io.druid.server.emitter.EmitterModule.java Source code

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Here is the source code for io.druid.server.emitter.EmitterModule.java

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/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Metamarkets 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 io.druid.server.emitter;

import com.google.common.base.Strings;
import com.google.common.base.Supplier;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Lists;
import com.google.inject.Binder;
import com.google.inject.Binding;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.Module;
import com.google.inject.Provider;
import com.google.inject.Provides;
import com.google.inject.TypeLiteral;
import com.google.inject.multibindings.MapBinder;
import com.google.inject.name.Named;
import com.google.inject.name.Names;
import com.metamx.emitter.EmittingLogger;
import com.metamx.emitter.core.Emitter;
import com.metamx.emitter.service.ServiceEmitter;
import io.druid.guice.LazySingleton;
import io.druid.guice.ManageLifecycle;
import io.druid.guice.annotations.Self;
import io.druid.java.util.common.ISE;
import io.druid.java.util.common.logger.Logger;
import io.druid.server.DruidNode;

import java.lang.annotation.Annotation;
import java.util.List;
import java.util.Map;
import java.util.Properties;

/**
 */
public class EmitterModule implements Module {
    private static final Logger log = new Logger(EmitterModule.class);
    private static final String EMITTER_PROPERTY = "druid.emitter";

    private final Properties props;

    @Inject
    public EmitterModule(Properties props) {
        this.props = props;
    }

    @Override
    public void configure(Binder binder) {
        String emitterType = props.getProperty(EMITTER_PROPERTY, "");

        binder.install(new NoopEmitterModule());
        binder.install(new LogEmitterModule());
        binder.install(new HttpEmitterModule());
        binder.install(new ParametrizedUriEmitterModule());
        binder.install(new ComposingEmitterModule());

        binder.bind(Emitter.class).toProvider(new EmitterProvider(emitterType)).in(LazySingleton.class);

        MapBinder<String, String> extraServiceDimensions = MapBinder.newMapBinder(binder, String.class,
                String.class, ExtraServiceDimensions.class);
        String version = getClass().getPackage().getImplementationVersion();
        extraServiceDimensions.addBinding("version").toInstance(Strings.nullToEmpty(version)); // Version is null during `mvn test`.
    }

    @Provides
    @ManageLifecycle
    public ServiceEmitter getServiceEmitter(@Self Supplier<DruidNode> configSupplier, Emitter emitter,
            @ExtraServiceDimensions Map<String, String> extraServiceDimensions) {
        final DruidNode config = configSupplier.get();
        log.info("Underlying emitter for ServiceEmitter: %s", emitter);
        log.info("Extra service dimensions: %s", extraServiceDimensions);
        final ServiceEmitter retVal = new ServiceEmitter(config.getServiceName(), config.getHostAndPortToUse(),
                emitter, ImmutableMap.copyOf(extraServiceDimensions));
        EmittingLogger.registerEmitter(retVal);
        return retVal;
    }

    private static class EmitterProvider implements Provider<Emitter> {
        private final String emitterType;

        private Emitter emitter = null;

        EmitterProvider(String emitterType) {
            this.emitterType = emitterType;
        }

        @Inject
        public void inject(Injector injector) {
            final List<Binding<Emitter>> emitterBindings = injector.findBindingsByType(new TypeLiteral<Emitter>() {
            });

            emitter = findEmitter(emitterType, emitterBindings);

            if (emitter == null) {
                emitter = findEmitter(NoopEmitterModule.EMITTER_TYPE, emitterBindings);
            }

            if (emitter == null) {
                List<String> knownTypes = Lists.newArrayList();
                for (Binding<Emitter> binding : emitterBindings) {
                    final Annotation annotation = binding.getKey().getAnnotation();
                    if (annotation != null) {
                        knownTypes.add(((Named) annotation).value());
                    }
                }
                throw new ISE("Unknown emitter type[%s]=[%s], known types[%s]", EMITTER_PROPERTY, emitterType,
                        knownTypes);
            }
        }

        private Emitter findEmitter(String emitterType, List<Binding<Emitter>> emitterBindings) {
            for (Binding<Emitter> binding : emitterBindings) {
                if (Names.named(emitterType).equals(binding.getKey().getAnnotation())) {
                    return binding.getProvider().get();
                }
            }
            return null;
        }

        @Override
        public Emitter get() {
            if (emitter == null) {
                throw new ISE("Emitter was null, that's bad!");
            }
            return emitter;
        }
    }
}