org.apache.hadoop.fs
Class FileSystem

java.lang.Object
  org.apache.hadoop.conf.Configured
      org.apache.hadoop.fs.FileSystem

All Implemented Interfaces:

Closeable, Configurable

Direct Known Subclasses:

FilterFileSystem, FTPFileSystem, NativeS3FileSystem, RawLocalFileSystem, S3FileSystem, ViewFileSystem

@InterfaceAudience.Public
@InterfaceStability.Stable
public abstract class FileSystem
extends Configured
implements Closeable

An abstract base class for a fairly generic filesystem. It may be implemented as a distributed filesystem, or as a "local" one that reflects the locally-connected disk. The local version exists for small Hadoop instances and for testing.

All user code that may potentially use the Hadoop Distributed File System should be written to use a FileSystem object. The Hadoop DFS is a multi-machine system that appears as a single disk. It's useful because of its fault tolerance and potentially very large capacity.

The local implementation is LocalFileSystem and distributed implementation is DistributedFileSystem.

Field Summary

static String	DEFAULT_FS
static String	FS_DEFAULT_NAME_KEY
static org.apache.commons.logging.Log	LOG
static int	SHUTDOWN_HOOK_PRIORITY Priority of the FileSystem shutdown hook.
protected org.apache.hadoop.fs.FileSystem.Statistics	statistics The statistics for this file system.

Constructor Summary

protected

FileSystem()

