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.coders;
  
  import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkNotNull;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.math.MathContext;
  
  /**
   * A {@link BigDecimalCoder} encodes a {@link BigDecimal} as an integer scale encoded with {@link
   * VarIntCoder} and a {@link BigInteger} encoded using {@link BigIntegerCoder}. The {@link
   * BigInteger}, when scaled (with unlimited precision, aka {@link MathContext#UNLIMITED}), yields
   * the expected {@link BigDecimal}.
   */
  public class BigDecimalCoder extends AtomicCoder<BigDecimal> {
  
    public static BigDecimalCoder of() {
      return INSTANCE;
    }
  
    /////////////////////////////////////////////////////////////////////////////
  
    private static final BigDecimalCoder INSTANCE = new BigDecimalCoder();
  
    private static final VarIntCoder VAR_INT_CODER = VarIntCoder.of();
    private static final BigIntegerCoder BIG_INT_CODER = BigIntegerCoder.of();
  
    private BigDecimalCoder() {}
  
    @Override
    public void encode(BigDecimal value, OutputStream outStream) throws IOException, CoderException {
      encode(value, outStream, Context.NESTED);
    }
  
    @Override
    public void encode(BigDecimal value, OutputStream outStream, Context context)
        throws IOException, CoderException {
      checkNotNull(value, String.format("cannot encode a null %s", BigDecimal.class.getSimpleName()));
      VAR_INT_CODER.encode(value.scale(), outStream);
      BIG_INT_CODER.encode(value.unscaledValue(), outStream, context);
    }
  
    @Override
    public BigDecimal decode(InputStream inStream) throws IOException, CoderException {
      return decode(inStream, Context.NESTED);
    }
  
    @Override
    public BigDecimal decode(InputStream inStream, Context context)
        throws IOException, CoderException {
      int scale = VAR_INT_CODER.decode(inStream);
      BigInteger bigInteger = BIG_INT_CODER.decode(inStream, context);
      return new BigDecimal(bigInteger, scale);
    }
  
    @Override
    public void verifyDeterministic() throws NonDeterministicException {
      VAR_INT_CODER.verifyDeterministic();
      BIG_INT_CODER.verifyDeterministic();
    }
  
    /**
     * {@inheritDoc}
     *
     * @return {@code true}. This coder is injective.
     */
    @Override
    public boolean consistentWithEquals() {
      return true;
    }
  
    /**
     * {@inheritDoc}
     *
     * @return {@code true}, because {@link #getEncodedElementByteSize} runs in constant time.
     */
    @Override
    public boolean isRegisterByteSizeObserverCheap(BigDecimal value) {
      return true;
    }
  
    /**
     * {@inheritDoc}
     *
     * @return {@code 4} (the size of an integer denoting the scale) plus {@code 4} (the size of an
     *     integer length prefix for the following bytes) plus the size of the two's-complement
     *     representation of the {@link BigInteger} that, when scaled, equals the given value.
     */
    @Override
    protected long getEncodedElementByteSize(BigDecimal value) throws Exception {
      checkNotNull(value, String.format("cannot encode a null %s", BigDecimal.class.getSimpleName()));
      return VAR_INT_CODER.getEncodedElementByteSize(value.scale())
          + BIG_INT_CODER.getEncodedElementByteSize(value.unscaledValue());
    }
  }
  