Package org.apache.hadoop.fs.viewfs

Class ViewFs

java.lang.Object

org.apache.hadoop.fs.AbstractFileSystem

org.apache.hadoop.fs.viewfs.ViewFs

All Implemented Interfaces:

PathCapabilities

@Public
@Evolving
public class ViewFs
extends AbstractFileSystem

ViewFs (extends the AbstractFileSystem interface) implements a client-side mount table. The viewFs file system is implemented completely in memory on the client side. The client-side mount table allows a client to provide a customized view of a file system namespace that is composed from one or more individual file systems (a localFs or Hdfs, S3fs, etc). For example one could have a mount table that provides links such as

• /user -> hdfs://nnContainingUserDir/user
• /project/foo -> hdfs://nnProject1/projects/foo
• /project/bar -> hdfs://nnProject2/projects/bar
• /tmp -> hdfs://nnTmp/privateTmpForUserXXX

ViewFs is specified with the following URI: viewfs:///

To use viewfs one would typically set the default file system in the config (i.e. fs.defaultFS < = viewfs:///) along with the mount table config variables as described below.

** Config variables to specify the mount table entries **

The file system is initialized from the standard Hadoop config through config variables. See FsConstants for URI and Scheme constants; See Constants for config var constants; see ConfigUtil for convenient lib.

All the mount table config entries for view fs are prefixed by fs.viewfs.mounttable. For example the above example can be specified with the following config variables:

• fs.viewfs.mounttable.default.link./user= hdfs://nnContainingUserDir/user
• fs.viewfs.mounttable.default.link./project/foo= hdfs://nnProject1/projects/foo
• fs.viewfs.mounttable.default.link./project/bar= hdfs://nnProject2/projects/bar
• fs.viewfs.mounttable.default.link./tmp= hdfs://nnTmp/privateTmpForUserXXX

The default mount table (when no authority is specified) is from config variables prefixed by fs.viewFs.mounttable.default The authority component of a URI can be used to specify a different mount table. For example,

• viewfs://sanjayMountable/

is initialized from fs.viewFs.mounttable.sanjayMountable.* config variables.

**** Merge Mounts **** (NOTE: merge mounts are not implemented yet.)

One can also use "MergeMounts" to merge several directories (this is sometimes called union-mounts or junction-mounts in the literature. For example of the home directories are stored on say two file systems (because they do not fit on one) then one could specify a mount entry such as following merges two dirs:

• /user -> hdfs://nnUser1/user,hdfs://nnUser2/user

Such a mergeLink can be specified with the following config var where "," is used as the separator for each of links to be merged:

• fs.viewfs.mounttable.default.linkMerge./user= hdfs://nnUser1/user,hdfs://nnUser1/user

A special case of the merge mount is where mount table's root is merged with the root (slash) of another file system:

• fs.viewfs.mounttable.default.linkMergeSlash=hdfs://nn99/

In this cases the root of the mount table is merged with the root of hdfs://nn99/

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ViewFs.MountPoint

Field Summary

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

statistics

Constructor Summary

Constructors

Constructor	Description
ViewFs(Configuration conf)

