// Copyright Christophe Bertrand.
// This class is very special: it tries to build & contain a class that will be constructed with the values of its own (private or internal) fields.
// That is risky, but it can help a lot with classes with no no-param (default) constructors.
using System;
using System.Collections.Generic;
using System.Reflection;
using System.Linq;
#if DEBUG
using System.Diagnostics;
#endif
namespace UniversalSerializerLib2
{
/// <summary>
/// For classes not serializable by the other ITypeContainers.
/// It tries to call the class parameter constructors with the fields as parameters.
/// </summary>
internal static class ParametricConstructorsManager
{
/// <summary>
/// A list of valid types.
/// IntelligentConstructorContainer can contain these types safely.
/// String format is 'Type'.AssemblyQualifiedName .
/// </summary>
internal static readonly string[] ValidatedTypes = new string[] { };
/// <summary>
/// A list of invalid types.
/// IntelligentConstructorContainer can not contain these types safely.
/// String format is 'Type'.AssemblyQualifiedName .
/// </summary>
internal static readonly string[] InvalidatedTypes = new string[] { };
static readonly Type[] _InvalidatedTypes;
static ParametricConstructorsManager()
{
_InvalidatedTypes = new Type[InvalidatedTypes.Length];
for (int i = 0; i < InvalidatedTypes.Length; i++)
_InvalidatedTypes[i] = Type.GetType(InvalidatedTypes[i]);
}
internal static object[] GetParameterFields(object o, ParametricConstructorDescriptor d)
{
var cons = d.constructorInfo;
var fields = d.ParameterFields;
var parameters = cons.GetParameters();
object[] ret = new object[parameters.Length];
for (int i = 0; i < parameters.Length; i++)
{
var field = fields[i];
ret[i] = field.GetValue(o);
}
return ret;
}
/// <summary>
/// Get a parametric constructor for this type.
/// If none applies, returns null.
/// </summary>
static internal ParametricConstructorDescriptor GetTypeParamDescriptorFromCache(Type type)
{
Contains<ParametricConstructorDescriptor> d;
if (paramDescriptorCache.TryGetValue(type, out d))
return d.Value; // can return null.
{
// We need to analyse the class type:
d = AnalyseClassType(type);
}
paramDescriptorCache.Add(type, d);
return d.Value;
}
static Dictionary<Type, Contains<ParametricConstructorDescriptor>> paramDescriptorCache =
new Dictionary<Type, Contains<ParametricConstructorDescriptor>>();
// ---------------------------
// ---------------------------
// ---------------------------
// ---------------------------
#region analysis logic
/// <summary>
/// Returns Value=null if this type does not apply.
/// </summary>
static Contains<ParametricConstructorDescriptor> AnalyseClassType(Type t)//, out ConstructorInfo cons)
{
if (!t.IsEnum && !_InvalidatedTypes.Contains(t))
{
bool AvoidDefaultConstructor = true; // Never uses a default constructor.
BindingFlags[] bflags = new BindingFlags[2] { BindingFlags.Public | BindingFlags.Instance, BindingFlags.NonPublic | BindingFlags.Instance };
// 2 passes: one with public constructors, and one with private constructors.
for (int iflags = 0; iflags < 2; iflags++)
{
var cs = t.GetConstructors(bflags[iflags]).Where((ci) => AvoidDefaultConstructor ? ci.GetParameters().Length != 0 : true);
ConstructorInfo cons;
var mf = AnalyseConstructors(cs, out cons);
if (mf != null)
return ParametricConstructorDescriptor.CreateDirectTypeParamDescriptor(cons, mf.ToArray());
}
}
return new Contains<ParametricConstructorDescriptor>(null); // This type does not apply.
