co.cask.cdap.internal.app.ServiceSpecificationCodec.java Source code

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Here is the source code for co.cask.cdap.internal.app.ServiceSpecificationCodec.java

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/*
 * Copyright  2014 Cask Data, Inc.
 *
 * Licensed 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 co.cask.cdap.internal.app;

import co.cask.cdap.api.Resources;
import co.cask.cdap.api.service.ServiceSpecification;
import co.cask.cdap.api.service.http.HttpServiceHandlerSpecification;
import co.cask.cdap.api.service.http.ServiceHttpEndpoint;
import co.cask.cdap.proto.codec.AbstractSpecificationCodec;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Maps;
import com.google.common.reflect.TypeToken;
import com.google.gson.Gson;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.google.gson.JsonSerializationContext;
import org.apache.twill.api.ResourceSpecification;
import org.apache.twill.api.RuntimeSpecification;
import org.apache.twill.api.TwillSpecification;
import org.apache.twill.internal.json.TwillSpecificationAdapter;

import java.lang.reflect.Type;
import java.util.List;
import java.util.Map;

/**
 * Codec to serialize and deserialize {@link ServiceSpecification}
 *
 * TODO: Move to cdap-proto
 */
public class ServiceSpecificationCodec extends AbstractSpecificationCodec<ServiceSpecification> {

    // For decoding old spec. Remove later.
    private static final Gson GSON = new Gson();

    private final TwillSpecificationAdapter twillSpecificationAdapter;

    public ServiceSpecificationCodec() {
        twillSpecificationAdapter = TwillSpecificationAdapter.create();
    }

    @Override
    public ServiceSpecification deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
            throws JsonParseException {
        JsonObject jsonObj = (JsonObject) json;

        if (isOldSpec(jsonObj)) {
            return decodeOldSpec(jsonObj);
        }

        String className = jsonObj.get("className").getAsString();
        String name = jsonObj.get("name").getAsString();
        String description = jsonObj.get("description").getAsString();
        Map<String, HttpServiceHandlerSpecification> handlers = deserializeMap(jsonObj.get("handlers"), context,
                HttpServiceHandlerSpecification.class);
        Resources resources = context.deserialize(jsonObj.get("resources"), Resources.class);
        int instances = jsonObj.get("instances").getAsInt();

        return new ServiceSpecification(className, name, description, handlers, resources, instances);
    }

    @Override
    public JsonElement serialize(ServiceSpecification spec, Type typeOfSrc, JsonSerializationContext context) {
        JsonObject object = new JsonObject();
        object.addProperty("className", spec.getClassName());
        object.addProperty("name", spec.getName());
        object.addProperty("description", spec.getDescription());
        object.add("handlers", serializeMap(spec.getHandlers(), context, HttpServiceHandlerSpecification.class));
        object.add("resources", context.serialize(spec.getResources(), Resources.class));
        object.addProperty("instances", spec.getInstances());
        return object;
    }

    private boolean isOldSpec(JsonObject json) {
        return json.has("classname"); // In old spec, it's misspelled as classname, not className.
    }

    private ServiceSpecification decodeOldSpec(JsonObject json) {
        String className = json.get("classname").getAsString();
        TwillSpecification twillSpec = twillSpecificationAdapter.fromJson(json.get("spec").getAsString());
        Map<String, HttpServiceHandlerSpecification> handlers = Maps.newHashMap();

        RuntimeSpecification handlerSpec = twillSpec.getRunnables().get(twillSpec.getName());
        Map<String, String> configs = handlerSpec.getRunnableSpecification().getConfigs();

        // Get the class names of all handlers. It is stored in the handler runnable spec configs
        List<String> handlerClasses = GSON.fromJson(configs.get("service.runnable.handlers"),
                new TypeToken<List<String>>() {
                }.getType());
        List<JsonObject> handlerSpecs = GSON.fromJson(configs.get("service.runnable.handler.spec"),
                new TypeToken<List<JsonObject>>() {
                }.getType());

        for (int i = 0; i < handlerClasses.size(); i++) {
            String handlerClass = handlerClasses.get(i);
            JsonObject spec = handlerSpecs.get(i);
            Map<String, String> properties = GSON.fromJson(spec.get("properties"),
                    new TypeToken<Map<String, String>>() {
                    }.getType());

            // Reconstruct the HttpServiceSpecification. However there is no way to determine the datasets or endpoints
            // as it is not recorded in old spec. It's ok since the spec is only used to load data from MDS during redeploy.
            handlers.put(spec.get("name").getAsString(),
                    new HttpServiceHandlerSpecification(handlerClass, spec.get("name").getAsString(),
                            spec.get("description").getAsString(), properties, ImmutableSet.<String>of(),
                            ImmutableList.<ServiceHttpEndpoint>of()));
        }

        ResourceSpecification resourceSpec = handlerSpec.getResourceSpecification();
        return new ServiceSpecification(className, twillSpec.getName(), twillSpec.getName(), handlers,
                new Resources(resourceSpec.getMemorySize(), resourceSpec.getVirtualCores()),
                resourceSpec.getInstances());
    }
}