Package org.apache.hadoop.fs.viewfs

Class ViewFileSystem

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.fs.FileSystem

org.apache.hadoop.fs.viewfs.ViewFileSystem

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, Configurable, BulkDeleteSource, PathCapabilities, DelegationTokenIssuer

Direct Known Subclasses:

ViewFileSystemOverloadScheme

@Public
@Evolving
public class ViewFileSystem
extends FileSystem

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

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ViewFileSystem.MountPoint	MountPoint representation built from the configuration.

Nested classes/interfaces inherited from class org.apache.hadoop.fs.FileSystem

FileSystem.DirectoryEntries, FileSystem.DirListingIterator<T extends FileStatus>, FileSystem.Statistics

Field Summary

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

DEFAULT_FS, FS_DEFAULT_NAME_KEY, LOG, SHUTDOWN_HOOK_PRIORITY, statistics, TRASH_PREFIX, USER_HOME_PREFIX

Fields inherited from interface org.apache.hadoop.security.token.DelegationTokenIssuer

TOKEN_LOG

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
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).
void	close()	Close this FileSystem instance.
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	createNonRecursive(Path f, FsPermission permission, java.util.EnumSet<CreateFlag> flags, int bufferSize, short replication, long blockSize, Progressable progress)	Opens an FSDataOutputStream at the indicated Path with write-progress reporting.
Path	createSnapshot(Path path, java.lang.String snapshotName)	Create a snapshot.
boolean	delete(Path f)	Delete a file/directory.
boolean	delete(Path f, boolean recursive)	Delete a file.
void	deleteSnapshot(Path path, java.lang.String snapshotName)	Delete a snapshot of a directory.
protected FsGetter	fsGetter()	Gets file system creator instance.
AclStatus	getAclStatus(Path path)	Gets the ACL of a file or directory.
java.util.Collection<? extends BlockStoragePolicySpi>	getAllStoragePolicies()	Retrieve all the storage policies supported by this file system.
FileSystem[]	getChildFileSystems()	Get all the immediate child FileSystems embedded in this FileSystem.
ContentSummary	getContentSummary(Path f)	Return the ContentSummary of a given Path.
long	getDefaultBlockSize()	Return the number of bytes that large input files should be optimally be split into to minimize I/O time.
long	getDefaultBlockSize(Path f)	Return the number of bytes that large input files should be optimally be split into to minimize I/O time.
short	getDefaultReplication()	Get the default replication.
short	getDefaultReplication(Path f)	Get the default replication for a path.
Path	getEnclosingRoot(Path path)	Return path of the enclosing root for a given path.
BlockLocation[]	getFileBlockLocations(FileStatus fs, long start, long len)	Return an array containing hostnames, offset and size of portions of the given file.
FileChecksum	getFileChecksum(Path f)	Get the checksum of a file, if the FS supports checksums.
FileChecksum	getFileChecksum(Path f, long length)	Get the checksum of a file, from the beginning of the file till the specific length.
FileStatus	getFileStatus(Path f)	Return a file status object that represents the path.
Path	getHomeDirectory()	Return the current user's home directory in this FileSystem.
Path	getLinkTarget(Path path)	See FileContext.getLinkTarget(Path).
ViewFileSystem.MountPoint[]	getMountPoints()
QuotaUsage	getQuotaUsage(Path f)	Return the QuotaUsage of a given Path.
java.lang.String	getScheme()	Return the protocol scheme for the FileSystem.
FsServerDefaults	getServerDefaults()	Return a set of server default configuration values.
