com.healthmarketscience.jackcess.impl
Class UsageMap

java.lang.Object
  com.healthmarketscience.jackcess.impl.UsageMap

public class UsageMap
extends Object

Describes which database pages a particular table uses

Author:

Tim McCune

Nested Class Summary

class

UsageMap.PageCursor Utility class to traverse over the pages in the UsageMap.

Field Summary

static byte	MAP_TYPE_INLINE Inline map type
static byte	MAP_TYPE_REFERENCE Reference map type, for maps that are too large to fit inline

Method Summary

void	addPageNumber(int pageNumber) Add a page number to this usage map
protected int	bitIndexToPageNumber(int bitIndex, int invalidPageNumber)
protected void	clearTableAndPages()
boolean	containsPageNumber(int pageNumber) Determines if the given page number is contained in this map.
UsageMap.PageCursor	cursor()
DatabaseImpl	getDatabase()
protected int	getEndPage()
protected int	getFirstPageNumber()
JetFormat	getFormat()
protected int	getLastPageNumber()
protected int	getNextBitIndex(int curIndex)
protected int	getNextPageNumber(int curPage)
PageChannel	getPageChannel()
int	getPageCount()
protected BitSet	getPageNumbers()
protected int	getPrevBitIndex(int curIndex)
protected int	getPrevPageNumber(int curPage)
protected int	getRowEnd()
protected short	getRowStart()
protected int	getStartOffset()
protected int	getStartPage()
protected ByteBuffer	getTableBuffer()
protected int	getTablePageNumber()
protected boolean	isPageWithinRange(int pageNumber)
protected int	pageNumberToBitIndex(int pageNumber)
protected void	processMap(ByteBuffer buffer, int bufferStartPage) Read in the page numbers in this inline map
static UsageMap	read(DatabaseImpl database, ByteBuffer buf)
void	removePageNumber(int pageNumber) Remove a page number from this usage map
protected void	setPageRange(int newStartPage, int newEndPage)
protected void	setStartOffset(int startOffset)
String	toString()
protected void	updateMap(int absolutePageNumber, int bufferRelativePageNumber, ByteBuffer buffer, boolean add, boolean force)
protected void	writeTable()

Methods inherited from class java.lang.Object

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

Field Detail

MAP_TYPE_INLINE

public static final byte MAP_TYPE_INLINE

Inline map type

See Also:

Constant Field Values

MAP_TYPE_REFERENCE

public static final byte MAP_TYPE_REFERENCE

Reference map type, for maps that are too large to fit inline

See Also:

Constant Field Values

Method Detail

getDatabase

public DatabaseImpl getDatabase()

getFormat

public JetFormat getFormat()

getPageChannel

public PageChannel getPageChannel()

read

public static UsageMap read(DatabaseImpl database,
                            ByteBuffer buf)
                     throws IOException

Parameters:

database - database that contains this usage map

buf - buffer which contains the usage map row info

Returns:

Either an InlineUsageMap or a ReferenceUsageMap, depending on which type of map is found

Throws:

IOException

cursor

public UsageMap.PageCursor cursor()

getPageCount

public int getPageCount()

getRowStart

protected short getRowStart()

getRowEnd

protected int getRowEnd()

setStartOffset

protected void setStartOffset(int startOffset)

getStartOffset

protected int getStartOffset()

getTableBuffer

protected ByteBuffer getTableBuffer()

getTablePageNumber

protected int getTablePageNumber()

getStartPage

protected int getStartPage()

getEndPage

protected int getEndPage()

getPageNumbers

protected BitSet getPageNumbers()

setPageRange

protected void setPageRange(int newStartPage,
                            int newEndPage)

isPageWithinRange

protected boolean isPageWithinRange(int pageNumber)

getFirstPageNumber

protected int getFirstPageNumber()

getNextPageNumber

protected int getNextPageNumber(int curPage)

getNextBitIndex

protected int getNextBitIndex(int curIndex)

getLastPageNumber

protected int getLastPageNumber()

getPrevPageNumber

protected int getPrevPageNumber(int curPage)

getPrevBitIndex

protected int getPrevBitIndex(int curIndex)

bitIndexToPageNumber

protected int bitIndexToPageNumber(int bitIndex,
                                   int invalidPageNumber)

pageNumberToBitIndex

protected int pageNumberToBitIndex(int pageNumber)

clearTableAndPages

protected void clearTableAndPages()

writeTable

protected void writeTable()
                   throws IOException

Throws:

IOException

processMap

protected void processMap(ByteBuffer buffer,
                          int bufferStartPage)

Read in the page numbers in this inline map

containsPageNumber

public boolean containsPageNumber(int pageNumber)

Determines if the given page number is contained in this map.

addPageNumber

public void addPageNumber(int pageNumber)
                   throws IOException

Add a page number to this usage map

Throws:

IOException

removePageNumber

public void removePageNumber(int pageNumber)
                      throws IOException

Remove a page number from this usage map

Throws:

IOException

updateMap

protected void updateMap(int absolutePageNumber,
                         int bufferRelativePageNumber,
                         ByteBuffer buffer,
                         boolean add,
                         boolean force)
                  throws IOException

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object