source: branches/PersistenceOverhaul/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory-5.5.0/Utils/FastSerializer.cs @ 13325

// Copyright (c) 2011 Daniel Grunwald
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.Serialization;

namespace ICSharpCode.NRefactory.Utils
{
  public class FastSerializer
  {
    #region Properties
    /// <summary>
    /// Gets/Sets the serialization binder that is being used.
    /// The default value is null, which will cause the FastSerializer to use the
    /// full assembly and type names.
    /// </summary>
    public SerializationBinder SerializationBinder { get; set; }
    
    /// <summary>
    /// Can be used to set several 'fixed' instances.
    /// When serializing, such instances will not be included; and any references to a fixed instance
    /// will be stored as the index in this array.
    /// When deserializing, the same (or equivalent) instances must be specified, and the deserializer
    /// will use them in place of the fixed instances.
    /// </summary>
    public object[] FixedInstances { get; set; }
    #endregion
    
    #region Constants
    const int magic = 0x71D28A5E;
    
    const byte Type_ReferenceType = 1;
    const byte Type_ValueType = 2;
    const byte Type_SZArray = 3;
    const byte Type_ParameterizedType = 4;
    #endregion
    
    #region Serialization
    sealed class SerializationType
    {
      public readonly int ID;
      public readonly Type Type;
      
      public SerializationType(int iD, Type type)
      {
        this.ID = iD;
        this.Type = type;
      }
      
      public ObjectScanner Scanner;
      public ObjectWriter Writer;
      public string TypeName;
      public int AssemblyNameID;
    }
    
    sealed class SerializationContext
    {
      readonly Dictionary<object, int> objectToID = new Dictionary<object, int>(ReferenceComparer.Instance);
      readonly List<object> instances = new List<object>(); // index: object ID
      readonly List<SerializationType> objectTypes = new List<SerializationType>(); // index: object ID
      SerializationType stringType;
      
      readonly Dictionary<Type, SerializationType> typeMap = new Dictionary<Type, SerializationType>();
      readonly List<SerializationType> types = new List<SerializationType>();
      
      readonly Dictionary<string, int> assemblyNameToID = new Dictionary<string, int>();
      readonly List<string> assemblyNames = new List<string>();
      
      readonly FastSerializer fastSerializer;
      public readonly BinaryWriter writer;
      int fixedInstanceCount;
      
      internal SerializationContext(FastSerializer fastSerializer, BinaryWriter writer)
      {
        this.fastSerializer = fastSerializer;
        this.writer = writer;
        instances.Add(null); // use object ID 0 for null
        objectTypes.Add(null);
      }
      
      #region Scanning
      public void MarkFixedInstances(object[] fixedInstances)
      {
        if (fixedInstances == null)
          return;
        foreach (object obj in fixedInstances) {
          if (!objectToID.ContainsKey(obj)) {
            objectToID.Add(obj, instances.Count);
            instances.Add(obj);
            fixedInstanceCount++;
          }
        }
      }
      
      /// <summary>
      /// Marks an instance for future scanning.
      /// </summary>
      public void Mark(object instance)
      {
        if (instance == null || objectToID.ContainsKey(instance))
          return;
        Log(" Mark {0}", instance.GetType().Name);
        
        objectToID.Add(instance, instances.Count);
        instances.Add(instance);
      }
      
      internal void Scan()
      {
        Log("Scanning...");
        // starting from 1, because index 0 is null
        // Also, do not scan any of the 'fixed instances'.
        for (int i = 1 + fixedInstanceCount; i < instances.Count; i++) {
          object instance = instances[i];
          ISerializable serializable = instance as ISerializable;
          Type type = instance.GetType();
          Log("Scan #{0}: {1}", i, type.Name);
          SerializationType sType = MarkType(type);
          objectTypes.Add(sType);
          if (serializable != null) {
            SerializationInfo info = new SerializationInfo(type, fastSerializer.formatterConverter);
            serializable.GetObjectData(info, fastSerializer.streamingContext);
            instances[i] = info;
            foreach (SerializationEntry entry in info) {
              Mark(entry.Value);
            }
            sType.Writer = serializationInfoWriter;
          } else {
            ObjectScanner objectScanner = sType.Scanner;
            if (objectScanner == null) {
              objectScanner = fastSerializer.GetScanner(type);
              sType.Scanner = objectScanner;
              sType.Writer = fastSerializer.GetWriter(type);
            }
            objectScanner(this, instance);
          }
        }
      }
      #endregion
      
      #region Scan Types
      SerializationType MarkType(Type type)
      {
        SerializationType sType;
        if (!typeMap.TryGetValue(type, out sType)) {
          string assemblyName = null;
          string typeName = null;
          if (type.HasElementType) {
            Debug.Assert(type.IsArray);
            MarkType(type.GetElementType());
          } else if (type.IsGenericType && !type.IsGenericTypeDefinition) {
            MarkType(type.GetGenericTypeDefinition());
            foreach (Type typeArg in type.GetGenericArguments())
              MarkType(typeArg);
          } else if (type.IsGenericParameter) {
            throw new NotSupportedException();
          } else {
            var serializationBinder = fastSerializer.SerializationBinder;
            if (serializationBinder != null) {
              serializationBinder.BindToName(type, out assemblyName, out typeName);
            } else {
              assemblyName = type.Assembly.FullName;
              typeName = type.FullName;
              Debug.Assert(typeName != null);
            }
          }
          
          sType = new SerializationType(typeMap.Count, type);
          sType.TypeName = typeName;
          if (assemblyName != null) {
            if (!assemblyNameToID.TryGetValue(assemblyName, out sType.AssemblyNameID)) {
              sType.AssemblyNameID = assemblyNames.Count;
              assemblyNameToID.Add(assemblyName, sType.AssemblyNameID);
              assemblyNames.Add(assemblyName);
              Log("Registered assembly #{0}: {1}", sType.AssemblyNameID, assemblyName);
            }
          }
          typeMap.Add(type, sType);
          types.Add(sType);
          Log("Registered type %{0}: {1}", sType.ID, type);
          if (type == typeof(string)) {
            stringType = sType;
          }
        }
        return sType;
      }
      
      internal void ScanTypes()
      {
        for (int i = 0; i < types.Count; i++) {
          Type type = types[i].Type;
          if (type.IsGenericTypeDefinition || type.HasElementType)
            continue;
          if (typeof(ISerializable).IsAssignableFrom(type))
            continue;
          foreach (FieldInfo field in GetSerializableFields(type)) {
            MarkType(field.FieldType);
          }
        }
      }
      #endregion
      