FsServerDefaults	getServerDefaults(Path f)	Return a set of server default configuration values.
FsStatus	getStatus()	Returns a status object describing the use and capacity of the filesystem.
FsStatus	getStatus(Path p)	Returns a status object describing the use and capacity of the filesystem.
BlockStoragePolicySpi	getStoragePolicy(Path src)	Query the effective storage policy ID for the given file or directory.
Path	getTrashRoot(Path path)	Get the trash root directory for current user when the path specified is deleted.
java.util.Collection<FileStatus>	getTrashRoots(boolean allUsers)	Get all the trash roots for current user or all users.
java.net.URI	getUri()	Returns a URI which identifies this FileSystem.
long	getUsed()	Return the total size of all files under "/", if Constants.CONFIG_VIEWFS_LINK_MERGE_SLASH is supported and is a valid mount point.
Path	getWorkingDirectory()	Get the current working directory for the given FileSystem
byte[]	getXAttr(Path path, java.lang.String name)	Get an xattr name and value for a file or directory.
java.util.Map<java.lang.String,byte[]>	getXAttrs(Path path)	Get all of the xattr name/value pairs 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 name/value pairs for a file or directory.
boolean	hasPathCapability(Path path, java.lang.String capability)	Reject the concat operation; forward the rest to the viewed FS.
void	initialize(java.net.URI theUri, Configuration conf)	Called after a new FileSystem instance is constructed.
RemoteIterator<LocatedFileStatus>	listLocatedStatus(Path f, PathFilter filter)	List a directory.
FileStatus[]	listStatus(Path f)	List the statuses of the files/directories in the given path if the path is a directory.
java.util.List<java.lang.String>	listXAttrs(Path path)	Get all of the xattr names for a file or directory.
boolean	mkdirs(Path dir)	Call FileSystem.mkdirs(Path, FsPermission) with default permission.
boolean	mkdirs(Path dir, FsPermission permission)	Make the given file and all non-existent parents into directories.
void	modifyAclEntries(Path path, java.util.List<AclEntry> aclSpec)	Modifies ACL entries of files and directories.
FSDataInputStream	open(Path f, int bufferSize)	Opens an FSDataInputStream at the indicated Path.
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.
boolean	rename(Path src, Path dst)	Renames Path src to Path dst.
void	renameSnapshot(Path path, java.lang.String snapshotOldName, java.lang.String snapshotNewName)	Rename a snapshot.
Path	resolvePath(Path f)	Return the fully-qualified path of path, resolving the path through any symlinks or mount point.
void	satisfyStoragePolicy(Path src)	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)	Set owner of a path (i.e.
void	setPermission(Path f, FsPermission permission)	Set permission of a path.
boolean	setReplication(Path f, short replication)	Set the replication for an existing file.
void	setStoragePolicy(Path src, java.lang.String policyName)	Set the storage policy for a given file or directory.
void	setTimes(Path f, long mtime, long atime)	Set access time of a file.
void	setVerifyChecksum(boolean verifyChecksum)	Set the verify checksum flag.
void	setWorkingDirectory(Path new_dir)	Set the current working directory for the given FileSystem.
void	setWriteChecksum(boolean writeChecksum)	Set the write checksum flag.
void	setXAttr(Path path, java.lang.String name, byte[] value, java.util.EnumSet<XAttrSetFlag> flag)	Set an xattr of a file or directory.
boolean	truncate(Path f, long newLength)	Truncate the file in the indicated path to the indicated size.
void	unsetStoragePolicy(Path src)	Unset the storage policy set for a given file or directory.

