_nondeleted_rowcnt(int startslot)           Return the number of non-deleted rows from slot 1 through "startslot"
protected  ControlRow	getLeftChild(OpenBTree btree)           Return the left child pointer for the page.
protected  int	getNumberOfControlRowColumns()           Get the number of columns in the control row.
protected  ControlRow	getRightChild(OpenBTree btree)           Return the right child pointer for the page.
int	getTypeFormatId()           Return my format identifier.
private static void	growRoot(OpenBTree open_btree, org.apache.derby.iapi.types.DataValueDescriptor[] template, LeafControlRow leafroot)           Grow a new root page from a leaf page.
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.
protected  ControlRow	searchLeft(OpenBTree btree)           Search and return the left most leaf page.
protected  ControlRow	searchRight(OpenBTree btree)           Search and return the right most leaf page.
protected  boolean	shrinkFor(OpenBTree btree, org.apache.derby.iapi.types.DataValueDescriptor[] key)           Perform a recursive shrink operation for the key.
protected  long	splitFor(OpenBTree open_btree, org.apache.derby.iapi.types.DataValueDescriptor[] template, BranchControlRow parent_page, org.apache.derby.iapi.types.DataValueDescriptor[] splitrow, int flag)           Perform a top down split pass making room for the the key in "row".

 

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

auxObjectInvalidated, checkGeneric, checkRowOrder, checkSiblings, CompareIndexRowFromPageToKey, CompareIndexRowToKey, compareRowsOnSiblings, debugPage, Get, Get, getConglom, GetControlRowForPage, getIsRoot, getLeftSibling, getleftSiblingPageNumber, getLevel, GetNoWait, getPage, getParentPageNumber, getRightSibling, getrightSiblingPageNumber, getRow, getRowTemplate, getVersion, linkRight, release, searchForEntry, searchForEntryBackward, setIsRoot, setLeftSibling, setLevel, setParent, setRightSibling, setVersion, toString, unlink

 

Methods inherited from class java.lang.Object

clone, equals, finalize, 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.

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LeafControlRow

LeafControlRow(OpenBTree btree,
               org.apache.derby.iapi.store.raw.Page page,
               ControlRow parent,
               boolean isRoot)
         throws org.apache.derby.iapi.error.StandardException

Constructs a leaf-page control row, for a newly allocated leaf page.

Method Detail

Allocate

private static LeafControlRow Allocate(OpenBTree btree,
                                       ControlRow parent)
                                throws org.apache.derby.iapi.error.StandardException

Allocate a new leaf page to the conglomerate.

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get_left_nondeleted_rowcnt

private float get_left_nondeleted_rowcnt(int startslot)
                                  throws org.apache.derby.iapi.error.StandardException

Return the number of non-deleted rows from slot 1 through "startslot"

Return the number of non-deleted rows that exist on the page starting at slot one through "startslot".

RESOLVE (mikem) - is the expense of this routine worth it, it is only used for costing. Could an estimate from the nonDeletedRecordCount() be used instead?

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ControlRowInit

protected final void ControlRowInit()

Perform page specific initialization.

Specified by:

ControlRowInit in class ControlRow

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initEmptyBtree

public static void initEmptyBtree(OpenBTree open_btree)
                           throws org.apache.derby.iapi.error.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.

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getNumberOfControlRowColumns

protected final int getNumberOfControlRowColumns()

Get the number of columns in the control row.

Control rows all share the first columns as defined by this class and then add columns to the end of the control row. For instance a branch control row add a child page pointer field.

Specified by:

getNumberOfControlRowColumns in class ControlRow

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isLeftmostLeaf

public boolean isLeftmostLeaf()
                       throws org.apache.derby.iapi.error.StandardException

Is the current page the leftmost leaf of tree?

Specified by:

isLeftmostLeaf in class ControlRow

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isRightmostLeaf

public boolean isRightmostLeaf()
                        throws org.apache.derby.iapi.error.StandardException

Is the current page the rightmost leaf of tree?

