PageBtree

A page that contains index data.

Methods
int	addRowTry(SearchRow row) Add a row if possible.
int	addRowTry(SearchRow row) Add a row if possible. If it is possible this method returns -1, otherwise the split point. It is always possible to add one row. Parameters: row - the row to add Returns: the split point of this page, or -1 if no split is required
boolean	canRemove()
boolean	canRemove()
int	find(SearchRow compare, boolean bigger, boolean add, boolean compareKeys) Find an entry.
int	find(SearchRow compare, boolean bigger, boolean add, boolean compareKeys) Find an entry. Parameters: compare - the row bigger - if looking for a larger row add - if the row should be added (check for duplicate keys) compareKeys - compare the row keys as well Returns: the index of the found row
void	find(PageBtreeCursor cursor, SearchRow first, boolean bigger) Find the first row.
void	find(PageBtreeCursor cursor, SearchRow first, boolean bigger) Find the first row. Parameters: cursor - the cursor first - the row to find bigger - if the row should be bigger
void	freeRecursive() Free this page and all child pages.
void	freeRecursive() Free this page and all child pages.
PageBtreeLeaf	getFirstLeaf() Get the first child leaf page of a page.
PageBtreeLeaf	getFirstLeaf() Get the first child leaf page of a page. Returns: the page
PageBtreeLeaf	getLastLeaf() Get the first child leaf page of a page.
PageBtreeLeaf	getLastLeaf() Get the first child leaf page of a page. Returns: the page
int	getMemory() Get the estimated memory size.
int	getMemory() Get the estimated memory size. Returns: number of double words (4 bytes)
SearchRow	getRow(int at) Get the row at this position.
SearchRow	getRow(int at) Get the row at this position. Parameters: at - the index Returns: the row
int	getRowCount() Get the real row count.
int	getRowCount() Get the real row count. If required, this will read all child pages. Returns: the row count
void	last(PageBtreeCursor cursor) Find the last row.
void	last(PageBtreeCursor cursor) Find the last row. Parameters: cursor - the cursor
void	memoryChange() The memory usage of this page was changed.
void	memoryChange() The memory usage of this page was changed. Propagate the change if needed.
void	readAllRows() Ensure all rows are read in memory.
void	readAllRows() Ensure all rows are read in memory.
void	remapChildren() Update the parent id of all children.
void	remapChildren() Update the parent id of all children.
SearchRow	remove(SearchRow row) Remove a row.
SearchRow	remove(SearchRow row) Remove a row. Parameters: row - the row to remove Returns: null if the last row didn't change, the deleted row if the page is now empty, otherwise the new last row of this page
void	setPageId(int id) Change the page id.
void	setPageId(int id) Change the page id. Parameters: id - the new page id
void	setParentPageId(int id) Change the parent page id.
void	setParentPageId(int id) Change the parent page id. Parameters: id - the new parent page id
void	setRowCountStored(int rowCount) Set the stored row count.
void	setRowCountStored(int rowCount) Set the stored row count. This will write the page. Parameters: rowCount - the stored row count
PageBtree	split(int splitPoint) Split the index page at the given point.
PageBtree	split(int splitPoint) Split the index page at the given point. Parameters: splitPoint - the index where to split Returns: the new page that contains about half the entries

Fields
static int	ROOT = 0
static int	UNKNOWN_ROWCOUNT = -1
static Data	data
static int	entryCount
static PageBtreeIndex	index
static int[]	offsets
static boolean	onlyPosition
static int	parentPageId
static SearchRow[]	rows
static int	start
static boolean	written

UNKNOWN_ROWCOUNT = -1

Indicator that the row count is not known.

ROOT = 0

This is a root page.

data

The data page.

entryCount

The number of entries.

index

The index.

offsets

The row offsets.

onlyPosition

If only the position of the row is stored in the page

parentPageId

The page number of the parent.

rows

The index data

start

The start of the data area.

written

Whether the data page is up-to-date.