      #region Writing
      public void WriteObjectID(object instance)
      {
        int id = (instance == null) ? 0 : objectToID[instance];
        if (instances.Count <= ushort.MaxValue)
          writer.Write((ushort)id);
        else
          writer.Write(id);
      }
      
      void WriteTypeID(Type type)
      {
        Debug.Assert(typeMap.ContainsKey(type));
        int typeID = typeMap[type].ID;
        if (types.Count <= ushort.MaxValue)
          writer.Write((ushort)typeID);
        else
          writer.Write(typeID);
      }
      
      internal void Write()
      {
        Log("Writing...");
        writer.Write(magic);
        // Write out type information
        writer.Write(instances.Count);
        writer.Write(types.Count);
        writer.Write(assemblyNames.Count);
        writer.Write(fixedInstanceCount);
        
        foreach (string assemblyName in assemblyNames) {
          writer.Write(assemblyName);
        }
        
        foreach (SerializationType sType in types) {
          Type type = sType.Type;
          if (type.HasElementType) {
            if (type.IsArray) {
              if (type.GetArrayRank() == 1)
                writer.Write(Type_SZArray);
              else
                throw new NotSupportedException();
            } else {
              throw new NotSupportedException();
            }
            WriteTypeID(type.GetElementType());
          } else if (type.IsGenericType && !type.IsGenericTypeDefinition) {
            writer.Write(Type_ParameterizedType);
            WriteTypeID(type.GetGenericTypeDefinition());
            foreach (Type typeArg in type.GetGenericArguments()) {
              WriteTypeID(typeArg);
            }
          } else {
            if (type.IsValueType) {
              writer.Write(Type_ValueType);
            } else {
              writer.Write(Type_ReferenceType);
            }
            if (assemblyNames.Count <= ushort.MaxValue)
              writer.Write((ushort)sType.AssemblyNameID);
            else
              writer.Write(sType.AssemblyNameID);
            writer.Write(sType.TypeName);
          }
        }
        foreach (SerializationType sType in types) {
          Type type = sType.Type;
          if (type.IsGenericTypeDefinition || type.HasElementType)
            continue;
          writer.Write(FastSerializerVersionAttribute.GetVersionNumber(type));
          if (type.IsPrimitive || typeof(ISerializable).IsAssignableFrom(type)) {
            writer.Write(byte.MaxValue);
          } else {
            var fields = GetSerializableFields(type);
            if (fields.Count >= byte.MaxValue)
              throw new SerializationException("Too many fields.");
            writer.Write((byte)fields.Count);
            foreach (var field in fields) {
              WriteTypeID(field.FieldType);
              writer.Write(field.Name);
            }
          }
        }
        
        // Write out information necessary to create the instances
        // starting from 1, because index 0 is null
        for (int i = 1 + fixedInstanceCount; i < instances.Count; i++) {
          SerializationType sType = objectTypes[i];
          if (types.Count <= ushort.MaxValue)
            writer.Write((ushort)sType.ID);
          else
            writer.Write(sType.ID);
          if (sType == stringType) {
            // Strings are written to the output immediately
            // - we can't create an empty string and fill it later
            writer.Write((string)instances[i]);
          } else if (sType.Type.IsArray) {
            // For arrays, write down the length, because we need that to create the array instance
            writer.Write(((Array)instances[i]).Length);
          }
        }
        // Write out information necessary to fill data into the instances
        for (int i = 1 + fixedInstanceCount; i < instances.Count; i++) {
          Log("0x{2:x6}, Write #{0}: {1}", i, objectTypes[i].Type.Name, writer.BaseStream.Position);
          objectTypes[i].Writer(this, instances[i]);
        }
        Log("Serialization done.");
      }
      #endregion
    }
    
    #region Object Scanners
    delegate void ObjectScanner(SerializationContext context, object instance);
    
    static readonly MethodInfo mark = typeof(SerializationContext).GetMethod("Mark", new[] { typeof(object) });
    static readonly FieldInfo writerField = typeof(SerializationContext).GetField("writer");
    
    Dictionary<Type, ObjectScanner> scanners = new Dictionary<Type, ObjectScanner>();
    
    ObjectScanner GetScanner(Type type)
    {
      ObjectScanner scanner;
      if (!scanners.TryGetValue(type, out scanner)) {
        scanner = CreateScanner(type);
        scanners.Add(type, scanner);
      }
      return scanner;
    }
    
    ObjectScanner CreateScanner(Type type)
    {
      bool isArray = type.IsArray;
      if (isArray) {
        if (type.GetArrayRank() != 1)
          throw new NotSupportedException();
        type = type.GetElementType();
        if (!type.IsValueType) {
          return delegate (SerializationContext context, object array) {
            foreach (object val in (object[])array) {
              context.Mark(val);
            }
          };
        }
      }
      for (Type baseType = type; baseType != null; baseType = baseType.BaseType) {
        if (!baseType.IsSerializable)
          throw new SerializationException("Type " + baseType + " is not [Serializable].");
      }
      List<FieldInfo> fields = GetSerializableFields(type);
      fields.RemoveAll(f => !IsReferenceOrContainsReferences(f.FieldType));
      if (fields.Count == 0) {
        // The scanner has nothing to do for this object.
        return delegate { };
      }
      
      DynamicMethod dynamicMethod = new DynamicMethod(
        (isArray ? "ScanArray_" : "Scan_") + type.Name,
        typeof(void), new [] { typeof(SerializationContext), typeof(object) },
        true);
      ILGenerator il = dynamicMethod.GetILGenerator();
      
      
      if (isArray) {
        var instance = il.DeclareLocal(type.MakeArrayType());
        il.Emit(OpCodes.Ldarg_1);
        il.Emit(OpCodes.Castclass, type.MakeArrayType());
        il.Emit(OpCodes.Stloc, instance); // instance = (type[])arg_1;
        