Method Summary

FSDataOutputStream	append(Path f) Append to an existing file (optional operation).
FSDataOutputStream	append(Path f, int bufferSize) Append to an existing file (optional operation).
abstract FSDataOutputStream	append(Path f, int bufferSize, Progressable progress) Append to an existing file (optional operation).
static boolean	areSymlinksEnabled()
boolean	cancelDeleteOnExit(Path f) Cancel the deletion of the path when the FileSystem is closed
protected URI	canonicalizeUri(URI uri) Canonicalize the given URI.
protected void	checkPath(Path path) Check that a Path belongs to this FileSystem.
static void	clearStatistics() Reset all statistics for all file systems
void	close() No more filesystem operations are needed.
static void	closeAll() Close all cached filesystems.
static void	closeAllForUGI(org.apache.hadoop.security.UserGroupInformation ugi) Close all cached filesystems for a given UGI.
void	completeLocalOutput(Path fsOutputFile, Path tmpLocalFile) Called when we're all done writing to the target.
void	concat(Path trg, Path[] psrcs) Concat existing files together.
void	copyFromLocalFile(boolean delSrc, boolean overwrite, Path[] srcs, Path dst) The src files are on the local disk.
void	copyFromLocalFile(boolean delSrc, boolean overwrite, Path src, Path dst) The src file is on the local disk.
void	copyFromLocalFile(boolean delSrc, Path src, Path dst) The src file is on the local disk.
void	copyFromLocalFile(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.
void	copyToLocalFile(boolean delSrc, Path src, Path dst, boolean useRawLocalFileSystem) The src file is under FS, and the dst is on the local disk.
void	copyToLocalFile(Path src, Path dst) The src file is under FS, and the dst is on the local disk.
static FSDataOutputStream	create(FileSystem fs, Path file, FsPermission permission) create a file with the provided permission The permission of the file is set to be the provided permission as in setPermission, not permission&~umask It is implemented using two RPCs.
FSDataOutputStream	create(Path f) Create an FSDataOutputStream at the indicated Path.
FSDataOutputStream	create(Path f, boolean overwrite) Create an FSDataOutputStream at the indicated Path.
FSDataOutputStream	create(Path f, boolean overwrite, int bufferSize) Create an FSDataOutputStream at the indicated Path.
FSDataOutputStream	create(Path f, boolean overwrite, int bufferSize, Progressable progress) Create an FSDataOutputStream at the indicated Path with write-progress reporting.
FSDataOutputStream	create(Path f, boolean overwrite, int bufferSize, short replication, long blockSize) Create an FSDataOutputStream at the indicated Path.
FSDataOutputStream	create(Path f, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress) Create an FSDataOutputStream at the indicated Path with write-progress reporting.
abstract 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.
FSDataOutputStream	create(Path f, FsPermission permission, EnumSet<CreateFlag> flags, int bufferSize, short replication, long blockSize, Progressable progress) Create an FSDataOutputStream at the indicated Path with write-progress reporting.
FSDataOutputStream	create(Path f, FsPermission permission, EnumSet<CreateFlag> flags, int bufferSize, short replication, long blockSize, Progressable progress, org.apache.hadoop.fs.Options.ChecksumOpt checksumOpt) Create an FSDataOutputStream at the indicated Path with a custom checksum option
FSDataOutputStream	create(Path f, Progressable progress) Create an FSDataOutputStream at the indicated Path with write-progress reporting.
FSDataOutputStream	create(Path f, short replication) Create an FSDataOutputStream at the indicated Path.
FSDataOutputStream	create(Path f, short replication, Progressable progress) Create an FSDataOutputStream at the indicated Path with write-progress reporting.
boolean	createNewFile(Path f) Creates the given Path as a brand-new zero-length file.
FSDataOutputStream	createNonRecursive(Path f, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress) Deprecated. API only for 0.20-append
FSDataOutputStream	createNonRecursive(Path f, FsPermission permission, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress) Deprecated. API only for 0.20-append
FSDataOutputStream	createNonRecursive(Path f, FsPermission permission, EnumSet<CreateFlag> flags, int bufferSize, short replication, long blockSize, Progressable progress) Deprecated. API only for 0.20-append
Path	createSnapshot(Path path) Create a snapshot with a default name.
Path	createSnapshot(Path path, String snapshotName) Create a snapshot
void	createSymlink(Path target, Path link, boolean createParent) See FileContext.createSymlink(Path, Path, boolean)
boolean	delete(Path f) Deprecated. Use delete(Path, boolean) instead.
abstract boolean	delete(Path f, boolean recursive) Delete a file.
boolean	deleteOnExit(Path f) Mark a path to be deleted when FileSystem is closed.
void	deleteSnapshot(Path path, String snapshotName) Delete a snapshot of a directory
static void	enableSymlinks()
boolean	exists(Path f) Check if exists.
protected Path	fixRelativePart(Path p) See FileContext.fixRelativePart(org.apache.hadoop.fs.Path)
static FileSystem	get(Configuration conf) Returns the configured filesystem implementation.
static FileSystem	get(URI uri, Configuration conf) Returns the FileSystem for this URI's scheme and authority.
static FileSystem	get(URI uri, Configuration conf, String user) Get a filesystem instance based on the uri, the passed configuration and the user
AclStatus	getAclStatus(Path path) Gets the ACL of a file or directory.
static List<org.apache.hadoop.fs.FileSystem.Statistics>	getAllStatistics() Return the FileSystem classes that have Statistics
long	getBlockSize(Path f) Deprecated. Use getFileStatus() instead
protected URI	getCanonicalUri() Return a canonicalized form of this FileSystem's URI.
ContentSummary	getContentSummary(Path f) Return the ContentSummary of a given Path.
long	getDefaultBlockSize() Deprecated. use getDefaultBlockSize(Path) instead
long	getDefaultBlockSize(Path f) Return the number of bytes that large input files should be optimally be split into to minimize i/o time.
protected int	getDefaultPort() Get the default port for this file system.
short	getDefaultReplication() Deprecated. use getDefaultReplication(Path) instead
short	getDefaultReplication(Path path) Get the default replication for a path.
static URI	getDefaultUri(Configuration conf) Get the default filesystem URI from a configuration.
BlockLocation[]	getFileBlockLocations(FileStatus file, long start, long len) Return an array containing hostnames, offset and size of portions of the given file.
BlockLocation[]	getFileBlockLocations(Path p, 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.
FileChecksum	getFileChecksum(Path f, long length) Get the checksum of a file, from the beginning of the file till the specific length.
FileStatus	getFileLinkStatus(Path f) See FileContext.getFileLinkStatus(Path)
abstract FileStatus	getFileStatus(Path f) Return a file status object that represents the path.
static Class<? extends FileSystem>	getFileSystemClass(String scheme, Configuration conf)
protected static FileSystem	getFSofPath(Path absOrFqPath, Configuration conf)
Path	getHomeDirectory() Return the current user's home directory in this filesystem.
protected Path	getInitialWorkingDirectory() Note: with the new FilesContext class, getWorkingDirectory() will be removed.
long	getLength(Path f) Deprecated. Use getFileStatus() instead
Path	getLinkTarget(Path f) See FileContext.getLinkTarget(Path)
static LocalFileSystem	getLocal(Configuration conf) Get the local file system.
String	getName() Deprecated. call #getUri() instead.
static FileSystem	getNamed(String name, Configuration conf) Deprecated. call #get(URI,Configuration) instead.
short	getReplication(Path src) Deprecated. Use getFileStatus() instead
String	getScheme() Return the protocol scheme for the FileSystem.
FsServerDefaults	getServerDefaults() Deprecated. use getServerDefaults(Path) instead
FsServerDefaults	getServerDefaults(Path p) Return a set of server default configuration values
static Map<String,org.apache.hadoop.fs.FileSystem.Statistics>	getStatistics() Deprecated. use getAllStatistics() instead
static org.apache.hadoop.fs.FileSystem.Statistics	getStatistics(String scheme, Class<? extends FileSystem> cls) Get the statistics for a particular file system
FsStatus	getStatus() Returns a status object describing the use and capacity of the file system.
FsStatus	getStatus(Path p) Returns a status object describing the use and capacity of the file system.
abstract URI	getUri() Returns a URI whose scheme and authority identify this FileSystem.
long	getUsed() Return the total size of all files in the filesystem.
abstract Path	getWorkingDirectory() Get the current working directory for the given file system
byte[]	getXAttr(Path path, String name) Get an xattr name and value for a file or directory.
Map<String,byte[]>	getXAttrs(Path path) Get all of the xattr name/value pairs for a file or directory.
Map<String,byte[]>	getXAttrs(Path path, List<String> names) Get all of the xattrs name/value pairs for a file or directory.
FileStatus[]	globStatus(Path pathPattern) Return all the files that match filePattern and are not checksum files.
FileStatus[]	globStatus(Path pathPattern, PathFilter filter) Return an array of FileStatus objects whose path names match pathPattern and is accepted by the user-supplied path filter.
void	initialize(URI name, Configuration conf) Called after a new FileSystem instance is constructed.
boolean	isDirectory(Path f) True iff the named path is a directory.
boolean	isFile(Path f) True iff the named path is a regular file.
org.apache.hadoop.fs.RemoteIterator<Path>	listCorruptFileBlocks(Path path)
org.apache.hadoop.fs.RemoteIterator<LocatedFileStatus>	listFiles(Path f, boolean recursive) List the statuses and block locations of the files in the given path.
org.apache.hadoop.fs.RemoteIterator<LocatedFileStatus>	listLocatedStatus(Path f) List the statuses of the files/directories in the given path if the path is a directory.
protected org.apache.hadoop.fs.RemoteIterator<LocatedFileStatus>	listLocatedStatus(Path f, PathFilter filter) Listing a directory The returned results include its block location if it is a file The results are filtered by the given path filter
abstract FileStatus[]	listStatus(Path f) List the statuses of the files/directories in the given path if the path is a directory.
FileStatus[]	listStatus(Path[] files) Filter files/directories in the given list of paths using default path filter.
FileStatus[]	listStatus(Path[] files, PathFilter filter) Filter files/directories in the given list of paths using user-supplied path filter.
FileStatus[]	listStatus(Path f, PathFilter filter) Filter files/directories in the given path using the user-supplied path filter.
List<String>	listXAttrs(Path path) Get all of the xattr names for a file or directory.
Path	makeQualified(Path path) Make sure that a path specifies a FileSystem.
static boolean	mkdirs(FileSystem fs, Path dir, FsPermission permission) create a directory with the provided permission The permission of the directory is set to be the provided permission as in setPermission, not permission&~umask
boolean	mkdirs(Path f) Call mkdirs(Path, FsPermission) with default permission.
abstract boolean	mkdirs(Path f, FsPermission permission) Make the given file and all non-existent parents into directories.
void	modifyAclEntries(Path path, List<AclEntry> aclSpec) Modifies ACL entries of files and directories.
void	moveFromLocalFile(Path[] srcs, Path dst) The src files is on the local disk.
void	moveFromLocalFile(Path src, Path dst) The src file is on the local disk.
void	moveToLocalFile(Path src, Path dst) The src file is under FS, and the dst is on the local disk.
static FileSystem	newInstance(Configuration conf) Returns a unique configured filesystem implementation.
static FileSystem	newInstance(URI uri, Configuration conf) Returns the FileSystem for this URI's scheme and authority.
static FileSystem	newInstance(URI uri, Configuration conf, String user) Returns the FileSystem for this URI's scheme and authority and the passed user.
static LocalFileSystem	newInstanceLocal(Configuration conf) Get a unique local file system object
FSDataInputStream	open(Path f) Opens an FSDataInputStream at the indicated Path.
abstract FSDataInputStream	open(Path f, int bufferSize) Opens an FSDataInputStream at the indicated Path.
protected FSDataOutputStream	primitiveCreate(Path f, FsPermission absolutePermission, EnumSet<CreateFlag> flag, int bufferSize, short replication, long blockSize, Progressable progress, org.apache.hadoop.fs.Options.ChecksumOpt checksumOpt) Deprecated.
protected boolean	primitiveMkdir(Path f, FsPermission absolutePermission) Deprecated.
protected void	primitiveMkdir(Path f, FsPermission absolutePermission, boolean createParent) Deprecated.
static void	printStatistics() Print all statistics for all file systems
protected void	processDeleteOnExit() Delete all files that were marked as delete-on-exit.
void	removeAcl(Path path) Removes all but the base ACL entries of files and directories.
void	removeAclEntries(Path path, List<AclEntry> aclSpec) Removes ACL entries from files and directories.
void	removeDefaultAcl(Path path) Removes all default ACL entries from files and directories.
void	removeXAttr(Path path, String name) Remove an xattr of a file or directory.
abstract boolean	rename(Path src, Path dst) Renames Path src to Path dst.
protected void	rename(Path src, Path dst, org.apache.hadoop.fs.Options.Rename... options) Deprecated.
void	renameSnapshot(Path path, String snapshotOldName, String snapshotNewName) Rename a snapshot
protected Path	resolveLink(Path f) See AbstractFileSystem.getLinkTarget(Path)
Path	resolvePath(Path p) Return the fully-qualified path of path f resolving the path through any symlinks or mount point
void	setAcl(Path path, List<AclEntry> aclSpec) Fully replaces ACL of files and directories, discarding all existing entries.
static void	setDefaultUri(Configuration conf, String uri) Set the default filesystem URI in a configuration.
static void	setDefaultUri(Configuration conf, URI uri) Set the default filesystem URI in a configuration.
void	setOwner(Path p, String username, String groupname) Set owner of a path (i.e.
void	setPermission(Path p, FsPermission permission) Set permission of a path.
boolean	setReplication(Path src, short replication) Set replication for an existing file.
void	setTimes(Path p, long mtime, long atime) Set access time of a file
void	setVerifyChecksum(boolean verifyChecksum) Set the verify checksum flag.
abstract void	setWorkingDirectory(Path new_dir) Set the current working directory for the given file system.
void	setWriteChecksum(boolean writeChecksum) Set the write checksum flag.
void	setXAttr(Path path, String name, byte[] value) Set an xattr of a file or directory.
void	setXAttr(Path path, String name, byte[] value, EnumSet<XAttrSetFlag> flag) Set an xattr of a file or directory.
Path	startLocalOutput(Path fsOutputFile, Path tmpLocalFile) Returns a local File that the user can write output to.
boolean	supportsSymlinks() See AbstractFileSystem.supportsSymlinks()

