c# - JSON.NET ANY ContractResolver 导致性能不佳

Question

在对吞吐量非常高的应用程序进行性能测试时，我们发现 JSON.NET 的 ContractResolver 存在问题。不幸的是，当您指定 ContractResolver 时，性能变得难以忍受，包括 DefaultContractResolver

寻求其他专家的建议，了解有关如何提高性能而不锁定 CPU 和占用不合理时间的任何建议。现在，由于这个问题，我们发现性能降低了 87%(定义任何 ContractResolver 时每秒 80 个请求，没有定义 ContractResolver 时每秒 600 个请求定义。

测试运行的输出是:

默认解析器:耗时 3736 毫秒

NoOp 解析器:耗时 4150 毫秒

无解析器:已用 8 毫秒

SnakeCase:耗时 4753 毫秒

第三方 (SnakeCase.JsonNet):耗时 3881 毫秒

强调这一点的测试如下:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using SnakeCase.JsonNet;

namespace Anonymous.Public.Namespace
{
    public class Person
    {
        public string Name { get; set; }
        public DateTime DateOfBirth { get; set; }
        public bool EatsMeat { get; set; }
        public decimal YearlyHouseholdIncome { get; set; }

        public List<Car> CarList { get; set; }
    }

    public class Car
    {
        public string Make { get; set; }
        public string Model { get; set; }
        public int Year { get; set; }
    }

    public class NoOpNamingStrategy : NamingStrategy
    {
        public NoOpNamingStrategy(bool processDictionaryKeys, bool overrideSpecifiedNames)
        {
            base.ProcessDictionaryKeys = processDictionaryKeys;
            base.OverrideSpecifiedNames = overrideSpecifiedNames;
        }

        public NoOpNamingStrategy(bool processDictionaryKeys, bool overrideSpecifiedNames, bool processExtensionDataNames) : this(processDictionaryKeys, overrideSpecifiedNames)
        {
            base.ProcessExtensionDataNames = processExtensionDataNames;
        }

        public NoOpNamingStrategy()
        {
        }

        protected override string ResolvePropertyName(string name)
        {
            return name;
        }
    }

    [TestClass]
    public class SerializationTest
    {
        public static Person p { get; set; } = new Person
        {
            Name = "Foo Bar",
            DateOfBirth = new DateTime(1970, 01, 01),
            EatsMeat = true,
            YearlyHouseholdIncome = 47333M,
            CarList = new List<Car>
            {
                new Car
                {
                    Make = "Honda",
                    Model = "Civic",
                    Year = 2019
                }
            }
        };

        public const int ITERATIONS = 1000;

        [TestMethod]
        public void TestSnakeCase()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < ITERATIONS; i++)
            {
                var str = JsonConvert.SerializeObject(p, new JsonSerializerSettings
                {
                    ContractResolver = new DefaultContractResolver
                    {
                        NamingStrategy = new SnakeCaseNamingStrategy()
                    }
                });
            }

            sw.Stop();
            var elapsed = sw.ElapsedMilliseconds;
            Debug.WriteLine($"Time elapsed {elapsed} milliseconds");
        }

        [TestMethod]
        public void TestNoResolver()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < ITERATIONS; i++)
            {
                var str = JsonConvert.SerializeObject(p);
            }

            sw.Stop();
            var elapsed = sw.ElapsedMilliseconds;
            Debug.WriteLine($"Time elapsed {elapsed} milliseconds");
        }

        [TestMethod]
        public void TestDefaultResolver()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < ITERATIONS; i++)
            {
                var str = JsonConvert.SerializeObject(p, new JsonSerializerSettings
                {
                    ContractResolver = new DefaultContractResolver()
                });
            }

            sw.Stop();
            var elapsed = sw.ElapsedMilliseconds;
            Debug.WriteLine($"Time elapsed {elapsed} milliseconds");
        }

        [TestMethod]
        public void TestThirdPartySnakeResolver()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < ITERATIONS; i++)
            {
                var str = JsonConvert.SerializeObject(p, new JsonSerializerSettings
                {
                    ContractResolver = new SnakeCaseContractResolver()
                });
            }

            sw.Stop();
            var elapsed = sw.ElapsedMilliseconds;
            Debug.WriteLine($"Time elapsed {elapsed} milliseconds");
        }

        [TestMethod]
        public void TestNoOpResolver()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < ITERATIONS; i++)
            {
                var str = JsonConvert.SerializeObject(p, new JsonSerializerSettings
                {
                    ContractResolver = new DefaultContractResolver
                    {
                        NamingStrategy = new NoOpNamingStrategy()
                    }
                });
            }

            sw.Stop();
            var elapsed = sw.ElapsedMilliseconds;
            Debug.WriteLine($"Time elapsed {elapsed} milliseconds");
        }
    }
}