        // for (int i = 0; i < instance.Length; i++) scan instance[i];
        var loopStart = il.DefineLabel();
        var loopHead = il.DefineLabel();
        var loopVariable = il.DeclareLocal(typeof(int));
        il.Emit(OpCodes.Ldc_I4_0);
        il.Emit(OpCodes.Stloc, loopVariable); // loopVariable = 0
        il.Emit(OpCodes.Br, loopHead); // goto loopHead;
        
        il.MarkLabel(loopStart);
        
        il.Emit(OpCodes.Ldloc, instance); // instance
        il.Emit(OpCodes.Ldloc, loopVariable); // instance, loopVariable
        il.Emit(OpCodes.Ldelem, type); // &instance[loopVariable]
        EmitScanValueType(il, type);
        
        
        il.Emit(OpCodes.Ldloc, loopVariable); // loopVariable
        il.Emit(OpCodes.Ldc_I4_1); // loopVariable, 1
        il.Emit(OpCodes.Add); // loopVariable+1
        il.Emit(OpCodes.Stloc, loopVariable); // loopVariable++;
        
        il.MarkLabel(loopHead);
        il.Emit(OpCodes.Ldloc, loopVariable); // loopVariable
        il.Emit(OpCodes.Ldloc, instance); // loopVariable, instance
        il.Emit(OpCodes.Ldlen); // loopVariable, instance.Length
        il.Emit(OpCodes.Conv_I4);
        il.Emit(OpCodes.Blt, loopStart); // if (loopVariable < instance.Length) goto loopStart;
      } else if (type.IsValueType) {
        // boxed value type
        il.Emit(OpCodes.Ldarg_1);
        il.Emit(OpCodes.Unbox_Any, type);
        EmitScanValueType(il, type);
      } else {
        // reference type
        var instance = il.DeclareLocal(type);
        il.Emit(OpCodes.Ldarg_1);
        il.Emit(OpCodes.Castclass, type);
        il.Emit(OpCodes.Stloc, instance); // instance = (type)arg_1;
        
        foreach (FieldInfo field in fields) {
          EmitScanField(il, instance, field); // scan instance.Field
        }
      }
      il.Emit(OpCodes.Ret);
      return (ObjectScanner)dynamicMethod.CreateDelegate(typeof(ObjectScanner));
    }

    /// <summary>
    /// Emit 'scan instance.Field'.
    /// Stack transition: ... => ...
    /// </summary>
    void EmitScanField(ILGenerator il, LocalBuilder instance, FieldInfo field)
    {
      if (field.FieldType.IsValueType) {
        il.Emit(OpCodes.Ldloc, instance); // instance
        il.Emit(OpCodes.Ldfld, field); // instance.field
        EmitScanValueType(il, field.FieldType);
      } else {
        il.Emit(OpCodes.Ldarg_0); // context
        il.Emit(OpCodes.Ldloc, instance); // context, instance
        il.Emit(OpCodes.Ldfld, field); // context, instance.field
        il.Emit(OpCodes.Call, mark); // context.Mark(instance.field);
      }
    }

    /// <summary>
    /// Stack transition: ..., value => ...
    /// </summary>
    void EmitScanValueType(ILGenerator il, Type valType)
    {
      var fieldRef = il.DeclareLocal(valType);
      il.Emit(OpCodes.Stloc, fieldRef);
      
      foreach (FieldInfo field in GetSerializableFields(valType)) {
        if (IsReferenceOrContainsReferences(field.FieldType)) {
          EmitScanField(il, fieldRef, field);
        }
      }
    }

    static List<FieldInfo> GetSerializableFields(Type type)
    {
      List<FieldInfo> fields = new List<FieldInfo>();
      for (Type baseType = type; baseType != null; baseType = baseType.BaseType) {
        FieldInfo[] declFields = baseType.GetFields(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.DeclaredOnly);
        Array.Sort(declFields, (a,b) => string.Compare(a.Name, b.Name, StringComparison.Ordinal));
        fields.AddRange(declFields);
      }
      fields.RemoveAll(f => f.IsNotSerialized);
      return fields;
    }

    static bool IsReferenceOrContainsReferences(Type type)
    {
      if (!type.IsValueType)
        return true;
      if (type.IsPrimitive)
        return false;
      foreach (FieldInfo field in GetSerializableFields(type)) {
        if (IsReferenceOrContainsReferences(field.FieldType))
          return true;
      }
      return false;
    }
    #endregion

    #region Object Writers
    delegate void ObjectWriter(SerializationContext context, object instance);

    static readonly MethodInfo writeObjectID = typeof(SerializationContext).GetMethod("WriteObjectID", new[] { typeof(object) });

    static readonly MethodInfo writeByte = typeof(BinaryWriter).GetMethod("Write", new[] { typeof(byte) });
    static readonly MethodInfo writeShort = typeof(BinaryWriter).GetMethod("Write", new[] { typeof(short) });
    static readonly MethodInfo writeInt = typeof(BinaryWriter).GetMethod("Write", new[] { typeof(int) });
    static readonly MethodInfo writeLong = typeof(BinaryWriter).GetMethod("Write", new[] { typeof(long) });
    static readonly MethodInfo writeFloat = typeof(BinaryWriter).GetMethod("Write", new[] { typeof(float) });
    static readonly MethodInfo writeDouble = typeof(BinaryWriter).GetMethod("Write", new[] { typeof(double) });
    OpCode callVirt = OpCodes.Callvirt;

    static readonly ObjectWriter serializationInfoWriter = delegate(SerializationContext context, object instance) {
      BinaryWriter writer = context.writer;
      SerializationInfo info = (SerializationInfo)instance;
      writer.Write(info.MemberCount);
      foreach (SerializationEntry entry in info) {
        writer.Write(entry.Name);
        context.WriteObjectID(entry.Value);
      }
    };

    Dictionary<Type, ObjectWriter> writers = new Dictionary<Type, ObjectWriter>();

    ObjectWriter GetWriter(Type type)
    {
      ObjectWriter writer;
      if (!writers.TryGetValue(type, out writer)) {
        writer = CreateWriter(type);
        writers.Add(type, writer);
      }
      return writer;
    }

    ObjectWriter CreateWriter(Type type)
    {
      if (type == typeof(string)) {
        // String contents are written in the object creation section,
        // not into the field value section.
        return delegate {};
      }
      bool isArray = type.IsArray;
      if (isArray) {
        if (type.GetArrayRank() != 1)
          throw new NotSupportedException();
        type = type.GetElementType();
        if (!type.IsValueType) {
          return delegate (SerializationContext context, object array) {
            foreach (object val in (object[])array) {
              context.WriteObjectID(val);
            }
          };
        } else if (type == typeof(byte)) {
          return delegate (SerializationContext context, object array) {
            context.writer.Write((byte[])array);
          };
        }
      }
      List<FieldInfo> fields = GetSerializableFields(type);
      if (fields.Count == 0) {
        // The writer has nothing to do for this object.
        return delegate { };
      }
      
