alluxio.underfs.hdfs

Class HdfsUnderFileSystem

java.lang.Object

alluxio.underfs.BaseUnderFileSystem

alluxio.underfs.ConsistentUnderFileSystem

alluxio.underfs.hdfs.HdfsUnderFileSystem

All Implemented Interfaces:

AtomicFileOutputStreamCallback, UnderFileSystem, Closeable, AutoCloseable

Direct Known Subclasses:

AbfsUnderFileSystem, AdlUnderFileSystem, CephfsHadoopUnderFileSystem, CosnUnderFileSystem, OzoneUnderFileSystem, WasbUnderFileSystem

@ThreadSafe
public class HdfsUnderFileSystem
extends ConsistentUnderFileSystem
implements AtomicFileOutputStreamCallback

HDFS UnderFileSystem implementation.

Nested Class Summary

Nested classes/interfaces inherited from interface alluxio.underfs.UnderFileSystem

UnderFileSystem.Factory, UnderFileSystem.SpaceType

Field Summary

Fields inherited from class alluxio.underfs.BaseUnderFileSystem

EMPTY_ACL, mUfsConf, mUri

Constructor Summary

Constructors

Constructor and Description
HdfsUnderFileSystem(AlluxioURI ufsUri, UnderFileSystemConfiguration conf, org.apache.hadoop.conf.Configuration hdfsConf) Constructs a new HDFS UnderFileSystem.

Method Summary

Modifier and Type	Method and Description
void	cleanup() Cleans up the under file system.
void	close()
void	connectFromMaster(String host) Takes any necessary actions required to establish a connection to the under file system from the given master host e.g.
void	connectFromWorker(String host) Takes any necessary actions required to establish a connection to the under file system from the given worker host e.g.
OutputStream	create(String path, CreateOptions options) Creates a file in the under file system with the specified CreateOptions.
static org.apache.hadoop.conf.Configuration	createConfiguration(UnderFileSystemConfiguration conf) Prepares the Hadoop configuration necessary to successfully obtain a FileSystem instance that can access the provided path.
OutputStream	createDirect(String path, CreateOptions options) Creates a file in the under file system with the specified CreateOptions.
static HdfsUnderFileSystem	createInstance(AlluxioURI ufsUri, UnderFileSystemConfiguration conf) Factory method to constructs a new HDFS UnderFileSystem instance.
boolean	deleteDirectory(String path, DeleteOptions options) Deletes a directory from the under file system with the indicated name.
boolean	deleteFile(String path) Deletes a file from the under file system with the indicated name.
boolean	exists(String path) Checks if a file or directory exists in under file system.
Pair<AccessControlList,DefaultAccessControlList>	getAclPair(String path) Gets the ACL and the Default ACL of a file or directory in under file system.
SyncInfo	getActiveSyncInfo() Return the active sync info for the specified syncPoints.
long	getBlockSizeByte(String path) Gets the block size of a file in under file system, in bytes.
UfsDirectoryStatus	getDirectoryStatus(String path) Gets the directory status.
List<String>	getFileLocations(String path) Gets the list of locations of the indicated path.
List<String>	getFileLocations(String path, FileLocationOptions options) Gets the list of locations of the indicated path given options.
UfsFileStatus	getFileStatus(String path) Gets the file status.
long	getSpace(String path, UnderFileSystem.SpaceType type) Queries the under file system about the space of the indicated path (e.g., space left, space used and etc).
UfsStatus	getStatus(String path) Gets the file or directory status.
String	getUnderFSType() Returns the name of the under filesystem implementation.
boolean	isDirectory(String path) Checks if a directory exists in under file system.
boolean	isFile(String path) Checks if a file exists in under file system.
boolean	isSeekable() Denotes if the under storage supports seeking.
UfsStatus[]	listStatus(String path) Returns an array of statuses of the files and directories in the directory denoted by this abstract pathname.
boolean	mkdirs(String path, MkdirsOptions options) Creates the directory named by this abstract pathname, with specified MkdirsOptions.
InputStream	open(String path, OpenOptions options) Opens an InputStream for a file in under filesystem at the indicated path.
boolean	renameDirectory(String src, String dst) Renames a directory from src to dst in under file system.
boolean	renameFile(String src, String dst) Renames a file from src to dst in under file system.
void	setAclEntries(String path, List<AclEntry> aclEntries) Sets the access control list of a file or directory in under file system.
void	setMode(String path, short mode) Changes posix file mode.
void	setOwner(String path, String user, String group) Sets the user and group of the given path.
boolean	startActiveSyncPolling(long txId) Start Active Sync.
void	startSync(AlluxioURI ufsUri) Add Sync Point.
boolean	stopActiveSyncPolling() Stop Active Sync.
void	stopSync(AlluxioURI ufsUri) Stop Sync Point.
boolean	supportsActiveSync() Whether this type of UFS supports active sync.
boolean	supportsFlush() Whether this type of UFS supports flush.

