Package org.apache.hadoop.io.nativeio

Class NativeIO.POSIX

java.lang.Object

org.apache.hadoop.io.nativeio.NativeIO.POSIX

Enclosing class:

NativeIO

public static class NativeIO.POSIX
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	NativeIO.POSIX.CacheManipulator	Used to manipulate the operating system cache.
static class	NativeIO.POSIX.NoMlockCacheManipulator	A CacheManipulator used for testing which does not actually call mlock.
static class	NativeIO.POSIX.Pmem	JNI wrapper of persist memory operations.
static class	NativeIO.POSIX.PmemMappedRegion	Denote memory region for a file mapped.
static class	NativeIO.POSIX.Stat	Result type of the fstat call
static enum	NativeIO.POSIX.SupportState	Keeps the support state of PMDK.

Field Summary

Fields

Modifier and Type	Field	Description
static boolean	fadvisePossible
static final int	MMAP_PROT_EXEC
static final int	MMAP_PROT_READ
static final int	MMAP_PROT_WRITE
static int	O_APPEND
static int	O_CREAT
static int	O_EXCL
static int	O_NOCTTY
static int	O_NONBLOCK
static int	O_RDONLY
static int	O_RDWR
static int	O_SYNC
static int	O_TRUNC
static int	O_WRONLY
static int	POSIX_FADV_DONTNEED
static int	POSIX_FADV_NOREUSE
static int	POSIX_FADV_NORMAL
static int	POSIX_FADV_RANDOM
static int	POSIX_FADV_SEQUENTIAL
static int	POSIX_FADV_WILLNEED
static int	SYNC_FILE_RANGE_WAIT_AFTER
static int	SYNC_FILE_RANGE_WAIT_BEFORE
static int	SYNC_FILE_RANGE_WRITE

Constructor Summary

Constructors

Constructor	Description
POSIX()

Method Summary

Modifier and Type	Method	Description
static void	chmod(String path, int mode)
static NativeIO.POSIX.CacheManipulator	getCacheManipulator()
static NativeIO.POSIX.Stat	getFstat(FileDescriptor fd)	Returns the file stat for a file descriptor.
static String	getPmdkSupportStateMessage()
static NativeIO.POSIX.Stat	getStat(String path)	Return the file stat for a file path.
static boolean	isAvailable()
static boolean	isPmdkAvailable()
static long	mmap(FileDescriptor fd, int prot, boolean shared, long length)
static void	munmap(long addr, long length)
static void	munmap(MappedByteBuffer buffer)	Unmaps the block from memory.
static FileDescriptor	open(String path, int flags, int mode)	Wrapper around open(2) .
static void	setCacheManipulator(NativeIO.POSIX.CacheManipulator cacheManipulator)
static void	setPmdkSupportState(int stateCode)
static void	syncFileRangeIfPossible(FileDescriptor fd, long offset, long nbytes, int flags)	Call sync_file_range on the given file descriptor.

Methods inherited from class java.lang.Object

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

Field Details

O_RDONLY

public static int O_RDONLY

O_WRONLY

public static int O_WRONLY

O_RDWR

public static int O_RDWR

O_CREAT

public static int O_CREAT

O_EXCL

public static int O_EXCL

O_NOCTTY

public static int O_NOCTTY

O_TRUNC

public static int O_TRUNC

O_APPEND

public static int O_APPEND

O_NONBLOCK

public static int O_NONBLOCK

O_SYNC

public static int O_SYNC

POSIX_FADV_NORMAL

public static int POSIX_FADV_NORMAL

POSIX_FADV_RANDOM

public static int POSIX_FADV_RANDOM

POSIX_FADV_SEQUENTIAL

public static int POSIX_FADV_SEQUENTIAL

POSIX_FADV_WILLNEED

public static int POSIX_FADV_WILLNEED

POSIX_FADV_DONTNEED

public static int POSIX_FADV_DONTNEED

POSIX_FADV_NOREUSE

public static int POSIX_FADV_NOREUSE

SYNC_FILE_RANGE_WAIT_BEFORE

public static int SYNC_FILE_RANGE_WAIT_BEFORE

SYNC_FILE_RANGE_WRITE

public static int SYNC_FILE_RANGE_WRITE

SYNC_FILE_RANGE_WAIT_AFTER

public static int SYNC_FILE_RANGE_WAIT_AFTER

fadvisePossible

public static boolean fadvisePossible

MMAP_PROT_READ

public static final int MMAP_PROT_READ

See Also:

• Constant Field Values

MMAP_PROT_WRITE

public static final int MMAP_PROT_WRITE

See Also:

• Constant Field Values

MMAP_PROT_EXEC

public static final int MMAP_PROT_EXEC

See Also:

• Constant Field Values

Constructor Details

POSIX

public POSIX()

Method Details

getCacheManipulator

public static NativeIO.POSIX.CacheManipulator getCacheManipulator()

setCacheManipulator

public static void setCacheManipulator(NativeIO.POSIX.CacheManipulator cacheManipulator)

setPmdkSupportState

public static void setPmdkSupportState(int stateCode)

getPmdkSupportStateMessage

public static String getPmdkSupportStateMessage()

isPmdkAvailable

public static boolean isPmdkAvailable()

isAvailable

public static boolean isAvailable()

Returns:

Return true if the JNI-based native IO extensions are available.

open

public static FileDescriptor open(String path,
 int flags,
 int mode)
                           throws IOException

Wrapper around open(2) .

Parameters:

path - input path.

flags - input flags.

mode - input mode.

Returns:

FileDescriptor.

Throws:

IOException - raised on errors performing I/O.

chmod

public static void chmod(String path,
 int mode)
                  throws IOException

Throws:

IOException

syncFileRangeIfPossible

public static void syncFileRangeIfPossible(FileDescriptor fd,
 long offset,
 long nbytes,
 int flags)
                                    throws NativeIOException

Call sync_file_range on the given file descriptor. See the manpage for this syscall for more information. On systems where this call is not available, does nothing.

Parameters:

fd - input fd.

offset - input offset.

nbytes - input nbytes.

flags - input flag.

Throws:

NativeIOException - if there is an error with the syscall

munmap

public static void munmap(MappedByteBuffer buffer)

Unmaps the block from memory. See munmap(2). There isn't any portable way to unmap a memory region in Java. So we use the sun.nio method here. Note that unmapping a memory region could cause crashes if code continues to reference the unmapped code. However, if we don't manually unmap the memory, we are dependent on the finalizer to do it, and we have no idea when the finalizer will run.

Parameters:

buffer - The buffer to unmap.

getFstat

public static NativeIO.POSIX.Stat getFstat(FileDescriptor fd)
                                    throws IOException

Returns the file stat for a file descriptor.

Parameters:

fd - file descriptor.

Returns:

the file descriptor file stat.

Throws:

IOException - thrown if there was an IO error while obtaining the file stat.

getStat

public static NativeIO.POSIX.Stat getStat(String path)
                                   throws IOException

Return the file stat for a file path.

Parameters:

path - file path

Returns:

the file stat

Throws:

IOException - thrown if there is an IO error while obtaining the file stat

mmap

public static long mmap(FileDescriptor fd,
 int prot,
 boolean shared,
 long length)
                 throws IOException

Throws:

IOException

munmap

public static void munmap(long addr,
 long length)
                   throws IOException

Throws:

IOException