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

Field Detail

FS_DEFAULT_NAME_KEY

public static final String FS_DEFAULT_NAME_KEY

See Also:

Constant Field Values

DEFAULT_FS

public static final String DEFAULT_FS

See Also:

Constant Field Values

LOG

public static final org.apache.commons.logging.Log LOG

SHUTDOWN_HOOK_PRIORITY

public static final int SHUTDOWN_HOOK_PRIORITY

Priority of the FileSystem shutdown hook.

See Also:

Constant Field Values

statistics

protected org.apache.hadoop.fs.FileSystem.Statistics statistics

The statistics for this file system.

Constructor Detail

FileSystem

protected FileSystem()

Method Detail

get

public static FileSystem get(URI uri,
                             Configuration conf,
                             String user)
                      throws IOException,
                             InterruptedException

Get a filesystem instance based on the uri, the passed configuration and the user

Parameters:

uri - of the filesystem

conf - the configuration to use

user - to perform the get as

Returns:

the filesystem instance

Throws:

IOException

InterruptedException

get

public static FileSystem get(Configuration conf)
                      throws IOException

Returns the configured filesystem implementation.

Parameters:

conf - the configuration to use

Throws:

IOException

getDefaultUri

public static URI getDefaultUri(Configuration conf)

Get the default filesystem URI from a configuration.

Parameters:

conf - the configuration to use

Returns:

the uri of the default filesystem

setDefaultUri

public static void setDefaultUri(Configuration conf,
                                 URI uri)

Set the default filesystem URI in a configuration.

Parameters:

conf - the configuration to alter

uri - the new default filesystem uri

setDefaultUri

public static void setDefaultUri(Configuration conf,
                                 String uri)

Set the default filesystem URI in a configuration.

Parameters:

conf - the configuration to alter

uri - the new default filesystem uri

initialize

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

Called after a new FileSystem instance is constructed.

Parameters:

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

conf - the configuration

Throws:

IOException

getScheme

public String getScheme()

Return the protocol scheme for the FileSystem.

This implementation throws an UnsupportedOperationException.

Returns:

the protocol scheme for the FileSystem.

getUri

public abstract URI getUri()

Returns a URI whose scheme and authority identify this FileSystem.

getCanonicalUri

protected URI getCanonicalUri()

Return a canonicalized form of this FileSystem's URI. The default implementation simply calls canonicalizeUri(URI) on the filesystem's own URI, so subclasses typically only need to implement that method.

See Also:

canonicalizeUri(URI)

canonicalizeUri

protected URI canonicalizeUri(URI uri)

Canonicalize the given URI. This is filesystem-dependent, but may for example consist of canonicalizing the hostname using DNS and adding the default port if not specified. The default implementation simply fills in the default port if not specified and if the filesystem has a default port.

Returns:

URI

See Also:

NetUtils.getCanonicalUri(URI, int)

getDefaultPort

protected int getDefaultPort()

Get the default port for this file system.

Returns:

the default port or 0 if there isn't one

getFSofPath

protected static FileSystem getFSofPath(Path absOrFqPath,
                                        Configuration conf)
                                 throws UnsupportedFileSystemException,
                                        IOException

Throws:

UnsupportedFileSystemException

IOException

getName

@Deprecated
public String getName()

Deprecated. call #getUri() instead.

getNamed

@Deprecated
public static FileSystem getNamed(String name,
                                             Configuration conf)
                           throws IOException

Deprecated. call #get(URI,Configuration) instead.

Throws:

IOException

getLocal

public static LocalFileSystem getLocal(Configuration conf)
                                throws IOException

Get the local file system.

Parameters:

conf - the configuration to configure the file system with

Returns:

a LocalFileSystem

Throws:

IOException

get

public static FileSystem get(URI uri,
                             Configuration conf)
                      throws IOException

Returns the FileSystem for this URI's scheme and authority. The scheme of the URI determines a configuration property name, fs.scheme.class whose value names the FileSystem class. The entire URI is passed to the FileSystem instance's initialize method.

Throws:

IOException

newInstance

public static FileSystem newInstance(URI uri,
                                     Configuration conf,
                                     String user)
                              throws IOException,
                                     InterruptedException

Returns the FileSystem for this URI's scheme and authority and the passed user. Internally invokes newInstance(URI, Configuration)

Parameters:

uri - of the filesystem

conf - the configuration to use

user - to perform the get as

Returns:

filesystem instance

Throws:

IOException

InterruptedException

newInstance

public static FileSystem newInstance(URI uri,
                                     Configuration conf)
                              throws IOException

Returns the FileSystem for this URI's scheme and authority. The scheme of the URI determines a configuration property name, fs.scheme.class whose value names the FileSystem class. The entire URI is passed to the FileSystem instance's initialize method. This always returns a new FileSystem object.

Throws:

IOException

newInstance

public static FileSystem newInstance(Configuration conf)
                              throws IOException

Returns a unique configured filesystem implementation. This always returns a new FileSystem object.

