Package org.apache.hadoop.io.nativeio

Class NativeIO.Windows

java.lang.Object

org.apache.hadoop.io.nativeio.NativeIO.Windows

Enclosing class:

NativeIO

public static class NativeIO.Windows
extends java.lang.Object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	NativeIO.Windows.AccessRight	Supported list of Windows access right flags

Field Summary

Fields

Modifier and Type	Field	Description
static long	CREATE_ALWAYS
static long	CREATE_NEW
static long	FILE_ATTRIBUTE_NORMAL
static long	FILE_BEGIN
static long	FILE_CURRENT
static long	FILE_END
static long	FILE_SHARE_DELETE
static long	FILE_SHARE_READ
static long	FILE_SHARE_WRITE
static long	GENERIC_READ
static long	GENERIC_WRITE
static long	OPEN_ALWAYS
static long	OPEN_EXISTING
static long	TRUNCATE_EXISTING

Constructor Summary

Constructors

Constructor	Description
Windows()

Method Summary

Modifier and Type	Method	Description
static boolean	access(java.lang.String path, NativeIO.Windows.AccessRight desiredAccess)	Checks whether the current process has desired access rights on the given path.
static void	createDirectoryWithMode(java.io.File path, int mode)	Create a directory with permissions set to the specified mode.
static java.io.FileDescriptor	createFile(java.lang.String path, long desiredAccess, long shareMode, long creationDisposition)
static java.io.FileOutputStream	createFileOutputStreamWithMode(java.io.File path, boolean append, int mode)	Create a file for write with permissions set to the specified mode.
static void	extendWorkingSetSize(long delta)	Extends both the minimum and maximum working set size of the current process.
static long	setFilePointer(java.io.FileDescriptor fd, long distanceToMove, long moveMethod)

Methods inherited from class java.lang.Object

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

Field Detail

GENERIC_READ

public static final long GENERIC_READ

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Constant Field Values

GENERIC_WRITE

public static final long GENERIC_WRITE

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Constant Field Values

FILE_SHARE_READ

public static final long FILE_SHARE_READ

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Constant Field Values

FILE_SHARE_WRITE

public static final long FILE_SHARE_WRITE

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Constant Field Values

FILE_SHARE_DELETE

public static final long FILE_SHARE_DELETE

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Constant Field Values

CREATE_NEW

public static final long CREATE_NEW

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Constant Field Values

CREATE_ALWAYS

public static final long CREATE_ALWAYS

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Constant Field Values

OPEN_EXISTING

public static final long OPEN_EXISTING

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Constant Field Values

OPEN_ALWAYS

public static final long OPEN_ALWAYS

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Constant Field Values

TRUNCATE_EXISTING

public static final long TRUNCATE_EXISTING

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Constant Field Values

FILE_BEGIN

public static final long FILE_BEGIN

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Constant Field Values

FILE_CURRENT

public static final long FILE_CURRENT

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Constant Field Values

FILE_END

public static final long FILE_END

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Constant Field Values

FILE_ATTRIBUTE_NORMAL

public static final long FILE_ATTRIBUTE_NORMAL

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Constant Field Values

Constructor Detail

Windows

public Windows()

Method Detail

createDirectoryWithMode

public static void createDirectoryWithMode(java.io.File path,
                                           int mode)
                                    throws java.io.IOException

Create a directory with permissions set to the specified mode. By setting permissions at creation time, we avoid issues related to the user lacking WRITE_DAC rights on subsequent chmod calls. One example where this can occur is writing to an SMB share where the user does not have Full Control rights, and therefore WRITE_DAC is denied.

Parameters:

path - directory to create

mode - permissions of new directory

Throws:

java.io.IOException - if there is an I/O error

createFile

public static java.io.FileDescriptor createFile(java.lang.String path,
                                                long desiredAccess,
                                                long shareMode,
                                                long creationDisposition)
                                         throws java.io.IOException

Parameters:

path - input path.

desiredAccess - input desiredAccess.

shareMode - input shareMode.

creationDisposition - input creationDisposition.

Returns:

Wrapper around CreateFile() on Windows.

Throws:

java.io.IOException - raised on errors performing I/O.

createFileOutputStreamWithMode

public static java.io.FileOutputStream createFileOutputStreamWithMode(java.io.File path,
                                                                      boolean append,
                                                                      int mode)
                                                               throws java.io.IOException

Create a file for write with permissions set to the specified mode. By setting permissions at creation time, we avoid issues related to the user lacking WRITE_DAC rights on subsequent chmod calls. One example where this can occur is writing to an SMB share where the user does not have Full Control rights, and therefore WRITE_DAC is denied. This method mimics the semantics implemented by the JDK in FileOutputStream. The file is opened for truncate or append, the sharing mode allows other readers and writers, and paths longer than MAX_PATH are supported. (See io_util_md.c in the JDK.)

Parameters:

path - file to create

append - if true, then open file for append

mode - permissions of new directory

Returns:

FileOutputStream of opened file

Throws:

java.io.IOException - if there is an I/O error

setFilePointer

public static long setFilePointer(java.io.FileDescriptor fd,
                                  long distanceToMove,
                                  long moveMethod)
                           throws java.io.IOException

Parameters:

fd - input fd.

distanceToMove - input distanceToMove.

moveMethod - input moveMethod.

Returns:

Wrapper around SetFilePointer() on Windows.

Throws:

java.io.IOException - raised on errors performing I/O.

access

public static boolean access(java.lang.String path,
                             NativeIO.Windows.AccessRight desiredAccess)
                      throws java.io.IOException

Checks whether the current process has desired access rights on the given path. Longer term this native function can be substituted with JDK7 function Files#isReadable, isWritable, isExecutable.

Parameters:

path - input path

desiredAccess - ACCESS_READ, ACCESS_WRITE or ACCESS_EXECUTE

Returns:

true if access is allowed

Throws:

java.io.IOException - I/O exception on error

extendWorkingSetSize

public static void extendWorkingSetSize(long delta)
                                 throws java.io.IOException

Extends both the minimum and maximum working set size of the current process. This method gets the current minimum and maximum working set size, adds the requested amount to each and then sets the minimum and maximum working set size to the new values. Controlling the working set size of the process also controls the amount of memory it can lock.

Parameters:

delta - amount to increment minimum and maximum working set size

Throws:

java.io.IOException - for any error

See Also:

NativeIO.POSIX.mlock(ByteBuffer, long)