com.bigdata.service

Class ResourceService

java.lang.Object

com.bigdata.service.ResourceService

Direct Known Subclasses:

ManagedResourceService

public abstract class ResourceService
extends Object

A service which permits resources (managed files or buffers) identified by a UUID to be read by a remote service. This class runs one thread to accept connections and thread pool to send data.

Version:

$Id$

Author:

Bryan Thompson

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ResourceService.Counters Performance counters for the ResourceService.
static class	ResourceService.FetchResourceTask<S,T> Client for a BufferService reads a single resource from the specified service, writing it into the local file system.
static class	ResourceService.ReadBufferTask Class sends a request for a remote ByteBuffer and then receives the data into a local ByteBuffer.
static class	ResourceService.ReadResourceTask Task sends a request for a file's data and then receives the data onto a local file.
static class	ResourceService.ResourceTypeEnum Type safe enumeration of the kinds of resources which can be served.
static class	ResourceService.StatusEnum Known status codes.

Field Summary

Fields

Modifier and Type	Field and Description
ResourceService.Counters	counters Performance counters for this service.
protected static org.apache.log4j.Logger	log

Constructor Summary

Constructors

Constructor and Description
ResourceService(InetSocketAddress addr, int requestServicePoolSize) Create and start the service.

Method Summary

Methods

Modifier and Type	Method and Description
void	awaitRunning(long timeout, TimeUnit unit) Wait until the service is running.
protected void	finalize() Overridden to ensure that the service is always shutdown.
InetSocketAddress	getAddr() Return the address at which this service is accepting connections.
protected abstract ByteBuffer	getBuffer(UUID uuid) Return ByteBuffer identified by the UUID.
protected abstract File	getResource(UUID uuid) Return file identified by the UUID.
boolean	isOpen()
void	shutdown()
void	shutdownNow()

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static final org.apache.log4j.Logger log

counters

public final ResourceService.Counters counters

Performance counters for this service.

Constructor Detail

ResourceService

public ResourceService(InetSocketAddress addr,
               int requestServicePoolSize)
                throws IOException

Create and start the service.

Parameters:

addr - The IP address and port at which the service will accept connections. The port MAY be zero to use an ephemeral port.

requestServicePoolSize - The size of the thread pool that will handle requests. When ZERO (0) a cached thread pool will be used with no specific size limit.

Throws:

IOException

Method Detail

getAddr

public InetSocketAddress getAddr()

Return the address at which this service is accepting connections.

finalize

protected void finalize()
                 throws Throwable

Overridden to ensure that the service is always shutdown.

Overrides:

finalize in class Object

Throws:

Throwable

awaitRunning

public void awaitRunning(long timeout,
                TimeUnit unit)
                  throws InterruptedException,
                         TimeoutException

Wait until the service is running.

Parameters:

timeout - The timeout.

unit - The unit for the timeout.

Throws:

InterruptedException - if interrupted while waiting.

TimeoutException - if the timeout expired before the service was running.

isOpen

public boolean isOpen()

shutdown

public void shutdown()

shutdownNow

public void shutdownNow()

getResource

protected abstract File getResource(UUID uuid)
                             throws Exception

Return file identified by the UUID.

Parameters:

uuid -

Returns:

The file -or- null if there is no file associated with that UUID.

Throws:

Exception - if the resource may not be served.

getBuffer

protected abstract ByteBuffer getBuffer(UUID uuid)
                                 throws Exception

Return ByteBuffer identified by the UUID.

Parameters:

uuid -

Returns:

The ByteBuffer -or- null if there is no buffer associated with that UUID.

Throws:

Exception - if the resource may not be served.