org.apache.ignite.internal.processors.compress

Class NativeFileSystemLinux

java.lang.Object

org.apache.ignite.internal.processors.compress.NativeFileSystemPosix

org.apache.ignite.internal.processors.compress.NativeFileSystemLinux

All Implemented Interfaces:

NativeFileSystem

public final class NativeFileSystemLinux
extends NativeFileSystemPosix

Linux native file system API.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	NativeFileSystemLinux.LinuxNativeLibC

Field Summary

Fields

Modifier and Type	Field and Description
static int	FALLOC_FL_COLLAPSE_RANGE FALLOC_FL_COLLAPSE_RANGE is used to remove a range of a file without leaving a hole in the file.
static int	FALLOC_FL_INSERT_RANGE FALLOC_FL_INSERT_RANGE is use to insert space within the file size without overwriting any existing data.
static int	FALLOC_FL_KEEP_SIZE default is extend size
static int	FALLOC_FL_NO_HIDE_STALE reserved codepoint
static int	FALLOC_FL_PUNCH_HOLE de-allocates range
static int	FALLOC_FL_UNSHARE_RANGE FALLOC_FL_UNSHARE_RANGE is used to unshare shared blocks within the file size without overwriting any existing data.
static int	FALLOC_FL_ZERO_RANGE FALLOC_FL_ZERO_RANGE is used to convert a range of file to zeros preferably without issuing data IO.

Constructor Summary

Constructors

Constructor and Description
NativeFileSystemLinux()

Method Summary

Modifier and Type	Method and Description
void	punchHole(int fd, long off, long len)

Methods inherited from class org.apache.ignite.internal.processors.compress.NativeFileSystemPosix

getFileSystemBlockSize, getFileSystemBlockSize, getSparseFileSize

Methods inherited from class java.lang.Object

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

Field Detail

FALLOC_FL_KEEP_SIZE

public static final int FALLOC_FL_KEEP_SIZE

default is extend size

See Also:

Constant Field Values

FALLOC_FL_PUNCH_HOLE

public static final int FALLOC_FL_PUNCH_HOLE

de-allocates range

See Also:

Constant Field Values

FALLOC_FL_NO_HIDE_STALE

public static final int FALLOC_FL_NO_HIDE_STALE

reserved codepoint

See Also:

Constant Field Values

FALLOC_FL_COLLAPSE_RANGE

public static final int FALLOC_FL_COLLAPSE_RANGE

FALLOC_FL_COLLAPSE_RANGE is used to remove a range of a file without leaving a hole in the file. The contents of the file beyond the range being removed is appended to the start offset of the range being removed (i.e. the hole that was punched is "collapsed"), resulting in a file layout that looks like the range that was removed never existed. As such collapsing a range of a file changes the size of the file, reducing it by the same length of the range that has been removed by the operation. Different filesystems may implement different limitations on the granularity of the operation. Most will limit operations to filesystem block size boundaries, but this boundary may be larger or smaller depending on the filesystem and/or the configuration of the filesystem or file. Attempting to collapse a range that crosses the end of the file is considered an illegal operation - just use ftruncate(2) if you need to collapse a range that crosses EOF.

See Also:

Constant Field Values

FALLOC_FL_ZERO_RANGE

public static final int FALLOC_FL_ZERO_RANGE

FALLOC_FL_ZERO_RANGE is used to convert a range of file to zeros preferably without issuing data IO. Blocks should be preallocated for the regions that span holes in the file, and the entire range is preferable converted to unwritten extents - even though file system may choose to zero out the extent or do whatever which will result in reading zeros from the range while the range remains allocated for the file. This can be also used to preallocate blocks past EOF in the same way as with fallocate. Flag FALLOC_FL_KEEP_SIZE should cause the inode size to remain the same.

See Also:

Constant Field Values

FALLOC_FL_INSERT_RANGE

public static final int FALLOC_FL_INSERT_RANGE

FALLOC_FL_INSERT_RANGE is use to insert space within the file size without overwriting any existing data. The contents of the file beyond offset are shifted towards right by len bytes to create a hole. As such, this operation will increase the size of the file by len bytes. Different filesystems may implement different limitations on the granularity of the operation. Most will limit operations to filesystem block size boundaries, but this boundary may be larger or smaller depending on the filesystem and/or the configuration of the filesystem or file. Attempting to insert space using this flag at OR beyond the end of the file is considered an illegal operation - just use ftruncate(2) or fallocate(2) with mode 0 for such type of operations.

See Also:

Constant Field Values

FALLOC_FL_UNSHARE_RANGE

public static final int FALLOC_FL_UNSHARE_RANGE

FALLOC_FL_UNSHARE_RANGE is used to unshare shared blocks within the file size without overwriting any existing data. The purpose of this call is to preemptively reallocate any blocks that are subject to copy-on-write. Different filesystems may implement different limitations on the granularity of the operation. Most will limit operations to filesystem block size boundaries, but this boundary may be larger or smaller depending on the filesystem and/or the configuration of the filesystem or file. This flag can only be used with allocate-mode fallocate, which is to say that it cannot be used with the punch, zero, collapse, or insert range modes.

See Also:

Constant Field Values

Constructor Detail

NativeFileSystemLinux

public NativeFileSystemLinux()

Method Detail

punchHole

public void punchHole(int fd,
                      long off,
                      long len)

Specified by:

punchHole in interface NativeFileSystem

Overrides:

punchHole in class NativeFileSystemPosix