gr.uoa.di.madgik.grs.proxy.http

Class HTTPStoreReaderProxy

java.lang.Object

gr.uoa.di.madgik.grs.proxy.http.HTTPReaderProxy

gr.uoa.di.madgik.grs.proxy.http.HTTPStoreReaderProxy

All Implemented Interfaces:

IProxy, IReaderProxy

public class HTTPStoreReaderProxy
extends HTTPReaderProxy

This proxy extends the HTTPReaderProxy capabilities by adding an additional logic layer on top of the original extended base capabilities. This additional logic layer serves to contact the IBufferStore that can then create a locator capable of being managed by the underlying HTTPReaderProxy instance.

Author:

Alex Antoniadis

Nested Class Summary

Nested classes/interfaces inherited from interface gr.uoa.di.madgik.grs.proxy.IProxy

IProxy.ProxyType

Field Summary

Fields inherited from interface gr.uoa.di.madgik.grs.proxy.IProxy

ProxyScheme, ProxyStoreScheme

Constructor Summary

Constructors

Constructor and Description
HTTPStoreReaderProxy() Creates a new instance

Method Summary

Methods

Modifier and Type	Method and Description
void	fromLocator(URI locator) Populates an instance of the IReaderProxy implementer with the information provided through the specific locator URI
IBuffer	getBuffer() After the proxy has been initialized, through this method, the IBuffer that can be used by the reader to access the writer side IBuffer can be retrieved
static boolean	isOfType(URI locator) Checks if the provided URI is of a type that can be managed by an instance of this class.

Methods inherited from class gr.uoa.di.madgik.grs.proxy.http.HTTPReaderProxy

getHostname, getPort, overrideBufferCapacity

Methods inherited from class java.lang.Object

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

Constructor Detail

HTTPStoreReaderProxy

public HTTPStoreReaderProxy()

Creates a new instance

Method Detail

fromLocator

public void fromLocator(URI locator)
                 throws GRS2ProxyInvalidArgumentException,
                        GRS2ProxyInvalidOperationException

Populates an instance of the IReaderProxy implementer with the information provided through the specific locator URI

This method parses the provided URI to retrieve the needed information. An example of the URI this proxy can manage is grs2-proxy://foo.bar.gr:53361?key=272b934d-e796-4c30-944c-44ec2aec7eb7#HTTP

This method parses the provided URI locator that is expected to be in the form of the following example http://foo.bar.gr:53361?key=272b934d-e796-4c30-944c-44ec2aec7eb7#HTTPStore. After the parsing is completed, a connection is made to the provided host and port where it is expected that an instance of the HTTPStoreConnectionHandler is listening. The key of the IBufferStore is send and the URI locator is retrieved which is then forwarded to the underlying HTTPReaderProxy to take over any subsequent actions

Specified by:

fromLocator in interface IReaderProxy

Overrides:

fromLocator in class HTTPReaderProxy

Throws:

GRS2ProxyInvalidArgumentException - If the provided locator is not of the expected type of the parsing procedure does not provide the valid information needed

GRS2ProxyInvalidOperationException - if there was a problem initializing the underlying HTTPReaderProxy

See Also:

HTTPReaderProxy.fromLocator(java.net.URI)

getBuffer

public IBuffer getBuffer()
                  throws GRS2ProxyInvalidOperationException

After the proxy has been initialized, through this method, the IBuffer that can be used by the reader to access the writer side IBuffer can be retrieved

Initializes a HTTPReaderMirror to handle the reader side mirroring procedure. The mirror is set with the information available to the proxy, using the HTTPReaderMirror.setKey(String), HTTPReaderMirror.setPort(int) and HTTPReaderMirror.setHostname(String) and then the HTTPReaderMirror.handle() method is invoked. The proxy waits for the mirroring procedure to be initialized blocking using HTTPReaderMirror.waitInitialization() and if there was any error during the initialization procedure, it is retrieved and thrown using HTTPReaderMirror.getInitializationError(). After this procedure is completed, the mirroring procedure continues in the HTTPReaderMirror thread of execution. The returned IBuffer is the one available though HTTPReaderMirror.getBuffer() and is populated from HTTPReaderMirror

This method should only be used after the initialization step of the fromLocator(URI) has been completed. After this is done, any call to this method simple forwards the request to he underlying HTTPReaderProxy.getBuffer() method

Specified by:

getBuffer in interface IReaderProxy

Overrides:

getBuffer in class HTTPReaderProxy

Returns:

The IBuffer that is serving the reader

Throws:

GRS2ProxyInvalidOperationException - if a call to this overriding method is done even after the the store has been contacted and the underlying HTTPReaderProxy needs to be used.

See Also:

HTTPReaderProxy.getBuffer()

isOfType

public static boolean isOfType(URI locator)

Checks if the provided URI is of a type that can be managed by an instance of this class. It bases its checks on the URI scheme and the fragment type. An example of the URI this proxy can manage is http://foo.bar.gr:53361?key=272b934d-e796-4c30-944c-44ec2aec7eb7#HTTPStore

Parameters:

locator - the locator URI that needs to be checked

Returns:

true is this proxy class can handle the locator, false otherwise