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

append, append, append, append, appendFile, areSymlinksEnabled, cancelDeleteOnExit, canonicalizeUri, checkPath, clearStatistics, closeAll, closeAllForUGI, completeLocalOutput, concat, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyToLocalFile, copyToLocalFile, copyToLocalFile, create, create, create, create, create, create, create, create, create, create, create, create, createBulkDelete, createDataInputStreamBuilder, createDataInputStreamBuilder, createDataOutputStreamBuilder, createFid, createFile, createMultipartUploader, createNewFile, createNonRecursive, createNonRecursive, createPathHandle, createPathId, createSnapshot, createSymlink, deleteFid, deleteOnExit, enableSymlinks, exists, fixRelativePart, get, get, get, getAdditionalTokenIssuers, getAllStatistics, getBlockSize, getCanonicalServiceName, getCanonicalUri, getDefaultPort, getDefaultUri, getDelegationToken, getFileBlockLocations, getFileLinkStatus, getFileSystemClass, getFSofPath, getGlobalStorageStatistics, getInitialWorkingDirectory, getJobTrackerAddrs, getLength, getLocal, getName, getNamed, getPathHandle, getReplication, getStatistics, getStatistics, getStorageStatistics, getUsed, getZkConnectString, globStatus, globStatus, isDirectory, isFile, listCorruptFileBlocks, listFiles, listLocatedStatus, listStatus, listStatus, listStatus, listStatusBatch, listStatusIterator, makeQualified, mkdirs, mkdirsFid, mkdirsFid, moveFromLocalFile, moveFromLocalFile, moveToLocalFile, msync, newInstance, newInstance, newInstance, newInstanceLocal, open, open, open, openFid, openFid, openFid2, openFile, openFile, openFileWithOptions, openFileWithOptions, primitiveCreate, primitiveMkdir, primitiveMkdir, printStatistics, processDeleteOnExit, rename, resolveLink, setDefaultUri, setDefaultUri, setOwnerFid, setQuota, setQuotaByStorageType, setXAttr, startLocalOutput, supportsSymlinks

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

getConf, setConf

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.security.token.DelegationTokenIssuer

addDelegationTokens

Constructor Detail

ViewFileSystem

public ViewFileSystem()
               throws java.io.IOException

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

Throws:

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

ViewFileSystem

public ViewFileSystem(Configuration conf)
               throws java.io.IOException

Convenience Constructor for apps to call directly.

Parameters:

conf - configuration.

Throws:

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

Method Detail

fsGetter

protected FsGetter fsGetter()

Gets file system creator instance.

Returns:

fs getter.

getScheme

public java.lang.String getScheme()

Return the protocol scheme for the FileSystem.

Overrides:

getScheme in class FileSystem

Returns:

viewfs

initialize

public void initialize(java.net.URI theUri,
                       Configuration conf)
                throws java.io.IOException

Called after a new FileSystem instance is constructed.

Overrides:

initialize in class FileSystem

Parameters:

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

conf - the configuration

Throws:

java.io.IOException - on any failure to initialize this instance.

getUri

public java.net.URI getUri()

Description copied from class: FileSystem

Returns a URI which identifies this FileSystem.

Specified by:

getUri in class FileSystem

Returns:

the URI of this filesystem.

resolvePath

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

Description copied from class: FileSystem

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

Overrides:

resolvePath in class FileSystem

Parameters:

f - path to be resolved

Returns:

fully qualified path

Throws:

java.io.FileNotFoundException - if the path is not present

java.io.IOException - for any other error

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

Returns:

the path.

getWorkingDirectory

public Path getWorkingDirectory()

Description copied from class: FileSystem

Get the current working directory for the given FileSystem

Specified by:

getWorkingDirectory in class FileSystem

Returns:

the directory pathname

setWorkingDirectory

public void setWorkingDirectory(Path new_dir)

Description copied from class: FileSystem

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

Specified by:

setWorkingDirectory in class FileSystem

Parameters:

new_dir - Path of new working directory

append

public FSDataOutputStream append(Path f,
                                 int bufferSize,
                                 Progressable progress)
                          throws java.io.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.

Returns:

output stream.

Throws:

java.io.IOException - IO failure

createNonRecursive

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

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

permission - file permission

flags - CreateFlags to use for this stream.

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

blockSize - block size

progress - the progress reporter

Returns:

output stream.

Throws:

java.io.IOException - IO failure

See Also:

FileSystem.setPermission(Path, FsPermission)

create

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

permission - file permission

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

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

blockSize - block size

progress - the progress reporter

Returns:

output stream.

Throws:

java.io.IOException - IO failure

See Also:

FileSystem.setPermission(Path, FsPermission)

delete

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

Description copied from class: FileSystem

Delete a file.

Specified by:

delete in class FileSystem

Parameters:

f - the path to delete.

recursive - if path is a directory and set to true, the directory is deleted else throws an exception. In case of a file the recursive can be set to either true or false.

