org.apache.flink.state.forst.fs

Class ForStFlinkFileSystem

java.lang.Object

org.apache.flink.core.fs.FileSystem

org.apache.flink.state.forst.fs.ForStFlinkFileSystem

@Experimental
public class ForStFlinkFileSystem
extends FileSystem

A FileSystem delegates some requests to file system loaded by Flink FileSystem mechanism.

All methods in this class maybe used by ForSt, please start a discussion firstly if it has to be modified.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.flink.core.fs.FileSystem

FileSystem.WriteMode

Constructor Summary

Constructors

Constructor and Description
ForStFlinkFileSystem(FileSystem delegateFS)

Method Summary

Modifier and Type	Method and Description
ByteBufferWritableFSDataOutputStream	create(Path path) Create ByteBufferWritableFSDataOutputStream from specific path which supports to write data to ByteBuffer with FileSystem.WriteMode.OVERWRITE mode.
ByteBufferWritableFSDataOutputStream	create(Path path, FileSystem.WriteMode overwriteMode) Opens an FSDataOutputStream to a new file at the given path.
boolean	delete(Path path, boolean recursive) Delete a file.
static FileSystem	get(URI uri) Returns a reference to the FileSystem instance for accessing the file system identified by the given URI.
BlockLocation[]	getFileBlockLocations(FileStatus file, long start, long len) Return an array containing hostnames, offset and size of portions of the given file.
FileStatus	getFileStatus(Path path) Return a file status object that represents the path.
Path	getHomeDirectory() Returns the path of the user's home directory in this file system.
FileSystemKind	getKind() Gets a description of the characteristics of this file system.
URI	getUri() Returns a URI whose scheme and authority identify this file system.
Path	getWorkingDirectory() Returns the path of the file system's current working directory.
boolean	isDistributedFS() Returns true if this is a distributed file system.
FileStatus[]	listStatus(Path path) List the statuses of the files/directories in the given path if the path is a directory.
boolean	mkdirs(Path path) Make the given file and all non-existent parents into directories.
ByteBufferReadableFSDataInputStream	open(Path path) Opens an FSDataInputStream at the indicated Path.
ByteBufferReadableFSDataInputStream	open(Path path, int bufferSize) Opens an FSDataInputStream at the indicated Path.
boolean	rename(Path src, Path dst) Renames the file/directory src to dst.

Methods inherited from class org.apache.flink.core.fs.FileSystem

create, create, createRecoverableWriter, exists, getDefaultBlockSize, getDefaultFsUri, getLocalFileSystem, getUnguardedFileSystem, initialize, initialize, initOutPathDistFS, initOutPathLocalFS

Methods inherited from class java.lang.Object

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

Constructor Detail

ForStFlinkFileSystem

public ForStFlinkFileSystem(FileSystem delegateFS)

Method Detail

get

public static FileSystem get(URI uri)
                      throws IOException

Returns a reference to the FileSystem instance for accessing the file system identified by the given URI.

Parameters:

uri - the URI identifying the file system.

Returns:

a reference to the FileSystem instance for accessing the file system identified by the given URI.

Throws:

IOException - thrown if a reference to the file system instance could not be obtained.

create

public ByteBufferWritableFSDataOutputStream create(Path path)
                                            throws IOException

Create ByteBufferWritableFSDataOutputStream from specific path which supports to write data to ByteBuffer with FileSystem.WriteMode.OVERWRITE mode.

Parameters:

path - The file path to write to.

Returns:

The stream to the new file at the target path.

Throws:

IOException - Thrown, if the stream could not be opened because of an I/O, or because a file already exists at that path and the write mode indicates to not overwrite the file.

create

public ByteBufferWritableFSDataOutputStream create(Path path,
                                                   FileSystem.WriteMode overwriteMode)
                                            throws IOException

Description copied from class: FileSystem

Opens an FSDataOutputStream to a new file at the given path.

If the file already exists, the behavior depends on the given WriteMode. If the mode is set to FileSystem.WriteMode.NO_OVERWRITE, then this method fails with an exception.

Specified by:

create in class FileSystem

Parameters:

path - The file path to write to

overwriteMode - The action to take if a file or directory already exists at the given path.

Returns:

The stream to the new file at the target path.

