| #region License |
| |
| /* |
| * 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. |
| */ |
| |
| #endregion |
| |
| using System; |
| using System.IO; |
| using System.Numerics; |
| using System.Threading.Tasks; |
| |
| namespace Gremlin.Net.Structure.IO.GraphBinary.Types |
| { |
| /// <summary> |
| /// A serializer that serializes <see cref="decimal"/> values as BigDecimal in GraphBinary. |
| /// </summary> |
| public class BigDecimalSerializer : SimpleTypeSerializer<decimal> |
| { |
| /// <summary> |
| /// Initializes a new instance of the <see cref="BigDecimalSerializer" /> class. |
| /// </summary> |
| public BigDecimalSerializer() : base(DataType.BigDecimal) |
| { |
| } |
| |
| /// <inheritdoc /> |
| protected override async Task WriteValueAsync(decimal value, Stream stream, GraphBinaryWriter writer) |
| { |
| var (unscaledValue, scale) = GetUnscaledValueAndScale(value); |
| await writer.WriteValueAsync(scale, stream, false).ConfigureAwait(false); |
| await writer.WriteValueAsync(unscaledValue, stream, false).ConfigureAwait(false); |
| } |
| |
| private static (BigInteger, int) GetUnscaledValueAndScale(decimal input) |
| { |
| var parts = decimal.GetBits(input); |
| |
| var sign = (parts[3] & 0x80000000) != 0; |
| |
| var scale = (parts[3] >> 16) & 0x7F; |
| |
| var lowBytes = BitConverter.GetBytes(parts[0]); |
| var middleBytes = BitConverter.GetBytes(parts[1]); |
| var highBytes = BitConverter.GetBytes(parts[2]); |
| var valueBytes = new byte[12]; |
| lowBytes.CopyTo(valueBytes, 0); |
| middleBytes.CopyTo(valueBytes, 4); |
| highBytes.CopyTo(valueBytes, 8); |
| var bigInt = new BigInteger(valueBytes); |
| |
| if (sign) |
| { |
| bigInt = -bigInt; |
| } |
| |
| return (bigInt, scale); |
| } |
| |
| /// <inheritdoc /> |
| protected override async Task<decimal> ReadValueAsync(Stream stream, GraphBinaryReader reader) |
| { |
| var scale = (int) await reader.ReadValueAsync<int>(stream, false).ConfigureAwait(false); |
| var unscaled = (BigInteger) await reader.ReadValueAsync<BigInteger>(stream, false).ConfigureAwait(false); |
| |
| return ConvertScaleAndUnscaledValue(scale, unscaled); |
| } |
| |
| private static decimal ConvertScaleAndUnscaledValue(int scale, BigInteger unscaledValue) |
| { |
| return (decimal) unscaledValue * (decimal) Math.Pow(10, -scale); |
| } |
| } |
| } |