      
      DynamicMethod dynamicMethod = new DynamicMethod(
        (isArray ? "WriteArray_" : "Write_") + type.Name,
        typeof(void), new [] { typeof(SerializationContext), typeof(object) },
        true);
      ILGenerator il = dynamicMethod.GetILGenerator();
      
      var writer = il.DeclareLocal(typeof(BinaryWriter));
      
      il.Emit(OpCodes.Ldarg_0);
      il.Emit(OpCodes.Ldfld, writerField);
      il.Emit(OpCodes.Stloc, writer); // writer = context.writer;
      
      if (isArray) {
        var instance = il.DeclareLocal(type.MakeArrayType());
        il.Emit(OpCodes.Ldarg_1);
        il.Emit(OpCodes.Castclass, type.MakeArrayType());
        il.Emit(OpCodes.Stloc, instance); // instance = (type[])arg_1;
        
        // for (int i = 0; i < instance.Length; i++) write instance[i];
        
        var loopStart = il.DefineLabel();
        var loopHead = il.DefineLabel();
        var loopVariable = il.DeclareLocal(typeof(int));
        il.Emit(OpCodes.Ldc_I4_0);
        il.Emit(OpCodes.Stloc, loopVariable); // loopVariable = 0
        il.Emit(OpCodes.Br, loopHead); // goto loopHead;
        
        il.MarkLabel(loopStart);
        
        if (type.IsEnum || type.IsPrimitive) {
          if (type.IsEnum) {
            type = type.GetEnumUnderlyingType();
          }
          Debug.Assert(type.IsPrimitive);
          il.Emit(OpCodes.Ldloc, writer); // writer
          il.Emit(OpCodes.Ldloc, instance); // writer, instance
          il.Emit(OpCodes.Ldloc, loopVariable); // writer, instance, loopVariable
          switch (Type.GetTypeCode(type)) {
            case TypeCode.Boolean:
            case TypeCode.SByte:
            case TypeCode.Byte:
              il.Emit(OpCodes.Ldelem_I1); // writer, instance[loopVariable]
              il.Emit(callVirt, writeByte); // writer.Write(instance[loopVariable]);
              break;
            case TypeCode.Char:
            case TypeCode.Int16:
            case TypeCode.UInt16:
              il.Emit(OpCodes.Ldelem_I2); // writer, instance[loopVariable]
              il.Emit(callVirt, writeShort); // writer.Write(instance[loopVariable]);
              break;
            case TypeCode.Int32:
            case TypeCode.UInt32:
              il.Emit(OpCodes.Ldelem_I4);  // writer, instance[loopVariable]
              il.Emit(callVirt, writeInt); // writer.Write(instance[loopVariable]);
              break;
            case TypeCode.Int64:
            case TypeCode.UInt64:
              il.Emit(OpCodes.Ldelem_I8);  // writer, instance[loopVariable]
              il.Emit(callVirt, writeLong); // writer.Write(instance[loopVariable]);
              break;
            case TypeCode.Single:
              il.Emit(OpCodes.Ldelem_R4);  // writer, instance[loopVariable]
              il.Emit(callVirt, writeFloat); // writer.Write(instance[loopVariable]);
              break;
            case TypeCode.Double:
              il.Emit(OpCodes.Ldelem_R8);  // writer, instance[loopVariable]
              il.Emit(callVirt, writeDouble); // writer.Write(instance[loopVariable]);
              break;
            default:
              throw new NotSupportedException("Unknown primitive type " + type);
          }
        } else {
          il.Emit(OpCodes.Ldloc, instance); // instance
          il.Emit(OpCodes.Ldloc, loopVariable); // instance, loopVariable
          il.Emit(OpCodes.Ldelem, type); // instance[loopVariable]
          EmitWriteValueType(il, writer, type);
        }
        
        il.Emit(OpCodes.Ldloc, loopVariable); // loopVariable
        il.Emit(OpCodes.Ldc_I4_1); // loopVariable, 1
        il.Emit(OpCodes.Add); // loopVariable+1
        il.Emit(OpCodes.Stloc, loopVariable); // loopVariable++;
        
        il.MarkLabel(loopHead);
        il.Emit(OpCodes.Ldloc, loopVariable); // loopVariable
        il.Emit(OpCodes.Ldloc, instance); // loopVariable, instance
        il.Emit(OpCodes.Ldlen); // loopVariable, instance.Length
        il.Emit(OpCodes.Conv_I4);
        il.Emit(OpCodes.Blt, loopStart); // if (loopVariable < instance.Length) goto loopStart;
      } else if (type.IsValueType) {
        // boxed value type
        if (type.IsEnum || type.IsPrimitive) {
          il.Emit(OpCodes.Ldloc, writer);
          il.Emit(OpCodes.Ldarg_1);
          il.Emit(OpCodes.Unbox_Any, type);
          WritePrimitiveValue(il, type);
        } else {
          il.Emit(OpCodes.Ldarg_1);
          il.Emit(OpCodes.Unbox_Any, type);
          EmitWriteValueType(il, writer, type);
        }
      } else {
        // reference type
        var instance = il.DeclareLocal(type);
        il.Emit(OpCodes.Ldarg_1);
        il.Emit(OpCodes.Castclass, type);
        il.Emit(OpCodes.Stloc, instance); // instance = (type)arg_1;
        
        foreach (FieldInfo field in fields) {
          EmitWriteField(il, writer, instance, field); // write instance.Field
        }
      }
      il.Emit(OpCodes.Ret);
      return (ObjectWriter)dynamicMethod.CreateDelegate(typeof(ObjectWriter));
    }

    /// <summary>
    /// Emit 'write instance.Field'.
    /// Stack transition: ... => ...
    /// </summary>
    void EmitWriteField(ILGenerator il, LocalBuilder writer, LocalBuilder instance, FieldInfo field)
    {
      Type fieldType = field.FieldType;
      if (fieldType.IsValueType) {
        if (fieldType.IsPrimitive || fieldType.IsEnum) {
          il.Emit(OpCodes.Ldloc, writer); // writer
          il.Emit(OpCodes.Ldloc, instance); // writer, instance
          il.Emit(OpCodes.Ldfld, field); // writer, instance.field
          WritePrimitiveValue(il, fieldType);
        } else {
          il.Emit(OpCodes.Ldloc, instance); // instance
          il.Emit(OpCodes.Ldfld, field); // instance.field
          EmitWriteValueType(il, writer, fieldType);
        }
      } else {
        il.Emit(OpCodes.Ldarg_0); // context
        il.Emit(OpCodes.Ldloc, instance); // context, instance
        il.Emit(OpCodes.Ldfld, field); // context, instance.field
        il.Emit(OpCodes.Call, writeObjectID); // context.WriteObjectID(instance.field);
      }
    }
    