Returns:

true if delete is successful else false.

Throws:

java.io.IOException - IO failure

AccessControlException

java.io.FileNotFoundException

delete

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

Description copied from class: FileSystem

Delete a file/directory.

Overrides:

delete in class FileSystem

Parameters:

f - the path.

Returns:

if delete success true, not false.

Throws:

java.io.IOException - IO failure.

AccessControlException

java.io.FileNotFoundException

getFileBlockLocations

public BlockLocation[] getFileBlockLocations(FileStatus fs,
                                             long start,
                                             long len)
                                      throws java.io.IOException

Description copied from class: FileSystem

Return an array containing hostnames, offset and size of portions of the given file. For nonexistent file or regions, null is returned.

   if f == null :
     result = null
   elif f.getLen() <= start:
     result = []
   else result = [ locations(FS, b) for b in blocks(FS, p, s, s+l)]
 

This call is most helpful with and distributed filesystem where the hostnames of machines that contain blocks of the given file can be determined. The default implementation returns an array containing one element:

 BlockLocation( { "localhost:9866" },  { "localhost" }, 0, file.getLen())
 

In HDFS, if file is three-replicated, the returned array contains elements like:

 BlockLocation(offset: 0, length: BLOCK_SIZE,
   hosts: {"host1:9866", "host2:9866, host3:9866"})
 BlockLocation(offset: BLOCK_SIZE, length: BLOCK_SIZE,
   hosts: {"host2:9866", "host3:9866, host4:9866"})
 

And if a file is erasure-coded, the returned BlockLocation are logical block groups. Suppose we have a RS_3_2 coded file (3 data units and 2 parity units). 1. If the file size is less than one stripe size, say 2 * CELL_SIZE, then there will be one BlockLocation returned, with 0 offset, actual file size and 4 hosts (2 data blocks and 2 parity blocks) hosting the actual blocks. 3. If the file size is less than one group size but greater than one stripe size, then there will be one BlockLocation returned, with 0 offset, actual file size with 5 hosts (3 data blocks and 2 parity blocks) hosting the actual blocks. 4. If the file size is greater than one group size, 3 * BLOCK_SIZE + 123 for example, then the result will be like:

 BlockLocation(offset: 0, length: 3 * BLOCK_SIZE, hosts: {"host1:9866",
   "host2:9866","host3:9866","host4:9866","host5:9866"})
 BlockLocation(offset: 3 * BLOCK_SIZE, length: 123, hosts: {"host1:9866",
   "host4:9866", "host5:9866"})
 

Overrides:

getFileBlockLocations in class FileSystem

Parameters:

fs - FilesStatus to get data from

start - offset into the given file

len - length for which to get locations for

Returns:

block location array.

Throws:

java.io.IOException - IO failure

getFileChecksum

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

Description copied from class: FileSystem

Get the checksum of a file, if the FS supports checksums.

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:

java.io.IOException - IO failure

AccessControlException

java.io.FileNotFoundException

getFileChecksum

public FileChecksum getFileChecksum(Path f,
                                    long length)
                             throws AccessControlException,
                                    java.io.FileNotFoundException,
                                    java.io.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 or null if checksums are not supported.

Throws:

java.io.IOException - IO failure

AccessControlException

java.io.FileNotFoundException

getFileStatus

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

Return a file status object that represents 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 FileSystem

Parameters:

f - The path we want information from

Returns:

a FileStatus object

Throws:

java.io.FileNotFoundException - when the path does not exist

java.io.IOException - see specific implementation

AccessControlException

access

public void access(Path path,
                   FsAction mode)
            throws AccessControlException,
                   java.io.FileNotFoundException,
                   java.io.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 calls FileSystem.getFileStatus(Path) and checks the returned permissions against the requested permissions. Note that the FileSystem.getFileStatus(Path) 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.