}
// ------------------------------
static List<FieldInfo> AnalyseConstructors(
IEnumerable<ConstructorInfo> constructors,
out ConstructorInfo FoundConstructor)
{
// Sort the list from much parameters to none:
var sorted = new List<ConstructorInfo>(constructors);
if (sorted.Count > 1)
sorted.Sort((a, b) => b.GetParameters().Length - a.GetParameters().Length);
foreach (var cons in sorted)
{
var mf = AnalyseConstructor(cons);
if (mf != null)
{
FoundConstructor = cons;
return mf;
}
}
FoundConstructor = null;
return null;
}
/// <summary>
/// Try to find a field for each parameter of the constructor.
/// </summary>
/// <param name="constructor"></param>
static List<FieldInfo> AnalyseConstructor(ConstructorInfo constructor)
{
var pars = constructor.GetParameters();
var availableFields = new List<FieldInfo>(constructor.DeclaringType.GetFields(
BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance));
List<FieldInfo> MatchingFields = new List<FieldInfo>(availableFields.Count);
foreach (var par in pars)
{
FieldInfo field = FindMatchingField(par, availableFields);
if (field == null)
return null; // If only one param is not found, we abandon.
MatchingFields.Add(field);
availableFields.Remove(field); // no more available.
}
return MatchingFields;
}
static FieldInfo FindMatchingField(ParameterInfo par, List<FieldInfo> availableFields)
{
string paramName = par.Name;
Type paramType = par.ParameterType;
foreach (var field in availableFields)
{
if (paramType.Is(field.FieldType))
{
if (paramName == field.Name) // parameter and field have the same name.
return field;
if (field.IsPrivate)
{
string privname = "_" + paramName; // Ex: "MyField" -> "_MyField".
if (privname == field.Name)
return field;
privname = "_" + paramName.ToLower()[0] + paramName.Substring(1); // Ex: "MyField" -> "_myField".
if (privname == field.Name)
return field;
}
string privname3 = paramName.ToUpper()[0] + paramName.Substring(1); // Ex: "myField" -> "MyField".
if (privname3 == field.Name)
return field;
}
}
return null;
}
#endregion analysis logic
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// ###################################################################################
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internal class Contains<T> where T : class
{
internal T Value;
internal Contains(T value)
{
this.Value = value;
}
}
}
// ###################################################################################
// ###################################################################################
/// <summary>
/// One instance per Type.
/// That will NOT be serialized.
/// </summary>
internal class ParametricConstructorDescriptor
{
internal readonly FieldInfo[] ParameterFields;
//internal readonly int[] FieldIndexes;
internal readonly ConstructorInfo constructorInfo;
// ------------------------------
/// <summary>
/// Warning: You have to check GetTypeParamDescriptor first.
/// </summary>
ParametricConstructorDescriptor(
FieldInfo[] ParameterFields,
//int[] FieldIndexes,
ConstructorInfo constructorInfo
)
{
this.constructorInfo = constructorInfo;
this.ParameterFields = ParameterFields;
}
// ------------------------------
/// <summary>
/// Warning: You have to check GetTypeParamDescriptor first.
/// </summary>
static internal ParametricConstructorsManager.Contains<ParametricConstructorDescriptor> CreateDirectTypeParamDescriptor(
ConstructorInfo constructorInfo, FieldInfo[] Fields)
{
return new ParametricConstructorsManager.Contains<ParametricConstructorDescriptor>(
new ParametricConstructorDescriptor(Fields, constructorInfo));
}
// ------------------------------
/// <summary>
/// For each parameter, find its index in the SelectedFields, in the order of this.ParameterFields.
/// </summary>
/// <param name="SelectedFields">Concatenated selected public and private fields of a particular TypeManager.</param>
/// <returns>int[this.ParameterFields.Length]</returns>
internal int[] GetParameterIndexes(FieldInfo[] SelectedFields)
{
int[] indexes = new int[this.ParameterFields.Length];
for (int i = 0; i < this.ParameterFields.Length; i++)
{
var fi = ParameterFields[i];
indexes[i] = Array.IndexOf(SelectedFields, fi);
#if DEBUG
if (indexes[i] < 0)
throw new Exception();
#endif
}
return indexes;
}
// ------------------------------
// ------------------------------
}
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// ###################################################################################
// ###################################################################################
}
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