{

// Binding flags to determine which members to expose in Python.

// This is complicated because inheritance in Python is name

// based. We can't just find DeclaredOnly members, because we

// could have a base class A that defines two overloads of a

// method and a class B that defines two more. The name-based

// descriptor Python will find needs to know about inherited

// overloads as well as those declared on the sub class.

internal static readonly BindingFlags BindingFlags = BindingFlags.Static |

BindingFlags.Instance |

BindingFlags.Public |

BindingFlags.NonPublic;

private static Dictionary<MaybeType, ClassBase> cache;

private static readonly Type dtype;

private ClassManager()

{

}

static ClassManager()

{

// SEE: https://msdn.microsoft.com/en-us/library/96b1ayy4(v=vs.100).aspx

// ""All delegates inherit from MulticastDelegate, which inherits from Delegate.""

// Was Delegate, which caused a null MethodInfo returned from GetMethode("Invoke")

// and crashed on Linux under Mono.

dtype = typeof(MulticastDelegate);

}

public static void Reset()

{

cache = new Dictionary<MaybeType, ClassBase>(128);

}

internal static void DisposePythonWrappersForClrTypes()

{

var visited = new HashSet<IntPtr>();

var visitedHandle = GCHandle.Alloc(visited);

var visitedPtr = (IntPtr)visitedHandle;

try

{

foreach (var cls in cache.Values)

{

// XXX: Force to release instance's managed resources

// but not dealloc itself immediately.

// These managed resources should preserve vacant shells

// since others may still referencing it.

cls.CallTypeTraverse(TraverseTypeClear, visitedPtr);

cls.CallTypeClear();

cls.DecrRefCount();

}

}

finally

{

visitedHandle.Free();

}

cache.Clear();

}

private static int TraverseTypeClear(IntPtr ob, IntPtr arg)

{

var visited = (HashSet<IntPtr>)GCHandle.FromIntPtr(arg).Target;

if (!visited.Add(ob))

{

return 0;

}

var clrObj = ManagedType.GetManagedObject(ob);

if (clrObj != null)

{

clrObj.CallTypeTraverse(TraverseTypeClear, arg);

clrObj.CallTypeClear();

}

return 0;

}

internal static void SaveRuntimeData(RuntimeDataStorage storage)

{

var contexts = storage.AddValue("contexts",

new Dictionary<IntPtr, InterDomainContext>());

storage.AddValue("cache", cache);

foreach (var cls in cache)

{

if (!cls.Key.Valid)

{

// Don't serialize an invalid class

continue;

}

// This incref is for cache to hold the cls,

// thus no need for decreasing it at RestoreRuntimeData.

Runtime.XIncref(cls.Value.pyHandle);

var context = contexts[cls.Value.pyHandle] = new InterDomainContext();

cls.Value.Save(context);

// Remove all members added in InitBaseClass.

// this is done so that if domain reloads and a member of a

// reflected dotnet class is removed, it is removed from the

// Python object's dictionary tool; thus raising an AttributeError

// instead of a TypeError.

// Classes are re-initialized on in RestoreRuntimeData.

var dict = new BorrowedReference(Marshal.ReadIntPtr(cls.Value.tpHandle, TypeOffset.tp_dict));

foreach (var member in cls.Value.dotNetMembers)

{

// No need to decref the member, the ClassBase instance does

// not own the reference.

if ((Runtime.PyDict_DelItemString(dict, member) == -1) &&

(Exceptions.ExceptionMatches(Exceptions.KeyError)))

{

// Trying to remove a key that's not in the dictionary

// raises an error. We don't care about it.

Runtime.PyErr_Clear();

}

else if (Exceptions.ErrorOccurred())

{

throw new PythonException();

}

}

// We modified the Type object, notify it we did.

