org.apache.hadoop.fs
Class HarFileSystem

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

All Implemented Interfaces:

Closeable, Configurable

public class HarFileSystem
extends FilterFileSystem

This is an implementation of the Hadoop Archive Filesystem. This archive Filesystem has index files of the form _index* and has contents of the form part-*. The index files store the indexes of the real files. The index files are of the form _masterindex and _index. The master index is a level of indirection in to the index file to make the look ups faster. the index file is sorted with hash code of the paths that it contains and the master index contains pointers to the positions in index for ranges of hashcodes.

Nested Class Summary

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

FileSystem.Statistics

Field Summary

static int

VERSION

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

fs

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

FS_DEFAULT_NAME_KEY, LOG, statistics

Constructor Summary

HarFileSystem()
public construction of harfilesystem

HarFileSystem(FileSystem fs)
Constructor to create a HarFileSystem with an underlying filesystem.

Method Summary

void	close() No more filesystem operations are needed.
void	completeLocalOutput(Path fsOutputFile, Path tmpLocalFile) not implemented.
void	copyFromLocalFile(boolean delSrc, Path src, Path dst) not implemented.
void	copyToLocalFile(boolean delSrc, Path src, Path dst) copies the file in the har filesystem to a local file.
FSDataOutputStream	create(Path f, FsPermission permission, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress) Opens an FSDataOutputStream at the indicated Path with write-progress reporting.
FSDataOutputStream	create(Path f, int bufferSize)
boolean	delete(Path f, boolean recursive) Not implemented.
String	getCanonicalServiceName() Get a canonical service name for this file system.
BlockLocation[]	getFileBlockLocations(FileStatus file, long start, long len) Get block locations from the underlying fs and fix their offsets and lengths.
FileChecksum	getFileChecksum(Path f) Get the checksum of a file.
FileStatus	getFileStatus(Path f) return the filestatus of files in har archive.
static int	getHarHash(Path p) the hash of the path p inside iniside the filesystem
int	getHarVersion()
Path	getHomeDirectory() return the top level archive path.
URI	getUri() Returns the uri of this filesystem.
Path	getWorkingDirectory() return the top level archive.
void	initialize(URI name, Configuration conf) Initialize a Har filesystem per har archive.
FileStatus[]	listStatus(Path f) liststatus returns the children of a directory after looking up the index files.
Path	makeQualified(Path path) Make sure that a path specifies a FileSystem.
boolean	mkdirs(Path f, FsPermission permission) not implemented.
FSDataInputStream	open(Path f, int bufferSize) Returns a har input stream which fakes end of file.
void	setOwner(Path p, String username, String groupname) not implemented.
void	setPermission(Path p, FsPermission permisssion) Not implemented.
boolean	setReplication(Path src, short replication) Not implemented.
void	setWorkingDirectory(Path newDir) Set the current working directory for the given file system.
Path	startLocalOutput(Path fsOutputFile, Path tmpLocalFile) not implemented.

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

append, checkPath, concat, delete, getConf, getDefaultBlockSize, getDefaultReplication, getName, rename, setVerifyChecksum

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

addFileSystemForTesting, append, append, clearStatistics, closeAll, closeAllForUGI, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyToLocalFile, create, create, create, create, create, create, create, create, create, create, createNewFile, createNonRecursive, createNonRecursive, deleteOnExit, exists, get, get, get, getAllStatistics, getBlockSize, getCacheSize, getCanonicalUri, getContentSummary, getDefaultBlockSize, getDefaultPort, getDefaultReplication, getDefaultUri, getDelegationToken, getLength, getLocal, getNamed, getReplication, getStatistics, getStatistics, getUsed, globStatus, globStatus, isDirectory, isFile, listStatus, listStatus, listStatus, mkdirs, mkdirs, moveFromLocalFile, moveFromLocalFile, moveToLocalFile, open, printStatistics, processDeleteOnExit, setDefaultUri, setDefaultUri, setTimes

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

setConf

Methods inherited from class java.lang.Object

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

Field Detail

VERSION

public static final int VERSION

See Also:

Constant Field Values

Constructor Detail

HarFileSystem

public HarFileSystem()

public construction of harfilesystem

HarFileSystem

public HarFileSystem(FileSystem fs)

Constructor to create a HarFileSystem with an underlying filesystem.

Parameters:

fs -

Method Detail

initialize

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

Initialize a Har filesystem per har archive. The archive home directory is the top level directory in the filesystem that contains the HAR archive. Be careful with this method, you do not want to go on creating new Filesystem instances per call to path.getFileSystem(). the uri of Har is har://underlyingfsscheme-host:port/archivepath. or har:///archivepath. This assumes the underlying filesystem to be used in case not specified.

Overrides:

initialize in class FilterFileSystem

Parameters:

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

conf - the configuration

Throws:

IOException

getHarVersion

public int getHarVersion()
                  throws IOException

Throws:

IOException

getWorkingDirectory

public Path getWorkingDirectory()

return the top level archive.

