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fastJSON - Smallest, Fastest Polymorphic JSON Serializer

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23 Jan 2021CPOL37 min read 5.6M   63.7K   984  
In this article I demonstrate why fastJSON is the smallest, fastest polymorphic JSON serializer (with Silverlight4, MonoDroid and .NET core support)
Here we look at: the what and why of JSON, features of this implementation, some of the JSON alternatives that I have personally used, using the code, and performance tests.
using System;
using System.Collections.Generic;
using System.Text;
using NUnit.Framework;
using System.Data;
using System.Collections;
using System.Threading;
using fastJSON;

namespace UnitTests
{
    public class Tests
    {
        #region [  helpers  ]
        static int count = 1000;
        static int tcount = 5;
        static DataSet ds = new DataSet();
        static bool exotic = false;
        static bool dsser = false;

        public enum Gender
        {
            Male,
            Female
        }

        public class colclass
        {
            public colclass()
            {
                items = new List<baseclass>();
                date = DateTime.Now;
                multilineString = @"
            AJKLjaskljLA
       ahjksjkAHJKS سلام فارسی
       AJKHSKJhaksjhAHSJKa
       AJKSHajkhsjkHKSJKash
       ASJKhasjkKASJKahsjk
            ";
                isNew = true;
                booleanValue = true;
                ordinaryDouble = 0.001;
                gender = Gender.Female;
                intarray = new int[5] { 1, 2, 3, 4, 5 };
            }
            public bool booleanValue { get; set; }
            public DateTime date { get; set; }
            public string multilineString { get; set; }
            public List<baseclass> items { get; set; }
            public decimal ordinaryDecimal { get; set; }
            public double ordinaryDouble { get; set; }
            public bool isNew { get; set; }
            public string laststring { get; set; }
            public Gender gender { get; set; }

            public DataSet dataset { get; set; }
            public Dictionary<string, baseclass> stringDictionary { get; set; }
            public Dictionary<baseclass, baseclass> objectDictionary { get; set; }
            public Dictionary<int, baseclass> intDictionary { get; set; }
            public Guid? nullableGuid { get; set; }
            public decimal? nullableDecimal { get; set; }
            public double? nullableDouble { get; set; }
            public Hashtable hash { get; set; }
            public baseclass[] arrayType { get; set; }
            public byte[] bytes { get; set; }
            public int[] intarray { get; set; }

        }

        public static colclass CreateObject()
        {
            var c = new colclass();

            c.booleanValue = true;
            c.ordinaryDecimal = 3;

            if (exotic)
            {
                c.nullableGuid = Guid.NewGuid();
                c.hash = new Hashtable();
                c.bytes = new byte[1024];
                c.stringDictionary = new Dictionary<string, baseclass>();
                c.objectDictionary = new Dictionary<baseclass, baseclass>();
                c.intDictionary = new Dictionary<int, baseclass>();
                c.nullableDouble = 100.003;

                if (dsser)
                    c.dataset = ds;
                c.nullableDecimal = 3.14M;

                c.hash.Add(new class1("0", "hello", Guid.NewGuid()), new class2("1", "code", "desc"));
                c.hash.Add(new class2("0", "hello", "pppp"), new class1("1", "code", Guid.NewGuid()));

                c.stringDictionary.Add("name1", new class2("1", "code", "desc"));
                c.stringDictionary.Add("name2", new class1("1", "code", Guid.NewGuid()));

                c.intDictionary.Add(1, new class2("1", "code", "desc"));
                c.intDictionary.Add(2, new class1("1", "code", Guid.NewGuid()));

                c.objectDictionary.Add(new class1("0", "hello", Guid.NewGuid()), new class2("1", "code", "desc"));
                c.objectDictionary.Add(new class2("0", "hello", "pppp"), new class1("1", "code", Guid.NewGuid()));

                c.arrayType = new baseclass[2];
                c.arrayType[0] = new class1();
                c.arrayType[1] = new class2();
            }


            c.items.Add(new class1("1", "1", Guid.NewGuid()));
            c.items.Add(new class2("2", "2", "desc1"));
            c.items.Add(new class1("3", "3", Guid.NewGuid()));
            c.items.Add(new class2("4", "4", "desc2"));