Overrides:

access in class FileSystem

Parameters:

path - Path to check

mode - type of access to check

Throws:

AccessControlException - if access is denied

java.io.FileNotFoundException - if the path does not exist

java.io.IOException - see specific implementation

listStatus

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

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

Does not guarantee to return the List of files/directories status in a sorted order.

Will not return null. Expect IOException upon access error. 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 ViewFileSystem, by default the mount links are represented as symlinks.

Specified by:

listStatus in class FileSystem

Parameters:

f - given path

Returns:

the statuses of the files/directories in the given patch

Throws:

java.io.FileNotFoundException - when the path does not exist

java.io.IOException - see specific implementation

AccessControlException

listLocatedStatus

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

Description copied from class: FileSystem

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

Overrides:

listLocatedStatus in class FileSystem

Parameters:

f - a path

filter - a path filter

Returns:

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

Throws:

java.io.FileNotFoundException - if f does not exist

java.io.IOException - if any I/O error occurred

mkdirs

public boolean mkdirs(Path dir)
               throws java.io.IOException

Description copied from class: FileSystem

Call FileSystem.mkdirs(Path, FsPermission) with default permission.

Overrides:

mkdirs in class FileSystem

Parameters:

dir - path

Returns:

true if the directory was created

Throws:

java.io.IOException - IO failure

mkdirs

public boolean mkdirs(Path dir,
                      FsPermission permission)
               throws java.io.IOException

Description copied from class: FileSystem

Make the given file and all non-existent parents into directories. Has roughly the semantics of Unix @{code mkdir -p}. Existence of the directory hierarchy is not an error.

Specified by:

mkdirs in class FileSystem

Parameters:

dir - path to create

permission - to apply to f

Returns:

if mkdir success true, not false.

Throws:

java.io.IOException - IO failure

open

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

Description copied from class: FileSystem

Opens an FSDataInputStream at the indicated Path.

Specified by:

open in class FileSystem

Parameters:

f - the file name to open

bufferSize - the size of the buffer to be used.

Returns:

input stream.

Throws:

java.io.IOException - IO failure

AccessControlException

java.io.FileNotFoundException

rename

public boolean rename(Path src,
                      Path dst)
               throws java.io.IOException

Description copied from class: FileSystem

Renames Path src to Path dst.

Specified by:

rename in class FileSystem

Parameters:

src - path to be renamed

dst - new path after rename

Returns:

true if rename is successful

Throws:

java.io.IOException - on failure

truncate

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

Description copied from class: FileSystem

Truncate the file in the indicated path to the indicated size.

• Fails if path is a directory.
• Fails if path does not exist.
• Fails if path is not closed.
• Fails if new size is greater than current size.

Overrides:

truncate in class FileSystem

Parameters:

f - The path to the file to be truncated

newLength - The size the file is to be truncated to

Returns:

true if the file has been truncated to the desired newLength and is immediately available to be reused for write operations such as append, or false if a background process of adjusting the length of the last block has been started, and clients should wait for it to complete before proceeding with further file updates.

Throws:

java.io.IOException - IO failure

setOwner

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

Description copied from class: FileSystem

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

Overrides:

setOwner in class FileSystem

Parameters:

f - The path

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

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

Throws:

java.io.IOException - IO failure

AccessControlException

java.io.FileNotFoundException

setPermission

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

Description copied from class: FileSystem

Set permission of a path.

Overrides:

setPermission in class FileSystem

Parameters:

f - The path

permission - permission

Throws:

java.io.IOException - IO failure

AccessControlException

java.io.FileNotFoundException

setReplication

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

Description copied from class: FileSystem

Set the replication for an existing file. If a filesystem does not support replication, it will always return true: the check for a file existing may be bypassed. This is the default behavior.

Overrides:

setReplication in class FileSystem

Parameters:

f - file name

replication - new replication

Returns:

true if successful, or the feature in unsupported; false if replication is supported but the file does not exist, or is a directory

Throws:

java.io.IOException - an IO failure.

AccessControlException

java.io.FileNotFoundException

setTimes

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

Description copied from class: FileSystem

Set access time of a file.

