org.apache.hadoop.fs.viewfs

Class ViewFileSystem

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.fs.FileSystem

org.apache.hadoop.fs.viewfs.ViewFileSystem

All Implemented Interfaces:

Closeable, AutoCloseable, Configurable

@InterfaceAudience.Public
@InterfaceStability.Evolving
public class ViewFileSystem
extends FileSystem

ViewFileSystem (extends the FileSystem interface) implements a client-side mount table. Its spec and implementation is identical to ViewFs.

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
ViewFileSystem() This is the constructor with the signature needed by FileSystem.createFileSystem(URI, Configuration) After this constructor is called initialize() is called.
ViewFileSystem(Configuration conf) Convenience Constructor for apps to call directly

Method Summary

Methods

Modifier and Type	Method and Description
FSDataOutputStream	append(Path f, int bufferSize, Progressable progress) Append to an existing file (optional operation).
FSDataOutputStream	create(Path f, 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 f) Delete a file
boolean	delete(Path f, boolean recursive) Delete a file.
FileSystem[]	getChildFileSystems() Get all the immediate child FileSystems embedded in this FileSystem.
ContentSummary	getContentSummary(Path f) Return the ContentSummary of a given Path.
long	getDefaultBlockSize() Return the number of bytes that large input files should be optimally be split into to minimize i/o time.
long	getDefaultBlockSize(Path f) 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.
short	getDefaultReplication(Path f) Get the default replication for a path.
BlockLocation[]	getFileBlockLocations(FileStatus fs, long start, long len) Return an array containing hostnames, offset and size of portions of the given file.
FileChecksum	getFileChecksum(Path f) Get the checksum of a file.
FileStatus	getFileStatus(Path f) Return a file status object that represents the path.
Path	getHomeDirectory() Return the current user's home directory in this filesystem.
org.apache.hadoop.fs.viewfs.ViewFileSystem.MountPoint[]	getMountPoints()
FsServerDefaults	getServerDefaults() Return a set of server default configuration values
FsServerDefaults	getServerDefaults(Path f) Return a set of server default configuration values
Path	getTrashCanLocation(Path f)
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 theUri, Configuration conf) Called after a new FileSystem instance is constructed.
FileStatus[]	listStatus(Path f) List the statuses of the files/directories in the given path if the path is a directory.
boolean	mkdirs(Path dir, FsPermission permission) Make the given file and all non-existent parents into directories.
FSDataInputStream	open(Path f, int bufferSize) Opens an FSDataInputStream at the indicated Path.
boolean	rename(Path src, Path dst) Renames Path src to Path dst.
Path	resolvePath(Path f) Return the fully-qualified path of path f resolving the path through any symlinks or mount point
void	setOwner(Path f, String username, String groupname) Set owner of a path (i.e.
void	setPermission(Path f, FsPermission permission) Set permission of a path.
boolean	setReplication(Path f, short replication) Set replication for an existing file.
void	setTimes(Path f, long mtime, long atime) Set access time of a file
void	setVerifyChecksum(boolean verifyChecksum) Set the verify checksum flag.
void	setWorkingDirectory(Path new_dir) Set the current working directory for the given file system.
void	setWriteChecksum(boolean writeChecksum) Set the write checksum flag.

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

append, append, cancelDeleteOnExit, checkPath, clearStatistics, close, closeAll, closeAllForUGI, completeLocalOutput, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyToLocalFile, copyToLocalFile, copyToLocalFile, create, create, create, create, create, create, create, create, create, create, create, createNewFile, createNonRecursive, createNonRecursive, deleteOnExit, exists, get, get, get, getAllStatistics, getBlockSize, getCanonicalUri, getDefaultPort, getDefaultUri, getFileBlockLocations, getInitialWorkingDirectory, getLength, getLocal, getName, getNamed, getReplication, getStatistics, getStatistics, getStatus, getStatus, getUsed, globStatus, globStatus, isDirectory, isFile, listCorruptFileBlocks, listFiles, listLocatedStatus, listLocatedStatus, listStatus, listStatus, listStatus, makeQualified, mkdirs, mkdirs, moveFromLocalFile, moveFromLocalFile, moveToLocalFile, newInstance, newInstance, newInstance, newInstanceLocal, open, primitiveCreate, primitiveMkdir, primitiveMkdir, printStatistics, processDeleteOnExit, rename, setDefaultUri, setDefaultUri, startLocalOutput

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

ViewFileSystem

public ViewFileSystem()
               throws IOException

This is the constructor with the signature needed by FileSystem.createFileSystem(URI, Configuration) After this constructor is called initialize() is called.