            c.laststring = "" + DateTime.Now;

            return c;
        }

        public class baseclass
        {
            public string Name { get; set; }
            public string Code { get; set; }
        }

        public class class1 : baseclass
        {
            public class1() { }
            public class1(string name, string code, Guid g)
            {
                Name = name;
                Code = code;
                guid = g;
            }
            public Guid guid { get; set; }
        }

        public class class2 : baseclass
        {
            public class2() { }
            public class2(string name, string code, string desc)
            {
                Name = name;
                Code = code;
                description = desc;
            }
            public string description { get; set; }
        }

        public class NoExt
        {
            [System.Xml.Serialization.XmlIgnore()]
            public string Name { get; set; }
            public string Address { get; set; }
            public int Age { get; set; }
            public baseclass[] objs { get; set; }
            public Dictionary<string, class1> dic { get; set; }
            public NoExt intern { get; set; }
        }

        public class Retclass
        {
            public object ReturnEntity { get; set; }
            public string Name { get; set; }
            public string Field1;
            public int Field2;
            public object obj;
            public string ppp { get { return "sdfas df "; } }
            public DateTime date { get; set; }
            public DataTable ds { get; set; }
        }

        public struct Retstruct
        {
            public object ReturnEntity { get; set; }
            public string Name { get; set; }
            public string Field1;
            public int Field2;
            public string ppp { get { return "sdfas df "; } }
            public DateTime date { get; set; }
            public DataTable ds { get; set; }
        }

        private static long CreateLong(string s)
        {
            long num = 0;
            bool neg = false;
            foreach (char cc in s)
            {
                if (cc == '-')
                    neg = true;
                else if (cc == '+')
                    neg = false;
                else
                {
                    num *= 10;
                    num += (int)(cc - '0');
                }
            }

            return neg ? -num : num;
        }

        private static DataSet CreateDataset()
        {
            DataSet ds = new DataSet();
            for (int j = 1; j < 3; j++)
            {
                DataTable dt = new DataTable();
                dt.TableName = "Table" + j;
                dt.Columns.Add("col1", typeof(int));
                dt.Columns.Add("col2", typeof(string));
                dt.Columns.Add("col3", typeof(Guid));
                dt.Columns.Add("col4", typeof(string));
                dt.Columns.Add("col5", typeof(bool));
                dt.Columns.Add("col6", typeof(string));
                dt.Columns.Add("col7", typeof(string));
                ds.Tables.Add(dt);
                Random rrr = new Random();
                for (int i = 0; i < 100; i++)
                {
                    DataRow dr = dt.NewRow();
                    dr[0] = rrr.Next(int.MaxValue);
                    dr[1] = "" + rrr.Next(int.MaxValue);
                    dr[2] = Guid.NewGuid();
                    dr[3] = "" + rrr.Next(int.MaxValue);
                    dr[4] = true;
                    dr[5] = "" + rrr.Next(int.MaxValue);
                    dr[6] = "" + rrr.Next(int.MaxValue);

                    dt.Rows.Add(dr);
                }
            }
            return ds;
        }

        public class RetNestedclass
        {
            public Retclass Nested { get; set; }
        }

        #endregion

        [Test]
        public static void objectarray()
        {
            var o = new object[] { 1, "sdaffs", DateTime.Now };
            var s = fastJSON.JSON.Instance.ToJSON(o);
            var p = fastJSON.JSON.Instance.ToObject(s);
        }

        [Test]
        public static void ClassTest()
        {
            Retclass r = new Retclass();
            r.Name = "hello";
            r.Field1 = "dsasdF";
            r.Field2 = 2312;
            r.date = DateTime.Now;
            r.ds = CreateDataset().Tables[0];

            var s = fastJSON.JSON.Instance.ToJSON(r);
            Console.WriteLine(s);
            var o = fastJSON.JSON.Instance.ToObject(s);