Parameters:

conf - the configuration to use

Throws:

IOException

newInstanceLocal

public static LocalFileSystem newInstanceLocal(Configuration conf)
                                        throws IOException

Get a unique local file system object

Parameters:

conf - the configuration to configure the file system with

Returns:

a LocalFileSystem This always returns a new FileSystem object.

Throws:

IOException

closeAll

public static void closeAll()
                     throws IOException

Close all cached filesystems. Be sure those filesystems are not used anymore.

Throws:

IOException

closeAllForUGI

public static void closeAllForUGI(org.apache.hadoop.security.UserGroupInformation ugi)
                           throws IOException

Close all cached filesystems for a given UGI. Be sure those filesystems are not used anymore.

Parameters:

ugi - user group info to close

Throws:

IOException

makeQualified

public Path makeQualified(Path path)

Make sure that a path specifies a FileSystem.

Parameters:

path - to use

create

public static FSDataOutputStream create(FileSystem fs,
                                        Path file,
                                        FsPermission permission)
                                 throws IOException

create a file with the provided permission The permission of the file is set to be the provided permission as in setPermission, not permission&~umask It is implemented using two RPCs. It is understood that it is inefficient, but the implementation is thread-safe. The other option is to change the value of umask in configuration to be 0, but it is not thread-safe.

Parameters:

fs - file system handle

file - the name of the file to be created

permission - the permission of the file

Returns:

an output stream

Throws:

IOException

mkdirs

public static boolean mkdirs(FileSystem fs,
                             Path dir,
                             FsPermission permission)
                      throws IOException

create a directory with the provided permission The permission of the directory is set to be the provided permission as in setPermission, not permission&~umask

Parameters:

fs - file system handle

dir - the name of the directory to be created

permission - the permission of the directory

Returns:

true if the directory creation succeeds; false otherwise

Throws:

IOException

See Also:

create(FileSystem, Path, FsPermission)

checkPath

protected void checkPath(Path path)

Check that a Path belongs to this FileSystem.

Parameters:

path - to check

getFileBlockLocations

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

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'.

Parameters:

file - FilesStatus to get data from

start - offset into the given file

len - length for which to get locations for

Throws:

IOException

getFileBlockLocations

public BlockLocation[] getFileBlockLocations(Path p,
                                             long start,
                                             long len)
                                      throws IOException

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'.

Parameters:

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

start - offset into the given file

len - length for which to get locations for

Throws:

IOException

getServerDefaults

@Deprecated
public FsServerDefaults getServerDefaults()
                                   throws IOException

Deprecated. use getServerDefaults(Path) instead

Return a set of server default configuration values

Returns:

server default configuration values

Throws:

IOException

getServerDefaults

public FsServerDefaults getServerDefaults(Path p)
                                   throws IOException

Return a set of server default configuration values

Parameters:

p - 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

resolvePath

public Path resolvePath(Path p)
                 throws IOException

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

Parameters:

p - path to be resolved

Returns:

fully qualified path

Throws:

FileNotFoundException

IOException

open

public abstract FSDataInputStream open(Path f,
                                       int bufferSize)
                                throws IOException

Opens an FSDataInputStream at the indicated Path.

Parameters:

f - the file name to open

bufferSize - the size of the buffer to be used.

Throws:

IOException

open

public FSDataInputStream open(Path f)
                       throws IOException

Opens an FSDataInputStream at the indicated Path.

Parameters:

f - the file to open

Throws:

IOException

create

public FSDataOutputStream create(Path f)
                          throws IOException

Create an FSDataOutputStream at the indicated Path. Files are overwritten by default.

Parameters:

f - the file to create

Throws:

IOException

create

public FSDataOutputStream create(Path f,
                                 boolean overwrite)
                          throws IOException

Create an FSDataOutputStream at the indicated Path.

Parameters:

f - the file to create

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

Throws:

IOException

create

public FSDataOutputStream create(Path f,
                                 Progressable progress)
                          throws IOException

Create an FSDataOutputStream at the indicated Path with write-progress reporting. Files are overwritten by default.

Parameters:

f - the file to create

progress - to report progress

Throws:

IOException

create

public FSDataOutputStream create(Path f,
                                 short replication)
                          throws IOException

Create an FSDataOutputStream at the indicated Path. Files are overwritten by default.

Parameters:

f - the file to create

replication - the replication factor

Throws:

IOException

create

public FSDataOutputStream create(Path f,
                                 short replication,
                                 Progressable progress)
                          throws IOException

Create an FSDataOutputStream at the indicated Path with write-progress reporting. Files are overwritten by default.

Parameters:

f - the file to create

replication - the replication factor

progress - to report progress

Throws:

IOException

create

public FSDataOutputStream create(Path f,
                                 boolean overwrite,
                                 int bufferSize)
                          throws IOException

Create an FSDataOutputStream at the indicated Path.

Parameters:

f - the file name to create

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.

Throws:

IOException

create

public FSDataOutputStream create(Path f,
                                 boolean overwrite,
                                 int bufferSize,
                                 Progressable progress)
                          throws IOException

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

Parameters:

f - the path of the file 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.

Throws:

IOException

create

public FSDataOutputStream create(Path f,
                                 boolean overwrite,
                                 int bufferSize,
                                 short replication,
                                 long blockSize)
                          throws IOException

Create an FSDataOutputStream at the indicated Path.

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

create

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

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

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

create

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

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

Parameters:

f - the file name to open

permission -

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.

blockSize -

progress -

Throws:

IOException

See Also:

setPermission(Path, FsPermission)

create

public FSDataOutputStream create(Path f,
                                 FsPermission permission,
                                 EnumSet<CreateFlag> flags,
                                 int bufferSize,
                                 short replication,
                                 long blockSize,
                                 Progressable progress)
                          throws IOException

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

Parameters:

f - the file name to open

permission -

flags - CreateFlags to use for this stream.

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

blockSize -

progress -

Throws:

IOException

See Also:

setPermission(Path, FsPermission)

create

public FSDataOutputStream create(Path f,
                                 FsPermission permission,
                                 EnumSet<CreateFlag> flags,
                                 int bufferSize,
                                 short replication,
                                 long blockSize,
                                 Progressable progress,
                                 org.apache.hadoop.fs.Options.ChecksumOpt checksumOpt)
                          throws IOException

Create an FSDataOutputStream at the indicated Path with a custom checksum option

Parameters:

f - the file name to open

permission -

flags - CreateFlags to use for this stream.

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

blockSize -

progress -

checksumOpt - checksum parameter. If null, the values found in conf will be used.

Throws:

IOException

See Also:

setPermission(Path, FsPermission)

primitiveCreate

@Deprecated
protected FSDataOutputStream primitiveCreate(Path f,
                                                        FsPermission absolutePermission,
                                                        EnumSet<CreateFlag> flag,
                                                        int bufferSize,
                                                        short replication,
                                                        long blockSize,
                                                        Progressable progress,
                                                        org.apache.hadoop.fs.Options.ChecksumOpt checksumOpt)
                                      throws IOException

Deprecated.