Throws:

IOException

ViewFileSystem

public ViewFileSystem(Configuration conf)
               throws IOException

Convenience Constructor for apps to call directly

Parameters:

conf -

Throws:

IOException

Method Detail

initialize

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

Called after a new FileSystem instance is constructed.

Overrides:

initialize in class FileSystem

Parameters:

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

conf - the configuration

Throws:

IOException

getTrashCanLocation

public Path getTrashCanLocation(Path f)
                         throws FileNotFoundException

Throws:

FileNotFoundException

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

resolvePath

public Path resolvePath(Path f)
                 throws IOException

Description copied from class: FileSystem

Return the fully-qualified path of path f resolving the path through any symlinks or mount point

Overrides:

resolvePath in class FileSystem

Parameters:

f - path to be resolved

Returns:

fully qualified path

Throws:

FileNotFoundException

IOException

getHomeDirectory

public Path getHomeDirectory()

Description copied from class: FileSystem

Return the current user's home directory in this filesystem. The default implementation returns "/user/$USER/".

Overrides:

getHomeDirectory in class FileSystem

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 new_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

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 f,
                        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:

f - 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)

delete

public boolean delete(Path f,
             boolean recursive)
               throws org.apache.hadoop.security.AccessControlException,
                      FileNotFoundException,
                      IOException

Description copied from class: FileSystem

Delete a file.

Specified by:

delete in class FileSystem

Parameters:

f - 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

org.apache.hadoop.security.AccessControlException

FileNotFoundException

delete

public boolean delete(Path f)
               throws org.apache.hadoop.security.AccessControlException,
                      FileNotFoundException,
                      IOException

Description copied from class: FileSystem

Delete a file

Overrides:

delete in class FileSystem

Throws:

org.apache.hadoop.security.AccessControlException

FileNotFoundException

IOException

getFileBlockLocations

public BlockLocation[] getFileBlockLocations(FileStatus fs,
                                    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'.

Overrides:

getFileBlockLocations in class FileSystem

Parameters:

fs - FilesStatus to get data from

start - offset into the given file

len - length for which to get locations for

Throws:

IOException

getFileChecksum

public FileChecksum getFileChecksum(Path f)
                             throws org.apache.hadoop.security.AccessControlException,
                                    FileNotFoundException,
                                    IOException

Description copied from class: FileSystem

Get the checksum of a file.

Overrides:

getFileChecksum in class FileSystem

Parameters:

f - The file path

Returns:

The file checksum. The default return value is null, which indicates that no checksum algorithm is implemented in the corresponding FileSystem.

Throws:

org.apache.hadoop.security.AccessControlException

FileNotFoundException

IOException

getFileStatus

public FileStatus getFileStatus(Path f)
                         throws org.apache.hadoop.security.AccessControlException,
                                FileNotFoundException,
                                IOException

Description copied from class: FileSystem

Return a file status object that represents the path.

Specified by:

getFileStatus in class FileSystem

Parameters:

f - The path we want information from

Returns:

a FileStatus object

Throws:

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

org.apache.hadoop.security.AccessControlException

IOException

listStatus

public FileStatus[] listStatus(Path f)
                        throws org.apache.hadoop.security.AccessControlException,
                               FileNotFoundException,
                               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:

f - 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

org.apache.hadoop.security.AccessControlException

IOException

mkdirs

public boolean mkdirs(Path dir,
             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:

dir - path to create

permission - to apply to f

Throws:

IOException

open

public FSDataInputStream open(Path f,
                     int bufferSize)
                       throws org.apache.hadoop.security.AccessControlException,
                              FileNotFoundException,
                              IOException

Description copied from class: FileSystem

Opens an FSDataInputStream at the indicated Path.

Specified by:

open in class FileSystem

Parameters:

f - the file name to open

bufferSize - the size of the buffer to be used.

Throws:

org.apache.hadoop.security.AccessControlException

FileNotFoundException

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

setOwner

public void setOwner(Path f,
            String username,
            String groupname)
              throws org.apache.hadoop.security.AccessControlException,
                     FileNotFoundException,
                     IOException

Description copied from class: FileSystem

Set owner of a path (i.e. a file or a directory). The parameters username and groupname cannot both be null.

