net.nutch.fs
Class NDFSClient

java.lang.Object
  net.nutch.fs.NDFSClient

All Implemented Interfaces:

FSConstants

public class NDFSClient

extends Object

implements FSConstants

NDFSClient does what's necessary to connect to a Nutch Filesystem and perform basic file tasks.

Author:

Mike Cafarella, Tessa MacDuff

Field Summary

Fields inherited from interface net.nutch.fs.FSConstants

BLOCK_SIZE, BLOCKREPORT_INTERVAL, CHUNKED_ENCODING, DATANODE_STARTUP_PERIOD, FILE_COMPLETE_FAILED, FILE_COMPLETE_ONGOING, FILE_COMPLETE_SUCCESS, HEARTBEAT_INTERVAL, OP_ACK, OP_BLOCKRECEIVED, OP_BLOCKREPORT, OP_CLIENT_ADDBLOCK, OP_CLIENT_ADDBLOCK_ACK, OP_CLIENT_COMPLETEFILE, OP_CLIENT_COMPLETEFILE_ACK, OP_CLIENT_DELETE, OP_CLIENT_DELETE_ACK, OP_CLIENT_LISTING, OP_CLIENT_LISTING_ACK, OP_CLIENT_OPEN, OP_CLIENT_OPEN_ACK, OP_CLIENT_RENAMETO, OP_CLIENT_RENAMETO_ACK, OP_CLIENT_STARTFILE, OP_CLIENT_STARTFILE_ACK, OP_CLIENT_TRYAGAIN, OP_ERROR, OP_FAILURE, OP_HEARTBEAT, OP_INVALIDATE_BLOCKS, OP_READ_BLOCK, OP_TRANSFERBLOCKS, OP_TRANSFERDATA, OP_WRITE_BLOCK, RUNLENGTH_ENCODING, SYSTEM_STARTUP_PERIOD

Constructor Summary

NDFSClient(InetSocketAddress namenode)

Method Summary

OutputStream	create(UTF8 src) Create an output stream that writes to all the right places.
boolean	delete(UTF8 src) Make a direct connection to namenode and manipulate structures there.
UTF8[]	listing(UTF8 src)
InputStream	open(UTF8 src) Create an input stream that obtains a nodelist from the namenode, and then reads from all the right places.
boolean	rename(UTF8 src, UTF8 dst) Make a direct connection to namenode and manipulate structures there.

Methods inherited from class java.lang.Object

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

Constructor Detail

NDFSClient

public NDFSClient(InetSocketAddress namenode)

Method Detail

open

public InputStream open(UTF8 src)
                 throws IOException

Create an input stream that obtains a nodelist from the namenode, and then reads from all the right places. Creates inner subclass of InputStream that does the right out-of-band work.

Throws:

IOException

create

public OutputStream create(UTF8 src)
                    throws IOException

Create an output stream that writes to all the right places. Basically creates instance of inner subclass of OutputStream that handles datanode/namenode negotiation.

Throws:

IOException

rename

public boolean rename(UTF8 src,
                      UTF8 dst)
               throws IOException

Make a direct connection to namenode and manipulate structures there.

Throws:

IOException

delete

public boolean delete(UTF8 src)
               throws IOException

Make a direct connection to namenode and manipulate structures there.

Throws:

IOException

listing

public UTF8[] listing(UTF8 src)
               throws IOException

Throws:

IOException