Package org.epics.archiverappliance.common

Class BasicContext

java.lang.Object

org.epics.archiverappliance.common.BasicContext

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

ETLContext

public class BasicContext
extends Object
implements Closeable

All the main units of work in the appliance that deal with plugins pass in a context that can be used to hold state that pertains to the unit of work. For now, these are

1. The main writer thread in the engine that writes to the short term store.
2. The ETL jobs that transfer data from one store to the other.
3. A client retrieval that gets data from the plugin.

This class contains functionality that plugins can rely on in all these contexts. Callers are expected to call the close method on completion of the unit of work. Contexts are not expected to be thread safe and are particular to the thread of execution.

Author:

mshankar

Constructor Summary

Constructors

Constructor	Description
BasicContext()
BasicContext(ArchDBRTypes retrievalExpectedDBRType, String pvNameFromRequest)

Method Summary

Modifier and Type	Method	Description
void	addResource(Closeable resource)	Add a resource that needs to be closed once we finish the unit of work..
void	close()
ArchPaths	getPaths()	The PlainPB plugin deals with paths that can be translated into NIO by our implementation of Paths.
String	getPvNameFromRequest()
ArchDBRTypes	getRetrievalExpectedDBRType()

Methods inherited from class java.lang.Object

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

Constructor Details

BasicContext

public BasicContext()

BasicContext

public BasicContext(ArchDBRTypes retrievalExpectedDBRType,
 String pvNameFromRequest)

Method Details

getPaths

public ArchPaths getPaths()

The PlainPB plugin deals with paths that can be translated into NIO by our implementation of Paths. We generate one per context so that things can be closed correctly.

Returns:

paths ArchPaths

addResource

public void addResource(Closeable resource)

Add a resource that needs to be closed once we finish the unit of work..

Parameters:

resource - Closeable resouce

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException

getRetrievalExpectedDBRType

public ArchDBRTypes getRetrievalExpectedDBRType()

Returns:

retrievalExpectedDBRType ArchDBRTypes

getPvNameFromRequest

public String getPvNameFromRequest()

Returns:

pvNameFromRequest