Throws:

IOException

primitiveMkdir

@Deprecated
protected boolean primitiveMkdir(Path f,
                                            FsPermission absolutePermission)
                          throws IOException

Deprecated.

This version of the mkdirs method assumes that the permission is absolute. It has been added to support the FileContext that processes the permission with umask before calling this method. This a temporary method added to support the transition from FileSystem to FileContext for user applications.

Throws:

IOException

primitiveMkdir

@Deprecated
protected void primitiveMkdir(Path f,
                                         FsPermission absolutePermission,
                                         boolean createParent)
                       throws IOException

Deprecated.

This version of the mkdirs method assumes that the permission is absolute. It has been added to support the FileContext that processes the permission with umask before calling this method. This a temporary method added to support the transition from FileSystem to FileContext for user applications.

Throws:

IOException

createNonRecursive

@Deprecated
public FSDataOutputStream createNonRecursive(Path f,
                                                        boolean overwrite,
                                                        int bufferSize,
                                                        short replication,
                                                        long blockSize,
                                                        Progressable progress)
                                      throws IOException

Deprecated. API only for 0.20-append

Opens an FSDataOutputStream at the indicated Path with write-progress reporting. Same as create(), except fails if parent directory doesn't already exist.

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.

blockSize -

progress -

Throws:

IOException

See Also:

setPermission(Path, FsPermission)

createNonRecursive

@Deprecated
public FSDataOutputStream createNonRecursive(Path f,
                                                        FsPermission permission,
                                                        boolean overwrite,
                                                        int bufferSize,
                                                        short replication,
                                                        long blockSize,
                                                        Progressable progress)
                                      throws IOException

Deprecated. API only for 0.20-append

Opens an FSDataOutputStream at the indicated Path with write-progress reporting. Same as create(), except fails if parent directory doesn't already exist.

Parameters:

f - the file name to open

permission -

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.

blockSize -

progress -

Throws:

IOException

See Also:

setPermission(Path, FsPermission)

createNonRecursive

@Deprecated
public FSDataOutputStream createNonRecursive(Path f,
                                                        FsPermission permission,
                                                        EnumSet<CreateFlag> flags,
                                                        int bufferSize,
                                                        short replication,
                                                        long blockSize,
                                                        Progressable progress)
                                      throws IOException

Deprecated. API only for 0.20-append

Opens an FSDataOutputStream at the indicated Path with write-progress reporting. Same as create(), except fails if parent directory doesn't already exist.

Parameters:

f - the file name to open

permission -

flags - CreateFlags to use for this stream.

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

blockSize -

progress -

Throws:

IOException

See Also:

setPermission(Path, FsPermission)

createNewFile

public boolean createNewFile(Path f)
                      throws IOException

Creates the given Path as a brand-new zero-length file. If create fails, or if it already existed, return false.

Parameters:

f - path to use for create

Throws:

IOException

append

public FSDataOutputStream append(Path f)
                          throws IOException

Append to an existing file (optional operation). Same as append(f, getConf().getInt("io.file.buffer.size", 4096), null)

Parameters:

f - the existing file to be appended.

Throws:

IOException

append

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

Append to an existing file (optional operation). Same as append(f, bufferSize, null).

Parameters:

f - the existing file to be appended.

bufferSize - the size of the buffer to be used.

Throws:

IOException

append

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

Append to an existing file (optional operation).

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

concat

public void concat(Path trg,
                   Path[] psrcs)
            throws IOException

Concat existing files together.

Parameters:

trg - the path to the target destination.

psrcs - the paths to the sources to use for the concatenation.

Throws:

IOException

getReplication

@Deprecated
public short getReplication(Path src)
                     throws IOException

Deprecated. Use getFileStatus() instead

Get replication.

Parameters:

src - file name

Returns:

file replication

Throws:

IOException

setReplication

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

Set replication for an existing file.

Parameters:

src - file name

replication - new replication

Returns:

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

Throws:

IOException

rename

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

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

Parameters:

src - path to be renamed

dst - new path after rename

Returns:

true if rename is successful

Throws:

IOException - on failure

rename

@Deprecated
protected void rename(Path src,
                                 Path dst,
                                 org.apache.hadoop.fs.Options.Rename... options)
               throws IOException

Deprecated.

Renames Path src to Path dst

• Fails if src is a file and dst is a directory.
• Fails if src is a directory and dst is a file.
• Fails if the parent of dst does not exist or is a file.

If OVERWRITE option is not passed as an argument, rename fails if the dst already exists.

If OVERWRITE option is passed as an argument, rename overwrites the dst if it is a file or an empty directory. Rename fails if dst is a non-empty directory.

Note that atomicity of rename is dependent on the file system implementation. Please refer to the file system documentation for details. This default implementation is non atomic.

This method is deprecated since it is a temporary method added to support the transition from FileSystem to FileContext for user applications.

Parameters:

src - path to be renamed

dst - new path after rename

Throws:

IOException - on failure

delete

@Deprecated
public boolean delete(Path f)
               throws IOException

Deprecated. Use delete(Path, boolean) instead.

Delete a file

Throws:

IOException

delete

public abstract boolean delete(Path f,
                               boolean recursive)
                        throws IOException

Delete a file.

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

deleteOnExit

public boolean deleteOnExit(Path f)
                     throws IOException

Mark a path to be deleted when FileSystem is closed. When the JVM shuts down, all FileSystem objects will be closed automatically. Then, the marked path will be deleted as a result of closing the FileSystem. The path has to exist in the file system.

Parameters:

f - the path to delete.

Returns:

true if deleteOnExit is successful, otherwise false.

Throws:

IOException

cancelDeleteOnExit

public boolean cancelDeleteOnExit(Path f)

Cancel the deletion of the path when the FileSystem is closed

Parameters:

f - the path to cancel deletion

processDeleteOnExit

protected void processDeleteOnExit()

Delete all files that were marked as delete-on-exit. This recursively deletes all files in the specified paths.

exists

public boolean exists(Path f)
               throws IOException

Check if exists.

Parameters:

f - source file

Throws:

IOException

isDirectory

public boolean isDirectory(Path f)
                    throws IOException

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

Parameters:

f - path to check

Throws:

IOException

isFile

public boolean isFile(Path f)
               throws IOException

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

Parameters:

f - path to check

Throws:

IOException

getLength

@Deprecated
public long getLength(Path f)
               throws IOException

Deprecated. Use getFileStatus() instead

Throws:

IOException

getContentSummary

public ContentSummary getContentSummary(Path f)
                                 throws IOException

Return the ContentSummary of a given Path.

Parameters:

f - path to use

Throws:

IOException

listStatus

public abstract FileStatus[] listStatus(Path f)
                                 throws FileNotFoundException,
                                        IOException

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

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

IOException

listCorruptFileBlocks

public org.apache.hadoop.fs.RemoteIterator<Path> listCorruptFileBlocks(Path path)
                                                                throws IOException

Returns:

an iterator over the corrupt files under the given path (may contain duplicates if a file has more than one corrupt block)

Throws:

IOException

listStatus

public FileStatus[] listStatus(Path f,
                               PathFilter filter)
                        throws FileNotFoundException,
                               IOException

Filter files/directories in the given path using the user-supplied path filter.

