Module org.cojen.tupl

Package org.cojen.tupl.io

Class MappedPageArray

java.lang.Object

org.cojen.tupl.io.PageArray

org.cojen.tupl.io.MappedPageArray

All Implemented Interfaces:

Closeable, AutoCloseable, CauseCloseable

public abstract class MappedPageArray
extends PageArray

PageArray implementation which accesses a fixed sized file, fully mapped to memory.

Method Summary

Modifier and Type	Method	Description
final void	close(Throwable cause)
long	copyPage(long srcIndex, long dstIndex)
long	copyPageFromPointer(long srcPointer, long dstIndex)
long	directPagePointer(long index)
void	expandPageCount(long count)	Attempt to expand the total count of pages.
boolean	isEmpty()
final boolean	isFullyMapped()
final boolean	isReadOnly()
static boolean	isSupported()
MappedPageArray	open()	Attempt to open or reopen the page array.
static MappedPageArray	open(int pageSize, long pageCount, File file, EnumSet<OpenOption> options)
long	pageCount()	Returns the total count of pages in the array, or Long.MAX_VALUE if not applicable.
long	pageCountLimit()	Return maximum allowed page count, or -1 if not applicable.
void	readPage(long index, byte[] dst, int offset, int length)
void	readPage(long index, byte[] dst, int offset, int length, ByteBuffer tail)
void	readPage(long index, long dstPtr, int offset, int length)
void	readPage(long index, long dstPtr, int offset, int length, ByteBuffer tail)
void	sync(boolean metadata)	Durably flushes all writes to the underlying device.
void	syncPage(long index)	Durably flushes the page at the given index, but implementation might flush more pages.
void	truncatePageCount(long count)	Attempt to truncate the total count of pages.
void	writePage(long index, byte[] src, int offset)	Writes a page, which is lazily flushed.
void	writePage(long index, byte[] src, int offset, ByteBuffer tail)
void	writePage(long index, long srcPtr, int offset)	Writes a page, which is lazily flushed.
void	writePage(long index, long srcPtr, int offset, ByteBuffer tail)

Methods inherited from class org.cojen.tupl.io.PageArray

close, directPageSize, dirtyPage, evictPage, evictPage, isDirectIO, pageSize, readPage, readPage, writePage, writePage

Methods inherited from class java.lang.Object

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

Method Details

isSupported

public static boolean isSupported()

open

public static MappedPageArray open(int pageSize,
 long pageCount,
 File file,
 EnumSet<OpenOption> options)
                            throws IOException

Parameters:

file - file to store pages, or null if anonymous

Throws:

UnsupportedOperationException - if not running on a 64-bit platform

IOException

isFullyMapped

public final boolean isFullyMapped()

Overrides:

isFullyMapped in class PageArray

isReadOnly

public final boolean isReadOnly()

Specified by:

isReadOnly in class PageArray

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in class PageArray

pageCount

public long pageCount()

Description copied from class: PageArray

Returns the total count of pages in the array, or Long.MAX_VALUE if not applicable.

Specified by:

pageCount in class PageArray

truncatePageCount

public void truncatePageCount(long count)

Description copied from class: PageArray

Attempt to truncate the total count of pages. Array implementation might not support truncating the page count, in which case this method does nothing.

Specified by:

truncatePageCount in class PageArray

expandPageCount

public void expandPageCount(long count)

Description copied from class: PageArray

Attempt to expand the total count of pages. Array implementation might not support expanding the page count, in which case this method does nothing.

Specified by:

expandPageCount in class PageArray

pageCountLimit

public long pageCountLimit()

Description copied from class: PageArray

Return maximum allowed page count, or -1 if not applicable.

Overrides:

pageCountLimit in class PageArray

readPage

public void readPage(long index,
 byte[] dst,
 int offset,
 int length)
              throws IOException

Specified by:

readPage in class PageArray

Parameters:

index - zero-based page index to read

dst - receives read data

offset - offset into data buffer

Throws:

IOException - if index is greater than or equal to page count

readPage

public void readPage(long index,
 byte[] dst,
 int offset,
 int length,
 ByteBuffer tail)
              throws IOException

Overrides:

readPage in class PageArray

Throws:

IOException

readPage

public void readPage(long index,
 long dstPtr,
 int offset,
 int length)
              throws IOException

Overrides:

readPage in class PageArray

Parameters:

index - zero-based page index to read

dstPtr - receives read data

offset - offset into data buffer

Throws:

IOException - if index is greater than or equal to page count

readPage

public void readPage(long index,
 long dstPtr,
 int offset,
 int length,
 ByteBuffer tail)
              throws IOException

Overrides:

readPage in class PageArray

Throws:

IOException

writePage

public void writePage(long index,
 byte[] src,
 int offset)
               throws IOException

Description copied from class: PageArray

Writes a page, which is lazily flushed. The array grows automatically if the index is greater than or equal to the current page count. If array supports caching, page must be immediately copied into it.

Specified by:

writePage in class PageArray

Parameters:

index - zero-based page index to write

src - data to write

offset - offset into data buffer

Throws:

IOException

writePage

public void writePage(long index,
 byte[] src,
 int offset,
 ByteBuffer tail)
               throws IOException

Specified by:

writePage in class PageArray

Throws:

IOException

writePage

public void writePage(long index,
 long srcPtr,
 int offset)
               throws IOException

Description copied from class: PageArray

Writes a page, which is lazily flushed. The array grows automatically if the index is greater than or equal to the current page count. If array supports caching, page must be immediately copied into it.

Overrides:

writePage in class PageArray

Parameters:

index - zero-based page index to write

srcPtr - data to write

offset - offset into data buffer

Throws:

IOException

writePage

public void writePage(long index,
 long srcPtr,
 int offset,
 ByteBuffer tail)
               throws IOException

Overrides:

writePage in class PageArray

Throws:

IOException

directPagePointer

public long directPagePointer(long index)
                       throws IOException

Overrides:

directPagePointer in class PageArray

Throws:

IOException

copyPage

public long copyPage(long srcIndex,
 long dstIndex)
              throws IOException

Overrides:

copyPage in class PageArray

Returns:

direct pointer to destination

Throws:

IOException

copyPageFromPointer

public long copyPageFromPointer(long srcPointer,
 long dstIndex)
                         throws IOException

Overrides:

copyPageFromPointer in class PageArray

Returns:

direct pointer to destination

Throws:

IOException

sync

public void sync(boolean metadata)
          throws IOException

Description copied from class: PageArray

Durably flushes all writes to the underlying device.

Specified by:

sync in class PageArray

Parameters:

metadata - pass true to flush all file metadata

Throws:

IOException

syncPage

public void syncPage(long index)
              throws IOException

Description copied from class: PageArray

Durably flushes the page at the given index, but implementation might flush more pages. File metadata is not flushed.

Overrides:

syncPage in class PageArray

Throws:

IOException

close

public final void close(Throwable cause)
                 throws IOException

Specified by:

close in interface CauseCloseable

Specified by:

close in class PageArray

Parameters:

cause - null if close is not caused by a failure

Throws:

IOException

open

public MappedPageArray open()
                     throws IOException

Description copied from class: PageArray

Attempt to open or reopen the page array.

Overrides:

open in class PageArray

Returns:

existing or new page array

Throws:

IOException