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.dataflow.worker.windmill.state;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.List;
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.beam.sdk.coders.NullableCoder;
  import org.apache.beam.sdk.coders.StructuredCoder;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.BoundType;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Lists;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Range;
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  /** Coder for closed-open ranges. */
  class RangeCoder<T extends Comparable<?>> extends StructuredCoder<Range<T>> {
    private final Coder<T> boundCoder;
  
    RangeCoder(Coder<T> boundCoder) {
      this.boundCoder = NullableCoder.of(boundCoder);
    }
  
    @Override
    public List<? extends Coder<?>> getCoderArguments() {
      return Lists.newArrayList(boundCoder);
    }
  
    @Override
    public void verifyDeterministic() throws NonDeterministicException {
      boundCoder.verifyDeterministic();
    }
  
    @Override
    public void encode(Range<T> value, OutputStream outStream) throws IOException {
      Preconditions.checkState(
          value.lowerBoundType().equals(BoundType.CLOSED), "unexpected range " + value);
      Preconditions.checkState(
          value.upperBoundType().equals(BoundType.OPEN), "unexpected range " + value);
      boundCoder.encode(value.hasLowerBound() ? value.lowerEndpoint() : null, outStream);
      boundCoder.encode(value.hasUpperBound() ? value.upperEndpoint() : null, outStream);
    }
  
    @Override
    public Range<T> decode(InputStream inStream) throws IOException {
      @Nullable T lower = boundCoder.decode(inStream);
      @Nullable T upper = boundCoder.decode(inStream);
      if (lower == null) {
        return upper != null ? Range.lessThan(upper) : Range.all();
      } else if (upper == null) {
        return Range.atLeast(lower);
      } else {
        return Range.closedOpen(lower, upper);
      }
    }
  }
  