Parameters:

f - a path name

filter - the user-supplied path filter

Returns:

an array of FileStatus objects for the files under the given path after applying the filter

Throws:

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

IOException

listStatus

public FileStatus[] listStatus(Path[] files)
                        throws FileNotFoundException,
                               IOException

Filter files/directories in the given list of paths using default path filter.

Parameters:

files - a list of paths

Returns:

a list of statuses for the files under the given paths after applying the filter default Path filter

Throws:

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

IOException

listStatus

public FileStatus[] listStatus(Path[] files,
                               PathFilter filter)
                        throws FileNotFoundException,
                               IOException

Filter files/directories in the given list of paths using user-supplied path filter.

Parameters:

files - a list of paths

filter - the user-supplied path filter

Returns:

a list of statuses for the files under the given paths after applying the filter

Throws:

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

IOException

globStatus

public FileStatus[] globStatus(Path pathPattern)
                        throws IOException

Return all the files that match filePattern and are not checksum files. Results are sorted by their names.

A filename pattern is composed of regular characters and special pattern matching characters, which are:

?

Matches any single character.

*

Matches zero or more characters.

[abc]

Matches a single character from character set {a,b,c}.

[a-b]

Matches a single character from the character range {a...b}. Note that character a must be lexicographically less than or equal to character b.

[^a]

Matches a single character that is not from character set or range {a}. Note that the ^ character must occur immediately to the right of the opening bracket.

\c

Removes (escapes) any special meaning of character c.

{ab,cd}

Matches a string from the string set {ab, cd}

{ab,c{de,fh}}

Matches a string from the string set {ab, cde, cfh}

Parameters:

pathPattern - a regular expression specifying a pth pattern

Returns:

an array of paths that match the path pattern

Throws:

IOException

globStatus

public FileStatus[] globStatus(Path pathPattern,
                               PathFilter filter)
                        throws IOException

Return an array of FileStatus objects whose path names match pathPattern and is accepted by the user-supplied path filter. Results are sorted by their path names. Return null if pathPattern has no glob and the path does not exist. Return an empty array if pathPattern has a glob and no path matches it.

Parameters:

pathPattern - a regular expression specifying the path pattern

filter - a user-supplied path filter

Returns:

an array of FileStatus objects

Throws:

IOException - if any I/O error occurs when fetching file status

listLocatedStatus

public org.apache.hadoop.fs.RemoteIterator<LocatedFileStatus> listLocatedStatus(Path f)
                                                                         throws FileNotFoundException,
                                                                                IOException

List the statuses of the files/directories in the given path if the path is a directory. Return the file's status and block locations If the path is a file. If a returned status is a file, it contains the file's block locations.

Parameters:

f - is the path

Returns:

an iterator that traverses statuses of the files/directories in the given path

Throws:

FileNotFoundException - If f does not exist

IOException - If an I/O error occurred

listLocatedStatus

protected org.apache.hadoop.fs.RemoteIterator<LocatedFileStatus> listLocatedStatus(Path f,
                                                                                   PathFilter filter)
                                                                            throws FileNotFoundException,
                                                                                   IOException

Listing a directory The returned results include its block location if it is a file The results are filtered by the given path filter

Parameters:

f - a path

filter - a path filter

Returns:

an iterator that traverses statuses of the files/directories in the given path

Throws:

FileNotFoundException - if f does not exist

IOException - if any I/O error occurred

listFiles

public org.apache.hadoop.fs.RemoteIterator<LocatedFileStatus> listFiles(Path f,
                                                                        boolean recursive)
                                                                 throws FileNotFoundException,
                                                                        IOException

List the statuses and block locations of the files in the given path. If the path is a directory, if recursive is false, returns files in the directory; if recursive is true, return files in the subtree rooted at the path. If the path is a file, return the file's status and block locations.

Parameters:

f - is the path

recursive - if the subdirectories need to be traversed recursively

Returns:

an iterator that traverses statuses of the files

Throws:

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

IOException

getHomeDirectory

public Path getHomeDirectory()

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

setWorkingDirectory

public abstract void setWorkingDirectory(Path new_dir)

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

Parameters:

new_dir -

getWorkingDirectory

public abstract Path getWorkingDirectory()

Get the current working directory for the given file system

Returns:

the directory pathname

getInitialWorkingDirectory

protected Path getInitialWorkingDirectory()

Note: with the new FilesContext class, getWorkingDirectory() will be removed. The working directory is implemented in FilesContext. Some file systems like LocalFileSystem have an initial workingDir that we use as the starting workingDir. For other file systems like HDFS there is no built in notion of an initial workingDir.

Returns:

if there is built in notion of workingDir then it is returned; else a null is returned.

mkdirs

public boolean mkdirs(Path f)
               throws IOException

Call mkdirs(Path, FsPermission) with default permission.

Throws:

IOException

mkdirs

public abstract boolean mkdirs(Path f,
                               FsPermission permission)
                        throws IOException

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.

Parameters:

f - path to create

permission - to apply to f

Throws:

IOException

copyFromLocalFile

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

The src file is on the local disk. Add it to FS at the given dst name and the source is kept intact afterwards

Parameters:

src - path

dst - path

Throws:

IOException

moveFromLocalFile

public void moveFromLocalFile(Path[] srcs,
                              Path dst)
                       throws IOException

The src files is on the local disk. Add it to FS at the given dst name, removing the source afterwards.

Parameters:

srcs - path

dst - path

Throws:

IOException

moveFromLocalFile

public void moveFromLocalFile(Path src,
                              Path dst)
                       throws IOException

The src file is on the local disk. Add it to FS at the given dst name, removing the source afterwards.

Parameters:

src - path

dst - path

Throws:

IOException

copyFromLocalFile

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

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

Parameters:

delSrc - whether to delete the src

src - path

dst - path

Throws:

IOException

copyFromLocalFile

public void copyFromLocalFile(boolean delSrc,
                              boolean overwrite,
                              Path[] srcs,
                              Path dst)
                       throws IOException

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

Parameters:

delSrc - whether to delete the src

overwrite - whether to overwrite an existing file

srcs - array of paths which are source

dst - path

Throws:

IOException

copyFromLocalFile

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

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

Parameters:

delSrc - whether to delete the src

overwrite - whether to overwrite an existing file

src - path

dst - path

Throws:

IOException

copyToLocalFile

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

The src file is under FS, and the dst is on the local disk. Copy it from FS control to the local dst name.

Parameters:

src - path

dst - path

Throws:

IOException

moveToLocalFile

public void moveToLocalFile(Path src,
                            Path dst)
                     throws IOException

The src file is under FS, and the dst is on the local disk. Copy it from FS control to the local dst name. Remove the source afterwards

Parameters:

src - path

dst - path

Throws:

IOException

copyToLocalFile

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

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.

