com.pdd.pop.ext.glassfish.grizzly.Transformer Maven / Gradle / Ivy
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package com.pdd.pop.ext.glassfish.grizzly;
import com.pdd.pop.ext.glassfish.grizzly.attributes.AttributeStorage;
/**
* Transformer interface, which knows how to transform the original
* data to some custom representation.
* A Transformer implementation could be stateful or stateless. However
* it's very easy to write stateful Transformer, which actaully doesn't
* save any state internally, but uses {@link AttributeStorage} as an external
* state storage. Please note, that {@link AttributeStorage} is being passed
* as the parameter to all Transformer methods. This way it's
* possible to reuse single instance of a stateful Transformer to
* process lots of concurrent transformations.
*
* @author Alexey Stashok
*/
public interface Transformer {
/**
* Get the Transformer name. The name is used to store
* Transformer associated data.
*
* @return The Transformer name.
*/
String getName();
/**
* Transforms an input data to some custom representation.
* Input and output are not passed implicitly, which means that
* Transformer is able to retrieve input and output from its
* internal state or from external storage ({@link AttributeStorage}).
*
* @param storage the external state storage, where Transformer could
* get/put a state.
* @return the result {@link TransformationResult}
*
* @throws com.pdd.pop.ext.glassfish.grizzly.TransformationException
*/
TransformationResult transform(AttributeStorage storage, K input)
throws TransformationException;
/**
* Gets the last returned Transformer result.
* Last result could be either retrieved from internal state, or external
* storage, which is passed as the parameter.
*
* @param storage the external state storage, where Transformer
* could retrieve or store its state.
* @return the last returned Transformer result.
*/
TransformationResult getLastResult(AttributeStorage storage);
/**
* The Transformer has done its work and can release all
* associated resource.
*
* @param storage the external state storage, where Transformer
* could retrieve or store its state.
*/
void release(AttributeStorage storage);
boolean hasInputRemaining(AttributeStorage storage, K input);
}