@InterfaceAudience.Public @InterfaceStability.Evolving public class ViewFs extends AbstractFileSystem
To use viewfs one would typically set the default file system in the config (i.e. fs.default.name< = 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:
**** 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:
statistics
Constructor and Description |
---|
ViewFs(Configuration conf) |
Modifier and Type | Method and Description |
---|---|
FSDataOutputStream |
createInternal(Path f,
EnumSet<CreateFlag> flag,
FsPermission absolutePermission,
int bufferSize,
short replication,
long blockSize,
Progressable progress,
org.apache.hadoop.fs.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. |
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. |
List<org.apache.hadoop.security.token.Token<?>> |
getDelegationTokens(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)
The specification of this method matches that of
FileContext.getLinkTarget(Path) ; |
org.apache.hadoop.fs.viewfs.ViewFs.MountPoint[] |
getMountPoints() |
FsServerDefaults |
getServerDefaults()
Return a set of server default configuration values.
|
int |
getUriDefaultPort()
The default port of 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. |
org.apache.hadoop.fs.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. |
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. |
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 |
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. |
Path |
resolvePath(Path f)
Return the fully-qualified path of path f resolving the path
through any internal symlinks or mount point
|
void |
setOwner(Path f,
String username,
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 |
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. |
boolean |
supportsSymlinks()
Returns true if the file system supports symlinks, false otherwise.
|
checkPath, checkScheme, clearStatistics, create, createFileSystem, equals, get, getAllStatistics, getCanonicalServiceName, getFsStatus, getInitialWorkingDirectory, getStatistics, getStatistics, getUri, getUriPath, hashCode, listCorruptFileBlocks, listLocatedStatus, makeQualified, open, printStatistics, rename
public ViewFs(Configuration conf) throws IOException, URISyntaxException
IOException
URISyntaxException
public FsServerDefaults getServerDefaults() throws IOException
AbstractFileSystem
getServerDefaults
in class AbstractFileSystem
IOException
- an I/O error occurredpublic int getUriDefaultPort()
AbstractFileSystem
getUriDefaultPort
in class AbstractFileSystem
public Path getHomeDirectory()
AbstractFileSystem
getHomeDirectory
in class AbstractFileSystem
public Path resolvePath(Path f) throws FileNotFoundException, org.apache.hadoop.security.AccessControlException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
resolvePath
in class AbstractFileSystem
f
- path to be resolvedFileNotFoundException
org.apache.hadoop.security.AccessControlException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public FSDataOutputStream createInternal(Path f, EnumSet<CreateFlag> flag, FsPermission absolutePermission, int bufferSize, short replication, long blockSize, Progressable progress, org.apache.hadoop.fs.Options.ChecksumOpt checksumOpt, boolean createParent) throws org.apache.hadoop.security.AccessControlException, FileAlreadyExistsException, FileNotFoundException, ParentNotDirectoryException, UnsupportedFileSystemException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
AbstractFileSystem.create(Path, EnumSet, Options.CreateOpts...)
except that the opts
have been declared explicitly.createInternal
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileAlreadyExistsException
FileNotFoundException
ParentNotDirectoryException
UnsupportedFileSystemException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public boolean delete(Path f, boolean recursive) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
FileContext.delete(Path, boolean)
except that Path f must be for
this file system.delete
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public BlockLocation[] getFileBlockLocations(Path f, long start, long len) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
FileContext.getFileBlockLocations(Path, long, long)
except that
Path f must be for this file system.getFileBlockLocations
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public FileChecksum getFileChecksum(Path f) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
FileContext.getFileChecksum(Path)
except that Path f must be for
this file system.getFileChecksum
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public FileStatus getFileStatus(Path f) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
FileContext.getFileStatus(Path)
except that an UnresolvedLinkException may be thrown if a symlink is
encountered in the path.getFileStatus
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public FileStatus getFileLinkStatus(Path f) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, UnsupportedFileSystemException, IOException
AbstractFileSystem
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)
.getFileLinkStatus
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
UnsupportedFileSystemException
IOException
public FsStatus getFsStatus() throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, IOException
AbstractFileSystem
FileContext.getFsStatus(Path)
.getFsStatus
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
IOException
public org.apache.hadoop.fs.RemoteIterator<FileStatus> listStatusIterator(Path f) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
FileContext.listStatus(Path)
except that Path f must be for this
file system.listStatusIterator
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public FileStatus[] listStatus(Path f) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
FileContext.Util.listStatus(Path)
except that Path f must be
for this file system.listStatus
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public void mkdir(Path dir, FsPermission permission, boolean createParent) throws org.apache.hadoop.security.AccessControlException, FileAlreadyExistsException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
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).mkdir
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileAlreadyExistsException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public FSDataInputStream open(Path f, int bufferSize) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
FileContext.open(Path, int)
except that Path f must be for this
file system.open
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public void renameInternal(Path src, Path dst, boolean overwrite) throws IOException, org.apache.hadoop.fs.UnresolvedLinkException
AbstractFileSystem
FileContext.rename(Path, Path, Options.Rename...)
except that Path
f must be for this file system.renameInternal
in class AbstractFileSystem
IOException
org.apache.hadoop.fs.UnresolvedLinkException
public void renameInternal(Path src, Path dst) throws org.apache.hadoop.security.AccessControlException, FileAlreadyExistsException, FileNotFoundException, ParentNotDirectoryException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
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)
renameInternal
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileAlreadyExistsException
FileNotFoundException
ParentNotDirectoryException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public boolean supportsSymlinks()
AbstractFileSystem
supportsSymlinks
in class AbstractFileSystem
public void createSymlink(Path target, Path link, boolean createParent) throws IOException, org.apache.hadoop.fs.UnresolvedLinkException
AbstractFileSystem
FileContext.createSymlink(Path, Path, boolean)
;createSymlink
in class AbstractFileSystem
IOException
org.apache.hadoop.fs.UnresolvedLinkException
public Path getLinkTarget(Path f) throws IOException
AbstractFileSystem
FileContext.getLinkTarget(Path)
;getLinkTarget
in class AbstractFileSystem
IOException
public void setOwner(Path f, String username, String groupname) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
FileContext.setOwner(Path, String, String)
except that Path f must
be for this file system.setOwner
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public void setPermission(Path f, FsPermission permission) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
FileContext.setPermission(Path, FsPermission)
except that Path f
must be for this file system.setPermission
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public boolean setReplication(Path f, short replication) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
FileContext.setReplication(Path, short)
except that Path f must be
for this file system.setReplication
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public void setTimes(Path f, long mtime, long atime) throws org.apache.hadoop.security.AccessControlException, FileNotFoundException, org.apache.hadoop.fs.UnresolvedLinkException, IOException
AbstractFileSystem
FileContext.setTimes(Path, long, long)
except that Path f must be
for this file system.setTimes
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
FileNotFoundException
org.apache.hadoop.fs.UnresolvedLinkException
IOException
public void setVerifyChecksum(boolean verifyChecksum) throws org.apache.hadoop.security.AccessControlException, IOException
AbstractFileSystem
FileContext.setVerifyChecksum(boolean, Path)
except that Path f
must be for this file system.setVerifyChecksum
in class AbstractFileSystem
org.apache.hadoop.security.AccessControlException
IOException
public org.apache.hadoop.fs.viewfs.ViewFs.MountPoint[] getMountPoints()
public List<org.apache.hadoop.security.token.Token<?>> getDelegationTokens(String renewer) throws IOException
AbstractFileSystem
renewer
- the account name that is allowed to renew the token.IOException
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