org.apache.hadoop.fs
Class FilterFileSystem

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

All Implemented Interfaces:

Closeable, Configurable

Direct Known Subclasses:

ChecksumFileSystem

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

A FilterFileSystem contains some other file system, which it uses as its basic file system, possibly transforming the data along the way or providing additional functionality. The class FilterFileSystem itself simply overrides all methods of FileSystem with versions that pass all requests to the contained file system. Subclasses of FilterFileSystem may further override some of these methods and may also provide additional methods and fields.

Field Summary

protected FileSystem	fs
protected String	swapScheme

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

DEFAULT_FS, FS_DEFAULT_NAME_KEY, LOG, SHUTDOWN_HOOK_PRIORITY, statistics

Constructor Summary

FilterFileSystem()

FilterFileSystem(FileSystem fs)

Method Summary

void	access(Path path, FsAction mode) Checks if the user can access a path.
FSDataOutputStream	append(Path f, int bufferSize, Progressable progress) Append to an existing file (optional operation).
protected URI	canonicalizeUri(URI uri) Canonicalize the given URI.
protected void	checkPath(Path path) Check that a Path belongs to this FileSystem.
void	close() No more filesystem operations are needed.
void	completeLocalOutput(Path fsOutputFile, Path tmpLocalFile) Called when we're all done writing to the target.
void	concat(Path f, 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	copyToLocalFile(boolean delSrc, Path src, Path dst) The src file is under FS, and the dst is on the local disk.
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, org.apache.hadoop.fs.Options.ChecksumOpt checksumOpt) Create an FSDataOutputStream at the indicated Path with a custom checksum option
FSDataOutputStream	createNonRecursive(Path f, FsPermission permission, EnumSet<CreateFlag> flags, int bufferSize, short replication, long blockSize, Progressable progress) Deprecated.
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, boolean recursive) Delete a file
void	deleteSnapshot(Path path, String snapshotName) Delete a snapshot of a directory
AclStatus	getAclStatus(Path path) Gets the ACL of a file or directory.
protected URI	getCanonicalUri() Return a canonicalized form of this FileSystem's URI.
FileSystem[]	getChildFileSystems() Get all the immediate child FileSystems embedded in this FileSystem.
Configuration	getConf() Return the configuration used by this object.
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 file, 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)
FileStatus	getFileStatus(Path f) Get file status.
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.
Path	getLinkTarget(Path f) See FileContext.getLinkTarget(Path)
FileSystem	getRawFileSystem() Get the raw file system
FsServerDefaults	getServerDefaults() Return a set of server default configuration values
FsServerDefaults	getServerDefaults(Path f) Return a set of server default configuration values
FsStatus	getStatus(Path p) Returns a status object describing the use and capacity of the file system.
URI	getUri() Returns a URI whose scheme and authority identify this FileSystem.
long	getUsed() Return the total size of all files in the filesystem.
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.
void	initialize(URI name, Configuration conf) Called after a new FileSystem instance is constructed.
org.apache.hadoop.fs.RemoteIterator<Path>	listCorruptFileBlocks(Path path)
org.apache.hadoop.fs.RemoteIterator<LocatedFileStatus>	listLocatedStatus(Path f) List files and its block locations in a directory.
FileStatus[]	listStatus(Path f) List files in a directory.
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.
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.
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)
protected boolean	primitiveMkdir(Path f, FsPermission abdolutePermission) This version of the mkdirs method assumes that the permission is absolute.
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.
boolean	rename(Path src, Path dst) Renames Path src to Path dst.
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.
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.
void	setWorkingDirectory(Path newDir) 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.fs.FileSystem

append, append, areSymlinksEnabled, cancelDeleteOnExit, clearStatistics, closeAll, closeAllForUGI, copyFromLocalFile, copyToLocalFile, copyToLocalFile, create, create, create, create, create, create, create, create, create, create, create, createNewFile, createNonRecursive, createNonRecursive, createSnapshot, delete, deleteOnExit, enableSymlinks, exists, fixRelativePart, get, get, get, getAllStatistics, getBlockSize, getContentSummary, getDefaultPort, getDefaultUri, getFileBlockLocations, getFileSystemClass, getFSofPath, getLength, getLocal, getName, getNamed, getReplication, getScheme, getStatistics, getStatistics, getStatus, globStatus, globStatus, isDirectory, isFile, listFiles, listLocatedStatus, listStatus, listStatus, listStatus, mkdirs, mkdirs, moveFromLocalFile, moveFromLocalFile, moveToLocalFile, newInstance, newInstance, newInstance, newInstanceLocal, open, primitiveMkdir, printStatistics, processDeleteOnExit, rename, setDefaultUri, setDefaultUri

