// ==========================================================================

// This software is subject to the provisions of the Zope Public License,

// Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.

// THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED

// WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

// WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS

// FOR A PARTICULAR PURPOSE.

// ==========================================================================

using System;

using System.Runtime.InteropServices;

using System.Collections;

using System.Reflection;

namespace Python.Runtime {

//========================================================================

// Common base class for all objects that are implemented in managed

// code. It defines the common fields that associate CLR and Python

// objects and common utilities to convert between those identities.

//========================================================================

internal abstract class ManagedType {

internal GCHandle gcHandle; // Native handle

internal IntPtr pyHandle; // PyObject *

internal IntPtr tpHandle; // PyType *

//====================================================================

// Given a Python object, return the associated managed object or null.

//====================================================================

internal static ManagedType GetManagedObject(IntPtr ob) {

if (ob != IntPtr.Zero) {

IntPtr tp = Runtime.PyObject_TYPE(ob);

if (tp == Runtime.PyTypeType || tp == Runtime.PyCLRMetaType) {

tp = ob;

}

int flags = (int)Marshal.ReadIntPtr(tp, TypeOffset.tp_flags);

if ((flags & TypeFlags.Managed) != 0) {

IntPtr op = (tp == ob) ?

Marshal.ReadIntPtr(tp, TypeOffset.magic()) :

Marshal.ReadIntPtr(ob, ObjectOffset.magic());

GCHandle gc = (GCHandle)op;

return (ManagedType)gc.Target;

}

// In certain situations, we need to recognize a wrapped

// exception class and be willing to unwrap the class :(

if (Runtime.wrap_exceptions) {

IntPtr e = Exceptions.UnwrapExceptionClass(ob);

if ((e != IntPtr.Zero) && (e != ob)) {

ManagedType m = GetManagedObject(e);

Runtime.Decref(e);

return m;

}

}

}

return null;

}

internal static ManagedType GetManagedObjectErr(IntPtr ob) {

ManagedType result = GetManagedObject(ob);

if (result == null) {

Exceptions.SetError(Exceptions.TypeError,

"invalid argument, expected CLR type"

);

}

return result;

}

internal static bool IsManagedType(IntPtr ob) {

if (ob != IntPtr.Zero) {

IntPtr tp = Runtime.PyObject_TYPE(ob);

if (tp == Runtime.PyTypeType || tp == Runtime.PyCLRMetaType) {

tp = ob;

}

int flags = (int)Marshal.ReadIntPtr(tp, TypeOffset.tp_flags);

if ((flags & TypeFlags.Managed) != 0) {

return true;

}

}

return false;

}

}

}