void Initialize()
{
if (_memberHandlers is null)
{
InitializeCore();
}
void InitializeCore()
{
var pgType = (PostgresCompositeType)PostgresType;
_memberHandlers = CreateMemberHandlers(pgType, _typeMapper, _nameTranslator);
_constructorHandler = CreateConstructorHandler(pgType, _typeMapper, _nameTranslator);
_constructor = _constructorHandler is null
? Expression
.Lambda <Func <T> >(Expression.New(typeof(T)))
.Compile()
: null;
}
}
static CompositeConstructorHandler <T>?CreateConstructorHandler(PostgresCompositeType pgType, ConnectorTypeMapper typeMapper, INpgsqlNameTranslator nameTranslator)
{
var pgFields = pgType.Fields;
var clrType = typeof(T);
ConstructorInfo?clrDefaultConstructor = null;
foreach (var clrConstructor in clrType.GetConstructors())
{
var clrParameters = clrConstructor.GetParameters();
if (clrParameters.Length != pgFields.Count)
{
if (clrParameters.Length == 0)
{
clrDefaultConstructor = clrConstructor;
}
continue;
}
var clrParameterHandlerCount = 0;
var clrParametersMapped = new ParameterInfo[pgFields.Count];
foreach (var clrParameter in clrParameters)
{
var attr = clrParameter.GetCustomAttribute <PgNameAttribute>();
var name = attr?.PgName ?? (clrParameter.Name is string clrName ? nameTranslator.TranslateMemberName(clrName) : null);
if (name is null)
{
break;
}
for (var pgFieldIndex = pgFields.Count - 1; pgFieldIndex >= 0; --pgFieldIndex)
{
var pgField = pgFields[pgFieldIndex];
if (pgField.Name != name)
{
continue;
}
if (clrParametersMapped[pgFieldIndex] != null)
{
throw new AmbiguousMatchException($"Multiple constructor parameters are mapped to the '{pgField.Name}' field.");
}
clrParameterHandlerCount++;
clrParametersMapped[pgFieldIndex] = clrParameter;
break;
}
}
if (clrParameterHandlerCount < pgFields.Count)
{
continue;
}
var clrParameterHandlers = new CompositeParameterHandler[pgFields.Count];
for (var pgFieldIndex = 0; pgFieldIndex < pgFields.Count; ++pgFieldIndex)
{
var pgField = pgFields[pgFieldIndex];
if (!typeMapper.TryResolveByOID(pgField.Type.OID, out var handler))
{
throw new NpgsqlException($"PostgreSQL composite type {pgType.DisplayName} has field {pgField.Type.DisplayName} with an unknown type (OID = {pgField.Type.OID}).");
}
var clrParameter = clrParametersMapped[pgFieldIndex];
var clrParameterHandlerType = typeof(CompositeParameterHandler <>)
.MakeGenericType(clrParameter.ParameterType);
clrParameterHandlers[pgFieldIndex] = (CompositeParameterHandler)Activator.CreateInstance(
clrParameterHandlerType,
BindingFlags.Instance | BindingFlags.Public,
binder: null,
args: new object[] { handler, clrParameter },
culture: null) !;
}
return(CompositeConstructorHandler <T> .Create(pgType, clrConstructor, clrParameterHandlers));
}
if (clrDefaultConstructor is null && !clrType.IsValueType)
{
throw new InvalidOperationException($"No parameterless constructor defined for type '{clrType}'.");
}
return(null);
}
