using System;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Security;
namespace Python.Runtime
{
///
/// The ClassManager is responsible for creating and managing instances
/// that implement the Python type objects that reflect managed classes.
/// Each managed type reflected to Python is represented by an instance
/// of a concrete subclass of ClassBase. Each instance is associated with
/// a generated Python type object, whose slots point to static methods
/// of the managed instance's class.
///
internal class ClassManager
{
private static Dictionary cache;
private static Type dtype;
private ClassManager()
{
}
static ClassManager()
{
cache = new Dictionary(128);
// 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(128);
}
///
/// Return the ClassBase-derived instance that implements a particular
/// reflected managed type, creating it if it doesn't yet exist.
///
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;
}
///
/// Create a new ClassBase-derived instance that implements a reflected
/// managed type. The new object will be associated with a generated
/// Python type object.
///
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;
// 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);
impl.tpHandle = tp;
// Finally, initialize the class __dict__ and return the object.
IntPtr dict = Marshal.ReadIntPtr(tp, TypeOffset.tp_dict);
IDictionaryEnumerator iter = info.members.GetEnumerator();
while (iter.MoveNext())
{
var item = (ManagedType)iter.Value;
var name = (string)iter.Key;
Runtime.PyDict_SetItemString(dict, name, item.pyHandle);
}
// If class has constructors, generate an __doc__ attribute.
IntPtr doc = IntPtr.Zero;
Type marker = typeof(DocStringAttribute);
var attrs = (Attribute[])type.GetCustomAttributes(marker, false);
if (attrs.Length == 0)
{
doc = IntPtr.Zero;
}
else
{
var attr = (DocStringAttribute)attrs[0];
string docStr = attr.DocString;
doc = Runtime.PyString_FromString(docStr);
Runtime.PyDict_SetItemString(dict, "__doc__", doc);
Runtime.XDecref(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.ctors.Length > 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_SetItemString(dict, "__overloads__", ctors.pyHandle);
Runtime.PyDict_SetItemString(dict, "Overloads", ctors.pyHandle);
}
// don't generate the docstring if one was already set from a DocStringAttribute.
if (!CLRModule._SuppressDocs && doc == IntPtr.Zero)
{
doc = co.GetDocString();
Runtime.PyDict_SetItemString(dict, "__doc__", doc);
Runtime.XDecref(doc);
}
}
}
}
private static ClassInfo GetClassInfo(Type type)
{
var ci = new ClassInfo(type);
var methods = new Hashtable();
ArrayList list;
MethodInfo meth;
ManagedType ob;
string name;
object item;
Type tp;
int i, n;
// 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.
BindingFlags flags = BindingFlags.Static |
BindingFlags.Instance |
BindingFlags.Public |
BindingFlags.NonPublic;
MemberInfo[] info = type.GetMembers(flags);
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;
}
}
// 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(flags);
for (n = 0; n < imembers.Length; n++)
{
m = imembers[n];
if (local[m.Name] == null)
{
items.Add(m);
}
}
}
}
for (i = 0; i < items.Count; i++)
{
var mi = (MemberInfo)items[i];
switch (mi.MemberType)
{
case MemberTypes.Method:
meth = (MethodInfo)mi;
if (!(meth.IsPublic || meth.IsFamily ||
meth.IsFamilyOrAssembly))
{
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;
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.
continue;
}
if (mm == null)
{
continue;
}
if (!(mm.IsPublic || mm.IsFamily || mm.IsFamilyOrAssembly))
{
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 (!(fi.IsPublic || fi.IsFamily || fi.IsFamilyOrAssembly))
{
continue;
}
ob = new FieldObject(fi);
ci.members[mi.Name] = ob;
continue;
case MemberTypes.Event:
var ei = (EventInfo)mi;
MethodInfo me = ei.GetAddMethod(true);
if (!(me.IsPublic || me.IsFamily || me.IsFamilyOrAssembly))
{
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);
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;
}
return ci;
}
}
internal class ClassInfo
{
public Indexer indexer;
public Hashtable members;
internal ClassInfo(Type t)
{
members = new Hashtable();
indexer = null;
}
}
}