io.telicent.smart.cache.sources.file.yaml.YamlFileEventSource Maven / Gradle / Ivy

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/**
 * Copyright (C) Telicent Ltd
 *
 * 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 io.telicent.smart.cache.sources.file.yaml;

import io.telicent.smart.cache.sources.file.FileEventReaderWriter;
import io.telicent.smart.cache.sources.file.FileEventSource;
import io.telicent.smart.cache.sources.file.NumericFilenameComparator;
import io.telicent.smart.cache.sources.file.NumericallyNamedWithExtensionFilter;
import io.telicent.smart.cache.sources.file.gzip.GZipEventReaderWriter;
import org.apache.kafka.common.serialization.Deserializer;

import java.io.File;
import java.io.FileFilter;

/**
 * A file event source where the files are encoded with YAML
 *
 * @param    Key type
 * @param  Value type
 */
public class YamlFileEventSource extends FileEventSource {
    /**
     * The default file filter used to select YAML event files
     */
    public static final FileFilter YAML_FILTER = new NumericallyNamedWithExtensionFilter(".yaml");

    /**
     * The default filter used to select GZipped YAML event files
     */
    public static final FileFilter YAML_GZIPPED_FILTER = new NumericallyNamedWithExtensionFilter(".yaml.gz");

    /**
     * Creates a new file event source
     *
     * @param sourceDir         Source directory containing the events
     * @param keyDeserializer   Key deserializer
     * @param valueDeserializer Value deserializer
     */
    public YamlFileEventSource(File sourceDir, Deserializer keyDeserializer,
                               Deserializer valueDeserializer) {
        this(sourceDir, false, keyDeserializer, valueDeserializer);
    }

    /**
     * Creates a new file event source
     *
     * @param sourceDir         Source directory containing the events
     * @param gzip              Whether the event files are GZipped
     * @param keyDeserializer   Key deserializer
     * @param valueDeserializer Value deserializer
     */
    public YamlFileEventSource(File sourceDir, boolean gzip, Deserializer keyDeserializer,
                               Deserializer valueDeserializer) {
        super(sourceDir, selectFilter(gzip), new NumericFilenameComparator(),
              selectReader(gzip, keyDeserializer, valueDeserializer));
    }

    private static FileFilter selectFilter(boolean gzip) {
        return gzip ? YAML_GZIPPED_FILTER : YAML_FILTER;
    }

    private static  FileEventReaderWriter selectReader(boolean gzip,
                                                                                   Deserializer keyDeserializer,
                                                                                   Deserializer valueDeserializer) {
        return gzip ? new GZipEventReaderWriter<>(new YamlEventReaderWriter<>(keyDeserializer, valueDeserializer)) :
               new YamlEventReaderWriter<>(keyDeserializer, valueDeserializer);
    }

}