Module org.cojen.tupl

Package org.cojen.tupl.io

Class StripedPageArray

java.lang.Object

org.cojen.tupl.io.PageArray

org.cojen.tupl.io.StripedPageArray

All Implemented Interfaces:

Closeable, AutoCloseable, CauseCloseable

public class StripedPageArray
extends PageArray

PageArray implementation which stripes pages in a RAID 0 fashion.

Constructor Summary

Constructors

Constructor	Description
StripedPageArray(PageArray... arrays)

Method Summary

Modifier and Type	Method	Description
void	close(Throwable cause)
long	copyPage(long srcIndex, long dstIndex)
long	copyPageFromPointer(long srcPointer, long dstIndex)
long	directPagePointer(long index)
final int	directPageSize()	Returns a positive page size if not using direct I/O, else negate to get the page size to allocate for direct I/O.
byte[]	evictPage(long index, byte[] buf)	Same as writePage, except that the given buffer might be altered and a replacement might be returned.
long	evictPage(long index, long bufPtr)	Same as writePage, except that the given buffer might be altered and a replacement might be returned.
void	expandPageCount(long count)	Attempt to expand the total count of pages.
boolean	isEmpty()
boolean	isFullyMapped()
boolean	isReadOnly()
StripedPageArray	open()	Attempt to open or reopen the page array.
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 off, int len, ByteBuffer tail)
void	readPage(long index, long dstPtr, int offset, int length)
void	readPage(long index, long dstPtr, int off, int len, 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 off, ByteBuffer tail)
void	writePage(long index, long srcPtr, int offset)	Writes a page, which is lazily flushed.
void	writePage(long index, long srcPtr, int off, ByteBuffer tail)

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

close, dirtyPage, isDirectIO, pageSize, readPage, readPage, writePage, writePage

Methods inherited from class java.lang.Object

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

Constructor Details

StripedPageArray

public StripedPageArray(PageArray... arrays)

Method Details

directPageSize

public final int directPageSize()

Description copied from class: PageArray

Returns a positive page size if not using direct I/O, else negate to get the page size to allocate for direct I/O.

Overrides:

directPageSize in class PageArray

isFullyMapped

public boolean isFullyMapped()

Overrides:

isFullyMapped in class PageArray

isReadOnly

public boolean isReadOnly()

Specified by:

isReadOnly in class PageArray

isEmpty

public boolean isEmpty()
                throws IOException

Specified by:

isEmpty in class PageArray

Throws:

IOException

pageCount

public long pageCount()
               throws IOException

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

Throws:

IOException

truncatePageCount

public void truncatePageCount(long count)
                       throws IOException

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

Throws:

IOException

expandPageCount

public void expandPageCount(long count)
                     throws IOException

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

Throws:

IOException

pageCountLimit

public long pageCountLimit()
                    throws IOException

Description copied from class: PageArray

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

Overrides:

pageCountLimit in class PageArray

Throws:

IOException

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 off,
 int len,
 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 off,
 int len,
 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 off,
 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 off,
 ByteBuffer tail)
               throws IOException

Overrides:

writePage in class PageArray

Throws:

IOException

evictPage

public byte[] evictPage(long index,
 byte[] buf)
                 throws IOException

Description copied from class: PageArray

Same as writePage, except that the given buffer might be altered and a replacement might be returned. Caller must not alter the original buffer if a replacement was provided, and the contents of the replacement are undefined.

Overrides:

evictPage in class PageArray

Parameters:

index - zero-based page index to write

buf - data to write; implementation might alter the contents

Returns:

replacement buffer, or same instance if replacement was not performed

Throws:

IOException

evictPage

public long evictPage(long index,
 long bufPtr)
               throws IOException

Description copied from class: PageArray

Same as writePage, except that the given buffer might be altered and a replacement might be returned. Caller must not alter the original buffer if a replacement was provided, and the contents of the replacement are undefined.

Overrides:

evictPage in class PageArray

Parameters:

index - zero-based page index to write

bufPtr - data to write; implementation might alter the contents

Returns:

replacement buffer, or same instance if replacement was not performed

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 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 StripedPageArray 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