Method Summary

Modifier and Type	Method	Description
void	access(Path path, FsAction mode)	The specification of this method matches that of FileContext.access(Path, FsAction) except that an UnresolvedLinkException may be thrown if a symlink is encountered in the path.
FSDataOutputStream	createInternal(Path f, java.util.EnumSet<CreateFlag> flag, FsPermission absolutePermission, int bufferSize, short replication, long blockSize, Progressable progress, Options.ChecksumOpt checksumOpt, boolean createParent)	The specification of this method matches that of AbstractFileSystem.create(Path, EnumSet, Options.CreateOpts...) except that the opts have been declared explicitly.
Path	createSnapshot(Path path, java.lang.String snapshotName)	The specification of this method matches that of FileContext.createSnapshot(Path, String).
void	createSymlink(Path target, Path link, boolean createParent)	The specification of this method matches that of FileContext.createSymlink(Path, Path, boolean);
boolean	delete(Path f, boolean recursive)	The specification of this method matches that of FileContext.delete(Path, boolean) except that Path f must be for this file system.
void	deleteSnapshot(Path path, java.lang.String snapshotName)	The specification of this method matches that of FileContext.deleteSnapshot(Path, String).
AclStatus	getAclStatus(Path path)	Gets the ACLs of files and directories.
java.util.List<Token<?>>	getDelegationTokens(java.lang.String renewer)	Get one or more delegation tokens associated with the filesystem.
BlockLocation[]	getFileBlockLocations(Path f, long start, long len)	The specification of this method matches that of FileContext.getFileBlockLocations(Path, long, long) except that Path f must be for this file system.
FileChecksum	getFileChecksum(Path f)	The specification of this method matches that of FileContext.getFileChecksum(Path) except that Path f must be for this file system.
FileStatus	getFileLinkStatus(Path f)	The specification of this method matches that of FileContext.getFileLinkStatus(Path) except that an UnresolvedLinkException may be thrown if a symlink is encountered in the path leading up to the final path component.
FileStatus	getFileStatus(Path f)	The specification of this method matches that of FileContext.getFileStatus(Path) except that an UnresolvedLinkException may be thrown if a symlink is encountered in the path.
FsStatus	getFsStatus()	The specification of this method matches that of FileContext.getFsStatus(Path).
Path	getHomeDirectory()	Return the current user's home directory in this file system.
Path	getLinkTarget(Path f)	Partially resolves the path.
ViewFs.MountPoint[]	getMountPoints()
FsServerDefaults	getServerDefaults()	Deprecated.
FsServerDefaults	getServerDefaults(Path f)	Return a set of server default configuration values based on path.
BlockStoragePolicySpi	getStoragePolicy(Path src)	Retrieve the storage policy for a given file or directory.
int	getUriDefaultPort()	The default port of this file system.
byte[]	getXAttr(Path path, java.lang.String name)	Get an xattr for a file or directory.
java.util.Map<java.lang.String,byte[]>	getXAttrs(Path path)	Get all of the xattrs for a file or directory.
java.util.Map<java.lang.String,byte[]>	getXAttrs(Path path, java.util.List<java.lang.String> names)	Get all of the xattrs for a file or directory.
boolean	isValidName(java.lang.String src)	Returns true if the specified string is considered valid in the path part of a URI by this file system.
RemoteIterator<LocatedFileStatus>	listLocatedStatus(Path f)	The specification of this method matches that of FileContext.listLocatedStatus(Path) except that Path f must be for this file system.
FileStatus[]	listStatus(Path f)	The specification of this method matches that of FileContext.Util.listStatus(Path) except that Path f must be for this file system.
RemoteIterator<FileStatus>	listStatusIterator(Path f)	The specification of this method matches that of FileContext.listStatus(Path) except that Path f must be for this file system.
java.util.List<java.lang.String>	listXAttrs(Path path)	Get all of the xattr names for a file or directory.
void	mkdir(Path dir, FsPermission permission, boolean createParent)	The specification of this method matches that of FileContext.mkdir(Path, FsPermission, boolean) except that the Path f must be fully qualified and the permission is absolute (i.e.
void	modifyAclEntries(Path path, java.util.List<AclEntry> aclSpec)	Modifies ACL entries of files and directories.
FSDataInputStream	open(Path f, int bufferSize)	The specification of this method matches that of FileContext.open(Path, int) except that Path f must be for this file system.
void	removeAcl(Path path)	Removes all but the base ACL entries of files and directories.
void	removeAclEntries(Path path, java.util.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, java.lang.String name)	Remove an xattr of a file or directory.
void	renameInternal(Path src, Path dst)	The specification of this method matches that of FileContext.rename(Path, Path, Options.Rename...) except that Path f must be for this file system and NO OVERWRITE is performed.
void	renameInternal(Path src, Path dst, boolean overwrite)	The specification of this method matches that of FileContext.rename(Path, Path, Options.Rename...) except that Path f must be for this file system.
void	renameSnapshot(Path path, java.lang.String snapshotOldName, java.lang.String snapshotNewName)	The specification of this method matches that of FileContext.renameSnapshot(Path, String, String).
Path	resolvePath(Path f)	Return the fully-qualified path of path f resolving the path through any internal symlinks or mount point
void	satisfyStoragePolicy(Path path)	Set the source path to satisfy storage policy.
void	setAcl(Path path, java.util.List<AclEntry> aclSpec)	Fully replaces ACL of files and directories, discarding all existing entries.
void	setOwner(Path f, java.lang.String username, java.lang.String groupname)	The specification of this method matches that of FileContext.setOwner(Path, String, String) except that Path f must be for this file system.
void	setPermission(Path f, FsPermission permission)	The specification of this method matches that of FileContext.setPermission(Path, FsPermission) except that Path f must be for this file system.
boolean	setReplication(Path f, short replication)	The specification of this method matches that of FileContext.setReplication(Path, short) except that Path f must be for this file system.
void	setStoragePolicy(Path path, java.lang.String policyName)	Set the storage policy for a given file or directory.
void	setTimes(Path f, long mtime, long atime)	The specification of this method matches that of FileContext.setTimes(Path, long, long) except that Path f must be for this file system.
void	setVerifyChecksum(boolean verifyChecksum)	The specification of this method matches that of FileContext.setVerifyChecksum(boolean, Path) except that Path f must be for this file system.
void	setXAttr(Path path, java.lang.String name, byte[] value, java.util.EnumSet<XAttrSetFlag> flag)	Set an xattr of a file or directory.
boolean	supportsSymlinks()	Returns true if the file system supports symlinks, false otherwise.
boolean	truncate(Path f, long newLength)	The specification of this method matches that of FileContext.truncate(Path, long) except that Path f must be for this file system.
void	unsetStoragePolicy(Path src)	Unset the storage policy set for a given file or directory.

