PProcessor.java

/*
 * Copyright 2016 Providence Authors
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package net.morimekta.providence;

import net.morimekta.providence.descriptor.PService;
import net.morimekta.providence.serializer.SerializerException;

import javax.annotation.Nonnull;
import java.io.IOException;

/**
 * Service processor is an extension to the service call handler that can
 * provide it's own service definition. This is the base interface for
 * the handlers on the server side processing of a providence call.
 */
public interface PProcessor extends PServiceCallHandler {
    /**
     * Get the descriptor for the given service.
     *
     * @return The service descriptor.
     */
    @Nonnull
    PService getDescriptor();

    /**
     * Handle a service call.
     *
     * @param call The request call.
     * @param <Request> Request type.
     * @param <Response> Response type.
     * @return The response service call object, or null if none (e.g. oneway).
     * @throws IOException On read or write failure.
     * @throws SerializerException On serialization problems.
     */
    default <Request extends PMessage<Request>,
             Response extends PMessage<Response>>
    PServiceCall<Response> handleCall(PServiceCall<Request> call)
            throws IOException {
        return handleCall(call, getDescriptor());
    }
}