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)) { bytes = new byte[sizeof(int)]; stream.Read(bytes, 0, bytes.Length); value = BitConverter.ToInt32(bytes, 0); } else if (property.PropertyType == typeof(short)) { bytes = new byte[sizeof(short)]; stream.Read(bytes, 0, bytes.Length); value = BitConverter.ToInt16(bytes, 0); } else if (property.PropertyType == typeof(float)) { bytes = new byte[sizeof(float)]; stream.Read(bytes, 0, bytes.Length); value = BitConverter.ToSingle(bytes, 0); } else if (property.PropertyType == typeof(double)) { bytes = new byte[sizeof(double)]; stream.Read(bytes, 0, bytes.Length); value = BitConverter.ToDouble(bytes, 0); } property.SetValue(price, value); index += bytes.Length; } result.Add(price); } return result; } }

Name	Serialize(ms)	Deserialize(ms)	Bytes
ReflectionSerializer	413	431	103,246

好像好了一些，但性能大幅下降。我好像记得有人说过.NET会将反射缓存让我不必担心反射带来的性能问题，看来我的理解有出入。索性自己缓存些反射结果：

private readonly IEnumerable<PropertyInfo> _properties; public ExtendReflectionSerializer() { _properties = typeof(StockPriceSlim).GetProperties().Where(p => p.GetCustomAttribute(typeof(DataMemberAttribute)) != null).ToList(); }

Name	Serialize(ms)	Deserialize(ms)	Bytes
ExtendReflectionSerializer	11	11	103,246

这样改进后性能还可以接受。

6. 最后试试压缩#

最后试试在序列化的基础上再随便压缩一下：

public byte[] SerializeWithZip(List<StockPriceSlim> instance) { var bytes = SerializeSlim(instance); using (var memoryStream = new MemoryStream()) { using (var deflateStream = new DeflateStream(memoryStream, CompressionLevel.Fastest)) { deflateStream.Write(bytes, 0, bytes.Length); } return memoryStream.ToArray(); } } public List<StockPriceSlim> DeserializeWithZip(byte[] source) { using (var originalFileStream = new MemoryStream(source)) { using (var memoryStream = new MemoryStream()) { using (var decompressionStream = new DeflateStream(originalFileStream, CompressionMode.Decompress)) { decompressionStream.CopyTo(memoryStream); } var bytes = memoryStream.ToArray(); return DeserializeSlim(bytes); } } }

结果看来不错：

Name	Serialize(ms)	Deserialize(ms)	Bytes	Serialize With Zip(ms)	Deserialize With Zip(ms)	Bytes With Zip
BinarySerializer	11	12	141,930	22	12	72,954
XmlSerializer	42	24	977,248	24	28	108,839
SoapSerializer	48	89	2,586,720	61	87	140,391
JsonSerializer	17	33	411,942	24	35	90,125
ProtobufSerializer	7	3	130,416	7	6	65,644
CustomSerializer	5	1	103,246	9	3	57,697
ReflectionSerializer	413	431	103,246	401	376	59,285
ExtendReflectionSerializer	11	11	103,246	13	14	59,285

7. 结语#

满足了好奇心，顺便复习了一下各种序列化的方式。

因为原来的需求就很单一，没有测试各种数据量下的对比。

虽然Protobuf十分优秀，但在本地存储序列化文件时为了可读性我通常都会选择XML或JSON。

8. 参考#

二进制序列化 XML 和 SOAP 序列化 Json.NET Protocol Buffers - Google's data interchange format

9. 源码#

StockDataSample