Methods inherited from class alluxio.underfs.ConsistentUnderFileSystem

createNonexistingFile, createNonexistingFile, deleteExistingDirectory, deleteExistingDirectory, deleteExistingFile, getExistingDirectoryStatus, getExistingFileStatus, getExistingStatus, isExistingDirectory, openExistingFile, openExistingFile, renameRenamableDirectory, renameRenamableFile

Methods inherited from class alluxio.underfs.BaseUnderFileSystem

create, deleteDirectory, getConfiguration, getFingerprint, getOperationMode, getParsedFingerprint, getParsedFingerprint, getPhysicalStores, isObjectStorage, listStatus, mkdirs, open, resolveUri, validatePath

Methods inherited from class java.lang.Object

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

Methods inherited from interface alluxio.underfs.UnderFileSystem

create, createNonexistingFile, createNonexistingFile, deleteDirectory, deleteExistingDirectory, deleteExistingDirectory, deleteExistingFile, getConfiguration, getExistingDirectoryStatus, getExistingFileStatus, getExistingStatus, getFingerprint, getOperationMode, getParsedFingerprint, getParsedFingerprint, getPhysicalStores, isExistingDirectory, isObjectStorage, listStatus, mkdirs, open, openExistingFile, openExistingFile, renameRenamableDirectory, renameRenamableFile, resolveUri

Constructor Detail

HdfsUnderFileSystem

public HdfsUnderFileSystem(AlluxioURI ufsUri,
                           UnderFileSystemConfiguration conf,
                           org.apache.hadoop.conf.Configuration hdfsConf)

Constructs a new HDFS UnderFileSystem.

Parameters:

ufsUri - the AlluxioURI for this UFS

conf - the configuration for this UFS

hdfsConf - the configuration for HDFS

Method Detail

createInstance

public static HdfsUnderFileSystem createInstance(AlluxioURI ufsUri,
                                                 UnderFileSystemConfiguration conf)

Factory method to constructs a new HDFS UnderFileSystem instance.

Parameters:

ufsUri - the AlluxioURI for this UFS

conf - the configuration for Hadoop

Returns:

a new HDFS UnderFileSystem instance

getUnderFSType

public String getUnderFSType()

Description copied from interface: UnderFileSystem

Returns the name of the under filesystem implementation. The name should be lowercase and not include any spaces, e.g. "hdfs", "s3".

Specified by:

getUnderFSType in interface UnderFileSystem

Returns:

name of the under filesystem implementation

createConfiguration

public static org.apache.hadoop.conf.Configuration createConfiguration(UnderFileSystemConfiguration conf)

Prepares the Hadoop configuration necessary to successfully obtain a FileSystem instance that can access the provided path.

Derived implementations that work with specialised Hadoop FileSystem API compatible implementations can override this method to add implementation specific configuration necessary for obtaining a usable FileSystem instance.

Parameters:

conf - the configuration for this UFS

Returns:

the configuration for HDFS

cleanup

public void cleanup()

Description copied from interface: UnderFileSystem

Cleans up the under file system. If any data or files are created and not completed/aborted correctly in normal ways, they should be cleaned in this method.

Specified by:

cleanup in interface UnderFileSystem

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

create

public OutputStream create(String path,
                           CreateOptions options)
                    throws IOException

Description copied from interface: UnderFileSystem

Creates a file in the under file system with the specified CreateOptions. Implementations should make sure that the path under creation appears in listings only after a successful close and that contents are written in its entirety or not at all.