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

checkPath, checkScheme, clearStatistics, create, createFileSystem, createMultipartUploader, equals, get, getAllStatistics, getAllStoragePolicies, getCanonicalServiceName, getEnclosingRoot, getFsStatus, getInitialWorkingDirectory, getStatistics, getStatistics, getUri, getUriPath, hashCode, hasPathCapability, listCorruptFileBlocks, makeQualified, methodNotSupported, msync, open, openFileWithOptions, printStatistics, rename, setXAttr

Methods inherited from class java.lang.Object

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

Constructor Detail

ViewFs

public ViewFs(Configuration conf)
       throws java.io.IOException,
              java.net.URISyntaxException

Throws:

java.io.IOException

java.net.URISyntaxException

Method Detail

getServerDefaults

@Deprecated
public FsServerDefaults getServerDefaults()
                                   throws java.io.IOException

Deprecated.

Description copied from class: AbstractFileSystem

Return a set of server default configuration values.

Specified by:

getServerDefaults in class AbstractFileSystem

Returns:

server default configuration values

Throws:

java.io.IOException - an I/O error occurred

getServerDefaults

public FsServerDefaults getServerDefaults(Path f)
                                   throws java.io.IOException

Description copied from class: AbstractFileSystem

Return a set of server default configuration values based on path.

Overrides:

getServerDefaults in class AbstractFileSystem

Parameters:

f - path to fetch server defaults

Returns:

server default configuration values for path

Throws:

java.io.IOException - an I/O error occurred

getUriDefaultPort

public int getUriDefaultPort()

Description copied from class: AbstractFileSystem

The default port of this file system.

Specified by:

getUriDefaultPort in class AbstractFileSystem

Returns:

default port of this file system's Uri scheme A uri with a port of -1 => default port;

getHomeDirectory

public Path getHomeDirectory()

Description copied from class: AbstractFileSystem

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

Overrides:

getHomeDirectory in class AbstractFileSystem

Returns:

current user's home directory.

resolvePath

public Path resolvePath(Path f)
                 throws java.io.FileNotFoundException,
                        AccessControlException,
                        UnresolvedLinkException,
                        java.io.IOException

Description copied from class: AbstractFileSystem

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

Overrides:

resolvePath in class AbstractFileSystem

Parameters:

f - path to be resolved

Returns:

fully qualified path

Throws:

java.io.FileNotFoundException - when file not find throw.

AccessControlException - when accees control error throw.

