tachyon.util.io

Class FileUtils

java.lang.Object

tachyon.util.io.FileUtils

public final class FileUtils
extends Object

Provides utility methods for working with files and directories. By convention, methods take file path strings as parameters.

Method Summary

Methods

Modifier and Type	Method and Description
static void	changeLocalFilePermission(String filePath, String perms) Changes local file's permission.
static void	changeLocalFileToFullPermission(String filePath) Changes local file's permission to be 777.
static void	createBlockPath(String path) Creates the local block path and all the parent directories.
static void	createDir(String path) Creates an empty directory and its intermediate directories if necessary.
static void	createFile(String filePath) Creates an empty file and its intermediate directories if necessary.
static void	createStorageDirPath(String path) Creates the storage directory path, including any necessary but nonexistent parent directories.
static void	delete(String path) Deletes the file or directory.
static boolean	exists(String path) Checks if a path exists.
static void	move(String srcPath, String dstPath) Moves file from one place to another, can across storage devices (e.g., from memory to SSD) when File.renameTo(java.io.File) may not work.
static void	setLocalDirStickyBit(String dir) Sticky bit can be set primarily on directories in UNIX / Linux.

Methods inherited from class java.lang.Object

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

Method Detail

changeLocalFilePermission

public static void changeLocalFilePermission(String filePath,
                             String perms)
                                      throws IOException

Changes local file's permission.

Parameters:

filePath - that will change permission

perms - the permission, e.g. "775"

Throws:

IOException - when fails to change permission

changeLocalFileToFullPermission

public static void changeLocalFileToFullPermission(String filePath)
                                            throws IOException

Changes local file's permission to be 777.

Parameters:

filePath - that will change permission

Throws:

IOException - when fails to change file's permission to 777

setLocalDirStickyBit

public static void setLocalDirStickyBit(String dir)

Sticky bit can be set primarily on directories in UNIX / Linux. If the sticky bit of is enabled on a directory, only the owner and the root user can delete / rename the files or directories within that directory. No one else can delete other users data in this directory(Where sticky bit is set). This is a security measure to avoid deletion of folders and their content (sub-folders and files), though other users have full permissions. Setting the sticky bit on a file is pretty much useless, and it doesn’t do anything.

Parameters:

dir - absolute dir path to set the sticky bit

createBlockPath

public static void createBlockPath(String path)
                            throws IOException

Creates the local block path and all the parent directories. Also, sets the appropriate permissions.

Parameters:

path - The path of the block.

Throws:

IOException - when fails to create block path and parent directories with appropriate permissions.

move

public static void move(String srcPath,
        String dstPath)
                 throws IOException

Moves file from one place to another, can across storage devices (e.g., from memory to SSD) when File.renameTo(java.io.File) may not work. Current implementation uses Files.move(File, File), may change if there is a better solution.

Parameters:

srcPath - pathname string of source file

dstPath - pathname string of destination file

Throws:

IOException - when fails to move

delete

public static void delete(String path)
                   throws IOException

Deletes the file or directory. Current implementation uses File.delete(), may change if there is a better solution.

Parameters:

path - pathname string of file or directory

Throws:

IOException - when fails to delete

createStorageDirPath

public static void createStorageDirPath(String path)
                                 throws IOException

Creates the storage directory path, including any necessary but nonexistent parent directories. If the directory already exists, do nothing. Also, appropriate directory permissions (777 + StickyBit, namely "drwxrwxrwt") are set.

Parameters:

path - storage directory path to create

Throws:

IOException - when fails to create storage directory path

createFile

public static void createFile(String filePath)
                       throws IOException

Creates an empty file and its intermediate directories if necessary.

Parameters:

filePath - pathname string of the file to create

Throws:

IOException - if an I/O error occurred or file already exists

createDir

public static void createDir(String path)
                      throws IOException

Creates an empty directory and its intermediate directories if necessary.

Parameters:

path - path of the directory to create

Throws:

IOException - if an I/O error occurred or directory already exists

exists

public static boolean exists(String path)

Checks if a path exists.

Parameters:

path - the given path

Returns:

true if path exists, false otherwise