content: /*
   * 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.beam.runners.twister2.translators.functions;
  
  import edu.iu.dsc.tws.api.tset.TSetContext;
  import edu.iu.dsc.tws.api.tset.fn.MapFunc;
  import java.io.ObjectStreamException;
  import org.apache.beam.runners.twister2.utils.TranslationUtils;
  import org.apache.beam.sdk.util.SerializableUtils;
  import org.apache.beam.sdk.values.WindowedValue;
  import org.apache.beam.sdk.values.WindowedValues.WindowedValueCoder;
  
  /** ByteToWindow function. */
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  public class ByteToElemFunction<V> implements MapFunc<WindowedValue<V>, byte[]> {
    private transient WindowedValueCoder<V> wvCoder;
  
    private transient boolean isInitialized = false;
    private byte[] wvCoderBytes;
  
    public ByteToElemFunction() {
      // non arg constructor needed for kryo
      isInitialized = false;
    }
  
    public ByteToElemFunction(final WindowedValueCoder<V> wvCoder) {
      this.wvCoder = wvCoder;
  
      wvCoderBytes = SerializableUtils.serializeToByteArray(wvCoder);
    }
  
    @Override
    public WindowedValue<V> map(byte[] input) {
      return TranslationUtils.fromByteArray(input, wvCoder);
    }
  
    @Override
    public void prepare(TSetContext context) {
      initTransient();
    }
  
    /**
     * Method used to initialize the transient variables that were sent over as byte arrays or proto
     * buffers.
     */
    private void initTransient() {
      if (isInitialized) {
        return;
      }
  
      wvCoder =
          (WindowedValueCoder<V>)
              SerializableUtils.deserializeFromByteArray(wvCoderBytes, "Custom Coder Bytes");
      this.isInitialized = true;
    }
  
    protected Object readResolve() throws ObjectStreamException {
      return this;
    }
  }
  