com.googlesource.gerrit.plugins.kafka.config.KafkaProperties.java Source code

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Here is the source code for com.googlesource.gerrit.plugins.kafka.config.KafkaProperties.java

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// Copyright (C) 2016 The Android Open Source Project
//
// 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 com.googlesource.gerrit.plugins.kafka.config;

import com.google.common.base.CaseFormat;
import com.google.common.base.Strings;
import com.google.gerrit.extensions.annotations.PluginName;
import com.google.gerrit.server.config.PluginConfig;
import com.google.gerrit.server.config.PluginConfigFactory;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import java.util.UUID;
import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.common.serialization.StringSerializer;

@Singleton
public class KafkaProperties extends java.util.Properties {
    private static final long serialVersionUID = 0L;

    public static final String KAFKA_STRING_SERIALIZER = StringSerializer.class.getName();

    private final String topic;

    @Inject
    public KafkaProperties(PluginConfigFactory configFactory, @PluginName String pluginName) {
        super();
        setDefaults();
        PluginConfig fromGerritConfig = configFactory.getFromGerritConfig(pluginName);
        topic = fromGerritConfig.getString("topic", "gerrit");
        applyConfig(fromGerritConfig);
        initDockerizedKafkaServer();
    }

    private void setDefaults() {
        put("acks", "all");
        put("retries", 0);
        put("batch.size", 16384);
        put("linger.ms", 1);
        put("buffer.memory", 33554432);
        put("key.serializer", KAFKA_STRING_SERIALIZER);
        put("value.serializer", KAFKA_STRING_SERIALIZER);
        put("reconnect.backoff.ms", 5000L);
    }

    private void applyConfig(PluginConfig config) {
        for (String name : config.getNames()) {
            Object value = config.getString(name);
            String propName = CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_HYPHEN, name).replaceAll("-", ".");
            put(propName, value);
        }
    }

    /** Bootstrap initialization of dockerized Kafka server environment */
    private void initDockerizedKafkaServer() {
        String testBootstrapServer = System.getProperty(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG);
        if (!Strings.isNullOrEmpty(testBootstrapServer)) {
            this.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, testBootstrapServer);
            this.put(ProducerConfig.CLIENT_ID_CONFIG, UUID.randomUUID().toString());
            this.put(ConsumerConfig.GROUP_ID_CONFIG, "tc-" + UUID.randomUUID());
            this.put(ConsumerConfig.HEARTBEAT_INTERVAL_MS_CONFIG, "1000");
            this.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
        }
    }

    public String getTopic() {
        return topic;
    }
}