streams/src/main/java/org/apache/kafka/streams/internals/StreamsConfigUtils.java

/*
 * 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 org.apache.kafka.streams.internals;

import org.apache.kafka.streams.StreamsConfig;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static org.apache.kafka.streams.StreamsConfig.CACHE_MAX_BYTES_BUFFERING_CONFIG;
import static org.apache.kafka.streams.StreamsConfig.STATESTORE_CACHE_MAX_BYTES_CONFIG;

public class StreamsConfigUtils {

    private static final Logger LOG = LoggerFactory.getLogger(StreamsConfigUtils.class);

    @SuppressWarnings("deprecation")
    public enum ProcessingMode {
        AT_LEAST_ONCE(StreamsConfig.AT_LEAST_ONCE),

        EXACTLY_ONCE_ALPHA(StreamsConfig.EXACTLY_ONCE),

        EXACTLY_ONCE_V2(StreamsConfig.EXACTLY_ONCE_V2);

        public final String name;

        ProcessingMode(final String name) {
            this.name = name;
        }
    }
    
    @SuppressWarnings("deprecation")
    public static ProcessingMode processingMode(final StreamsConfig config) {
        if (StreamsConfig.EXACTLY_ONCE.equals(config.getString(StreamsConfig.PROCESSING_GUARANTEE_CONFIG))) {
            return ProcessingMode.EXACTLY_ONCE_ALPHA;
        } else if (StreamsConfig.EXACTLY_ONCE_BETA.equals(config.getString(StreamsConfig.PROCESSING_GUARANTEE_CONFIG))) {
            return ProcessingMode.EXACTLY_ONCE_V2;
        } else if (StreamsConfig.EXACTLY_ONCE_V2.equals(config.getString(StreamsConfig.PROCESSING_GUARANTEE_CONFIG))) {
            return ProcessingMode.EXACTLY_ONCE_V2;
        } else {
            return ProcessingMode.AT_LEAST_ONCE;
        }
    }

    @SuppressWarnings("deprecation")
    public static String processingModeString(final ProcessingMode processingMode) {
        if (processingMode == ProcessingMode.EXACTLY_ONCE_V2) {
            return StreamsConfig.EXACTLY_ONCE_V2;
        } else if (processingMode == ProcessingMode.EXACTLY_ONCE_ALPHA) {
            return StreamsConfig.EXACTLY_ONCE;
        } else {
            return StreamsConfig.AT_LEAST_ONCE;
        }
    }

    public static boolean eosEnabled(final StreamsConfig config) {
        return eosEnabled(processingMode(config));
    }

    public static boolean eosEnabled(final ProcessingMode processingMode) {
        return processingMode == ProcessingMode.EXACTLY_ONCE_ALPHA ||
            processingMode == ProcessingMode.EXACTLY_ONCE_V2;
    }

    @SuppressWarnings("deprecation")
    public static long getTotalCacheSize(final StreamsConfig config) {
        // both deprecated and new config set. Warn and use the new one.
        if (config.originals().containsKey(CACHE_MAX_BYTES_BUFFERING_CONFIG) && config.originals().containsKey(STATESTORE_CACHE_MAX_BYTES_CONFIG)) {
            if (!config.getLong(CACHE_MAX_BYTES_BUFFERING_CONFIG).equals(config.getLong(STATESTORE_CACHE_MAX_BYTES_CONFIG))) {
                LOG.warn("Both deprecated config {} and the new config {} are set, hence {} is ignored and {} is used instead.",
                        CACHE_MAX_BYTES_BUFFERING_CONFIG,
                        STATESTORE_CACHE_MAX_BYTES_CONFIG,
                        CACHE_MAX_BYTES_BUFFERING_CONFIG,
                        STATESTORE_CACHE_MAX_BYTES_CONFIG);
            }
            return config.getLong(STATESTORE_CACHE_MAX_BYTES_CONFIG);
        } else if (config.originals().containsKey(CACHE_MAX_BYTES_BUFFERING_CONFIG)) {
            // only deprecated config set.
            LOG.warn("Deprecated config {} is set, and will be used; we suggest setting the new config {} instead as deprecated {} would be removed in the future.",
                    CACHE_MAX_BYTES_BUFFERING_CONFIG,
                    STATESTORE_CACHE_MAX_BYTES_CONFIG,
                    CACHE_MAX_BYTES_BUFFERING_CONFIG);
            return config.getLong(CACHE_MAX_BYTES_BUFFERING_CONFIG);
        }
        // only new or no config set. Use default or user specified value.
        return config.getLong(STATESTORE_CACHE_MAX_BYTES_CONFIG);
    }
}