src/main/java/parquet/format/Util.java

package parquet.format;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.thrift.TBase;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TCompactProtocol;
import org.apache.thrift.transport.TIOStreamTransport;

/**
 * Utility to read/write metadata
 * We use the TCompactProtocol to serialize metadata
 *
 * @author Julien Le Dem
 *
 */
public class Util {

  public static void writePageHeader(PageHeader pageHeader, OutputStream to) throws IOException {
    write(pageHeader, to);
  }

  public static PageHeader readPageHeader(InputStream from) throws IOException {
    return read(from, new PageHeader());
  }

  public static void writeFileMetaData(parquet.format.FileMetaData fileMetadata, OutputStream to) throws IOException {
    write(fileMetadata, to);
  }

  public static FileMetaData readFileMetaData(InputStream from) throws IOException {
    return read(from, new FileMetaData());
  }

  private static TCompactProtocol protocol(OutputStream to) {
    return new TCompactProtocol(new TIOStreamTransport(to));
  }

  private static TCompactProtocol protocol(InputStream from) {
    return new TCompactProtocol(new TIOStreamTransport(from));
  }

  private static <T extends TBase<?,?>> T read(InputStream from, T tbase) throws IOException {
    try {
      tbase.read(protocol(from));
      return tbase;
    } catch (TException e) {
      throw new IOException("can not read " + tbase.getClass() + ": " + e.getMessage(), e);
    }
  }

  private static void write(TBase<?, ?> tbase, OutputStream to) throws IOException {
    try {
      tbase.write(protocol(to));
    } catch (TException e) {
      throw new IOException("can not write " + tbase, e);
    }
  }
}