UnresolvedLinkException - if symbolic link on path cannot be resolved internally

java.io.IOException - raised on errors performing I/O.

createInternal

public FSDataOutputStream createInternal(Path f,
                                         java.util.EnumSet<CreateFlag> flag,
                                         FsPermission absolutePermission,
                                         int bufferSize,
                                         short replication,
                                         long blockSize,
                                         Progressable progress,
                                         Options.ChecksumOpt checksumOpt,
                                         boolean createParent)
                                  throws AccessControlException,
                                         FileAlreadyExistsException,
                                         java.io.FileNotFoundException,
                                         ParentNotDirectoryException,
                                         UnsupportedFileSystemException,
                                         UnresolvedLinkException,
                                         java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of AbstractFileSystem.create(Path, EnumSet, Options.CreateOpts...) except that the opts have been declared explicitly.

Specified by:

createInternal in class AbstractFileSystem

Parameters:

f - the path.

flag - create flag.

absolutePermission - absolute permission.

bufferSize - buffer size.

replication - replications.

blockSize - block size.

progress - progress.

checksumOpt - check sum opt.

createParent - create parent.

Returns:

output stream.

Throws:

AccessControlException - access control exception.

FileAlreadyExistsException - file already exists exception.

java.io.FileNotFoundException - file not found exception.

ParentNotDirectoryException - parent not directory exception.

UnsupportedFileSystemException - unsupported filesystem exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

delete

public boolean delete(Path f,
                      boolean recursive)
               throws AccessControlException,
                      java.io.FileNotFoundException,
                      UnresolvedLinkException,
                      java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.delete(Path, boolean) except that Path f must be for this file system.

Specified by:

delete in class AbstractFileSystem

Parameters:

f - the path.

recursive - recursive flag.

Returns:

if successfully deleted success true, not false.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

getFileBlockLocations

public BlockLocation[] getFileBlockLocations(Path f,
                                             long start,
                                             long len)
                                      throws AccessControlException,
                                             java.io.FileNotFoundException,
                                             UnresolvedLinkException,
                                             java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.getFileBlockLocations(Path, long, long) except that Path f must be for this file system.

Specified by:

getFileBlockLocations in class AbstractFileSystem

Parameters:

f - the path.

start - start.

len - length.

Returns:

BlockLocation Array.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

getFileChecksum

public FileChecksum getFileChecksum(Path f)
                             throws AccessControlException,
                                    java.io.FileNotFoundException,
                                    UnresolvedLinkException,
                                    java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.getFileChecksum(Path) except that Path f must be for this file system.

Specified by:

getFileChecksum in class AbstractFileSystem

Parameters:

f - the path.

Returns:

File Check sum.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

getFileStatus

public FileStatus getFileStatus(Path f)
                         throws AccessControlException,
                                java.io.FileNotFoundException,
                                UnresolvedLinkException,
                                java.io.IOException

The specification of this method matches that of FileContext.getFileStatus(Path) except that an UnresolvedLinkException may be thrown if a symlink is encountered in the path. If the given path is a symlink(mount link), the path will be resolved to a target path and it will get the resolved path's FileStatus object. It will not be represented as a symlink and isDirectory API returns true if the resolved path is a directory, false otherwise.

Specified by:

getFileStatus in class AbstractFileSystem

Parameters:

f - the path.

Returns:

File Status

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

access

public void access(Path path,
                   FsAction mode)
            throws AccessControlException,
                   java.io.FileNotFoundException,
                   UnresolvedLinkException,
                   java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.access(Path, FsAction) except that an UnresolvedLinkException may be thrown if a symlink is encountered in the path.

Overrides:

access in class AbstractFileSystem

Parameters:

path - the path.

mode - fsaction mode.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

getFileLinkStatus

public FileStatus getFileLinkStatus(Path f)
                             throws AccessControlException,
                                    java.io.FileNotFoundException,
                                    UnsupportedFileSystemException,
                                    java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.getFileLinkStatus(Path) except that an UnresolvedLinkException may be thrown if a symlink is encountered in the path leading up to the final path component. If the file system does not support symlinks then the behavior is equivalent to AbstractFileSystem.getFileStatus(Path).

Overrides:

getFileLinkStatus in class AbstractFileSystem

Parameters:

f - the path.

Returns:

file status.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnsupportedFileSystemException - UnSupported File System Exception.

java.io.IOException - raised on errors performing I/O.

getFsStatus

public FsStatus getFsStatus()
                     throws AccessControlException,
                            java.io.FileNotFoundException,
                            java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.getFsStatus(Path).

