uk.ac.rdg.resc.jstyx.gridservice.server
Class SGSOutputFile

java.lang.Object
  uk.ac.rdg.resc.jstyx.server.StyxFile
      uk.ac.rdg.resc.jstyx.gridservice.server.SGSOutputFile

All Implemented Interfaces:

SGSInstanceChangeListener

public class SGSOutputFile
extends StyxFile
implements SGSInstanceChangeListener

A file that can be read to obtain data from a file that is put out by an executable in a Styx Grid Service

Author:

Jon Blower $Revision: 579 $ $Date: 2006-02-17 09:26:08 +0000 (Fri, 17 Feb 2006) $ $Log$ Revision 1.3 2006/02/17 09:26:08 jonblower Removed reference to SGSParamFile Revision 1.2 2005/11/11 21:57:21 jonblower Implemented passing of URLs to input files Revision 1.1 2005/11/10 19:50:43 jonblower Added code to handle output files

Field Summary

Fields inherited from class uk.ac.rdg.resc.jstyx.server.StyxFile

auth, directory, lastModifiedTime, name, parent

Constructor Summary

SGSOutputFile(java.io.File file, uk.ac.rdg.resc.jstyx.gridservice.server.StyxGridServiceInstance instance)
Creates a new instance of SGSOutputFile

Method Summary

ULong	getLength()
void	read(StyxFileClient client, long offset, int count, int tag) Reads data from this file.
void	statusChanged(StatusCode newStatus) Called automatically when the status of the Styx Grid Service instance changes.

Methods inherited from class uk.ac.rdg.resc.jstyx.server.StyxFile

addChangeListener, addClient, checkSetLastModifiedTime, checkSetLength, checkSetMode, checkSetName, clientConnected, clientDisconnected, contentsChanged, delete, fireContentsChanged, getClient, getDirEntry, getFullPath, getGroup, getName, getNumClients, getOwner, getParent, getPermissions, getQid, getVersion, incrementVersion, isAppendOnly, isAuth, isDirectory, isExclusive, processAndReplyRead, processAndReplyRead, processAndReplyRead, refresh, remove, removeChangeListener, removeClient, rename, replyRead, replyRead, replyRead, replyRead, replyRead, replyWrite, setLastAccessTime, setLastModified, setLength, setMode, setName, setPermissions, setReadOnly, write

Methods inherited from class java.lang.Object

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

Constructor Detail

SGSOutputFile

public SGSOutputFile(java.io.File file,
                     uk.ac.rdg.resc.jstyx.gridservice.server.StyxGridServiceInstance instance)
              throws StyxException

Creates a new instance of SGSOutputFile

Throws:

StyxException

Method Detail

read

public void read(StyxFileClient client,
                 long offset,
                 int count,
                 int tag)
          throws StyxException

Description copied from class: StyxFile

Reads data from this file. This method could be synchronized in subclasses, but watch out for blocks if the read is expected to take some time to complete. Subclasses must make sure they reply to the read request by creating a java.nio.ByteBuffer or byte array of data, then calling the appropriate readReply() (this can be done at any time; it does not have to be done within the read() method). This default implementation simply throws a StyxException, which will result in an Rerror message being sent back to the client. Subclasses should override this to provide the desired behaviour when the file is read.

Overrides:

read in class StyxFile

Parameters:

client - The client that is performing the read

offset - The point in the file at which to start reading

count - The maximum number of bytes to read

tag - The tag of the incoming Tread message (this is needed when calling readReply())

Throws:

StyxException

getLength

public ULong getLength()

Overrides:

getLength in class StyxFile

Returns:

the length of the file. This default implementation returns zero; subclasses should override this method

statusChanged

public void statusChanged(StatusCode newStatus)

Called automatically when the status of the Styx Grid Service instance changes.

Specified by:

statusChanged in interface SGSInstanceChangeListener