Overrides:

setTimes in class FileSystem

Parameters:

f - The path

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

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

Throws:

java.io.IOException - IO failure

AccessControlException

java.io.FileNotFoundException

modifyAclEntries

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

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

removeDefaultAcl

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

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

removeAcl

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

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: 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, which 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: 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:

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: 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:

java.io.IOException - IO failure

getXAttr

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

java.io.IOException - IO failure

getXAttrs

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

java.io.IOException - IO failure

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: 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:

java.io.IOException - IO failure

listXAttrs

public java.util.List<java.lang.String> listXAttrs(Path path)
                                            throws java.io.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<String> of the XAttr names of the file or directory

Throws:

java.io.IOException - IO failure

removeXAttr

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

java.io.IOException - IO failure

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 checksums. By default doesn't do anything.

Overrides:

setVerifyChecksum in class FileSystem

Parameters:

verifyChecksum - Verify checksum flag

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

Returns:

default block size.

getDefaultReplication

public short getDefaultReplication()

Description copied from class: FileSystem

Get the default replication.

Overrides:

getDefaultReplication in class FileSystem

Returns:

the replication; the default value is "1".

getServerDefaults

public FsServerDefaults getServerDefaults()
                                   throws java.io.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:

java.io.IOException - IO failure

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 to query. 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 java.io.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:

java.io.IOException - IO failure

getContentSummary

public ContentSummary getContentSummary(Path f)
                                 throws java.io.IOException

Description copied from class: FileSystem

Return the ContentSummary of a given Path.

Overrides:

getContentSummary in class FileSystem

Parameters:

f - path to use

Returns:

content summary.

Throws:

java.io.FileNotFoundException - if the path does not resolve

java.io.IOException - IO failure

getQuotaUsage

public QuotaUsage getQuotaUsage(Path f)
                         throws java.io.IOException

Description copied from class: FileSystem

Return the QuotaUsage of a given Path.

Overrides:

getQuotaUsage in class FileSystem

Parameters:

f - path to use

Returns:

the quota usage

Throws:

java.io.IOException - IO failure

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 checksums. By default doesn't do anything.

Overrides:

setWriteChecksum in class FileSystem

Parameters:

writeChecksum - Write checksum flag

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 must return a unique list of those FileSystems. Default is to return null to signify no children.

Overrides:

getChildFileSystems in class FileSystem

Returns:

FileSystems that are direct children of this FileSystem, or null for "no children"

getMountPoints

public ViewFileSystem.MountPoint[] getMountPoints()

createSnapshot

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

java.io.IOException - IO failure

renameSnapshot

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

java.io.IOException - IO failure

deleteSnapshot

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

java.io.IOException - IO failure

satisfyStoragePolicy

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

Description copied from class: FileSystem

Set the source path to satisfy storage policy.

Overrides:

satisfyStoragePolicy in class FileSystem

Parameters:

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

Throws:

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

setStoragePolicy

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

Description copied from class: FileSystem

Set the storage policy for a given file or directory.

Overrides:

setStoragePolicy in class FileSystem

Parameters:

src - file or directory path.

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

Throws:

java.io.IOException - IO failure

unsetStoragePolicy

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

Description copied from class: FileSystem

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

Overrides:

unsetStoragePolicy in class FileSystem

Parameters:

src - file or directory path.

Throws:

java.io.IOException - IO failure

getStoragePolicy

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

Description copied from class: FileSystem

Query the effective storage policy ID for the given file or directory.

Overrides:

getStoragePolicy in class FileSystem

Parameters:

src - file or directory path.

Returns:

storage policy for give file.

Throws:

java.io.IOException - IO failure

getAllStoragePolicies

public java.util.Collection<? extends BlockStoragePolicySpi> getAllStoragePolicies()
                                                                            throws java.io.IOException

Description copied from class: FileSystem

Retrieve all the storage policies supported by this file system.

Overrides:

getAllStoragePolicies in class FileSystem

Returns:

all storage policies supported by this filesystem.