Specified by:

getFsStatus in class AbstractFileSystem

Returns:

Fs Status.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

java.io.IOException - raised on errors performing I/O.

listStatusIterator

public RemoteIterator<FileStatus> listStatusIterator(Path f)
                                              throws AccessControlException,
                                                     java.io.FileNotFoundException,
                                                     UnresolvedLinkException,
                                                     java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.listStatus(Path) except that Path f must be for this file system.

Overrides:

listStatusIterator in class AbstractFileSystem

Parameters:

f - path.

Returns:

FileStatus Iterator.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

listLocatedStatus

public RemoteIterator<LocatedFileStatus> listLocatedStatus(Path f)
                                                    throws AccessControlException,
                                                           java.io.FileNotFoundException,
                                                           UnresolvedLinkException,
                                                           java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.listLocatedStatus(Path) except that Path f must be for this file system. In HDFS implementation, the BlockLocation of returned LocatedFileStatus will have different formats for replicated and erasure coded file. Please refer to FileSystem.getFileBlockLocations(FileStatus, long, long) for more details.

Overrides:

listLocatedStatus in class AbstractFileSystem

Parameters:

f - the path.

Returns:

FileStatus Iterator.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

listStatus

public FileStatus[] listStatus(Path f)
                        throws AccessControlException,
                               java.io.FileNotFoundException,
                               UnresolvedLinkException,
                               java.io.IOException

The specification of this method matches that of FileContext.Util.listStatus(Path) except that Path f must be for this file system. Note: listStatus considers listing from fallbackLink if available. If the same directory path is present in configured mount path as well as in fallback fs, then only the fallback path will be listed in the returned result except for link. If any of the the immediate children of the given path f is a symlink(mount link), the returned FileStatus object of that children would be represented as a symlink. It will not be resolved to the target path and will not get the target path FileStatus object. The target path will be available via getSymlink on that children's FileStatus object. Since it represents as symlink, isDirectory on that children's FileStatus will return false. This behavior can be changed by setting an advanced configuration fs.viewfs.mount.links.as.symlinks to false. In this case, mount points will be represented as non-symlinks and all the file/directory attributes like permissions, isDirectory etc will be assigned from it's resolved target directory/file. If you want to get the FileStatus of target path for that children, you may want to use GetFileStatus API with that children's symlink path. Please see getFileStatus(Path f) Note: In ViewFs, by default the mount links are represented as symlinks.

Specified by:

listStatus in class AbstractFileSystem

Parameters:

f - the path.

Returns:

FileStatus Iterator.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

mkdir

public void mkdir(Path dir,
                  FsPermission permission,
                  boolean createParent)
           throws AccessControlException,
                  FileAlreadyExistsException,
                  java.io.FileNotFoundException,
                  UnresolvedLinkException,
                  java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.mkdir(Path, FsPermission, boolean) except that the Path f must be fully qualified and the permission is absolute (i.e. umask has been applied).

Specified by:

mkdir in class AbstractFileSystem

Parameters:

dir - directory.

permission - permission.

createParent - create parent flag.

Throws:

AccessControlException - access control exception.

FileAlreadyExistsException - file already exists exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

open

public FSDataInputStream open(Path f,
                              int bufferSize)
                       throws AccessControlException,
                              java.io.FileNotFoundException,
                              UnresolvedLinkException,
                              java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.open(Path, int) except that Path f must be for this file system.

Specified by:

open in class AbstractFileSystem

Parameters:

f - the path.

bufferSize - buffer size.

Returns:

if successfully open success true, not false.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

truncate

public boolean truncate(Path f,
                        long newLength)
                 throws AccessControlException,
                        java.io.FileNotFoundException,
                        UnresolvedLinkException,
                        java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.truncate(Path, long) except that Path f must be for this file system.

Overrides:

truncate in class AbstractFileSystem

Parameters:

f - the path.

newLength - new length.

Returns:

if successfully truncate success true, not false.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

renameInternal

public void renameInternal(Path src,
                           Path dst,
                           boolean overwrite)
                    throws java.io.IOException,
                           UnresolvedLinkException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.rename(Path, Path, Options.Rename...) except that Path f must be for this file system.

Overrides:

renameInternal in class AbstractFileSystem

Parameters:

src - src.

dst - dst.

overwrite - overwrite flag.

Throws:

AccessControlException - access control exception.

