Package net.haesleinhuepf.clij.coremem.memmap

Class MemoryMappedFileUtils

java.lang.Object

net.haesleinhuepf.clij.coremem.memmap.MemoryMappedFileUtils

public final class MemoryMappedFileUtils
extends Object

Author:

royer

Constructor Summary

Constructors

Constructor	Description
MemoryMappedFileUtils()

Method Summary

Modifier and Type	Method	Description
static MemoryMappedFileAccessMode	bestMode(StandardOpenOption[] pStandardOpenOption)	Determines best access mode gigen standard open options.
static long	filesize(FileChannel pFileChannel)	Returns the file size for a given file channel
static long	map(FileChannel pFileChannel, MemoryMappedFileAccessMode pAccessMode, long pFilePosition, long pMappedRegionLength, boolean pExtendIfNeeded)	Maps a region of a file.
static void	truncate(FileChannel pFileChannel, long pLength)	Truncates file for given file channel
static int	unmap(FileChannel pFileChannel, long pMemoryMapAddress, long pMappedRegionLength)	Unmaps memory mapped file.

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryMappedFileUtils

public MemoryMappedFileUtils()

Method Detail

map

public static final long map(FileChannel pFileChannel,
                             MemoryMappedFileAccessMode pAccessMode,
                             long pFilePosition,
                             long pMappedRegionLength,
                             boolean pExtendIfNeeded)
                      throws MemoryMapFileException

Maps a region of a file.

Parameters:

pFileChannel - file channel

pAccessMode - access mode

pFilePosition - file position in bytes

pMappedRegionLength - mapped region length

pExtendIfNeeded - extend file length if needed (file not as long as request mapping length).

Returns:

mapped address

Throws:

MemoryMapFileException - thrown if problem occurs while mapping.

unmap

public static final int unmap(FileChannel pFileChannel,
                              long pMemoryMapAddress,
                              long pMappedRegionLength)
                       throws MemoryMapFileException

Unmaps memory mapped file.

Parameters:

pFileChannel - file channel

pMemoryMapAddress - mapped address

pMappedRegionLength - mapped region length

Returns:

return code

Throws:

MemoryMapFileException - thrown if problem occurs while unmapping

filesize

public static final long filesize(FileChannel pFileChannel)
                           throws IOException

Returns the file size for a given file channel

Parameters:

pFileChannel - file channel

Returns:

file size in bytes

Throws:

IOException - exception

truncate

public static final void truncate(FileChannel pFileChannel,
                                  long pLength)
                           throws IOException

Truncates file for given file channel

Parameters:

pFileChannel - file channel

pLength - truncation length

Throws:

IOException - thrown if problem while truncating file

bestMode

public static MemoryMappedFileAccessMode bestMode(StandardOpenOption[] pStandardOpenOption)

Determines best access mode gigen standard open options.

Parameters:

pStandardOpenOption - standard open options

Returns:

best access mode