Throws:

java.io.IOException - IO failure

getTrashRoot

public Path getTrashRoot(Path path)

Get the trash root directory for current user when the path specified is deleted. If FORCE_INSIDE_MOUNT_POINT flag is not set, return the default trash root from targetFS. When FORCE_INSIDE_MOUNT_POINT is set to true,

1. If the trash root for path p is in the same mount point as path p, and one of:
   1. The mount point isn't at the top of the target fs.
   2. The resolved path of path is root (in fallback FS).
   3. The trash isn't in user's target fs home directory get the corresponding viewFS path for the trash root and return it.
2. else, return the trash root under the root of the mount point (/{mntpoint}/.Trash/{user}).

These conditions handle several different important cases:

• File systems may need to have more local trash roots, such as encryption zones or snapshot roots.
• The fallback mount should use the user's home directory.
• Cloud storage systems should not use trash in an implicity defined home directory, per a container, unless it is the fallback fs.

Overrides:

getTrashRoot in class FileSystem

Parameters:

path - the trash root of the path to be determined.

Returns:

the trash root path.

getTrashRoots

public java.util.Collection<FileStatus> getTrashRoots(boolean allUsers)

Get all the trash roots for current user or all users. When FORCE_INSIDE_MOUNT_POINT is set to true, we also return trash roots under the root of each mount point, with their viewFS paths.

Overrides:

getTrashRoots in class FileSystem

Parameters:

allUsers - return trash roots for all users if true.

Returns:

all Trash root directories.

getStatus

public FsStatus getStatus()
                   throws java.io.IOException

Description copied from class: FileSystem

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

Overrides:

getStatus in class FileSystem

Returns:

a FsStatus object

Throws:

java.io.IOException - see specific implementation

getStatus

public FsStatus getStatus(Path p)
                   throws java.io.IOException

Description copied from class: FileSystem

Returns a status object describing the use and capacity of the filesystem. If the filesystem 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:

java.io.IOException - see specific implementation

getUsed

public long getUsed()
             throws java.io.IOException

Return the total size of all files under "/", if Constants.CONFIG_VIEWFS_LINK_MERGE_SLASH is supported and is a valid mount point. Else, throw NotInMountpointException.

Overrides:

getUsed in class FileSystem

Returns:

the number of path used.

Throws:

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

getLinkTarget

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

Description copied from class: FileSystem

See FileContext.getLinkTarget(Path).

Overrides:

getLinkTarget in class FileSystem

Parameters:

path - the path.

Returns:

the path.

Throws:

java.io.IOException - IO failure.

hasPathCapability

public boolean hasPathCapability(Path path,
                                 java.lang.String capability)
                          throws java.io.IOException

Reject the concat operation; forward the rest to the viewed FS.

Specified by:

hasPathCapability in interface PathCapabilities

Overrides:

hasPathCapability in class FileSystem

Parameters:

path - path to query the capability of.

capability - string to query the stream support for.

Returns:

the capability

Throws:

java.io.IOException - if there is no resolved FS, or it raises an IOE.

getEnclosingRoot

public Path getEnclosingRoot(Path path)
                      throws java.io.IOException

Description copied from class: FileSystem

Return path of the enclosing root for a given path. The enclosing root path is a common ancestor that should be used for temp and staging dirs as well as within encryption zones and other restricted directories. Call makeQualified on the param path to ensure its part of the correct filesystem.

Overrides:

getEnclosingRoot in class FileSystem

Parameters:

path - file path to find the enclosing root path for

Returns:

a path to the enclosing root

Throws:

java.io.IOException - early checks like failure to resolve path cause IO failures

close

public void close()
           throws java.io.IOException

Description copied from class: FileSystem

Close this FileSystem instance. Will release any held locks, delete all files queued for deletion through calls to FileSystem.deleteOnExit(Path), and remove this FS instance from the cache, if cached. After this operation, the outcome of any method call on this FileSystem instance, or any input/output stream created by it is undefined.

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Overrides:

close in class FileSystem

Throws:

java.io.IOException - IO failure