FileAlreadyExistsException - file already exists exception.

java.io.FileNotFoundException - file not found exception.

ParentNotDirectoryException - parent not directory exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

renameInternal

public void renameInternal(Path src,
                           Path dst)
                    throws AccessControlException,
                           FileAlreadyExistsException,
                           java.io.FileNotFoundException,
                           ParentNotDirectoryException,
                           UnresolvedLinkException,
                           java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.rename(Path, Path, Options.Rename...) except that Path f must be for this file system and NO OVERWRITE is performed. File systems that do not have a built in overwrite need implement only this method and can take advantage of the default impl of the other AbstractFileSystem.renameInternal(Path, Path, boolean)

Specified by:

renameInternal in class AbstractFileSystem

Parameters:

src - src.

dst - dst.

Throws:

AccessControlException - access control exception.

FileAlreadyExistsException - file already exists exception.

java.io.FileNotFoundException - file not found exception.

ParentNotDirectoryException - parent not directory exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

supportsSymlinks

public boolean supportsSymlinks()

Description copied from class: AbstractFileSystem

Returns true if the file system supports symlinks, false otherwise.

Overrides:

supportsSymlinks in class AbstractFileSystem

Returns:

true if filesystem supports symlinks

createSymlink

public void createSymlink(Path target,
                          Path link,
                          boolean createParent)
                   throws java.io.IOException,
                          UnresolvedLinkException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.createSymlink(Path, Path, boolean);

Overrides:

createSymlink in class AbstractFileSystem

Parameters:

target - target.

link - link.

createParent - create parent.

Throws:

java.io.IOException - raised on errors performing I/O.

UnresolvedLinkException - unresolved link exception.

getLinkTarget

public Path getLinkTarget(Path f)
                   throws java.io.IOException

Description copied from class: AbstractFileSystem

Partially resolves the path. This is used during symlink resolution in FSLinkResolver, and differs from the similarly named method FileContext.getLinkTarget(Path).

Overrides:

getLinkTarget in class AbstractFileSystem

Parameters:

f - the path.

Returns:

target path.

Throws:

java.io.IOException - subclass implementations may throw IOException

setOwner

public void setOwner(Path f,
                     java.lang.String username,
                     java.lang.String groupname)
              throws AccessControlException,
                     java.io.FileNotFoundException,
                     UnresolvedLinkException,
                     java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.setOwner(Path, String, String) except that Path f must be for this file system.

Specified by:

setOwner in class AbstractFileSystem

Parameters:

f - the path.

username - username.

groupname - groupname.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

setPermission

public void setPermission(Path f,
                          FsPermission permission)
                   throws AccessControlException,
                          java.io.FileNotFoundException,
                          UnresolvedLinkException,
                          java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.setPermission(Path, FsPermission) except that Path f must be for this file system.

Specified by:

setPermission in class AbstractFileSystem

Parameters:

f - the path.

permission - permission.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

setReplication

public boolean setReplication(Path f,
                              short replication)
                       throws AccessControlException,
                              java.io.FileNotFoundException,
                              UnresolvedLinkException,
                              java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.setReplication(Path, short) except that Path f must be for this file system.

Specified by:

setReplication in class AbstractFileSystem

Parameters:

f - the path.

replication - replication.

Returns:

if successfully set replication success true, not false.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

setTimes

public void setTimes(Path f,
                     long mtime,
                     long atime)
              throws AccessControlException,
                     java.io.FileNotFoundException,
                     UnresolvedLinkException,
                     java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.setTimes(Path, long, long) except that Path f must be for this file system.

Specified by:

setTimes in class AbstractFileSystem

Parameters:

f - the path.

mtime - modify time.

atime - access time.

Throws:

AccessControlException - access control exception.

java.io.FileNotFoundException - file not found exception.

UnresolvedLinkException - unresolved link exception.

java.io.IOException - raised on errors performing I/O.

setVerifyChecksum

public void setVerifyChecksum(boolean verifyChecksum)
                       throws AccessControlException,
                              java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.setVerifyChecksum(boolean, Path) except that Path f must be for this file system.

Specified by:

setVerifyChecksum in class AbstractFileSystem

Parameters:

verifyChecksum - verify check sum flag.