            Assert.AreEqual(2312, (o as Retclass).Field2);
        }


        [Test]
        public static void StructTest()
        {
            Retstruct r = new Retstruct();
            r.Name = "hello";
            r.Field1 = "dsasdF";
            r.Field2 = 2312;
            r.date = DateTime.Now;
            r.ds = CreateDataset().Tables[0];

            var s = fastJSON.JSON.Instance.ToJSON(r);
            Console.WriteLine(s);
            var o = fastJSON.JSON.Instance.ToObject(s);

            Assert.AreEqual(2312, ((Retstruct)o).Field2);
        }

        [Test]
        public static void ParseTest()
        {
            Retclass r = new Retclass();
            r.Name = "hello";
            r.Field1 = "dsasdF";
            r.Field2 = 2312;
            r.date = DateTime.Now;
            r.ds = CreateDataset().Tables[0];

            var s = fastJSON.JSON.Instance.ToJSON(r);
            Console.WriteLine(s);
            var o = fastJSON.JSON.Instance.Parse(s);

            Assert.IsNotNull(o);
        }

        [Test]
        public static void StringListTest()
        {
            List<string> ls = new List<string>();
            ls.AddRange(new string[] { "a", "b", "c", "d" });

            var s = fastJSON.JSON.Instance.ToJSON(ls);
            Console.WriteLine(s);
            var o = fastJSON.JSON.Instance.ToObject(s);

            Assert.IsNotNull(o);
        }

        [Test]
        public static void IntListTest()
        {
            List<int> ls = new List<int>();
            ls.AddRange(new int[] { 1, 2, 3, 4, 5, 10 });

            var s = fastJSON.JSON.Instance.ToJSON(ls);
            Console.WriteLine(s);
            var p = fastJSON.JSON.Instance.Parse(s);
            var o = fastJSON.JSON.Instance.ToObject(s); // long[] {1,2,3,4,5,10}

            Assert.IsNotNull(o);
        }

        [Test]
        public static void List_int()
        {
            List<int> ls = new List<int>();
            ls.AddRange(new int[] { 1, 2, 3, 4, 5, 10 });

            var s = fastJSON.JSON.Instance.ToJSON(ls);
            Console.WriteLine(s);
            var p = fastJSON.JSON.Instance.Parse(s);
            var o = fastJSON.JSON.Instance.ToObject<List<int>>(s);

            Assert.IsNotNull(o);
        }

        [Test]
        public static void Variables()
        {
            var s = fastJSON.JSON.Instance.ToJSON(42);
            var o = fastJSON.JSON.Instance.ToObject(s);
            Assert.AreEqual(o, 42);

            s = fastJSON.JSON.Instance.ToJSON("hello");
            o = fastJSON.JSON.Instance.ToObject(s);
            Assert.AreEqual(o, "hello");

            s = fastJSON.JSON.Instance.ToJSON(42.42M);
            o = fastJSON.JSON.Instance.ToObject(s);
            Assert.AreEqual(42.42M, o);
        }

        [Test]
        public static void Dictionary_String_RetClass()
        {
            Dictionary<string, Retclass> r = new Dictionary<string, Retclass>();
            r.Add("11", new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            r.Add("12", new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            var s = fastJSON.JSON.Instance.ToJSON(r);
            Console.WriteLine(fastJSON.JSON.Instance.Beautify(s));
            var o = fastJSON.JSON.Instance.ToObject<Dictionary<string, Retclass>>(s);
            Assert.AreEqual(2, o.Count);
        }

        [Test]
        public static void Dictionary_String_RetClass_noextensions()
        {
            Dictionary<string, Retclass> r = new Dictionary<string, Retclass>();
            r.Add("11", new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            r.Add("12", new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            var s = fastJSON.JSON.Instance.ToJSON(r, new fastJSON.JSONParameters { UseExtensions = false });
            Console.WriteLine(fastJSON.JSON.Instance.Beautify(s));
            var o = fastJSON.JSON.Instance.ToObject<Dictionary<string, Retclass>>(s);
            Assert.AreEqual(2, o.Count);
        }