Throws:

IOException - Thrown, if the stream could not be opened because of an I/O, or because a file already exists at that path and the write mode indicates to not overwrite the file.

open

public ByteBufferReadableFSDataInputStream open(Path path,
                                                int bufferSize)
                                         throws IOException

Description copied from class: FileSystem

Opens an FSDataInputStream at the indicated Path.

Specified by:

open in class FileSystem

Parameters:

path - the file name to open

bufferSize - the size of the buffer to be used.

Throws:

IOException

open

public ByteBufferReadableFSDataInputStream open(Path path)
                                         throws IOException

Description copied from class: FileSystem

Opens an FSDataInputStream at the indicated Path.

Specified by:

open in class FileSystem

Parameters:

path - the file to open

Throws:

IOException

rename

public boolean rename(Path src,
                      Path dst)
               throws IOException

Description copied from class: FileSystem

Renames the file/directory src to dst.

Specified by:

rename in class FileSystem

Parameters:

src - the file/directory to rename

dst - the new name of the file/directory

Returns:

true if the renaming was successful, false otherwise

Throws:

IOException

getWorkingDirectory

public Path getWorkingDirectory()

Description copied from class: FileSystem

Returns the path of the file system's current working directory.

Specified by:

getWorkingDirectory in class FileSystem

Returns:

the path of the file system's current working directory

getHomeDirectory

public Path getHomeDirectory()

Description copied from class: FileSystem

Returns the path of the user's home directory in this file system.

Specified by:

getHomeDirectory in class FileSystem

Returns:

the path of the user's home directory in this file system.

getUri

public URI getUri()

Description copied from class: FileSystem

Returns a URI whose scheme and authority identify this file system.

Specified by:

getUri in class FileSystem

Returns:

a URI whose scheme and authority identify this file system

getFileStatus

public FileStatus getFileStatus(Path path)
                         throws IOException

Description copied from class: FileSystem

Return a file status object that represents the path.

Specified by:

getFileStatus in class FileSystem

Parameters:

path - The path we want information from

Returns:

a FileStatus object

Throws:

FileNotFoundException - when the path does not exist; IOException see specific implementation

IOException

getFileBlockLocations

public BlockLocation[] getFileBlockLocations(FileStatus file,
                                             long start,
                                             long len)
                                      throws IOException

Description copied from class: FileSystem

Return an array containing hostnames, offset and size of portions of the given file. For a nonexistent file or regions, null will be returned. This call is most helpful with DFS, where it returns hostnames of machines that contain the given file. The FileSystem will simply return an elt containing 'localhost'.

Specified by:

getFileBlockLocations in class FileSystem

Throws:

IOException

listStatus

public FileStatus[] listStatus(Path path)
                        throws IOException

Description copied from class: FileSystem

List the statuses of the files/directories in the given path if the path is a directory.

Specified by:

listStatus in class FileSystem

Parameters:

path - given path

Returns:

the statuses of the files/directories in the given path

Throws:

IOException

delete

public boolean delete(Path path,
                      boolean recursive)
               throws IOException

Description copied from class: FileSystem

Delete a file.

Specified by:

delete in class FileSystem

Parameters:

path - the path to delete

recursive - if path is a directory and set to true, the directory is deleted else throws an exception. In case of a file the recursive can be set to either true or false

Returns:

true if delete is successful, false otherwise

Throws:

IOException

mkdirs

public boolean mkdirs(Path path)
               throws IOException

Description copied from class: FileSystem

Make the given file and all non-existent parents into directories. Has the semantics of Unix 'mkdir -p'. Existence of the directory hierarchy is not an error.

Specified by:

mkdirs in class FileSystem

Parameters:

path - the directory/directories to be created

Returns:

true if at least one new directory has been created, false otherwise

Throws:

IOException - thrown if an I/O error occurs while creating the directory

isDistributedFS

public boolean isDistributedFS()

Description copied from class: FileSystem

Returns true if this is a distributed file system. A distributed file system here means that the file system is shared among all Flink processes that participate in a cluster or job and that all these processes can see the same files.

Specified by:

isDistributedFS in class FileSystem

Returns:

True, if this is a distributed file system, false otherwise.

getKind

public FileSystemKind getKind()

Description copied from class: FileSystem

Gets a description of the characteristics of this file system.

Specified by:

getKind in class FileSystem