Throws:

AccessControlException - access control exception.

java.io.IOException - raised on errors performing I/O.

getMountPoints

public ViewFs.MountPoint[] getMountPoints()

getDelegationTokens

public java.util.List<Token<?>> getDelegationTokens(java.lang.String renewer)
                                             throws java.io.IOException

Description copied from class: AbstractFileSystem

Get one or more delegation tokens associated with the filesystem. Normally a file system returns a single delegation token. A file system that manages multiple file systems underneath, could return set of delegation tokens for all the file systems it manages

Overrides:

getDelegationTokens in class AbstractFileSystem

Parameters:

renewer - the account name that is allowed to renew the token.

Returns:

List of delegation tokens. If delegation tokens not supported then return a list of size zero.

Throws:

java.io.IOException - raised on errors performing I/O.

isValidName

public boolean isValidName(java.lang.String src)

Description copied from class: AbstractFileSystem

Returns true if the specified string is considered valid in the path part of a URI by this file system. The default implementation enforces the rules of HDFS, but subclasses may override this method to implement specific validation rules for specific file systems.

Overrides:

isValidName in class AbstractFileSystem

Parameters:

src - String source filename to check, path part of the URI

Returns:

boolean true if the specified string is considered valid

modifyAclEntries

public void modifyAclEntries(Path path,
                             java.util.List<AclEntry> aclSpec)
                      throws java.io.IOException

Description copied from class: AbstractFileSystem

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 AbstractFileSystem

Parameters:

path - Path to modify

aclSpec - List<AclEntry> describing modifications

Throws:

java.io.IOException - if an ACL could not be modified

removeAclEntries

public void removeAclEntries(Path path,
                             java.util.List<AclEntry> aclSpec)
                      throws java.io.IOException

Description copied from class: AbstractFileSystem

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

Overrides:

removeAclEntries in class AbstractFileSystem

Parameters:

path - Path to modify

aclSpec - List<AclEntry> describing entries to remove

Throws:

java.io.IOException - if an ACL could not be modified

removeDefaultAcl

public void removeDefaultAcl(Path path)
                      throws java.io.IOException

Description copied from class: AbstractFileSystem

Removes all default ACL entries from files and directories.

Overrides:

removeDefaultAcl in class AbstractFileSystem

Parameters:

path - Path to modify

Throws:

java.io.IOException - if an ACL could not be modified

removeAcl

public void removeAcl(Path path)
               throws java.io.IOException

Description copied from class: AbstractFileSystem

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 AbstractFileSystem

Parameters:

path - Path to modify

Throws:

java.io.IOException - if an ACL could not be removed

setAcl

public void setAcl(Path path,
                   java.util.List<AclEntry> aclSpec)
            throws java.io.IOException

Description copied from class: AbstractFileSystem

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

Overrides:

setAcl in class AbstractFileSystem

Parameters:

path - Path to modify

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

Throws:

java.io.IOException - if an ACL could not be modified

getAclStatus

public AclStatus getAclStatus(Path path)
                       throws java.io.IOException

Description copied from class: AbstractFileSystem

Gets the ACLs of files and directories.

Overrides:

getAclStatus in class AbstractFileSystem

Parameters:

path - Path to get

Returns:

RemoteIterator<AclStatus> which returns each AclStatus

Throws:

java.io.IOException - if an ACL could not be read

setXAttr

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

Description copied from class: AbstractFileSystem

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 AbstractFileSystem

Parameters:

path - Path to modify

name - xattr name.

value - xattr value.

flag - xattr set flag

Throws:

java.io.IOException - raised on errors performing I/O.

getXAttr

public byte[] getXAttr(Path path,
                       java.lang.String name)
                throws java.io.IOException

Description copied from class: AbstractFileSystem

Get an xattr 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 AbstractFileSystem

Parameters:

path - Path to get extended attribute

name - xattr name.

Returns:

byte[] xattr value.