Parameters:

delSrc - whether to delete the src

src - path

dst - path

Throws:

IOException

copyToLocalFile

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

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. useRawLocalFileSystem indicates whether to use RawLocalFileSystem as local file system or not. RawLocalFileSystem is non crc file system.So, It will not create any crc files at local.

Parameters:

delSrc - whether to delete the src

src - path

dst - path

useRawLocalFileSystem - whether to use RawLocalFileSystem as local file system or not.

Throws:

IOException - - if any IO error

startLocalOutput

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

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.

Parameters:

fsOutputFile - path of output file

tmpLocalFile - path of local tmp file

Throws:

IOException

completeLocalOutput

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

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.

Parameters:

fsOutputFile - path of output file

tmpLocalFile - path to local tmp file

Throws:

IOException

close

public void close()
           throws IOException

No more filesystem operations are needed. Will release any held locks.

Specified by:

close in interface Closeable

Throws:

IOException

getUsed

public long getUsed()
             throws IOException

Return the total size of all files in the filesystem.

Throws:

IOException

getBlockSize

@Deprecated
public long getBlockSize(Path f)
                  throws IOException

Deprecated. Use getFileStatus() instead

Throws:

IOException

getDefaultBlockSize

@Deprecated
public long getDefaultBlockSize()

Deprecated. use getDefaultBlockSize(Path) instead

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

getDefaultBlockSize

public long getDefaultBlockSize(Path f)

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.

Parameters:

f - path of file

Returns:

the default block size for the path's filesystem

getDefaultReplication

@Deprecated
public short getDefaultReplication()

Deprecated. use getDefaultReplication(Path) instead

Get the default replication.

getDefaultReplication

public short getDefaultReplication(Path path)

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.

Parameters:

path - of the file

Returns:

default replication for the path's filesystem

getFileStatus

public abstract FileStatus getFileStatus(Path f)
                                  throws IOException

Return a file status object that represents the path.

Parameters:

f - The path we want information from

Returns:

a FileStatus object

Throws:

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

IOException

fixRelativePart

protected Path fixRelativePart(Path p)

See FileContext.fixRelativePart(org.apache.hadoop.fs.Path)

createSymlink

public void createSymlink(Path target,
                          Path link,
                          boolean createParent)
                   throws org.apache.hadoop.security.AccessControlException,
                          FileAlreadyExistsException,
                          FileNotFoundException,
                          ParentNotDirectoryException,
                          UnsupportedFileSystemException,
                          IOException

See FileContext.createSymlink(Path, Path, boolean)

Throws:

org.apache.hadoop.security.AccessControlException

FileAlreadyExistsException

FileNotFoundException

ParentNotDirectoryException

UnsupportedFileSystemException

IOException

getFileLinkStatus

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

See FileContext.getFileLinkStatus(Path)

Throws:

org.apache.hadoop.security.AccessControlException

FileNotFoundException

UnsupportedFileSystemException

IOException

supportsSymlinks

public boolean supportsSymlinks()

See AbstractFileSystem.supportsSymlinks()

getLinkTarget

public Path getLinkTarget(Path f)
                   throws IOException

See FileContext.getLinkTarget(Path)

Throws:

IOException

resolveLink

protected Path resolveLink(Path f)
                    throws IOException

See AbstractFileSystem.getLinkTarget(Path)

Throws:

IOException

getFileChecksum

public FileChecksum getFileChecksum(Path f)
                             throws IOException

Get the checksum of a file.

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:

IOException

getFileChecksum

public FileChecksum getFileChecksum(Path f,
                                    long length)
                             throws IOException

Get the checksum of a file, from the beginning of the file till the specific length.

Parameters:

f - The file path

length - The length of the file range for checksum calculation

Returns:

The file checksum.

Throws:

IOException

setVerifyChecksum

public void setVerifyChecksum(boolean verifyChecksum)

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

Parameters:

verifyChecksum -

setWriteChecksum

public void setWriteChecksum(boolean writeChecksum)

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

Parameters:

writeChecksum -

getStatus

public FsStatus getStatus()
                   throws IOException

Returns a status object describing the use and capacity of the file system. If the file system has multiple partitions, the use and capacity of the root partition is reflected.

Returns:

a FsStatus object

Throws:

IOException - see specific implementation

getStatus

public FsStatus getStatus(Path p)
                   throws IOException

Returns a status object describing the use and capacity of the file system. If the file system has multiple partitions, the use and capacity of the partition pointed to by the specified path is reflected.

Parameters:

p - Path for which status should be obtained. null means the default partition.

Returns:

a FsStatus object

Throws:

IOException - see specific implementation

setPermission

public void setPermission(Path p,
                          FsPermission permission)
                   throws IOException

Set permission of a path.

Parameters:

p -

permission -

Throws:

IOException

setOwner

public void setOwner(Path p,
                     String username,
                     String groupname)
              throws IOException

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

Parameters:

p - The path

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

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

Throws:

IOException

setTimes

public void setTimes(Path p,
                     long mtime,
                     long atime)
              throws IOException

Set access time of a file

Parameters:

p - 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:

IOException

createSnapshot

public final Path createSnapshot(Path path)
                          throws IOException

Create a snapshot with a default name.

Parameters:

path - The directory where snapshots will be taken.

Returns:

the snapshot path.

Throws:

IOException

createSnapshot

public Path createSnapshot(Path path,
                           String snapshotName)
                    throws IOException

Create a snapshot

Parameters:

path - The directory where snapshots will be taken.

snapshotName - The name of the snapshot

Returns:

the snapshot path.

Throws:

IOException

renameSnapshot

public void renameSnapshot(Path path,
                           String snapshotOldName,
                           String snapshotNewName)
                    throws IOException

Rename a snapshot

Parameters:

path - The directory path where the snapshot was taken

snapshotOldName - Old name of the snapshot

snapshotNewName - New name of the snapshot

Throws:

IOException

deleteSnapshot

public void deleteSnapshot(Path path,
                           String snapshotName)
                    throws IOException

Delete a snapshot of a directory

Parameters:

path - The directory that the to-be-deleted snapshot belongs to

snapshotName - The name of the snapshot

Throws:

IOException

modifyAclEntries

public void modifyAclEntries(Path path,
                             List<AclEntry> aclSpec)
                      throws IOException

Modifies ACL entries of files and directories. This method can add new ACL entries or modify the permissions on existing ACL entries. All existing ACL entries that are not specified in this call are retained without changes. (Modifications are merged into the current ACL.)

Parameters:

path - Path to modify

aclSpec - List describing modifications

Throws:

IOException - if an ACL could not be modified

removeAclEntries

public void removeAclEntries(Path path,
                             List<AclEntry> aclSpec)
                      throws IOException

Removes ACL entries from files and directories. Other ACL entries are retained.

Parameters:

path - Path to modify

aclSpec - List describing entries to remove

Throws:

IOException - if an ACL could not be modified

removeDefaultAcl

public void removeDefaultAcl(Path path)
                      throws IOException

Removes all default ACL entries from files and directories.