        [Test]
        public static void Dictionary_int_RetClass()
        {
            Dictionary<int, Retclass> r = new Dictionary<int, Retclass>();
            r.Add(11, new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            r.Add(12, new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            var s = fastJSON.JSON.Instance.ToJSON(r);
            Console.WriteLine(fastJSON.JSON.Instance.Beautify(s));
            var o = fastJSON.JSON.Instance.ToObject<Dictionary<int, Retclass>>(s);
            Assert.AreEqual(2, o.Count);
        }

        [Test]
        public static void Dictionary_int_RetClass_noextensions()
        {
            Dictionary<int, Retclass> r = new Dictionary<int, Retclass>();
            r.Add(11, new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            r.Add(12, new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            var s = fastJSON.JSON.Instance.ToJSON(r, new fastJSON.JSONParameters { UseExtensions = false });
            Console.WriteLine(fastJSON.JSON.Instance.Beautify(s));
            var o = fastJSON.JSON.Instance.ToObject<Dictionary<int, Retclass>>(s);
            Assert.AreEqual(2, o.Count);
        }

        [Test]
        public static void Dictionary_Retstruct_RetClass()
        {
            Dictionary<Retstruct, Retclass> r = new Dictionary<Retstruct, Retclass>();
            r.Add(new Retstruct { Field1 = "111", Field2 = 1, date = DateTime.Now }, new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            r.Add(new Retstruct { Field1 = "222", Field2 = 2, date = DateTime.Now }, new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            var s = fastJSON.JSON.Instance.ToJSON(r);
            Console.WriteLine(fastJSON.JSON.Instance.Beautify(s));
            var o = fastJSON.JSON.Instance.ToObject<Dictionary<Retstruct, Retclass>>(s);
            Assert.AreEqual(2, o.Count);
        }

        [Test]
        public static void Dictionary_Retstruct_RetClass_noextentions()
        {
            Dictionary<Retstruct, Retclass> r = new Dictionary<Retstruct, Retclass>();
            r.Add(new Retstruct { Field1 = "111", Field2 = 1, date = DateTime.Now }, new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            r.Add(new Retstruct { Field1 = "222", Field2 = 2, date = DateTime.Now }, new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            var s = fastJSON.JSON.Instance.ToJSON(r, new fastJSON.JSONParameters { UseExtensions = false });
            Console.WriteLine(fastJSON.JSON.Instance.Beautify(s));
            var o = fastJSON.JSON.Instance.ToObject<Dictionary<Retstruct, Retclass>>(s);
            Assert.AreEqual(2, o.Count);
        }

        [Test]
        public static void List_RetClass()
        {
            List<Retclass> r = new List<Retclass>();
            r.Add(new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            r.Add(new Retclass { Field1 = "222", Field2 = 3, date = DateTime.Now });
            var s = fastJSON.JSON.Instance.ToJSON(r);
            Console.WriteLine(fastJSON.JSON.Instance.Beautify(s));
            var o = fastJSON.JSON.Instance.ToObject<List<Retclass>>(s);
            Assert.AreEqual(2, o.Count);
        }

        [Test]
        public static void List_RetClass_noextensions()
        {
            List<Retclass> r = new List<Retclass>();
            r.Add(new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now });
            r.Add(new Retclass { Field1 = "222", Field2 = 3, date = DateTime.Now });
            var s = fastJSON.JSON.Instance.ToJSON(r, new fastJSON.JSONParameters { UseExtensions = false });
            Console.WriteLine(fastJSON.JSON.Instance.Beautify(s));
            var o = fastJSON.JSON.Instance.ToObject<List<Retclass>>(s);
            Assert.AreEqual(2, o.Count);
        }

        [Test]
        public static void Perftest()
        {
            string s = "123456";

            DateTime dt = DateTime.Now;
            int c = 1000000;

            for (int i = 0; i < c; i++)
            {
                var o = CreateLong(s);
            }

            Console.WriteLine("convertlong (ms): " + DateTime.Now.Subtract(dt).TotalMilliseconds);

            dt = DateTime.Now;

            for (int i = 0; i < c; i++)
            {
                var o = long.Parse(s);
            }