Answer 1

看起来好像 ContractResolver 需要反射，如果保留的话将缓存对象类型。在全局范围内存储 ContractResolver 会大大改变时间:

默认解析器:耗时 10 毫秒

NoOp 解析器:7 毫秒过去的时间

无解析器:耗时 7 毫秒

SnakeCase:耗时 178 毫秒

第三方 (SnakeCase.JsonNet):耗时 10 毫秒

更新的测试代码:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using SnakeCase.JsonNet;

namespace Anonymous.Public.Namespace
{
    public class Person
    {
        public string Name { get; set; }
        public DateTime DateOfBirth { get; set; }
        public bool EatsMeat { get; set; }
        public decimal YearlyHouseholdIncome { get; set; }

        public List<Car> CarList { get; set; }
    }

    public class Car
    {
        public string Make { get; set; }
        public string Model { get; set; }
        public int Year { get; set; }
    }
    public class NoOpNamingStrategy : NamingStrategy
    {
        public NoOpNamingStrategy(bool processDictionaryKeys, bool overrideSpecifiedNames)
        {
            base.ProcessDictionaryKeys = processDictionaryKeys;
            base.OverrideSpecifiedNames = overrideSpecifiedNames;
        }

        public NoOpNamingStrategy(bool processDictionaryKeys, bool overrideSpecifiedNames, bool processExtensionDataNames) : this(processDictionaryKeys, overrideSpecifiedNames)
        {
            base.ProcessExtensionDataNames = processExtensionDataNames;
        }

        public NoOpNamingStrategy()
        {
        }

        protected override string ResolvePropertyName(string name)
        {
            return name;
        }
    }

    [TestClass]
    public class SerializationTest
    {
        public static Person p { get; set; } = new Person
        {
            Name = "Foo Bar",
            DateOfBirth = new DateTime(1970, 01, 01),
            EatsMeat = true,
            YearlyHouseholdIncome = 47333M,
            CarList = new List<Car>
            {
                new Car
                {
                    Make = "Honda",
                    Model = "Civic",
                    Year = 2019
                }
            }
        };

        public static IContractResolver Default { get; set; } = new DefaultContractResolver();

        public static IContractResolver NoOp { get; set; } = new DefaultContractResolver
        {
            NamingStrategy = new NoOpNamingStrategy()
        };

        public static IContractResolver SnakeCase { get; set; } = new DefaultContractResolver
        {
            NamingStrategy = new SnakeCaseNamingStrategy()
        };

        public static IContractResolver ThirdParty { get; set; } = new SnakeCaseContractResolver();

        public const int ITERATIONS = 1000;

        [TestMethod]
        public void TestSnakeCase()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < ITERATIONS; i++)
            {
                var str = JsonConvert.SerializeObject(p, new JsonSerializerSettings
                {
                    ContractResolver = SnakeCase
                });
            }

            sw.Stop();
            var elapsed = sw.ElapsedMilliseconds;
            Debug.WriteLine($"Time elapsed {elapsed} milliseconds");
        }

        [TestMethod]
        public void TestNoResolver()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < ITERATIONS; i++)
            {
                var str = JsonConvert.SerializeObject(p);
            }

            sw.Stop();
            var elapsed = sw.ElapsedMilliseconds;
            Debug.WriteLine($"Time elapsed {elapsed} milliseconds");
        }

        [TestMethod]
        public void TestDefaultResolver()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < ITERATIONS; i++)
            {
                var str = JsonConvert.SerializeObject(p, new JsonSerializerSettings
                {
                    ContractResolver = Default
                });
            }

            sw.Stop();
            var elapsed = sw.ElapsedMilliseconds;
            Debug.WriteLine($"Time elapsed {elapsed} milliseconds");
        }

        [TestMethod]
        public void TestThirdPartySnakeResolver()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < ITERATIONS; i++)
            {
                var str = JsonConvert.SerializeObject(p, new JsonSerializerSettings
                {
                    ContractResolver = ThirdParty
                });
            }

            sw.Stop();
            var elapsed = sw.ElapsedMilliseconds;
            Debug.WriteLine($"Time elapsed {elapsed} milliseconds");
        }

        [TestMethod]
        public void TestNoOpResolver()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < ITERATIONS; i++)
            {
                var str = JsonConvert.SerializeObject(p, new JsonSerializerSettings
                {
                    ContractResolver = NoOp
                });
            }

            sw.Stop();
            var elapsed = sw.ElapsedMilliseconds;
            Debug.WriteLine($"Time elapsed {elapsed} milliseconds");
        }
    }
}