org.apache.nutch.ndfs
Class FSDirectory

java.lang.Object
  org.apache.nutch.ndfs.FSDirectory

All Implemented Interfaces:

FSConstants

public class FSDirectory

extends Object

implements FSConstants

FSDirectory stores the filesystem directory state. It handles writing/loading values to disk, and logging changes as we go. It keeps the filename->blockset mapping always-current and logged to disk.

Author:

Mike Cafarella

Field Summary

Fields inherited from interface org.apache.nutch.ndfs.FSConstants

BLOCK_SIZE, BLOCKREPORT_INTERVAL, CHUNKED_ENCODING, COMPLETE_SUCCESS, DATANODE_STARTUP_PERIOD, EXPIRE_INTERVAL, HEARTBEAT_INTERVAL, LEASE_PERIOD, OBSOLETE_INTERVAL, OP_ACK, OP_BLOCKRECEIVED, OP_BLOCKREPORT, OP_CLIENT_ABANDONBLOCK, OP_CLIENT_ABANDONBLOCK_ACK, OP_CLIENT_ADDBLOCK, OP_CLIENT_ADDBLOCK_ACK, OP_CLIENT_COMPLETEFILE, OP_CLIENT_COMPLETEFILE_ACK, OP_CLIENT_DATANODE_HINTS, OP_CLIENT_DATANODE_HINTS_ACK, OP_CLIENT_DATANODEREPORT, OP_CLIENT_DATANODEREPORT_ACK, OP_CLIENT_DELETE, OP_CLIENT_DELETE_ACK, OP_CLIENT_EXISTS, OP_CLIENT_EXISTS_ACK, OP_CLIENT_ISDIR, OP_CLIENT_ISDIR_ACK, OP_CLIENT_LISTING, OP_CLIENT_LISTING_ACK, OP_CLIENT_MKDIRS, OP_CLIENT_MKDIRS_ACK, OP_CLIENT_OBTAINLOCK, OP_CLIENT_OBTAINLOCK_ACK, OP_CLIENT_OPEN, OP_CLIENT_OPEN_ACK, OP_CLIENT_RAWSTATS, OP_CLIENT_RAWSTATS_ACK, OP_CLIENT_RELEASELOCK, OP_CLIENT_RELEASELOCK_ACK, OP_CLIENT_RENAMETO, OP_CLIENT_RENAMETO_ACK, OP_CLIENT_RENEW_LEASE, OP_CLIENT_RENEW_LEASE_ACK, OP_CLIENT_STARTFILE, OP_CLIENT_STARTFILE_ACK, OP_CLIENT_TRYAGAIN, OP_ERROR, OP_FAILURE, OP_HEARTBEAT, OP_INVALIDATE_BLOCKS, OP_READ_BLOCK, OP_READSKIP_BLOCK, OP_TRANSFERBLOCKS, OP_TRANSFERDATA, OP_WRITE_BLOCK, OPERATION_FAILED, RUNLENGTH_ENCODING, STILL_WAITING, SYSTEM_STARTUP_PERIOD, WRITE_COMPLETE

Constructor Summary

FSDirectory(File dir)
Create a FileSystem directory, and load its info from the indicated place.

Method Summary

boolean	addFile(UTF8 src, Block[] blocks) Add the given filename to the fs.
void	close() Shutdown the filestore
Block[]	delete(UTF8 src) Remove the file from management, return blocks
Block[]	getFile(UTF8 src) Get the blocks associated with the file
NDFSFileInfo[]	getListing(UTF8 src) Get a listing of files given path 'src' This function is admittedly very inefficient right now.
boolean	isDir(UTF8 src) Check whether it's a directory
boolean	isValidBlock(Block b) Returns whether the given block is one pointed-to by a file.
boolean	isValidToCreate(UTF8 src) Check whether the filepath could be created
boolean	mkdirs(UTF8 src) Create the given directory and all its parent dirs.
int	obtainLock(UTF8 src, UTF8 holder, boolean exclusive)
int	releaseLock(UTF8 src, UTF8 holder)
boolean	renameTo(UTF8 src, UTF8 dst) Change the filename

Methods inherited from class java.lang.Object

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

Constructor Detail

FSDirectory

public FSDirectory(File dir)
            throws IOException

Create a FileSystem directory, and load its info from the indicated place.

Method Detail

close

public void close()
           throws IOException

Shutdown the filestore

Throws:

IOException

addFile

public boolean addFile(UTF8 src,
                       Block[] blocks)

Add the given filename to the fs.

renameTo

public boolean renameTo(UTF8 src,
                        UTF8 dst)

Change the filename

delete

public Block[] delete(UTF8 src)

Remove the file from management, return blocks

obtainLock

public int obtainLock(UTF8 src,
                      UTF8 holder,
                      boolean exclusive)

releaseLock

public int releaseLock(UTF8 src,
                       UTF8 holder)

getListing

public NDFSFileInfo[] getListing(UTF8 src)

Get a listing of files given path 'src' This function is admittedly very inefficient right now. We'll make it better later.

getFile

public Block[] getFile(UTF8 src)

Get the blocks associated with the file

isValidToCreate

public boolean isValidToCreate(UTF8 src)

Check whether the filepath could be created

isDir

public boolean isDir(UTF8 src)

Check whether it's a directory

mkdirs

public boolean mkdirs(UTF8 src)

Create the given directory and all its parent dirs.

isValidBlock

public boolean isValidBlock(Block b)

Returns whether the given block is one pointed-to by a file.