org.apache.hadoop.fs.kfs

Class KosmosFileSystem

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.fs.FileSystem

org.apache.hadoop.fs.kfs.KosmosFileSystem

All Implemented Interfaces:

Closeable, AutoCloseable, Configurable

@InterfaceAudience.Public
@InterfaceStability.Stable
public class KosmosFileSystem
extends FileSystem

A FileSystem backed by KFS.

Field Summary

Fields inherited from class org.apache.hadoop.fs.FileSystem

DEFAULT_FILTER, DEFAULT_FS, FS_DEFAULT_NAME_KEY, LOG, SHUTDOWN_HOOK_PRIORITY, statistics

Constructor Summary

Constructors

Constructor and Description
KosmosFileSystem()

Method Summary

Methods

Modifier and Type	Method and Description
FSDataOutputStream	append(Path f, int bufferSize, Progressable progress) Append to an existing file (optional operation).
void	completeLocalOutput(Path fsOutputFile, Path tmpLocalFile) Called when we're all done writing to the target.
void	copyFromLocalFile(boolean delSrc, Path src, Path dst) The src file is on the local disk.
void	copyToLocalFile(boolean delSrc, Path src, Path dst) The src file is under FS, and the dst is on the local disk.
FSDataOutputStream	create(Path file, FsPermission permission, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress) Create an FSDataOutputStream at the indicated Path with write-progress reporting.
boolean	delete(Path path, boolean recursive) Delete a file.
long	getDefaultBlockSize() Return the number of bytes that large input files should be optimally be split into to minimize i/o time.
short	getDefaultReplication() Get the default replication.
BlockLocation[]	getFileBlockLocations(FileStatus file, long start, long len) Return null if the file doesn't exist; otherwise, get the locations of the various chunks of the file file from KFS.
FileStatus	getFileStatus(Path path) Return a file status object that represents the path.
URI	getUri() Returns a URI whose scheme and authority identify this FileSystem.
Path	getWorkingDirectory() Get the current working directory for the given file system
void	initialize(URI uri, Configuration conf) Called after a new FileSystem instance is constructed.
boolean	isDirectory(Path path) True iff the named path is a directory.
boolean	isFile(Path path) True iff the named path is a regular file.
FileStatus[]	listStatus(Path path) List the statuses of the files/directories in the given path if the path is a directory.
void	lock(Path path, boolean shared) Deprecated.
boolean	mkdirs(Path path, FsPermission permission) Make the given file and all non-existent parents into directories.
FSDataInputStream	open(Path path, int bufferSize) Opens an FSDataInputStream at the indicated Path.
void	release(Path path) Deprecated.
boolean	rename(Path src, Path dst) Renames Path src to Path dst.
boolean	setReplication(Path path, short replication) Set replication for an existing file.
void	setWorkingDirectory(Path dir) Set the current working directory for the given file system.
Path	startLocalOutput(Path fsOutputFile, Path tmpLocalFile) Returns a local File that the user can write output to.

Methods inherited from class org.apache.hadoop.fs.FileSystem

append, append, cancelDeleteOnExit, checkPath, clearStatistics, close, closeAll, closeAllForUGI, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyToLocalFile, copyToLocalFile, create, create, create, create, create, create, create, create, create, create, create, createNewFile, createNonRecursive, createNonRecursive, delete, deleteOnExit, exists, get, get, get, getAllStatistics, getBlockSize, getCanonicalUri, getContentSummary, getDefaultBlockSize, getDefaultPort, getDefaultReplication, getDefaultUri, getFileBlockLocations, getFileChecksum, getHomeDirectory, getInitialWorkingDirectory, getLength, getLocal, getName, getNamed, getReplication, getServerDefaults, getServerDefaults, getStatistics, getStatistics, getStatus, getStatus, getUsed, globStatus, globStatus, listCorruptFileBlocks, listFiles, listLocatedStatus, listLocatedStatus, listStatus, listStatus, listStatus, makeQualified, mkdirs, mkdirs, moveFromLocalFile, moveFromLocalFile, moveToLocalFile, newInstance, newInstance, newInstance, newInstanceLocal, open, primitiveCreate, primitiveMkdir, primitiveMkdir, printStatistics, processDeleteOnExit, rename, resolvePath, setDefaultUri, setDefaultUri, setOwner, setPermission, setTimes, setVerifyChecksum, setWriteChecksum

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

Methods inherited from class java.lang.Object

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

Constructor Detail

KosmosFileSystem

public KosmosFileSystem()

Method Detail

getUri

public URI getUri()

Description copied from class: FileSystem

Returns a URI whose scheme and authority identify this FileSystem.

Specified by:

getUri in class FileSystem

initialize

public void initialize(URI uri,
              Configuration conf)
                throws IOException

Description copied from class: FileSystem

Called after a new FileSystem instance is constructed.

Overrides:

initialize in class FileSystem

Parameters:

uri - a uri whose authority section names the host, port, etc. for this FileSystem

conf - the configuration

Throws:

IOException

getWorkingDirectory

public Path getWorkingDirectory()

Description copied from class: FileSystem

Get the current working directory for the given file system

Specified by:

getWorkingDirectory in class FileSystem

Returns:

the directory pathname

setWorkingDirectory

public void setWorkingDirectory(Path dir)

Description copied from class: FileSystem

Set the current working directory for the given file system. All relative paths will be resolved relative to it.