Runtime.PyType_Modified(cls.Value.tpHandle);

}

}

internal static Dictionary<ManagedType, InterDomainContext> RestoreRuntimeData(RuntimeDataStorage storage)

{

cache = storage.GetValue<Dictionary<MaybeType, ClassBase>>("cache");

var invalidClasses = new List<KeyValuePair<MaybeType, ClassBase>>();

var contexts = storage.GetValue <Dictionary<IntPtr, InterDomainContext>>("contexts");

var loadedObjs = new Dictionary<ManagedType, InterDomainContext>();

foreach (var pair in cache)

{

if (!pair.Key.Valid)

{

invalidClasses.Add(pair);

continue;

}

// re-init the class

InitClassBase(pair.Key.Value, pair.Value);

// We modified the Type object, notify it we did.

Runtime.PyType_Modified(pair.Value.tpHandle);

var context = contexts[pair.Value.pyHandle];

pair.Value.Load(context);

loadedObjs.Add(pair.Value, context);

}

foreach (var pair in invalidClasses)

{

cache.Remove(pair.Key);

Runtime.XDecref(pair.Value.pyHandle);

}

return loadedObjs;

}

/// <summary>

/// Return the ClassBase-derived instance that implements a particular

/// reflected managed type, creating it if it doesn't yet exist.

/// </summary>

/// <returns>A Borrowed reference to the ClassBase object</returns>

internal static ClassBase GetClass(Type type)

{

ClassBase cb = null;

cache.TryGetValue(type, out cb);

if (cb != null)

{

return cb;

}

cb = CreateClass(type);

cache.Add(type, cb);

// Initialize the object later, as this might call this GetClass method

// recursively (for example when a nested class inherits its declaring class...)

InitClassBase(type, cb);

return cb;

}

/// <summary>

/// Create a new ClassBase-derived instance that implements a reflected

/// managed type. The new object will be associated with a generated

/// Python type object.

/// </summary>

private static ClassBase CreateClass(Type type)

{

// Next, select the appropriate managed implementation class.

// Different kinds of types, such as array types or interface

// types, want to vary certain implementation details to make

// sure that the type semantics are consistent in Python.

ClassBase impl;

// Check to see if the given type extends System.Exception. This

// lets us check once (vs. on every lookup) in case we need to

// wrap Exception-derived types in old-style classes

if (type.ContainsGenericParameters)

{

impl = new GenericType(type);

}

else if (type.IsSubclassOf(dtype))

{

impl = new DelegateObject(type);

}

else if (type.IsArray)

{

impl = new ArrayObject(type);

}

else if (type.IsInterface)

{

impl = new InterfaceObject(type);

}

else if (type == typeof(Exception) ||

type.IsSubclassOf(typeof(Exception)))

{

impl = new ExceptionClassObject(type);

}

else if (null != type.GetField("__pyobj__"))

{

impl = new ClassDerivedObject(type);

}

else

{

impl = new ClassObject(type);

}

return impl;

}

private static void InitClassBase(Type type, ClassBase impl)

{

// First, we introspect the managed type and build some class

// information, including generating the member descriptors

// that we'll be putting in the Python class __dict__.

ClassInfo info = GetClassInfo(type);

impl.indexer = info.indexer;

impl.richcompare = new Dictionary<int, MethodObject>();

// Now we allocate the Python type object to reflect the given

// managed type, filling the Python type slots with thunks that

// point to the managed methods providing the implementation.

IntPtr tp = TypeManager.GetTypeHandle(impl, type);

// Finally, initialize the class __dict__ and return the object.

var dict = new BorrowedReference(Marshal.ReadIntPtr(tp, TypeOffset.tp_dict));

if (impl.dotNetMembers == null)

{

impl.dotNetMembers = new List<string>();

}

IDictionaryEnumerator iter = info.members.GetEnumerator();

while (iter.MoveNext())

{

var item = (ManagedType)iter.Value;

var name = (string)iter.Key;

impl.dotNetMembers.Add(name);

Runtime.PyDict_SetItemString(dict, name, item.ObjectReference);

// Decref the item now that it's been used.

item.DecrRefCount();

if (ClassBase.CilToPyOpMap.TryGetValue(name, out var pyOp)) {

impl.richcompare.Add(pyOp, (MethodObject)item);

}

}

// If class has constructors, generate an __doc__ attribute.