Specified by:

create in interface UnderFileSystem

Parameters:

path - the file name

options - the options for create

Returns:

A OutputStream object

Throws:

IOException

createDirect

public OutputStream createDirect(String path,
                                 CreateOptions options)
                          throws IOException

Description copied from interface: AtomicFileOutputStreamCallback

Creates a file in the under file system with the specified CreateOptions. This stream writes directly to the underlying storage without any atomicity guarantees.

Specified by:

createDirect in interface AtomicFileOutputStreamCallback

Parameters:

path - the file name

options - the options for create

Returns:

A OutputStream object

Throws:

IOException

deleteDirectory

public boolean deleteDirectory(String path,
                               DeleteOptions options)
                        throws IOException

Description copied from interface: UnderFileSystem

Deletes a directory from the under file system with the indicated name.

Specified by:

deleteDirectory in interface UnderFileSystem

Parameters:

path - of the directory to delete

options - for directory delete semantics

Returns:

true if directory was found and deleted, false otherwise

Throws:

IOException

deleteFile

public boolean deleteFile(String path)
                   throws IOException

Description copied from interface: UnderFileSystem

Deletes a file from the under file system with the indicated name.

Specified by:

deleteFile in interface UnderFileSystem

Parameters:

path - of the file to delete

Returns:

true if file was found and deleted, false otherwise

Throws:

IOException

exists

public boolean exists(String path)
               throws IOException

Description copied from interface: UnderFileSystem

Checks if a file or directory exists in under file system.

Specified by:

exists in interface UnderFileSystem

Overrides:

exists in class BaseUnderFileSystem

Parameters:

path - the absolute path

Returns:

true if the path exists, false otherwise

Throws:

IOException

getAclPair

public Pair<AccessControlList,DefaultAccessControlList> getAclPair(String path)
                                                            throws IOException

Description copied from interface: UnderFileSystem

Gets the ACL and the Default ACL of a file or directory in under file system.

Specified by:

getAclPair in interface UnderFileSystem

Overrides:

getAclPair in class BaseUnderFileSystem

Parameters:

path - the path to the file or directory

Returns:

the access control list, along with a Default ACL if it is a directory return null if ACL is unsupported or disabled

Throws:

IOException - if ACL is supported and enabled but cannot be retrieved

setAclEntries

public void setAclEntries(String path,
                          List<AclEntry> aclEntries)
                   throws IOException

Description copied from interface: UnderFileSystem

Sets the access control list of a file or directory in under file system. if the ufs does not support acls, this is a noop. This will overwrite the ACL and defaultACL in the UFS.

Specified by:

setAclEntries in interface UnderFileSystem

Overrides:

setAclEntries in class BaseUnderFileSystem

Parameters:

path - the path to the file or directory

aclEntries - the access control list + default acl represented in a list of acl entries

Throws:

IOException

getBlockSizeByte

public long getBlockSizeByte(String path)
                      throws IOException

Description copied from interface: UnderFileSystem

Gets the block size of a file in under file system, in bytes.

Specified by:

getBlockSizeByte in interface UnderFileSystem

Parameters:

path - the file name

Returns:

the block size in bytes

Throws:

IOException

getDirectoryStatus

public UfsDirectoryStatus getDirectoryStatus(String path)
                                      throws IOException

Description copied from interface: UnderFileSystem

Gets the directory status. The caller must already know the path is a directory. This method will throw an exception if the path exists, but is a file.

Specified by:

getDirectoryStatus in interface UnderFileSystem

Parameters:

path - the path to the directory

Returns:

the directory status

Throws:

FileNotFoundException - when the path does not exist

IOException

getFileLocations

public List<String> getFileLocations(String path)
                              throws IOException

Description copied from interface: UnderFileSystem

Gets the list of locations of the indicated path.

Specified by:

getFileLocations in interface UnderFileSystem

Parameters:

path - the file name

Returns:

The list of locations

Throws:

IOException

getFileLocations

@Nullable
public List<String> getFileLocations(String path,
                                               FileLocationOptions options)
                                        throws IOException

Description copied from interface: UnderFileSystem

Gets the list of locations of the indicated path given options.

