org.kitesdk.data.filesystem.ParquetAppender.java Source code

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Here is the source code for org.kitesdk.data.filesystem.ParquetAppender.java

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/**
 * Copyright 2013 Cloudera 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 org.kitesdk.data.filesystem;

import com.google.common.base.Objects;
import com.google.common.io.Closeables;
import java.io.IOException;
import org.apache.avro.Schema;
import org.apache.avro.generic.IndexedRecord;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.compress.SnappyCodec;
import org.kitesdk.data.spi.DynMethods;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import parquet.avro.AvroParquetWriter;
import parquet.hadoop.ParquetWriter;
import parquet.hadoop.metadata.CompressionCodecName;

class ParquetAppender<E extends IndexedRecord> implements FileSystemWriter.FileAppender<E> {

    private static final Logger logger = LoggerFactory.getLogger(ParquetAppender.class);
    private static final int DEFAULT_BLOCK_SIZE = 50 * 1024 * 1024;

    private static final DynMethods.StaticMethod isSnappyNative = new DynMethods.Builder(
            "SnappyCodec.isNativeCodeLoaded").impl(SnappyCodec.class, "isNativeCodeLoaded")
                    .impl(SnappyCodec.class, "isNativeSnappyLoaded", Configuration.class).buildStatic();

    private final Path path;
    private final Schema schema;
    private final FileSystem fileSystem;
    private final boolean enableCompression;

    private AvroParquetWriter<E> avroParquetWriter = null;

    public ParquetAppender(FileSystem fileSystem, Path path, Schema schema, boolean enableCompression) {
        this.fileSystem = fileSystem;
        this.path = path;
        this.schema = schema;
        this.enableCompression = enableCompression;
    }

    @Override
    public void open() throws IOException {
        CompressionCodecName codecName = CompressionCodecName.UNCOMPRESSED;
        if (enableCompression) {
            if ((Boolean) isSnappyNative.invoke(fileSystem.getConf())) {
                codecName = CompressionCodecName.SNAPPY;
            } else {
                logger.warn("Compression enabled, but Snappy native code not loaded. "
                        + "Parquet file will not be compressed.");
            }
        }
        avroParquetWriter = new AvroParquetWriter<E>(fileSystem.makeQualified(path), schema, codecName,
                DEFAULT_BLOCK_SIZE, ParquetWriter.DEFAULT_PAGE_SIZE);
    }

    @Override
    public void append(E entity) throws IOException {
        avroParquetWriter.write(entity);
    }

    @Override
    public void flush() {
        // Parquet doesn't (currently) expose a flush operation
    }

    @Override
    public void close() throws IOException {
        Closeables.close(avroParquetWriter, false);
    }

    @Override
    public String toString() {
        return Objects.toStringHelper(this).add("path", path).add("schema", schema).add("fileSystem", fileSystem)
                .add("avroParquetWriter", avroParquetWriter).toString();
    }

}