org.apache.hadoop.fs
Class HarFileSystem

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

All Implemented Interfaces:

Closeable, Configurable

public class HarFileSystem
extends FileSystem

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	METADATA_CACHE_ENTRIES_DEFAULT
static String	METADATA_CACHE_ENTRIES_KEY
static int	VERSION

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

DEFAULT_FS, FS_DEFAULT_NAME_KEY, SHUTDOWN_HOOK_PRIORITY, statistics

Constructor Summary

HarFileSystem()
public construction of harfilesystem

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

Method Summary

FSDataOutputStream	append(Path f) Append to an existing file (optional operation).
FSDataOutputStream	append(Path f, int bufferSize, Progressable progress) Append to an existing file (optional operation).
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) Create an FSDataOutputStream at the indicated Path with write-progress reporting.
boolean	delete(Path f, boolean recursive) Not implemented.
protected URI	getCanonicalUri() Return a canonicalized form of this FileSystem's URI.
Configuration	getConf() Return the configuration used by this object.
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 the filesystem
int	getHarVersion()
Path	getHomeDirectory() return the top level archive path.
String	getScheme() Return the protocol scheme for the FileSystem.
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.
boolean	rename(Path src, Path dst) Renames Path src to Path dst.
void	setOwner(Path p, String username, String groupname) not implemented.
void	setPermission(Path p, FsPermission permission) 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.FileSystem

append, cancelDeleteOnExit, canonicalizeUri, checkPath, clearStatistics, closeAll, closeAllForUGI, concat, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyToLocalFile, copyToLocalFile, create, create, create, create, create, create, create, create, create, create, create, create, createNewFile, createNonRecursive, createNonRecursive, createNonRecursive, createSnapshot, createSnapshot, createSymlink, delete, deleteOnExit, deleteSnapshot, enableSymlinks, exists, fixRelativePart, get, get, get, getAllStatistics, getBlockSize, getContentSummary, getDefaultBlockSize, getDefaultBlockSize, getDefaultPort, getDefaultReplication, getDefaultReplication, getDefaultUri, getFileBlockLocations, getFileLinkStatus, getFileSystemClass, getFSofPath, getInitialWorkingDirectory, getLength, getLinkTarget, getLocal, getName, getNamed, getReplication, getServerDefaults, getServerDefaults, getStatistics, getStatistics, getStatus, getStatus, getUsed, globStatus, globStatus, isDirectory, isFile, isSymlinksEnabled, listCorruptFileBlocks, listFiles, listLocatedStatus, listLocatedStatus, listStatus, listStatus, listStatus, mkdirs, mkdirs, moveFromLocalFile, moveFromLocalFile, moveToLocalFile, newInstance, newInstance, newInstance, newInstanceLocal, open, primitiveCreate, primitiveMkdir, primitiveMkdir, printStatistics, processDeleteOnExit, rename, renameSnapshot, resolveLink, resolvePath, setDefaultUri, setDefaultUri, setTimes, setVerifyChecksum, setWriteChecksum, supportsSymlinks

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

METADATA_CACHE_ENTRIES_KEY

public static final String METADATA_CACHE_ENTRIES_KEY

See Also:

Constant Field Values

METADATA_CACHE_ENTRIES_DEFAULT

public static final int METADATA_CACHE_ENTRIES_DEFAULT

See Also:

Constant Field Values

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 - underlying file system

Method Detail

getScheme

public String getScheme()

Return the protocol scheme for the FileSystem.

Overrides:

getScheme in class FileSystem

Returns:

har

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 FileSystem

Parameters:

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

conf - the configuration

Throws:

IOException

getConf

public Configuration getConf()

Description copied from interface: Configurable

Return the configuration used by this object.

Specified by:

getConf in interface Configurable

Overrides:

getConf in class Configured

getHarVersion

public int getHarVersion()
                  throws IOException

Throws:

IOException

getWorkingDirectory

public Path getWorkingDirectory()

return the top level archive.

Specified by:

getWorkingDirectory in class FileSystem

Returns:

the directory pathname

getCanonicalUri

protected URI getCanonicalUri()

Description copied from class: FileSystem

Return a canonicalized form of this FileSystem's URI. The default implementation simply calls FileSystem.canonicalizeUri(URI) on the filesystem's own URI, so subclasses typically only need to implement that method.

Overrides:

getCanonicalUri in class FileSystem

See Also:

FileSystem.canonicalizeUri(URI)

getUri

public URI getUri()

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

Specified by:

getUri in class FileSystem

makeQualified

public Path makeQualified(Path path)

Description copied from class: FileSystem

Make sure that a path specifies a FileSystem.

Overrides:

makeQualified in class FileSystem

Parameters:

path - to use

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 FileSystem

Parameters:

file - the input file status 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 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.

Specified by:

getFileStatus in class FileSystem

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: FileSystem

Get the checksum of a file.

Overrides:

getFileChecksum in class FileSystem

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.

Specified by:

open in class FileSystem

Parameters:

f - the file name to open

bufferSize - the size of the buffer to be used.

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

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

Specified by:

create in class FileSystem

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)

append

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

Throws:

IOException

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 FileSystem

Throws:

IOException

setReplication

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

Not implemented.

Overrides:

setReplication in class FileSystem

Parameters:

src - file name

replication - new replication

Returns:

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

Throws:

IOException

rename

public boolean rename(Path src,
                      Path dst)
               throws IOException

Description copied from class: FileSystem

Renames Path src to Path dst. Can take place on local fs or remote DFS.

Specified by:

rename in class FileSystem

Parameters:

src - path to be renamed

dst - new path after rename

Returns:

true if rename is successful

Throws:

IOException - on failure

append

public FSDataOutputStream append(Path f)
                          throws IOException

Description copied from class: FileSystem

Append to an existing file (optional operation). Same as append(f, getConf().getInt("io.file.buffer.size", 4096), null)

Overrides:

append in class FileSystem

Parameters:

f - the existing file to be appended.

Throws:

IOException

delete

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

Not implemented.

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:

IOException

listStatus

public FileStatus[] listStatus(Path f)
                        throws IOException

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

Specified by:

listStatus in class FileSystem

Parameters:

f - given path

Returns:

the statuses of the files/directories in the given patch

Throws:

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

IOException

getHomeDirectory

public Path getHomeDirectory()

return the top level archive path.

Overrides:

getHomeDirectory in class FileSystem

setWorkingDirectory

public void setWorkingDirectory(Path newDir)

Description copied from class: FileSystem

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

Specified by:

setWorkingDirectory in class FileSystem

mkdirs

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

not implemented.

Specified by:

mkdirs in class FileSystem

Parameters:

f - path to create

permission - to apply to f

Throws:

IOException

copyFromLocalFile

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

not implemented.

Overrides:

copyFromLocalFile in class FileSystem

Parameters:

delSrc - whether to delete the src

src - path

dst - path

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 FileSystem

Parameters:

delSrc - whether to delete the src

src - path

dst - path

Throws:

IOException

startLocalOutput

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

not implemented.

Overrides:

startLocalOutput in class FileSystem

Parameters:

fsOutputFile - path of output file

tmpLocalFile - path of local tmp file

Throws:

IOException

completeLocalOutput

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

not implemented.

Overrides:

completeLocalOutput in class FileSystem

Parameters:

fsOutputFile - path of output file

tmpLocalFile - path to local tmp file

Throws:

IOException

setOwner

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

not implemented.

Overrides:

setOwner in class FileSystem

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 permission)
                   throws IOException

Not implemented.

Overrides:

setPermission in class FileSystem

Throws:

IOException