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

setConf

Methods inherited from class java.lang.Object

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

Field Detail

fs

protected FileSystem fs

swapScheme

protected String swapScheme

Constructor Detail

FilterFileSystem

public FilterFileSystem()

FilterFileSystem

public FilterFileSystem(FileSystem fs)

Method Detail

getRawFileSystem

public FileSystem getRawFileSystem()

Get the raw file system

Returns:

FileSystem being filtered

initialize

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

Called after a new FileSystem instance is constructed.

Overrides:

initialize in class FileSystem

Parameters:

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

conf - the configuration

Throws:

IOException

getUri

public URI getUri()

Returns a URI whose scheme and authority identify this FileSystem.

Specified by:

getUri in class FileSystem

getCanonicalUri

protected URI getCanonicalUri()

Description copied from class: FileSystem

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

Overrides:

getCanonicalUri in class FileSystem

See Also:

FileSystem.canonicalizeUri(URI)

canonicalizeUri

protected URI canonicalizeUri(URI uri)

Description copied from class: FileSystem

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.

Overrides:

canonicalizeUri in class FileSystem

Returns:

URI

See Also:

NetUtils.getCanonicalUri(URI, int)

makeQualified

public Path makeQualified(Path path)

Make sure that a path specifies a FileSystem.

Overrides:

makeQualified in class FileSystem

Parameters:

path - to use

checkPath

protected void checkPath(Path path)

Check that a Path belongs to this FileSystem.

Overrides:

checkPath in class FileSystem

Parameters:

path - to check

getFileBlockLocations

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

Description copied from class: FileSystem

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

Overrides:

getFileBlockLocations in class FileSystem

Parameters:

file - FilesStatus to get data from

start - offset into the given file

len - length for which to get locations for

Throws:

IOException

resolvePath

public Path resolvePath(Path p)
                 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:

p - path to be resolved

Returns:

fully qualified path

Throws:

FileNotFoundException

IOException

open

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

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:

IOException

append

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

Description copied from class: FileSystem

Append to an existing file (optional operation).

Specified by:

append in class FileSystem

Parameters:

f - the existing file to be appended.

bufferSize - the size of the buffer to be used.

progress - for reporting progress if it is not null.

Throws:

IOException

concat

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

Description copied from class: FileSystem

Concat existing files together.

Overrides:

concat in class FileSystem

Parameters:

f - the path to the target destination.

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

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)

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

Description copied from class: FileSystem

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

Overrides:

create in class FileSystem

Parameters:

f - the file name to open

flags - CreateFlags to use for this stream.

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

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

Throws:

IOException

See Also:

FileSystem.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.

Description copied from class: FileSystem

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

Overrides:

createNonRecursive in class FileSystem

Parameters:

f - the file name to open

flags - CreateFlags to use for this stream.

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

Throws:

IOException

See Also:

FileSystem.setPermission(Path, FsPermission)

setReplication

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

Set replication for an existing file.

Overrides:

setReplication in class FileSystem

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 boolean rename(Path src,
                      Path dst)
               throws IOException

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

Specified by:

rename in class FileSystem

Parameters:

src - path to be renamed

dst - new path after rename

Returns:

true if rename is successful

Throws:

IOException - on failure

delete

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

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

listStatus

public FileStatus[] listStatus(Path f)
                        throws IOException

List files in 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

IOException

listCorruptFileBlocks

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

Overrides:

listCorruptFileBlocks in class FileSystem

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

listLocatedStatus

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

List files and its block locations in a directory.

Overrides:

listLocatedStatus in class FileSystem

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

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

setWorkingDirectory

public void setWorkingDirectory(Path newDir)

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

Parameters:

newDir -

getWorkingDirectory

public Path getWorkingDirectory()

Get the current working directory for the given file system

Specified by:

getWorkingDirectory in class FileSystem

Returns:

the directory pathname

getInitialWorkingDirectory

protected Path getInitialWorkingDirectory()

Description copied from class: FileSystem

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.