Overrides:

getWorkingDirectory in class FilterFileSystem

Returns:

the directory pathname

getUri

public URI getUri()

Returns the uri of this filesystem. The uri is of the form har://underlyingfsschema-host:port/pathintheunderlyingfs

Overrides:

getUri in class FilterFileSystem

getCanonicalServiceName

public String getCanonicalServiceName()

Description copied from class: FileSystem

Get a canonical service name for this file system. The token cache is the only user of this value, and uses it to lookup this filesystem's service tokens. The token cache will not attempt to acquire tokens if the service is null.

Overrides:

getCanonicalServiceName in class FilterFileSystem

Returns:

a service string that uniquely identifies this file system, null if the filesystem does not implement tokens

See Also:

SecurityUtil.buildDTServiceName(URI, int)

makeQualified

public Path makeQualified(Path path)

Description copied from class: FilterFileSystem

Make sure that a path specifies a FileSystem.

Overrides:

makeQualified in class FilterFileSystem

getFileBlockLocations

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

Get block locations from the underlying fs and fix their offsets and lengths.

Overrides:

getFileBlockLocations in class FilterFileSystem

Parameters:

file - the input filestatus to get block locations

start - the start of the desired range in the contained file

len - the length of the desired range

Returns:

block locations for this segment of file

Throws:

IOException

getHarHash

public static int getHarHash(Path p)

the hash of the path p inside iniside the filesystem

Parameters:

p - the path in the harfilesystem

Returns:

the hash code of the path.

getFileStatus

public FileStatus getFileStatus(Path f)
                         throws IOException

return the filestatus of files in har archive. The permission returned are that of the archive index files. The permissions are not persisted while creating a hadoop archive.

Overrides:

getFileStatus in class FilterFileSystem

Parameters:

f - the path in har filesystem

Returns:

filestatus.

Throws:

IOException

FileNotFoundException - when the path does not exist; IOException see specific implementation

getFileChecksum

public FileChecksum getFileChecksum(Path f)

Description copied from class: FilterFileSystem

Get the checksum of a file.

Overrides:

getFileChecksum in class FilterFileSystem

Parameters:

f - The file path

Returns:

null since no checksum algorithm is implemented.

open

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

Returns a har input stream which fakes end of file. It reads the index files to get the part file name and the size and start of the file.

Overrides:

open in class FilterFileSystem

Parameters:

f - the file name to open

bufferSize - the size of the buffer to be used.

Throws:

IOException

create

public FSDataOutputStream create(Path f,
                                 int bufferSize)
                          throws IOException

Throws:

IOException

create

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

Description copied from class: FileSystem

Opens an FSDataOutputStream at the indicated Path with write-progress reporting.

Overrides:

create in class FilterFileSystem

Parameters:

f - the file name to open

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

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

Throws:

IOException

See Also:

FileSystem.setPermission(Path, FsPermission)

close

public void close()
           throws IOException

Description copied from class: FileSystem

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

Specified by:

close in interface Closeable

Overrides:

close in class FilterFileSystem

Throws:

IOException

setReplication

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

Not implemented.

Overrides:

setReplication in class FilterFileSystem

Parameters:

src - file name

replication - new replication

Returns:

true if successful; false if file does not exist or is a directory

Throws:

IOException

delete

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

Not implemented.

Overrides:

delete in class FilterFileSystem

Parameters:

f - the path to delete.

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

Returns:

true if delete is successful else false.

Throws:

IOException

listStatus

public FileStatus[] listStatus(Path f)
                        throws IOException

liststatus returns the children of a directory after looking up the index files.

Overrides:

listStatus in class FilterFileSystem

Parameters:

f - given path

Returns:

the statuses of the files/directories in the given patch returns null, if Path f does not exist in the FileSystem

Throws:

IOException

getHomeDirectory

public Path getHomeDirectory()

return the top level archive path.

Overrides:

getHomeDirectory in class FilterFileSystem

setWorkingDirectory

public void setWorkingDirectory(Path newDir)

Description copied from class: FilterFileSystem

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

Overrides:

setWorkingDirectory in class FilterFileSystem

mkdirs

public boolean mkdirs(Path f,
                      FsPermission permission)
               throws IOException

not implemented.

Overrides:

mkdirs in class FilterFileSystem

Throws:

IOException

copyFromLocalFile

public void copyFromLocalFile(boolean delSrc,
                              Path src,
                              Path dst)
                       throws IOException

not implemented.

Overrides:

copyFromLocalFile in class FilterFileSystem

Throws:

IOException

copyToLocalFile

public void copyToLocalFile(boolean delSrc,
                            Path src,
                            Path dst)
                     throws IOException

copies the file in the har filesystem to a local file.

Overrides:

copyToLocalFile in class FilterFileSystem

Throws:

IOException

startLocalOutput

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

not implemented.

Overrides:

startLocalOutput in class FilterFileSystem

Throws:

IOException

completeLocalOutput

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

not implemented.

Overrides:

completeLocalOutput in class FilterFileSystem

Throws:

IOException

setOwner

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

not implemented.

Overrides:

setOwner in class FilterFileSystem

Parameters:

p - The path

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

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

Throws:

IOException

setPermission

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

Not implemented.

Overrides:

setPermission in class FilterFileSystem

Throws:

IOException