    /// <summary>
    /// Writes a primitive value of the specified type.
    /// Stack transition: ..., writer, value => ...
    /// </summary>
    void WritePrimitiveValue(ILGenerator il, Type fieldType)
    {
      if (fieldType.IsEnum) {
        fieldType = fieldType.GetEnumUnderlyingType();
        Debug.Assert(fieldType.IsPrimitive);
      }
      switch (Type.GetTypeCode(fieldType)) {
        case TypeCode.Boolean:
        case TypeCode.SByte:
        case TypeCode.Byte:
          il.Emit(callVirt, writeByte); // writer.Write(value);
          break;
        case TypeCode.Char:
        case TypeCode.Int16:
        case TypeCode.UInt16:
          il.Emit(callVirt, writeShort); // writer.Write(value);
          break;
        case TypeCode.Int32:
        case TypeCode.UInt32:
          il.Emit(callVirt, writeInt); // writer.Write(value);
          break;
        case TypeCode.Int64:
        case TypeCode.UInt64:
          il.Emit(callVirt, writeLong); // writer.Write(value);
          break;
        case TypeCode.Single:
          il.Emit(callVirt, writeFloat); // writer.Write(value);
          break;
        case TypeCode.Double:
          il.Emit(callVirt, writeDouble); // writer.Write(value);
          break;
        default:
          throw new NotSupportedException("Unknown primitive type " + fieldType);
      }
    }

    /// <summary>
    /// Stack transition: ..., value => ...
    /// </summary>
    void EmitWriteValueType(ILGenerator il, LocalBuilder writer, Type valType)
    {
      Debug.Assert(valType.IsValueType);
      Debug.Assert(!(valType.IsEnum || valType.IsPrimitive));
      
      var fieldVal = il.DeclareLocal(valType);
      il.Emit(OpCodes.Stloc, fieldVal);
      
      foreach (FieldInfo field in GetSerializableFields(valType)) {
        EmitWriteField(il, writer, fieldVal, field);
      }
    }
    #endregion

    StreamingContext streamingContext = new StreamingContext(StreamingContextStates.All);
    FormatterConverter formatterConverter = new FormatterConverter();

    public void Serialize(Stream stream, object instance)
    {
      Serialize(new BinaryWriterWith7BitEncodedInts(stream), instance);
    }

    public void Serialize(BinaryWriter writer, object instance)
    {
      SerializationContext context = new SerializationContext(this, writer);
      context.MarkFixedInstances(this.FixedInstances);
      context.Mark(instance);
      context.Scan();
      context.ScanTypes();
      context.Write();
      context.WriteObjectID(instance);
    }

    delegate void TypeSerializer(object instance, SerializationContext context);
    #endregion

    #region Deserialization
    sealed class DeserializationContext
    {
      public Type[] Types; // index: type ID
      
      public object[] Objects; // index: object ID
      
      public BinaryReader Reader;
      
      public object ReadObject()
      {
        if (this.Objects.Length <= ushort.MaxValue)
          return this.Objects[Reader.ReadUInt16()];
        else
          return this.Objects[Reader.ReadInt32()];
      }
      
      #region DeserializeTypeDescriptions
      internal int ReadTypeID()
      {
        if (this.Types.Length <= ushort.MaxValue)
          return Reader.ReadUInt16();
        else
          return Reader.ReadInt32();
      }
      
      internal void DeserializeTypeDescriptions()
      {
        for (int i = 0; i < this.Types.Length; i++) {
          Type type = this.Types[i];
          if (type.IsGenericTypeDefinition || type.HasElementType)
            continue;
          int versionNumber = Reader.ReadInt32();
          if (versionNumber != FastSerializerVersionAttribute.GetVersionNumber(type))
            throw new SerializationException("Type '" + type.FullName + "' was serialized with version " + versionNumber + ", but is version " + FastSerializerVersionAttribute.GetVersionNumber(type));
          
          bool isCustomSerialization = typeof(ISerializable).IsAssignableFrom(type);
          bool typeIsSpecial = type.IsPrimitive || isCustomSerialization;
          
          byte serializedFieldCount = Reader.ReadByte();
          if (serializedFieldCount == byte.MaxValue) {
            // special type
            if (!typeIsSpecial)
              throw new SerializationException("Type '" + type.FullName + "' was serialized as special type, but isn't special now.");
          } else {
            if (typeIsSpecial)
              throw new SerializationException("Type '" + type.FullName + "' wasn't serialized as special type, but is special now.");
            
            var availableFields = GetSerializableFields(this.Types[i]);
            if (availableFields.Count != serializedFieldCount)
              throw new SerializationException("Number of fields on " + type.FullName + " has changed.");
            for (int j = 0; j < serializedFieldCount; j++) {
              int fieldTypeID = ReadTypeID();
              
              string fieldName = Reader.ReadString();
              FieldInfo fieldInfo = availableFields[j];
              if (fieldInfo.Name != fieldName)
                throw new SerializationException("Field mismatch on type " + type.FullName);
              if (fieldInfo.FieldType != this.Types[fieldTypeID])
                throw new SerializationException(type.FullName + "." + fieldName + " was serialized as " + this.Types[fieldTypeID] + ", but now is " + fieldInfo.FieldType);
            }
          }
        }
      }
      #endregion
    }
    
    delegate void ObjectReader(DeserializationContext context, object instance);
    
    public object Deserialize(Stream stream)
    {
      return Deserialize(new BinaryReaderWith7BitEncodedInts(stream));
    }
    
    public object Deserialize(BinaryReader reader)
    {
      if (reader.ReadInt32() != magic)
        throw new SerializationException("The data cannot be read by FastSerializer (unknown magic value)");
      