Overrides:

getInitialWorkingDirectory in class FileSystem

Returns:

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

getStatus

public FsStatus getStatus(Path p)
                   throws IOException

Description copied from class: FileSystem

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.

Overrides:

getStatus in class FileSystem

Parameters:

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

Returns:

a FsStatus object

Throws:

IOException - see specific implementation

mkdirs

public boolean mkdirs(Path f,
                      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:

f - path to create

permission - to apply to f

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

Overrides:

copyFromLocalFile in class FileSystem

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

Overrides:

copyFromLocalFile in class FileSystem

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

Overrides:

copyFromLocalFile in class FileSystem

Parameters:

delSrc - whether to delete the src

overwrite - whether to overwrite an existing file

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.

Overrides:

copyToLocalFile in class FileSystem

Parameters:

delSrc - whether to delete the src

src - path

dst - path

Throws:

IOException

startLocalOutput

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

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

Overrides:

startLocalOutput in class FileSystem

Parameters:

fsOutputFile - path of output file

tmpLocalFile - path of local tmp file

Throws:

IOException

completeLocalOutput

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

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

Overrides:

completeLocalOutput in class FileSystem

Parameters:

fsOutputFile - path of output file

tmpLocalFile - path to local tmp file

Throws:

IOException

getUsed

public long getUsed()
             throws IOException

Return the total size of all files in the filesystem.

Overrides:

getUsed in class FileSystem

Throws:

IOException

getDefaultBlockSize

public long getDefaultBlockSize()

Description copied from class: FileSystem

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

Overrides:

getDefaultBlockSize in class FileSystem

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

getFileStatus

public FileStatus getFileStatus(Path f)
                         throws IOException

Get file status.

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

IOException

access

public void access(Path path,
                   FsAction mode)
            throws org.apache.hadoop.security.AccessControlException,
                   FileNotFoundException,
                   IOException

Description copied from class: FileSystem

Checks if the user can access a path. The mode specifies which access checks to perform. If the requested permissions are granted, then the method returns normally. If access is denied, then the method throws an AccessControlException.

The default implementation of this method calls FileSystem.getFileStatus(Path) and checks the returned permissions against the requested permissions. Note that the getFileStatus call will be subject to authorization checks. Typically, this requires search (execute) permissions on each directory in the path's prefix, but this is implementation-defined. Any file system that provides a richer authorization model (such as ACLs) may override the default implementation so that it checks against that model instead.

In general, applications should avoid using this method, due to the risk of time-of-check/time-of-use race conditions. The permissions on a file may change immediately after the access call returns. Most applications should prefer running specific file system actions as the desired user represented by a UserGroupInformation.

Parameters:

path - Path to check

mode - type of access to check

Throws:

org.apache.hadoop.security.AccessControlException - if access is denied

FileNotFoundException - if the path does not exist

IOException - see specific implementation

createSymlink

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

Description copied from class: FileSystem

See FileContext.createSymlink(Path, Path, boolean)

Overrides:

createSymlink in class FileSystem

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

Description copied from class: FileSystem

See FileContext.getFileLinkStatus(Path)

Overrides:

getFileLinkStatus in class FileSystem

Throws:

org.apache.hadoop.security.AccessControlException

FileNotFoundException

UnsupportedFileSystemException

IOException

supportsSymlinks

public boolean supportsSymlinks()

Description copied from class: FileSystem

See AbstractFileSystem.supportsSymlinks()

Overrides:

supportsSymlinks in class FileSystem

getLinkTarget

public Path getLinkTarget(Path f)
                   throws IOException

Description copied from class: FileSystem

See FileContext.getLinkTarget(Path)

Overrides:

getLinkTarget in class FileSystem

Throws:

IOException

resolveLink

protected Path resolveLink(Path f)
                    throws IOException

Description copied from class: FileSystem

See AbstractFileSystem.getLinkTarget(Path)

Overrides:

resolveLink in class FileSystem

Throws:

IOException

getFileChecksum

public FileChecksum getFileChecksum(Path f)
                             throws 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:

IOException

getFileChecksum

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

Description copied from class: FileSystem

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

Overrides:

getFileChecksum in class FileSystem

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)

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

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

getConf

public Configuration getConf()

Description copied from interface: Configurable

Return the configuration used by this object.

