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Core utilities.

There is a newer version: 4.17

package com.twitter.elephantbird.mapreduce.io;

import org.apache.thrift.TBase;
import org.apache.thrift.TDeserializer;
import org.apache.thrift.TException;
import org.apache.thrift.TSerializer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.twitter.elephantbird.thrift.ThriftBinaryDeserializer;
import com.twitter.elephantbird.util.TypeRef;

public class ThriftConverter> implements BinaryConverter {

  public static final Logger LOG = LoggerFactory.getLogger(ThriftConverter.class);

  private TypeRef typeRef;
  private TSerializer serializer;
  private TDeserializer deserializer;

  // limit the number of warnings in case of serialization errors.
  private static final int MAX_WARNINGS = 100;
  private static int numWarningsLogged = 0;

  private static void logWarning(String message, Throwable t) {
    // does not need to be thread safe
    if ( numWarningsLogged < MAX_WARNINGS ) {
      LOG.info(message, t);
      numWarningsLogged++;
    }
  }

  /**
   * Returns a ThriftConverter for a given Thrift class.
   */
  public static > ThriftConverter newInstance(Class tClass) {
    return new ThriftConverter(new TypeRef(tClass){});
  }

  public static > ThriftConverter newInstance(TypeRef typeRef) {
    return new ThriftConverter(typeRef);
  }

  public ThriftConverter(TypeRef typeRef) {
    this.typeRef = typeRef;
  }

  @Override
  public M fromBytes(byte[] messageBuffer) throws DecodeException {
    try {
      if (deserializer == null)
        deserializer = new ThriftBinaryDeserializer();
      M message = typeRef.safeNewInstance();
      deserializer.deserialize(message, messageBuffer);
      return message;
    } catch (Exception e) {
      // normally a TException. but some corrupt records can cause
      // other runtime exceptions (e.g. IndexOutOfBoundsException).
      throw new DecodeException(e);
    }
  }

  @Override
  public byte[] toBytes(M message) {
    if (serializer == null)
      serializer = new TSerializer();
    try {
      return serializer.serialize(message);
    } catch (TException e) {
      logWarning("failed to serialize", e);
      return null;
    }
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj)
      return true;
    try {
      return typeRef.getType().equals(((ThriftConverter)obj).typeRef.getType());
    } catch (ClassCastException e) {
      return false;
    }
  }
}