            Console.WriteLine("long.parse (ms): " + DateTime.Now.Subtract(dt).TotalMilliseconds);

            dt = DateTime.Now;

            for (int i = 0; i < c; i++)
            {
                var o = Convert.ToInt64(s);
            }

            Console.WriteLine("convert.toint64 (ms): " + DateTime.Now.Subtract(dt).TotalMilliseconds);
        }

        [Test]
        public static void FillObject()
        {
            NoExt ne = new NoExt();
            ne.Name = "hello";
            ne.Address = "here";
            ne.Age = 10;
            ne.dic = new Dictionary<string, class1>();
            ne.dic.Add("hello", new class1("asda", "asdas", Guid.NewGuid()));
            ne.objs = new baseclass[] { new class1("a", "1", Guid.NewGuid()), new class2("b", "2", "desc") };

            string str = fastJSON.JSON.Instance.ToJSON(ne, new fastJSON.JSONParameters { UseExtensions = false, UsingGlobalTypes = false });
            string strr = fastJSON.JSON.Instance.Beautify(str);
            Console.WriteLine(strr);
            object dic = fastJSON.JSON.Instance.Parse(str);
            object oo = fastJSON.JSON.Instance.ToObject<NoExt>(str);

            NoExt nee = new NoExt();
            nee.intern = new NoExt { Name = "aaa" };
            fastJSON.JSON.Instance.FillObject(nee, strr);
        }

        [Test]
        public static void AnonymousTypes()
        {
            var q = new { Name = "asassa", Address = "asadasd", Age = 12 };
            string sq = fastJSON.JSON.Instance.ToJSON(q, new fastJSON.JSONParameters { EnableAnonymousTypes = true });
            Console.WriteLine(sq);
        }

        [Test]
        public static void Speed_Test_Deserialize()
        {
            Console.Write("fastjson deserialize");
            colclass c = CreateObject();
            double t = 0;
            for (int pp = 0; pp < tcount; pp++)
            {
                DateTime st = DateTime.Now;
                colclass deserializedStore;
                string jsonText = fastJSON.JSON.Instance.ToJSON(c);
                //Console.WriteLine(" size = " + jsonText.Length);
                for (int i = 0; i < count; i++)
                {
                    deserializedStore = (colclass)fastJSON.JSON.Instance.ToObject(jsonText);
                }
                t += DateTime.Now.Subtract(st).TotalMilliseconds;
                Console.Write("\t" + DateTime.Now.Subtract(st).TotalMilliseconds);
            }
            Console.WriteLine("\tAVG = " + t / tcount);
        }

        [Test]
        public static void Speed_Test_Serialize()
        {
            Console.Write("fastjson serialize");
            //fastJSON.JSON.Instance.Parameters.UsingGlobalTypes = false;
            colclass c = CreateObject();
            double t = 0;
            for (int pp = 0; pp < tcount; pp++)
            {
                DateTime st = DateTime.Now;
                string jsonText = null;
                for (int i = 0; i < count; i++)
                {
                    jsonText = fastJSON.JSON.Instance.ToJSON(c);
                }
                t += DateTime.Now.Subtract(st).TotalMilliseconds;
                Console.Write("\t" + DateTime.Now.Subtract(st).TotalMilliseconds);
            }
            Console.WriteLine("\tAVG = " + t / tcount);
        }

        [Test]
        public static void List_NestedRetClass()
        {
            List<RetNestedclass> r = new List<RetNestedclass>();
            r.Add(new RetNestedclass { Nested = new Retclass { Field1 = "111", Field2 = 2, date = DateTime.Now } });
            r.Add(new RetNestedclass { Nested = new Retclass { Field1 = "222", Field2 = 3, date = DateTime.Now } });
            var s = fastJSON.JSON.Instance.ToJSON(r);
            Console.WriteLine(fastJSON.JSON.Instance.Beautify(s));
            var o = fastJSON.JSON.Instance.ToObject<List<RetNestedclass>>(s);
            Assert.AreEqual(2, o.Count);
        }

        [Test]
        public static void NullTest()
        {
            var s = fastJSON.JSON.Instance.ToJSON(null);
            Assert.AreEqual("null", s);
            var o = fastJSON.JSON.Instance.ToObject(s);
            Assert.AreEqual(null, o);
        }