Parameters:

path - Path to modify

Throws:

IOException - if an ACL could not be modified

removeAcl

public void removeAcl(Path path)
               throws IOException

Removes all but the base ACL entries of files and directories. The entries for user, group, and others are retained for compatibility with permission bits.

Parameters:

path - Path to modify

Throws:

IOException - if an ACL could not be removed

setAcl

public void setAcl(Path path,
                   List<AclEntry> aclSpec)
            throws IOException

Fully replaces ACL of files and directories, discarding all existing entries.

Parameters:

path - Path to modify

aclSpec - List describing modifications, must include entries for user, group, and others for compatibility with permission bits.

Throws:

IOException - if an ACL could not be modified

getAclStatus

public AclStatus getAclStatus(Path path)
                       throws IOException

Gets the ACL of a file or directory.

Parameters:

path - Path to get

Returns:

AclStatus describing the ACL of the file or directory

Throws:

IOException - if an ACL could not be read

setXAttr

public void setXAttr(Path path,
                     String name,
                     byte[] value)
              throws IOException

Set an xattr of a file or directory. The name must be prefixed with user/trusted/security/system and followed by ".". For example, "user.attr".

A regular user can only set an xattr for the "user" namespace. The super user can set an xattr of either the "user" or "trusted" namespaces. The xattrs of the "security" and "system" namespaces are only used/exposed internally by/to the FS impl.

The access permissions of an xattr in the "user" namespace are defined by the file and directory permission bits. An xattr can only be set when the logged-in user has the correct permissions. If the xattr exists, it will be replaced.

Parameters:

path - Path to modify

name - xattr name.

value - xattr value.

Throws:

IOException

See Also:

http://en.wikipedia.org/wiki/Extended_file_attributes

setXAttr

public void setXAttr(Path path,
                     String name,
                     byte[] value,
                     EnumSet<XAttrSetFlag> flag)
              throws IOException

Set an xattr of a file or directory. The name must be prefixed with user/trusted/security/system and followed by ".". For example, "user.attr".

A regular user can only set an xattr for the "user" namespace. The super user can set an xattr of either the "user" or "trusted" namespaces. The xattrs of the "security" and "system" namespaces are only used/exposed internally by/to the FS impl.

The access permissions of an xattr in the "user" namespace are defined by the file and directory permission bits. An xattr can only be set if the logged-in user has the correct permissions. If the xattr exists, it is replaced.

Parameters:

path - Path to modify

name - xattr name.

value - xattr value.

flag - xattr set flag

Throws:

IOException

See Also:

http://en.wikipedia.org/wiki/Extended_file_attributes

getXAttr

public byte[] getXAttr(Path path,
                       String name)
                throws IOException

Get an xattr name and value for a file or directory. The name must be prefixed with user/trusted/security/system and followed by ".". For example, "user.attr".

A regular user can only get an xattr for the "user" namespace. The super user can get an xattr of either the "user" or "trusted" namespaces. The xattrs of the "security" and "system" namespaces are only used/exposed internally by/to the FS impl.

An xattr will only be returned if the logged-in user has the correct permissions.

Parameters:

path - Path to get extended attribute

name - xattr name.

Returns:

byte[] xattr value.

Throws:

IOException

See Also:

http://en.wikipedia.org/wiki/Extended_file_attributes

getXAttrs

public Map<String,byte[]> getXAttrs(Path path)
                             throws IOException

Get all of the xattr name/value pairs for a file or directory. Only those xattrs which the logged-in user has permissions to view are returned.

A regular user can only get xattrs for the "user" namespace. The super user can only get xattrs for "user" and "trusted" namespaces. The xattrs of the "security" and "system" namespaces are only used/exposed internally by/to the FS impl.

Parameters:

path - Path to get extended attributes

Returns:

Map describing the XAttrs of the file or directory

Throws:

IOException

See Also:

http://en.wikipedia.org/wiki/Extended_file_attributes

getXAttrs

public Map<String,byte[]> getXAttrs(Path path,
                                    List<String> names)
                             throws IOException

Get all of the xattrs name/value pairs for a file or directory. Only those xattrs which the logged-in user has permissions to view are returned.

A regular user can only get xattrs for the "user" namespace. The super user can only get xattrs for "user" and "trusted" namespaces. The xattrs of the "security" and "system" namespaces are only used/exposed internally by/to the FS impl.

Parameters:

path - Path to get extended attributes

names - XAttr names.

Returns:

Map describing the XAttrs of the file or directory

Throws:

IOException

See Also:

http://en.wikipedia.org/wiki/Extended_file_attributes

listXAttrs

public List<String> listXAttrs(Path path)
                        throws IOException

Get all of the xattr names for a file or directory. Only those xattr names which the logged-in user has permissions to view are returned.

A regular user can only get xattr names for the "user" namespace. The super user can only get xattr names for "user" and "trusted" namespaces. The xattrs of the "security" and "system" namespaces are only used/exposed internally by/to the FS impl.

Parameters:

path - Path to get extended attributes

Returns:

Map describing the XAttrs of the file or directory

Throws:

IOException

See Also:

http://en.wikipedia.org/wiki/Extended_file_attributes

removeXAttr

public void removeXAttr(Path path,
                        String name)
                 throws IOException

Remove an xattr of a file or directory. The name must be prefixed with user/trusted/security/system and followed by ".". For example, "user.attr".

A regular user can only remove an xattr for the "user" namespace. The super user can remove an xattr of either the "user" or "trusted" namespaces. The xattrs of the "security" and "system" namespaces are only used/exposed internally by/to the FS impl.

The access permissions of an xattr in the "user" namespace are defined by the file and directory permission bits. An xattr can only be set when the logged-in user has the correct permissions. If the xattr exists, it will be replaced.

Parameters:

path - Path to remove extended attribute

name - xattr name

Throws:

IOException

See Also:

http://en.wikipedia.org/wiki/Extended_file_attributes

getFileSystemClass

public static Class<? extends FileSystem> getFileSystemClass(String scheme,
                                                             Configuration conf)
                                                      throws IOException

Throws:

IOException

getStatistics

@Deprecated
public static Map<String,org.apache.hadoop.fs.FileSystem.Statistics> getStatistics()

Deprecated. use getAllStatistics() instead

Get the Map of Statistics object indexed by URI Scheme.

Returns:

a Map having a key as URI scheme and value as Statistics object

getAllStatistics

public static List<org.apache.hadoop.fs.FileSystem.Statistics> getAllStatistics()

Return the FileSystem classes that have Statistics

getStatistics

public static org.apache.hadoop.fs.FileSystem.Statistics getStatistics(String scheme,
                                                                       Class<? extends FileSystem> cls)

Get the statistics for a particular file system

Parameters:

cls - the class to lookup

Returns:

a statistics object

clearStatistics

public static void clearStatistics()

Reset all statistics for all file systems

printStatistics

public static void printStatistics()
                            throws IOException

Print all statistics for all file systems

Throws:

IOException

areSymlinksEnabled

public static boolean areSymlinksEnabled()

enableSymlinks

public static void enableSymlinks()