Specified by:

isRightmostLeaf in class ControlRow

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search

public ControlRow search(SearchParameters sp)
                  throws org.apache.derby.iapi.error.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

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searchLeft

protected ControlRow searchLeft(OpenBTree btree)
                         throws org.apache.derby.iapi.error.StandardException

Search and return the left most leaf page.

Perform a recursive search, ultimately returning the leftmost leaf page which is the first leaf page in the leaf sibling chain. (This method might better be called getFirstLeafPage()).

Specified by:

searchLeft in class ControlRow

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searchRight

protected ControlRow searchRight(OpenBTree btree)
                          throws org.apache.derby.iapi.error.StandardException

Search and return the right most leaf page.

Perform a recursive search, ultimately returning the rightmost leaf page which is the last leaf page in the leaf sibling chain. (This method might better be called getLastLeafPage()).

Specified by:

searchRight in class ControlRow

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shrinkFor

protected boolean shrinkFor(OpenBTree btree,
                            org.apache.derby.iapi.types.DataValueDescriptor[] key)
                     throws org.apache.derby.iapi.error.StandardException

Perform a recursive shrink operation for the key. If this method returns true, the caller should remove the corresponding entry for the page. This routine is not guaranteed to successfully shrink anything. The page lead to by the key might turn out not to be empty by the time shrink gets there, and shrinks will give up if there is a deadlock.

The receiver page must be latched on entry and is returned unlatched.

Specified by:

shrinkFor in class ControlRow

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splitFor

protected long splitFor(OpenBTree open_btree,
                        org.apache.derby.iapi.types.DataValueDescriptor[] template,
                        BranchControlRow parent_page,
                        org.apache.derby.iapi.types.DataValueDescriptor[] splitrow,
                        int flag)
                 throws org.apache.derby.iapi.error.StandardException

Perform a top down split pass making room for the the key in "row".

Perform a split such that a subsequent call to insert given the argument index row will likely find room for it. Since latches are released the client must code for the case where another user has grabbed the space made available by the split pass and be ready to do another split.

On entry, the parent is either null or latched, and the current page is latched. On exit, all pages will have been unlatched. If the parent is null, then this page is a root leaf page.

Specified by:

splitFor in class ControlRow

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growRoot

private static void growRoot(OpenBTree open_btree,
                             org.apache.derby.iapi.types.DataValueDescriptor[] template,
                             LeafControlRow leafroot)
                      throws org.apache.derby.iapi.error.StandardException

Grow a new root page from a leaf page. Slightly tricky because we want to retain page 0 as the root.

On entry, the current leaf root page is expected to be latched. On exit, all latches will have been released.

The caller cannot not assume success. If we have to release latches this routine just returns and assumes the caller will retry the grow root if necessary.

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getLeftChild

protected ControlRow getLeftChild(OpenBTree btree)
                           throws org.apache.derby.iapi.error.StandardException

Return the left child pointer for the page.

Leaf pages don't have children, so they override this and return null.

Specified by:

getLeftChild in class ControlRow

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getRightChild

protected ControlRow getRightChild(OpenBTree btree)
                            throws org.apache.derby.iapi.error.StandardException

Return the right child pointer for the page.

Leaf pages don't have children, so they override this and return null.

Specified by:

getRightChild in class ControlRow

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checkConsistency

public int checkConsistency(OpenBTree btree,
                            ControlRow parent,
                            boolean check_other_pages)
                     throws org.apache.derby.iapi.error.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.

Specified by:

checkConsistency in class ControlRow

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printTree

public void printTree(OpenBTree btree)
               throws org.apache.derby.iapi.error.StandardException

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

Specified by:

printTree in class ControlRow

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getTypeFormatId

public int getTypeFormatId()

Return my format identifier.

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Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> impl >> store >> access >> [ btree overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

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