Overrides:

setOwner in class FileSystem

Parameters:

f - The path

username - If it is null, the original username remains unchanged.

groupname - If it is null, the original groupname remains unchanged.

Throws:

org.apache.hadoop.security.AccessControlException

FileNotFoundException

IOException

setPermission

public void setPermission(Path f,
                 FsPermission permission)
                   throws org.apache.hadoop.security.AccessControlException,
                          FileNotFoundException,
                          IOException

Description copied from class: FileSystem

Set permission of a path.

Overrides:

setPermission in class FileSystem

Throws:

org.apache.hadoop.security.AccessControlException

FileNotFoundException

IOException

setReplication

public boolean setReplication(Path f,
                     short replication)
                       throws org.apache.hadoop.security.AccessControlException,
                              FileNotFoundException,
                              IOException

Description copied from class: FileSystem

Set replication for an existing file.

Overrides:

setReplication in class FileSystem

Parameters:

f - file name

replication - new replication

Returns:

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

Throws:

IOException

org.apache.hadoop.security.AccessControlException

FileNotFoundException

setTimes

public void setTimes(Path f,
            long mtime,
            long atime)
              throws org.apache.hadoop.security.AccessControlException,
                     FileNotFoundException,
                     IOException

Description copied from class: FileSystem

Set access time of a file

Overrides:

setTimes in class FileSystem

Parameters:

f - The path

mtime - Set the modification time of this file. The number of milliseconds since Jan 1, 1970. A value of -1 means that this call should not set modification time.

atime - Set the access time of this file. The number of milliseconds since Jan 1, 1970. A value of -1 means that this call should not set access time.

Throws:

org.apache.hadoop.security.AccessControlException

FileNotFoundException

IOException

setVerifyChecksum

public void setVerifyChecksum(boolean verifyChecksum)

Description copied from class: FileSystem

Set the verify checksum flag. This is only applicable if the corresponding FileSystem supports checksum. By default doesn't do anything.

Overrides:

setVerifyChecksum in class FileSystem

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

getDefaultReplication

public short getDefaultReplication()

Description copied from class: FileSystem

Get the default replication.

Overrides:

getDefaultReplication in class FileSystem

getServerDefaults

public FsServerDefaults getServerDefaults()
                                   throws IOException

Description copied from class: FileSystem

Return a set of server default configuration values

Overrides:

getServerDefaults in class FileSystem

Returns:

server default configuration values

Throws:

IOException

getDefaultBlockSize

public long getDefaultBlockSize(Path f)

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. The given path will be used to locate the actual filesystem. The full path does not have to exist.

Overrides:

getDefaultBlockSize in class FileSystem

Parameters:

f - path of file

Returns:

the default block size for the path's filesystem

getDefaultReplication

public short getDefaultReplication(Path f)

Description copied from class: FileSystem

Get the default replication for a path. The given path will be used to locate the actual filesystem. The full path does not have to exist.

Overrides:

getDefaultReplication in class FileSystem

Parameters:

f - of the file

Returns:

default replication for the path's filesystem

getServerDefaults

public FsServerDefaults getServerDefaults(Path f)
                                   throws IOException

Description copied from class: FileSystem

Return a set of server default configuration values

Overrides:

getServerDefaults in class FileSystem

Parameters:

f - path is used to identify an FS since an FS could have another FS that it could be delegating the call to

Returns:

server default configuration values

Throws:

IOException

getContentSummary

public ContentSummary getContentSummary(Path f)
                                 throws IOException

Description copied from class: FileSystem

Return the ContentSummary of a given Path.

Overrides:

getContentSummary in class FileSystem

Parameters:

f - path to use

Throws:

IOException

setWriteChecksum

public void setWriteChecksum(boolean writeChecksum)

Description copied from class: FileSystem

Set the write checksum flag. This is only applicable if the corresponding FileSystem supports checksum. By default doesn't do anything.

Overrides:

setWriteChecksum in class FileSystem

getChildFileSystems

public FileSystem[] getChildFileSystems()

Description copied from class: FileSystem

Get all the immediate child FileSystems embedded in this FileSystem. It does not recurse and get grand children. If a FileSystem has multiple child FileSystems, then it should return a unique list of those FileSystems. Default is to return null to signify no children.

Returns:

FileSystems used by this FileSystem

getMountPoints

public org.apache.hadoop.fs.viewfs.ViewFileSystem.MountPoint[] getMountPoints()