Specified by:

getFileLocations in interface UnderFileSystem

Parameters:

path - the file name

options - method options

Returns:

The list of locations

Throws:

IOException

getFileStatus

public UfsFileStatus getFileStatus(String path)
                            throws IOException

Description copied from interface: UnderFileSystem

Gets the file status. The caller must already know the path is a file. This method will throw an exception if the path exists, but is a directory.

Specified by:

getFileStatus in interface UnderFileSystem

Parameters:

path - the path to the file

Returns:

the file status

Throws:

FileNotFoundException - when the path does not exist

IOException

getSpace

public long getSpace(String path,
                     UnderFileSystem.SpaceType type)
              throws IOException

Description copied from interface: UnderFileSystem

Queries the under file system about the space of the indicated path (e.g., space left, space used and etc).

Specified by:

getSpace in interface UnderFileSystem

Parameters:

path - the path to query

type - the type of queries

Returns:

The space in bytes

Throws:

IOException

getStatus

public UfsStatus getStatus(String path)
                    throws IOException

Description copied from interface: UnderFileSystem

Gets the file or directory status. The caller does not need to know if the path is a file or directory. This method will determine the path type, and will return the appropriate status.

Specified by:

getStatus in interface UnderFileSystem

Parameters:

path - the path to get the status

Returns:

the file or directory status

Throws:

FileNotFoundException - when the path does not exist

IOException

isDirectory

public boolean isDirectory(String path)
                    throws IOException

Description copied from interface: UnderFileSystem

Checks if a directory exists in under file system.

Specified by:

isDirectory in interface UnderFileSystem

Parameters:

path - the absolute directory path

Returns:

true if the path exists and is a directory, false otherwise

Throws:

IOException

isFile

public boolean isFile(String path)
               throws IOException

Description copied from interface: UnderFileSystem

Checks if a file exists in under file system.

Specified by:

isFile in interface UnderFileSystem

Parameters:

path - the absolute file path

Returns:

true if the path exists and is a file, false otherwise

Throws:

IOException

listStatus

@Nullable
public UfsStatus[] listStatus(String path)
                                 throws IOException

Description copied from interface: UnderFileSystem

Returns an array of statuses of the files and directories in the directory denoted by this abstract pathname.

If this abstract pathname does not denote a directory, then this method returns null. Otherwise an array of statuses is returned, one for each file or directory in the directory. Names denoting the directory itself and the directory's parent directory are not included in the result. Each string is a file name rather than a complete path.

There is no guarantee that the name strings in the resulting array will appear in any specific order; they are not, in particular, guaranteed to appear in alphabetical order.

Specified by:

listStatus in interface UnderFileSystem

Parameters:

path - the abstract pathname to list

Returns:

An array with the statuses of the files and directories in the directory denoted by this abstract pathname. The array will be empty if the directory is empty. Returns null if this abstract pathname does not denote a directory.

Throws:

IOException

connectFromMaster

public void connectFromMaster(String host)
                       throws IOException

Description copied from interface: UnderFileSystem

Takes any necessary actions required to establish a connection to the under file system from the given master host e.g. logging in

Depending on the implementation this may be a no-op

Specified by:

connectFromMaster in interface UnderFileSystem

Parameters:

host - the host that wants to connect to the under file system

Throws:

IOException

connectFromWorker

public void connectFromWorker(String host)
                       throws IOException

Description copied from interface: UnderFileSystem

Takes any necessary actions required to establish a connection to the under file system from the given worker host e.g. logging in

Depending on the implementation this may be a no-op

Specified by:

connectFromWorker in interface UnderFileSystem

Parameters:

host - the host that wants to connect to the under file system

Throws:

IOException

mkdirs

public boolean mkdirs(String path,
                      MkdirsOptions options)
               throws IOException

Description copied from interface: UnderFileSystem

Creates the directory named by this abstract pathname, with specified MkdirsOptions. If the folder already exists, the method returns false.

Specified by:

mkdirs in interface UnderFileSystem

Parameters:

path - the folder to create

options - the options for mkdirs

Returns:

true if and only if the directory was created; false otherwise

Throws:

IOException

open

public InputStream open(String path,
                        OpenOptions options)
                 throws IOException

Description copied from interface: UnderFileSystem

Opens an InputStream for a file in under filesystem at the indicated path.