Specified by:

getConf in interface Configurable

Overrides:

getConf in class Configured

close

public void close()
           throws IOException

Description copied from class: FileSystem

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

Specified by:

close in interface Closeable

Overrides:

close in class FileSystem

Throws:

IOException

setOwner

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

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

Description copied from class: FileSystem

Set access time of a file

Overrides:

setTimes in class FileSystem

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

setPermission

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

Description copied from class: FileSystem

Set permission of a path.

Overrides:

setPermission in class FileSystem

Throws:

IOException

primitiveCreate

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

Overrides:

primitiveCreate in class FileSystem

Throws:

IOException

primitiveMkdir

protected boolean primitiveMkdir(Path f,
                                 FsPermission abdolutePermission)
                          throws IOException

Description copied from class: FileSystem

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.

Overrides:

primitiveMkdir in class FileSystem

Throws:

IOException

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

createSnapshot

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

Description copied from class: FileSystem

Create a snapshot

Overrides:

createSnapshot in class FileSystem

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

Description copied from class: FileSystem

Rename a snapshot

Overrides:

renameSnapshot in class FileSystem

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

Description copied from class: FileSystem

Delete a snapshot of a directory

Overrides:

deleteSnapshot in class FileSystem

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

Description copied from class: FileSystem

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.)

Overrides:

modifyAclEntries in class FileSystem

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

Description copied from class: FileSystem

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

Overrides:

removeAclEntries in class FileSystem

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

Description copied from class: FileSystem

Removes all default ACL entries from files and directories.

Overrides:

removeDefaultAcl in class FileSystem

Parameters:

path - Path to modify

Throws:

IOException - if an ACL could not be modified

removeAcl

public void removeAcl(Path path)
               throws IOException

Description copied from class: FileSystem

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.

Overrides:

removeAcl in class FileSystem

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

Description copied from class: FileSystem

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

Overrides:

setAcl in class FileSystem

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

Description copied from class: FileSystem

Gets the ACL of a file or directory.

Overrides:

getAclStatus in class FileSystem

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

Description copied from class: FileSystem

Set an xattr of a file or directory. The name must be prefixed with the namespace followed by ".". For example, "user.attr".

Refer to the HDFS extended attributes user documentation for details.

Overrides:

setXAttr in class FileSystem

Parameters:

path - Path to modify

name - xattr name.

value - xattr value.

Throws:

IOException

setXAttr

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

Description copied from class: FileSystem

Set an xattr of a file or directory. The name must be prefixed with the namespace followed by ".". For example, "user.attr".

Refer to the HDFS extended attributes user documentation for details.

Overrides:

setXAttr in class FileSystem

Parameters:

path - Path to modify

name - xattr name.

value - xattr value.

flag - xattr set flag

Throws:

IOException

getXAttr

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

Description copied from class: FileSystem

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

Refer to the HDFS extended attributes user documentation for details.

Overrides:

getXAttr in class FileSystem

Parameters:

path - Path to get extended attribute

name - xattr name.

Returns:

byte[] xattr value.

Throws:

IOException

getXAttrs

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

Description copied from class: FileSystem

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.

Refer to the HDFS extended attributes user documentation for details.

Overrides:

getXAttrs in class FileSystem

Parameters:

path - Path to get extended attributes

Returns:

Map describing the XAttrs of the file or directory

Throws:

IOException

getXAttrs

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

Description copied from class: FileSystem

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.

Refer to the HDFS extended attributes user documentation for details.

Overrides:

getXAttrs in class FileSystem

Parameters:

path - Path to get extended attributes

names - XAttr names.

Returns:

Map describing the XAttrs of the file or directory

Throws:

IOException

listXAttrs

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

Description copied from class: FileSystem

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.

Refer to the HDFS extended attributes user documentation for details.

Overrides:

listXAttrs in class FileSystem

Parameters:

path - Path to get extended attributes

Returns:

List of the XAttr names of the file or directory

Throws:

IOException

removeXAttr

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

Description copied from class: FileSystem

Remove an xattr of a file or directory. The name must be prefixed with the namespace followed by ".". For example, "user.attr".

Refer to the HDFS extended attributes user documentation for details.

Overrides:

removeXAttr in class FileSystem

Parameters:

path - Path to remove extended attribute

name - xattr name

Throws:

IOException