Throws:

java.io.IOException - raised on errors performing I/O.

getXAttrs

public java.util.Map<java.lang.String,byte[]> getXAttrs(Path path)
                                                       throws java.io.IOException

Description copied from class: AbstractFileSystem

Get all of the xattrs for a file or directory. Only those xattrs for 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 AbstractFileSystem

Parameters:

path - Path to get extended attributes

Returns:

Map<String, byte[]> describing the XAttrs of the file or directory

Throws:

java.io.IOException - raised on errors performing I/O.

getXAttrs

public java.util.Map<java.lang.String,byte[]> getXAttrs(Path path,
                                                              java.util.List<java.lang.String> names)
                                                       throws java.io.IOException

Description copied from class: AbstractFileSystem

Get all of the xattrs for a file or directory. Only those xattrs for 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 AbstractFileSystem

Parameters:

path - Path to get extended attributes

names - XAttr names.

Returns:

Map<String, byte[]> describing the XAttrs of the file or directory

Throws:

java.io.IOException - raised on errors performing I/O.

listXAttrs

public java.util.List<java.lang.String> listXAttrs(Path path)
                                            throws java.io.IOException

Description copied from class: AbstractFileSystem

Get all of the xattr names for a file or directory. Only the xattr names for 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 AbstractFileSystem

Parameters:

path - Path to get extended attributes

Returns:

Map<String, byte[]> describing the XAttrs of the file or directory

Throws:

java.io.IOException - raised on errors performing I/O.

removeXAttr

public void removeXAttr(Path path,
                        java.lang.String name)
                 throws java.io.IOException

Description copied from class: AbstractFileSystem

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 AbstractFileSystem

Parameters:

path - Path to remove extended attribute

name - xattr name

Throws:

java.io.IOException - raised on errors performing I/O.

createSnapshot

public Path createSnapshot(Path path,
                           java.lang.String snapshotName)
                    throws java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.createSnapshot(Path, String).

Overrides:

createSnapshot in class AbstractFileSystem

Parameters:

path - the path.

snapshotName - snapshot name.

Returns:

path.

Throws:

java.io.IOException - raised on errors performing I/O.

renameSnapshot

public void renameSnapshot(Path path,
                           java.lang.String snapshotOldName,
                           java.lang.String snapshotNewName)
                    throws java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.renameSnapshot(Path, String, String).

Overrides:

renameSnapshot in class AbstractFileSystem

Parameters:

path - the path.

snapshotOldName - snapshot old name.

snapshotNewName - snapshot new name.

Throws:

java.io.IOException - raised on errors performing I/O.

deleteSnapshot

public void deleteSnapshot(Path path,
                           java.lang.String snapshotName)
                    throws java.io.IOException

Description copied from class: AbstractFileSystem

The specification of this method matches that of FileContext.deleteSnapshot(Path, String).

Overrides:

deleteSnapshot in class AbstractFileSystem

Parameters:

path - snapshot dir.

snapshotName - snapshot name.

Throws:

java.io.IOException - raised on errors performing I/O.

satisfyStoragePolicy

public void satisfyStoragePolicy(Path path)
                          throws java.io.IOException

Description copied from class: AbstractFileSystem

Set the source path to satisfy storage policy.

Overrides:

satisfyStoragePolicy in class AbstractFileSystem

Parameters:

path - The source path referring to either a directory or a file.

Throws:

java.io.IOException - raised on errors performing I/O.

setStoragePolicy

public void setStoragePolicy(Path path,
                             java.lang.String policyName)
                      throws java.io.IOException

Description copied from class: AbstractFileSystem

Set the storage policy for a given file or directory.

Overrides:

setStoragePolicy in class AbstractFileSystem

Parameters:

path - file or directory path.

policyName - the name of the target storage policy. The list of supported Storage policies can be retrieved via AbstractFileSystem.getAllStoragePolicies().

Throws:

java.io.IOException - raised on errors performing I/O.

unsetStoragePolicy

public void unsetStoragePolicy(Path src)
                        throws java.io.IOException

Description copied from class: AbstractFileSystem

Unset the storage policy set for a given file or directory.

Overrides:

unsetStoragePolicy in class AbstractFileSystem

Parameters:

src - file or directory path.

Throws:

java.io.IOException - raised on errors performing I/O.

getStoragePolicy

public BlockStoragePolicySpi getStoragePolicy(Path src)
                                       throws java.io.IOException

Retrieve the storage policy for a given file or directory.

Overrides:

getStoragePolicy in class AbstractFileSystem

Parameters:

src - file or directory path.

Returns:

storage policy for give file.

Throws:

java.io.IOException - raised on errors performing I/O.