Specified by:

open in interface UnderFileSystem

Parameters:

path - the file name

options - to open input stream

Returns:

The InputStream object

Throws:

IOException

renameDirectory

public boolean renameDirectory(String src,
                               String dst)
                        throws IOException

Description copied from interface: UnderFileSystem

Renames a directory from src to dst in under file system.

Specified by:

renameDirectory in interface UnderFileSystem

Parameters:

src - the source directory path

dst - the destination directory path

Returns:

true if succeed, false otherwise

Throws:

IOException

renameFile

public boolean renameFile(String src,
                          String dst)
                   throws IOException

Description copied from interface: UnderFileSystem

Renames a file from src to dst in under file system.

Specified by:

renameFile in interface UnderFileSystem

Parameters:

src - the source file path

dst - the destination file path

Returns:

true if succeed, false otherwise

Throws:

IOException

setOwner

public void setOwner(String path,
                     String user,
                     String group)
              throws IOException

Description copied from interface: UnderFileSystem

Sets the user and group of the given path. An empty implementation should be provided if unsupported.

Specified by:

setOwner in interface UnderFileSystem

Parameters:

path - the path of the file

user - the new owner to set, unchanged if null

group - the new group to set, unchanged if null

Throws:

IOException

setMode

public void setMode(String path,
                    short mode)
             throws IOException

Description copied from interface: UnderFileSystem

Changes posix file mode.

Specified by:

setMode in interface UnderFileSystem

Parameters:

path - the path of the file

mode - the mode to set in short format, e.g. 0777

Throws:

IOException

supportsFlush

public boolean supportsFlush()

Description copied from interface: UnderFileSystem

Whether this type of UFS supports flush.

Specified by:

supportsFlush in interface UnderFileSystem

Returns:

true if this type of UFS supports flush, false otherwise

supportsActiveSync

public boolean supportsActiveSync()

Description copied from interface: UnderFileSystem

Whether this type of UFS supports active sync.

Specified by:

supportsActiveSync in interface UnderFileSystem

Overrides:

supportsActiveSync in class BaseUnderFileSystem

Returns:

true if this type of UFS supports active sync, false otherwise

getActiveSyncInfo

public SyncInfo getActiveSyncInfo()

Description copied from interface: UnderFileSystem

Return the active sync info for the specified syncPoints.

Specified by:

getActiveSyncInfo in interface UnderFileSystem

Overrides:

getActiveSyncInfo in class BaseUnderFileSystem

Returns:

active sync info consisting of what changed for these sync points

startActiveSyncPolling

public boolean startActiveSyncPolling(long txId)
                               throws IOException

Description copied from interface: UnderFileSystem

Start Active Sync.

Specified by:

startActiveSyncPolling in interface UnderFileSystem

Overrides:

startActiveSyncPolling in class BaseUnderFileSystem

Parameters:

txId - the transaction id to start receiving event

Returns:

true if active sync started

Throws:

IOException

stopActiveSyncPolling

public boolean stopActiveSyncPolling()

Description copied from interface: UnderFileSystem

Stop Active Sync.

Specified by:

stopActiveSyncPolling in interface UnderFileSystem

Overrides:

stopActiveSyncPolling in class BaseUnderFileSystem

Returns:

true if active sync stopped

startSync

public void startSync(AlluxioURI ufsUri)

Description copied from interface: UnderFileSystem

Add Sync Point.

Specified by:

startSync in interface UnderFileSystem

Overrides:

startSync in class BaseUnderFileSystem

Parameters:

ufsUri - ufs uri to start

stopSync

public void stopSync(AlluxioURI ufsUri)

Description copied from interface: UnderFileSystem

Stop Sync Point.

Specified by:

stopSync in interface UnderFileSystem

Overrides:

stopSync in class BaseUnderFileSystem

Parameters:

ufsUri - ufs uri to stop

isSeekable

public boolean isSeekable()

Description copied from interface: UnderFileSystem

Denotes if the under storage supports seeking. Note, the under file system subclass that returns true for this method should return the input stream extending SeekableUnderFileInputStream in the UnderFileSystem.open(String, OpenOptions) method.

Specified by:

isSeekable in interface UnderFileSystem

Overrides:

isSeekable in class BaseUnderFileSystem

Returns:

true if under storage is seekable, false otherwise