        [Test]
        public static void DisableExtensions()
        {
            var p = new fastJSON.JSONParameters { UseExtensions = false, SerializeNullValues = false };
            var s = fastJSON.JSON.Instance.ToJSON(new Retclass { date = DateTime.Now, Name = "aaaaaaa" }, p);
            Console.WriteLine(fastJSON.JSON.Instance.Beautify(s));
            var o = fastJSON.JSON.Instance.ToObject<Retclass>(s);
            Assert.AreEqual("aaaaaaa", o.Name);
        }

        [Test]
        public static void ZeroArray()
        {
            var s = fastJSON.JSON.Instance.ToJSON(new object[] { });
            var o = fastJSON.JSON.Instance.ToObject(s);
            var a = o as object[];
            Assert.AreEqual(0, a.Length);
        }


        [Test]
        public static void GermanNumbers()
        {
            Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("de");
            decimal d = 3.141592654M;
            var s = fastJSON.JSON.Instance.ToJSON(d);
            var o = fastJSON.JSON.Instance.ToObject(s);
            Assert.AreEqual(d, (decimal)o);

            Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("en");
        }

        private static void GenerateJsonForAandB(out string jsonA, out string jsonB)
        {
            Console.WriteLine("Begin constructing the original objects. Please ignore trace information until I'm done.");

            // set all parameters to false to produce pure JSON
            fastJSON.JSON.Instance.Parameters = new JSONParameters { EnableAnonymousTypes = false, IgnoreCaseOnDeserialize = false, SerializeNullValues = false, ShowReadOnlyProperties = false, UseExtensions = false, UseFastGuid = false, UseOptimizedDatasetSchema = false, UseUTCDateTime = false, UsingGlobalTypes = false };

            var a = new ConcurrentClassA { PayloadA = new PayloadA() };
            var b = new ConcurrentClassB { PayloadB = new PayloadB() };

            // A is serialized with extensions and global types
            jsonA = JSON.Instance.ToJSON(a, new JSONParameters { EnableAnonymousTypes = false, IgnoreCaseOnDeserialize = false, SerializeNullValues = false, ShowReadOnlyProperties = false, UseExtensions = true, UseFastGuid = false, UseOptimizedDatasetSchema = false, UseUTCDateTime = false, UsingGlobalTypes = true });
            // B is serialized using the above defaults
            jsonB = JSON.Instance.ToJSON(b);

            Console.WriteLine("Ok, I'm done constructing the objects. Below is the generated json. Trace messages that follow below are the result of deserialization and critical for understanding the timing.");
            Console.WriteLine(jsonA);
            Console.WriteLine(jsonB);
        }

        [Test]
        public void UsingGlobalsBug_singlethread()
        {
            string jsonA;
            string jsonB;
            GenerateJsonForAandB(out jsonA, out jsonB);

            var ax = JSON.Instance.ToObject(jsonA); // A has type information in JSON-extended
            var bx = JSON.Instance.ToObject<ConcurrentClassB>(jsonB); // B needs external type info

            Assert.IsNotNull(ax);
            Assert.IsInstanceOf<ConcurrentClassA>(ax);
            Assert.IsNotNull(bx);
            Assert.IsInstanceOf<ConcurrentClassB>(bx);
        }

        [Test]
        public static void NullOutput()
        {
            var c = new ConcurrentClassA();
            var s = fastJSON.JSON.Instance.ToJSON(c, new JSONParameters { UseExtensions = false });
            Console.WriteLine(fastJSON.JSON.Instance.Beautify(s));
            Assert.False(s.Contains(",")); // should not have a comma
        }

        [Test]
        public void UsingGlobalsBug_multithread()
        {
            string jsonA;
            string jsonB;
            GenerateJsonForAandB(out jsonA, out jsonB);

            object ax = null;
            object bx = null;