NewReference doc = default;

Type marker = typeof(DocStringAttribute);

var attrs = (Attribute[])type.GetCustomAttributes(marker, false);

if (attrs.Length != 0)

{

var attr = (DocStringAttribute)attrs[0];

string docStr = attr.DocString;

doc = NewReference.DangerousFromPointer(Runtime.PyString_FromString(docStr));

Runtime.PyDict_SetItem(dict, PyIdentifier.__doc__, doc);

}

var co = impl as ClassObject;

// If this is a ClassObject AND it has constructors, generate a __doc__ attribute.

// required that the ClassObject.ctors be changed to internal

if (co != null)

{

if (co.NumCtors > 0)

{

// Implement Overloads on the class object

if (!CLRModule._SuppressOverloads)

{

var ctors = new ConstructorBinding(type, tp, co.binder);

// ExtensionType types are untracked, so don't Incref() them.

// TODO: deprecate __overloads__ soon...

Runtime.PyDict_SetItem(dict, PyIdentifier.__overloads__, ctors.ObjectReference);

Runtime.PyDict_SetItem(dict, PyIdentifier.Overloads, ctors.ObjectReference);

ctors.DecrRefCount();

}

// don't generate the docstring if one was already set from a DocStringAttribute.

if (!CLRModule._SuppressDocs && doc.IsNull())

{

doc = co.GetDocString();

Runtime.PyDict_SetItem(dict, PyIdentifier.__doc__, doc);

}

}

}

doc.Dispose();

// The type has been modified after PyType_Ready has been called

// Refresh the type

Runtime.PyType_Modified(tp);

}

internal static bool ShouldBindMethod(MethodBase mb)

{

return (mb.IsPublic || mb.IsFamily || mb.IsFamilyOrAssembly);

}

internal static bool ShouldBindField(FieldInfo fi)

{

return (fi.IsPublic || fi.IsFamily || fi.IsFamilyOrAssembly);

}

internal static bool ShouldBindProperty(PropertyInfo pi)

{

MethodInfo mm = null;

try

{

mm = pi.GetGetMethod(true);

if (mm == null)

{

mm = pi.GetSetMethod(true);

}

}

catch (SecurityException)

{

// GetGetMethod may try to get a method protected by

// StrongNameIdentityPermission - effectively private.

return false;

}

if (mm == null)

{

return false;

}

return ShouldBindMethod(mm);

}

internal static bool ShouldBindEvent(EventInfo ei)

{

return ShouldBindMethod(ei.GetAddMethod(true));

}

private static ClassInfo GetClassInfo(Type type)

{

var ci = new ClassInfo();

var methods = new Hashtable();

ArrayList list;

MethodInfo meth;

ManagedType ob;

string name;

object item;

Type tp;

int i, n;

MemberInfo[] info = type.GetMembers(BindingFlags);

var local = new Hashtable();

var items = new ArrayList();

MemberInfo m;

// Loop through once to find out which names are declared

for (i = 0; i < info.Length; i++)

{

m = info[i];

if (m.DeclaringType == type)

{

local[m.Name] = 1;

}

}

// only [Flags] enums support bitwise operations

if (type.IsEnum && type.IsFlagsEnum())

{

var opsImpl = typeof(EnumOps<>).MakeGenericType(type);

foreach (var op in opsImpl.GetMethods(OpsHelper.BindingFlags))

{

local[op.Name] = 1;

}

info = info.Concat(opsImpl.GetMethods(OpsHelper.BindingFlags)).ToArray();

}

// Now again to filter w/o losing overloaded member info

for (i = 0; i < info.Length; i++)

{

m = info[i];

if (local[m.Name] != null)

{

items.Add(m);

}

}

if (type.IsInterface)

{

// Interface inheritance seems to be a different animal:

// more contractual, less structural. Thus, a Type that

// represents an interface that inherits from another

// interface does not return the inherited interface's

// methods in GetMembers. For example ICollection inherits

// from IEnumerable, but ICollection's GetMemebers does not

// return GetEnumerator.

//

// Not sure if this is the correct way to fix this, but it

// seems to work. Thanks to Bruce Dodson for the fix.