      DeserializationContext context = new DeserializationContext();
      context.Reader = reader;
      context.Objects = new object[reader.ReadInt32()];
      context.Types = new Type[reader.ReadInt32()];
      string[] assemblyNames = new string[reader.ReadInt32()];
      int fixedInstanceCount = reader.ReadInt32();
      
      if (fixedInstanceCount != 0) {
        if (this.FixedInstances == null || this.FixedInstances.Length != fixedInstanceCount)
          throw new SerializationException("Number of fixed instances doesn't match");
        for (int i = 0; i < fixedInstanceCount; i++) {
          context.Objects[i + 1] = this.FixedInstances[i];
        }
      }
      
      for (int i = 0; i < assemblyNames.Length; i++) {
        assemblyNames[i] = reader.ReadString();
      }
      int stringTypeID = -1;
      for (int i = 0; i < context.Types.Length; i++) {
        byte typeKind = reader.ReadByte();
        switch (typeKind) {
          case Type_ReferenceType:
          case Type_ValueType:
            int assemblyID;
            if (assemblyNames.Length <= ushort.MaxValue)
              assemblyID = reader.ReadUInt16();
            else
              assemblyID = reader.ReadInt32();
            string assemblyName = assemblyNames[assemblyID];
            string typeName = reader.ReadString();
            Type type;
            if (SerializationBinder != null) {
              type = SerializationBinder.BindToType(assemblyName, typeName);
            } else {
              type = Assembly.Load(assemblyName).GetType(typeName);
            }
            if (type == null)
              throw new SerializationException("Could not find '" + typeName + "' in '" + assemblyName + "'");
            if (typeKind == Type_ValueType && !type.IsValueType)
              throw new SerializationException("Expected '" + typeName + "' to be a value type, but it is reference type");
            if (typeKind == Type_ReferenceType && type.IsValueType)
              throw new SerializationException("Expected '" + typeName + "' to be a reference type, but it is value type");
            context.Types[i] = type;
            if (type == typeof(string))
              stringTypeID = i;
            break;
          case Type_SZArray:
            context.Types[i] = context.Types[context.ReadTypeID()].MakeArrayType();
            break;
          case Type_ParameterizedType:
            Type genericType = context.Types[context.ReadTypeID()];
            int typeParameterCount = genericType.GetGenericArguments().Length;
            Type[] typeArguments = new Type[typeParameterCount];
            for (int j = 0; j < typeArguments.Length; j++) {
              typeArguments[j] = context.Types[context.ReadTypeID()];
            }
            context.Types[i] = genericType.MakeGenericType(typeArguments);
            break;
          default:
            throw new SerializationException("Unknown type kind");
        }
      }
      context.DeserializeTypeDescriptions();
      int[] typeIDByObjectID = new int[context.Objects.Length];
      for (int i = 1 + fixedInstanceCount; i < context.Objects.Length; i++) {
        int typeID = context.ReadTypeID();
        
        object instance;
        if (typeID == stringTypeID) {
          instance = reader.ReadString();
        } else {
          Type type = context.Types[typeID];
          if (type.IsArray) {
            int length = reader.ReadInt32();
            instance = Array.CreateInstance(type.GetElementType(), length);
          } else {
            instance = FormatterServices.GetUninitializedObject(type);
          }
        }
        context.Objects[i] = instance;
        typeIDByObjectID[i] = typeID;
      }
      List<CustomDeserialization> customDeserializatons = new List<CustomDeserialization>();
      ObjectReader[] objectReaders = new ObjectReader[context.Types.Length]; // index: type ID
      for (int i = 1 + fixedInstanceCount; i < context.Objects.Length; i++) {
        object instance = context.Objects[i];
        int typeID = typeIDByObjectID[i];
        Log("0x{2:x6} Read #{0}: {1}", i, context.Types[typeID].Name, reader.BaseStream.Position);
        ISerializable serializable = instance as ISerializable;
        if (serializable != null) {
          Type type = context.Types[typeID];
          SerializationInfo info = new SerializationInfo(type, formatterConverter);
          int count = reader.ReadInt32();
          for (int j = 0; j < count; j++) {
            string name = reader.ReadString();
            object val = context.ReadObject();
            info.AddValue(name, val);
          }
          CustomDeserializationAction action = GetCustomDeserializationAction(type);
          customDeserializatons.Add(new CustomDeserialization(instance, info, action));
        } else {
          ObjectReader objectReader = objectReaders[typeID];
          if (objectReader == null) {
            objectReader = GetReader(context.Types[typeID]);
            objectReaders[typeID] = objectReader;
          }
          objectReader(context, instance);
        }
      }
      Log("File was read successfully, now running {0} custom deserializations...", customDeserializatons.Count);
      foreach (CustomDeserialization customDeserializaton in customDeserializatons) {
        customDeserializaton.Run(streamingContext);
      }
      for (int i = 1 + fixedInstanceCount; i < context.Objects.Length; i++) {
        IDeserializationCallback dc = context.Objects[i] as IDeserializationCallback;
        if (dc != null)
          dc.OnDeserialization(null);
      }
      
      return context.ReadObject();
    }
    
    #region Object Reader
    static readonly FieldInfo readerField = typeof(DeserializationContext).GetField("Reader");
    static readonly MethodInfo readObject = typeof(DeserializationContext).GetMethod("ReadObject");
    
    static readonly MethodInfo readByte = typeof(BinaryReader).GetMethod("ReadByte");
    static readonly MethodInfo readShort = typeof(BinaryReader).GetMethod("ReadInt16");
    static readonly MethodInfo readInt = typeof(BinaryReader).GetMethod("ReadInt32");
    static readonly MethodInfo readLong = typeof(BinaryReader).GetMethod("ReadInt64");
    static readonly MethodInfo readFloat = typeof(BinaryReader).GetMethod("ReadSingle");
    static readonly MethodInfo readDouble = typeof(BinaryReader).GetMethod("ReadDouble");
    
    Dictionary<Type, ObjectReader> readers = new Dictionary<Type, ObjectReader>();

    ObjectReader GetReader(Type type)
    {
      ObjectReader reader;
      if (!readers.TryGetValue(type, out reader)) {
        reader = CreateReader(type);
        readers.Add(type, reader);
      }
      return reader;
    }
    
    ObjectReader CreateReader(Type type)
    {
      if (type == typeof(string)) {
        // String contents are written in the object creation section,
        // not into the field value section; so there's nothing to read here.
        return delegate {};
      }
      bool isArray = type.IsArray;
      if (isArray) {
        if (type.GetArrayRank() != 1)
          throw new NotSupportedException();
        type = type.GetElementType();
        if (!type.IsValueType) {
          return delegate (DeserializationContext context, object arrayInstance) {
            object[] array = (object[])arrayInstance;
            for (int i = 0; i < array.Length; i++) {
              array[i] = context.ReadObject();
            }
          };
        } else if (type == typeof(byte)) {
          return delegate (DeserializationContext context, object arrayInstance) {
            byte[] array = (byte[])arrayInstance;
            BinaryReader binaryReader = context.Reader;
            int pos = 0;
            int bytesRead;
            do {
              bytesRead = binaryReader.Read(array, pos, array.Length - pos);
              pos += bytesRead;
            } while (bytesRead > 0);
            if (pos != array.Length)
              throw new EndOfStreamException();
          };
        }
      }
      var fields = GetSerializableFields(type);
      if (fields.Count == 0) {
        // The reader has nothing to do for this object.
        return delegate { };
      }
      