Specified by:

setWorkingDirectory in class FileSystem

mkdirs

public boolean mkdirs(Path path,
             FsPermission permission)
               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 - path to create

permission - to apply to f

Throws:

IOException

isDirectory

public boolean isDirectory(Path path)
                    throws IOException

Description copied from class: FileSystem

True iff the named path is a directory. Note: Avoid using this method. Instead reuse the FileStatus returned by getFileStatus() or listStatus() methods.

Overrides:

isDirectory in class FileSystem

Parameters:

path - path to check

Throws:

IOException

isFile

public boolean isFile(Path path)
               throws IOException

Description copied from class: FileSystem

True iff the named path is a regular file. Note: Avoid using this method. Instead reuse the FileStatus returned by getFileStatus() or listStatus() methods.

Overrides:

isFile in class FileSystem

Parameters:

path - path to check

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 patch

Throws:

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

IOException

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

append

public FSDataOutputStream append(Path f,
                        int bufferSize,
                        Progressable progress)
                          throws IOException

Description copied from class: FileSystem

Append to an existing file (optional operation).

Specified by:

append in class FileSystem

Parameters:

f - the existing file to be appended.

bufferSize - the size of the buffer to be used.

progress - for reporting progress if it is not null.

Throws:

IOException

create

public FSDataOutputStream create(Path file,
                        FsPermission permission,
                        boolean overwrite,
                        int bufferSize,
                        short replication,
                        long blockSize,
                        Progressable progress)
                          throws IOException

Description copied from class: FileSystem

Create an FSDataOutputStream at the indicated Path with write-progress reporting.

Specified by:

create in class FileSystem

Parameters:

file - the file name to open

overwrite - if a file with this name already exists, then if true, the file will be overwritten, and if false an error will be thrown.

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

Throws:

IOException

See Also:

FileSystem.setPermission(Path, FsPermission)

open

public FSDataInputStream 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

rename

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

Description copied from class: FileSystem

Renames Path src to Path dst. Can take place on local fs or remote DFS.

Specified by:

rename in class FileSystem

Parameters:

src - path to be renamed

dst - new path after rename

Returns:

true if rename is successful

Throws:

IOException - on failure

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 else false.

Throws:

IOException

getDefaultReplication

public short getDefaultReplication()

Description copied from class: FileSystem

Get the default replication.

Overrides:

getDefaultReplication in class FileSystem

setReplication

public boolean setReplication(Path path,
                     short replication)
                       throws IOException

Description copied from class: FileSystem

Set replication for an existing file.

Overrides:

setReplication in class FileSystem

Parameters:

path - file name

replication - new replication

Returns:

true if successful; false if file does not exist or is a directory

Throws:

IOException

getDefaultBlockSize

public long getDefaultBlockSize()

Description copied from class: FileSystem

Return the number of bytes that large input files should be optimally be split into to minimize i/o time.

Overrides:

getDefaultBlockSize in class FileSystem

lock

@Deprecated
public void lock(Path path,
                   boolean shared)
          throws IOException

Deprecated.

Throws:

IOException

release

@Deprecated
public void release(Path path)
             throws IOException

Deprecated.

Throws:

IOException

getFileBlockLocations

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

Return null if the file doesn't exist; otherwise, get the locations of the various chunks of the file file from KFS.

Overrides:

getFileBlockLocations in class FileSystem

Parameters:

file - FilesStatus to get data from

start - offset into the given file

len - length for which to get locations for

Throws:

IOException

copyFromLocalFile

public void copyFromLocalFile(boolean delSrc,
                     Path src,
                     Path dst)
                       throws IOException

Description copied from class: FileSystem

The src file is on the local disk. Add it to FS at the given dst name. delSrc indicates if the source should be removed

Overrides:

copyFromLocalFile in class FileSystem

Parameters:

delSrc - whether to delete the src

src - path

dst - path

Throws:

IOException

copyToLocalFile

public void copyToLocalFile(boolean delSrc,
                   Path src,
                   Path dst)
                     throws IOException

Description copied from class: FileSystem

The src file is under FS, and the dst is on the local disk. Copy it from FS control to the local dst name. delSrc indicates if the src will be removed or not.

Overrides:

copyToLocalFile in class FileSystem

Parameters:

delSrc - whether to delete the src

src - path

dst - path

Throws:

IOException

startLocalOutput

public Path startLocalOutput(Path fsOutputFile,
                    Path tmpLocalFile)
                      throws IOException

Description copied from class: FileSystem

Returns a local File that the user can write output to. The caller provides both the eventual FS target name and the local working file. If the FS is local, we write directly into the target. If the FS is remote, we write into the tmp local area.

Overrides:

startLocalOutput in class FileSystem

Parameters:

fsOutputFile - path of output file

tmpLocalFile - path of local tmp file

Throws:

IOException

completeLocalOutput

public void completeLocalOutput(Path fsOutputFile,
                       Path tmpLocalFile)
                         throws IOException

Description copied from class: FileSystem

Called when we're all done writing to the target. A local FS will do nothing, because we've written to exactly the right place. A remote FS will copy the contents of tmpLocalFile to the correct target at fsOutputFile.

Overrides:

completeLocalOutput in class FileSystem

Parameters:

fsOutputFile - path of output file

tmpLocalFile - path to local tmp file

Throws:

IOException