Type[] inheritedInterfaces = type.GetInterfaces();

for (i = 0; i < inheritedInterfaces.Length; ++i)

{

Type inheritedType = inheritedInterfaces[i];

MemberInfo[] imembers = inheritedType.GetMembers(BindingFlags);

for (n = 0; n < imembers.Length; n++)

{

m = imembers[n];

if (local[m.Name] == null)

{

items.Add(m);

}

}

}

// All interface implementations inherit from Object,

// but GetMembers don't return them either.

var objFlags = BindingFlags.Public | BindingFlags.Instance;

foreach (var mi in typeof(object).GetMembers(objFlags))

{

if (local[mi.Name] == null)

{

items.Add(mi);

}

}

}

for (i = 0; i < items.Count; i++)

{

var mi = (MemberInfo)items[i];

switch (mi.MemberType)

{

case MemberTypes.Method:

meth = (MethodInfo)mi;

if (!ShouldBindMethod(meth))

{

continue;

}

name = meth.Name;

item = methods[name];

if (item == null)

{

item = methods[name] = new ArrayList();

}

list = (ArrayList)item;

list.Add(meth);

continue;

case MemberTypes.Property:

var pi = (PropertyInfo)mi;

if(!ShouldBindProperty(pi))

{

continue;

}

// Check for indexer

ParameterInfo[] args = pi.GetIndexParameters();

if (args.GetLength(0) > 0)

{

Indexer idx = ci.indexer;

if (idx == null)

{

ci.indexer = new Indexer();

idx = ci.indexer;

}

idx.AddProperty(pi);

continue;

}

ob = new PropertyObject(pi);

ci.members[pi.Name] = ob;

continue;

case MemberTypes.Field:

var fi = (FieldInfo)mi;

if (!ShouldBindField(fi))

{

continue;

}

ob = new FieldObject(fi);

ci.members[mi.Name] = ob;

continue;

case MemberTypes.Event:

var ei = (EventInfo)mi;

if (!ShouldBindEvent(ei))

{

continue;

}

ob = new EventObject(ei);

ci.members[ei.Name] = ob;

continue;

case MemberTypes.NestedType:

tp = (Type)mi;

if (!(tp.IsNestedPublic || tp.IsNestedFamily ||

tp.IsNestedFamORAssem))

{

continue;

}

// Note the given instance might be uninitialized

ob = GetClass(tp);

// GetClass returns a Borrowed ref. ci.members owns the reference.

ob.IncrRefCount();

ci.members[mi.Name] = ob;

continue;

}

}

IDictionaryEnumerator iter = methods.GetEnumerator();

while (iter.MoveNext())

{

name = (string)iter.Key;

list = (ArrayList)iter.Value;

var mlist = (MethodInfo[])list.ToArray(typeof(MethodInfo));

ob = new MethodObject(type, name, mlist);

ci.members[name] = ob;

if (mlist.Any(OperatorMethod.IsOperatorMethod))

{

string pyName = OperatorMethod.GetPyMethodName(name);

string pyNameReverse = OperatorMethod.ReversePyMethodName(pyName);

OperatorMethod.FilterMethods(mlist, out var forwardMethods, out var reverseMethods);

// Only methods where the left operand is the declaring type.

if (forwardMethods.Length > 0)

ci.members[pyName] = new MethodObject(type, name, forwardMethods);

// Only methods where only the right operand is the declaring type.

if (reverseMethods.Length > 0)

ci.members[pyNameReverse] = new MethodObject(type, name, reverseMethods);

}

}

if (ci.indexer == null && type.IsClass)

{

// Indexer may be inherited.

var parent = type.BaseType;

while (parent != null && ci.indexer == null)

{

foreach (var prop in parent.GetProperties()) {

var args = prop.GetIndexParameters();

if (args.GetLength(0) > 0)

{

ci.indexer = new Indexer();

ci.indexer.AddProperty(prop);

break;

}

}

parent = parent.BaseType;

}

}

return ci;

}

/// <summary>

/// This class owns references to PyObjects in the `members` member.

/// The caller has responsibility to DECREF them.

/// </summary>

private class ClassInfo

{

public Indexer indexer;

public Hashtable members;

internal ClassInfo()

{

members = new Hashtable();

indexer = null;

}

}