      DynamicMethod dynamicMethod = new DynamicMethod(
        (isArray ? "ReadArray_" : "Read_") + type.Name,
        MethodAttributes.Public | MethodAttributes.Static,
        CallingConventions.Standard,
        typeof(void), new [] { typeof(DeserializationContext), typeof(object) },
        type,
        true);
      ILGenerator il = dynamicMethod.GetILGenerator();
      
      var reader = il.DeclareLocal(typeof(BinaryReader));
      
      il.Emit(OpCodes.Ldarg_0);
      il.Emit(OpCodes.Ldfld, readerField);
      il.Emit(OpCodes.Stloc, reader); // reader = context.reader;
      
      if (isArray) {
        var instance = il.DeclareLocal(type.MakeArrayType());
        il.Emit(OpCodes.Ldarg_1);
        il.Emit(OpCodes.Castclass, type.MakeArrayType());
        il.Emit(OpCodes.Stloc, instance); // instance = (type[])arg_1;
        
        // for (int i = 0; i < instance.Length; i++) read &instance[i];
        
        var loopStart = il.DefineLabel();
        var loopHead = il.DefineLabel();
        var loopVariable = il.DeclareLocal(typeof(int));
        il.Emit(OpCodes.Ldc_I4_0);
        il.Emit(OpCodes.Stloc, loopVariable); // loopVariable = 0
        il.Emit(OpCodes.Br, loopHead); // goto loopHead;
        
        il.MarkLabel(loopStart);
        
        if (type.IsEnum || type.IsPrimitive) {
          if (type.IsEnum) {
            type = type.GetEnumUnderlyingType();
          }
          Debug.Assert(type.IsPrimitive);
          il.Emit(OpCodes.Ldloc, instance); // instance
          il.Emit(OpCodes.Ldloc, loopVariable); // instance, loopVariable
          ReadPrimitiveValue(il, reader, type); // instance, loopVariable, value
          switch (Type.GetTypeCode(type)) {
            case TypeCode.Boolean:
            case TypeCode.SByte:
            case TypeCode.Byte:
              il.Emit(OpCodes.Stelem_I1); // instance[loopVariable] = value;
              break;
            case TypeCode.Char:
            case TypeCode.Int16:
            case TypeCode.UInt16:
              il.Emit(OpCodes.Stelem_I2); // instance[loopVariable] = value;
              break;
            case TypeCode.Int32:
            case TypeCode.UInt32:
              il.Emit(OpCodes.Stelem_I4); // instance[loopVariable] = value;
              break;
            case TypeCode.Int64:
            case TypeCode.UInt64:
              il.Emit(OpCodes.Stelem_I8); // instance[loopVariable] = value;
              break;
            case TypeCode.Single:
              il.Emit(OpCodes.Stelem_R4); // instance[loopVariable] = value;
              break;
            case TypeCode.Double:
              il.Emit(OpCodes.Stelem_R8); // instance[loopVariable] = value;
              break;
            default:
              throw new NotSupportedException("Unknown primitive type " + type);
          }
        } else {
          il.Emit(OpCodes.Ldloc, instance); // instance
          il.Emit(OpCodes.Ldloc, loopVariable); // instance, loopVariable
          il.Emit(OpCodes.Ldelema, type); // instance[loopVariable]
          EmitReadValueType(il, reader, type);
        }
        
        il.Emit(OpCodes.Ldloc, loopVariable); // loopVariable
        il.Emit(OpCodes.Ldc_I4_1); // loopVariable, 1
        il.Emit(OpCodes.Add); // loopVariable+1
        il.Emit(OpCodes.Stloc, loopVariable); // loopVariable++;
        
        il.MarkLabel(loopHead);
        il.Emit(OpCodes.Ldloc, loopVariable); // loopVariable
        il.Emit(OpCodes.Ldloc, instance); // loopVariable, instance
        il.Emit(OpCodes.Ldlen); // loopVariable, instance.Length
        il.Emit(OpCodes.Conv_I4);
        il.Emit(OpCodes.Blt, loopStart); // if (loopVariable < instance.Length) goto loopStart;
      } else if (type.IsValueType) {
        // boxed value type
        il.Emit(OpCodes.Ldarg_1); // instance
        il.Emit(OpCodes.Unbox, type); // &(Type)instance
        if (type.IsEnum || type.IsPrimitive) {
          if (type.IsEnum) {
            type = type.GetEnumUnderlyingType();
          }
          Debug.Assert(type.IsPrimitive);
          ReadPrimitiveValue(il, reader, type); // &(Type)instance, value
          switch (Type.GetTypeCode(type)) {
            case TypeCode.Boolean:
            case TypeCode.SByte:
            case TypeCode.Byte:
              il.Emit(OpCodes.Stind_I1);
              break;
            case TypeCode.Char:
            case TypeCode.Int16:
            case TypeCode.UInt16:
              il.Emit(OpCodes.Stind_I2);
              break;
            case TypeCode.Int32:
            case TypeCode.UInt32:
              il.Emit(OpCodes.Stind_I4);
              break;
            case TypeCode.Int64:
            case TypeCode.UInt64:
              il.Emit(OpCodes.Stind_I8);
              break;
            case TypeCode.Single:
              il.Emit(OpCodes.Stind_R4);
              break;
            case TypeCode.Double:
              il.Emit(OpCodes.Stind_R8);
              break;
            default:
              throw new NotSupportedException("Unknown primitive type " + type);
          }
        } else {
          EmitReadValueType(il, reader, type);
        }
      } else {
        // reference type
        var instance = il.DeclareLocal(type);
        il.Emit(OpCodes.Ldarg_1);
        il.Emit(OpCodes.Castclass, type);
        il.Emit(OpCodes.Stloc, instance); // instance = (type)arg_1;
        
        foreach (FieldInfo field in fields) {
          EmitReadField(il, reader, instance, field); // read instance.Field
        }
      }
      il.Emit(OpCodes.Ret);
      return (ObjectReader)dynamicMethod.CreateDelegate(typeof(ObjectReader));
    }