            /*
* Intended timing to force CannotGetType bug in 2.0.5:
* the outer class ConcurrentClassA is deserialized first from json with extensions+global types. It reads the global types and sets _usingglobals to true.
* The constructor contains a sleep to force parallel deserialization of ConcurrentClassB while in A's constructor.
* The deserialization of B sets _usingglobals back to false.
* After B is done, A continues to deserialize its PayloadA. It finds type "2" but since _usingglobals is false now, it fails with "Cannot get type".
*/

            Exception exception = null;

            var thread = new Thread(() =>
                                        {
                                            try
                                            {
                                                Console.WriteLine(Thread.CurrentThread.ManagedThreadId + " A begins deserialization");
                                                ax = JSON.Instance.ToObject(jsonA); // A has type information in JSON-extended
                                                Console.WriteLine(Thread.CurrentThread.ManagedThreadId + " A is done");
                                            }
                                            catch (Exception ex)
                                            {
                                                exception = ex;
                                            }
                                        });

            thread.Start();

            Thread.Sleep(500); // wait to allow A to begin deserialization first

            Console.WriteLine(Thread.CurrentThread.ManagedThreadId + " B begins deserialization");
            bx = JSON.Instance.ToObject<ConcurrentClassB>(jsonB); // B needs external type info
            Console.WriteLine(Thread.CurrentThread.ManagedThreadId + " B is done");

            Console.WriteLine(Thread.CurrentThread.ManagedThreadId + " waiting for A to continue");
            thread.Join(); // wait for completion of A due to Sleep in A's constructor
            Console.WriteLine(Thread.CurrentThread.ManagedThreadId + " threads joined.");

            Assert.IsNull(exception, exception == null ? "" : exception.Message + " " + exception.StackTrace);

            Assert.IsNotNull(ax);
            Assert.IsInstanceOf<ConcurrentClassA>(ax);
            Assert.IsNotNull(bx);
            Assert.IsInstanceOf<ConcurrentClassB>(bx);
        }



        public class ConcurrentClassA
        {
            public ConcurrentClassA()
            {
                Console.WriteLine("ctor ConcurrentClassA. I will sleep for 2 seconds.");
                Thread.Sleep(2000);
                Thread.MemoryBarrier(); // just to be sure the caches on multi-core processors do not hide the bug. For me, the bug is present without the memory barrier, too.
                Console.WriteLine("ctor ConcurrentClassA. I am done sleeping.");
            }

            public PayloadA PayloadA { get; set; }
        }

        public class ConcurrentClassB
        {
            public ConcurrentClassB()
            {
                Console.WriteLine("ctor ConcurrentClassB.");
            }

            public PayloadB PayloadB { get; set; }
        }

        public class PayloadA
        {
            public PayloadA()
            {
                Console.WriteLine("ctor PayLoadA.");
            }
        }

        public class PayloadB
        {
            public PayloadB()
            {
                Console.WriteLine("ctor PayLoadB.");
            }
        }
        //[Test]
        //public static void LinkedList()
        //{
        //    LinkedList<Retclass> l = new LinkedList<Retclass>();
        //    var n = l.AddFirst(new Retclass { date = DateTime.Now, Name = "aaa" });
        //    l.AddAfter(n, new Retclass { Name = "bbbb", date = DateTime.Now });

        //    var s = fastJSON.JSON.Instance.ToJSON(l);
        //    var o = fastJSON.JSON.Instance.ToObject<LinkedList<Retclass>>(s);


        //}
        //[Test]
        //public static void SubClasses()
        //{

        //}

        //[Test]
        //public static void CasttoSomthing()
        //{

        //}

        //[Test]
        //public static void IgnoreCase()
        //{

        //}

        //[Test]
        //public static void Datasets()
        //{

        //}
    }
}

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License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Architect -
United Kingdom United Kingdom
Mehdi first started programming when he was 8 on BBC+128k machine in 6512 processor language, after various hardware and software changes he eventually came across .net and c# which he has been using since v1.0.
He is formally educated as a system analyst Industrial engineer, but his programming passion continues.

* Mehdi is the 5th person to get 6 out of 7 Platinum's on Code-Project (13th Jan'12)
* Mehdi is the 3rd person to get 7 out of 7 Platinum's on Code-Project (26th Aug'16)

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