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.sdk.fn.windowing;
  
  import com.google.auto.value.AutoValue;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import org.apache.beam.sdk.coders.AtomicCoder;
  import org.apache.beam.sdk.coders.CoderException;
  import org.apache.beam.sdk.transforms.windowing.BoundedWindow;
  import org.apache.beam.sdk.util.VarInt;
  import org.apache.beam.vendor.grpc.v1p69p0.com.google.protobuf.ByteString;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.io.ByteStreams;
  import org.joda.time.Instant;
  
  /**
   * An encoded {@link BoundedWindow} used within Runners to track window information without needing
   * to decode the window.
   *
   * <p>This allows for Runners to not need to know window format during execution.
   */
  @AutoValue
  public abstract class EncodedBoundedWindow extends BoundedWindow {
    public static EncodedBoundedWindow forEncoding(ByteString encodedWindow) {
      return new AutoValue_EncodedBoundedWindow(encodedWindow);
    }
  
    public abstract ByteString getEncodedWindow();
  
    @Override
    public Instant maxTimestamp() {
      throw new UnsupportedOperationException(
          "TODO: Add support for reading the timestamp from " + "the encoded window.");
    }
  
    /**
     * An {@link Coder} for {@link EncodedBoundedWindow}s.
     *
     * <p>This is a copy of {@code ByteStringCoder} to prevent a dependency on {@code
     * beam-java-sdk-extensions-protobuf}.
     */
    public static class Coder extends AtomicCoder<EncodedBoundedWindow> {
      public static final Coder INSTANCE = new Coder();
  
      // prevent instantiation
      private Coder() {}
  
      @Override
      public void encode(EncodedBoundedWindow value, OutputStream outStream)
          throws CoderException, IOException {
        VarInt.encode(value.getEncodedWindow().size(), outStream);
        value.getEncodedWindow().writeTo(outStream);
      }
  
      @Override
      public EncodedBoundedWindow decode(InputStream inStream) throws CoderException, IOException {
        int size = VarInt.decodeInt(inStream);
        ByteString encodedWindow = ByteString.readFrom(ByteStreams.limit(inStream, size));
        return EncodedBoundedWindow.forEncoding(encodedWindow);
      }
  
      @Override
      public boolean consistentWithEquals() {
        return true;
      }
  
      @Override
      public boolean isRegisterByteSizeObserverCheap(EncodedBoundedWindow value) {
        return true;
      }
  
      @Override
      protected long getEncodedElementByteSize(EncodedBoundedWindow value) throws Exception {
        return (long) VarInt.getLength(value.getEncodedWindow().size())
            + value.getEncodedWindow().size();
      }
    }
  }
  