    void EmitReadField(ILGenerator il, LocalBuilder reader, LocalBuilder instance, FieldInfo field)
    {
      Type fieldType = field.FieldType;
      if (fieldType.IsValueType) {
        if (fieldType.IsPrimitive || fieldType.IsEnum) {
          il.Emit(OpCodes.Ldloc, instance); // instance
          ReadPrimitiveValue(il, reader, fieldType); // instance, value
          il.Emit(OpCodes.Stfld, field); // instance.field = value;
        } else {
          il.Emit(OpCodes.Ldloc, instance); // instance
          il.Emit(OpCodes.Ldflda, field); // &instance.field
          EmitReadValueType(il, reader, fieldType);
        }
      } else {
        il.Emit(OpCodes.Ldloc, instance); // instance
        il.Emit(OpCodes.Ldarg_0); // instance, context
        il.Emit(OpCodes.Call, readObject); // instance, context.ReadObject()
        il.Emit(OpCodes.Castclass, fieldType);
        il.Emit(OpCodes.Stfld, field); // instance.field = (fieldType) context.ReadObject();
      }
    }

    /// <summary>
    /// Reads a primitive value of the specified type.
    /// Stack transition: ... => ..., value
    /// </summary>
    void ReadPrimitiveValue(ILGenerator il, LocalBuilder reader, Type fieldType)
    {
      if (fieldType.IsEnum) {
        fieldType = fieldType.GetEnumUnderlyingType();
        Debug.Assert(fieldType.IsPrimitive);
      }
      il.Emit(OpCodes.Ldloc, reader);
      switch (Type.GetTypeCode(fieldType)) {
        case TypeCode.Boolean:
        case TypeCode.SByte:
        case TypeCode.Byte:
          il.Emit(callVirt, readByte);
          break;
        case TypeCode.Char:
        case TypeCode.Int16:
        case TypeCode.UInt16:
          il.Emit(callVirt, readShort);
          break;
        case TypeCode.Int32:
        case TypeCode.UInt32:
          il.Emit(callVirt, readInt);
          break;
        case TypeCode.Int64:
        case TypeCode.UInt64:
          il.Emit(callVirt, readLong);
          break;
        case TypeCode.Single:
          il.Emit(callVirt, readFloat);
          break;
        case TypeCode.Double:
          il.Emit(callVirt, readDouble);
          break;
        default:
          throw new NotSupportedException("Unknown primitive type " + fieldType);
      }
    }

    /// <summary>
    /// Stack transition: ..., field-ref => ...
    /// </summary>
    void EmitReadValueType(ILGenerator il, LocalBuilder reader, Type valType)
    {
      Debug.Assert(valType.IsValueType);
      Debug.Assert(!(valType.IsEnum || valType.IsPrimitive));
      
      var fieldRef = il.DeclareLocal(valType.MakeByRefType());
      il.Emit(OpCodes.Stloc, fieldRef);
      
      foreach (FieldInfo field in GetSerializableFields(valType)) {
        EmitReadField(il, reader, fieldRef, field);
      }
    }
    #endregion
    
    #region Custom Deserialization
    struct CustomDeserialization
    {
      readonly object instance;
      readonly SerializationInfo serializationInfo;
      readonly CustomDeserializationAction action;
      
      public CustomDeserialization(object instance, SerializationInfo serializationInfo, CustomDeserializationAction action)
      {
        this.instance = instance;
        this.serializationInfo = serializationInfo;
        this.action = action;
      }
      
      public void Run(StreamingContext context)
      {
        action(instance, serializationInfo, context);
      }
    }
    
    delegate void CustomDeserializationAction(object instance, SerializationInfo info, StreamingContext context);
    
    Dictionary<Type, CustomDeserializationAction> customDeserializationActions = new Dictionary<Type, CustomDeserializationAction>();
    
    CustomDeserializationAction GetCustomDeserializationAction(Type type)
    {
      CustomDeserializationAction action;
      if (!customDeserializationActions.TryGetValue(type, out action)) {
        action = CreateCustomDeserializationAction(type);
        customDeserializationActions.Add(type, action);
      }
      return action;
    }
    
    static CustomDeserializationAction CreateCustomDeserializationAction(Type type)
    {
      ConstructorInfo ctor = type.GetConstructor(
        BindingFlags.DeclaredOnly | BindingFlags.ExactBinding | BindingFlags.Instance
        | BindingFlags.NonPublic | BindingFlags.Public,
        null,
        new Type [] { typeof(SerializationInfo), typeof(StreamingContext) },
        null);
      if (ctor == null)
        throw new SerializationException("Could not find deserialization constructor for " + type.FullName);
      
      DynamicMethod dynamicMethod = new DynamicMethod(
        "CallCtor_" + type.Name,
        MethodAttributes.Public | MethodAttributes.Static,
        CallingConventions.Standard,
        typeof(void), new [] { typeof(object), typeof(SerializationInfo), typeof(StreamingContext) },
        type,
        true);
      ILGenerator il = dynamicMethod.GetILGenerator();
      il.Emit(OpCodes.Ldarg_0);
      il.Emit(OpCodes.Ldarg_1);
      il.Emit(OpCodes.Ldarg_2);
      il.Emit(OpCodes.Call, ctor);
      il.Emit(OpCodes.Ret);
      return (CustomDeserializationAction)dynamicMethod.CreateDelegate(typeof(CustomDeserializationAction));
    }
    #endregion
    #endregion
    
    [Conditional("DEBUG_SERIALIZER")]
    static void Log(string format, params object[] args)
    {
      Debug.WriteLine(format, args);
    }
  }
  
  /// <summary>
  /// Specifies the version of the class.
  /// The <see cref="FastSerializer"/> will refuse to deserialize an instance that was stored by
  /// a different version of the class than the current one.
  /// </summary>
  [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum)]
  public class FastSerializerVersionAttribute : Attribute
  {
    readonly int versionNumber;
    
    public FastSerializerVersionAttribute(int versionNumber)
    {
      this.versionNumber = versionNumber;
    }
    
    public int VersionNumber {
      get {
        return versionNumber;
      }
    }
    
    internal static int GetVersionNumber(Type type)
    {
      var arr = type.GetCustomAttributes(typeof(FastSerializerVersionAttribute), false);
      if (arr.Length == 0)
        return 0;
      else
        return ((FastSerializerVersionAttribute)arr[0]).VersionNumber;
    }
  }
}