using System;
using System.Collections.Generic;
using System.Reflection;
namespace Python.Runtime
{
///
/// Implements a Python binding type for CLR methods. These work much like
/// standard Python method bindings, but the same type is used to bind
/// both static and instance methods.
///
internal class MethodBinding : ExtensionType
{
internal MethodInfo info;
internal MethodObject m;
internal IntPtr target;
internal IntPtr targetType;
public MethodBinding(MethodObject m, IntPtr target, IntPtr targetType)
{
Runtime.XIncref(target);
this.target = target;
Runtime.XIncref(targetType);
if (targetType == IntPtr.Zero)
{
targetType = Runtime.PyObject_Type(target);
}
this.targetType = targetType;
this.info = null;
this.m = m;
}
public MethodBinding(MethodObject m, IntPtr target) : this(m, target, IntPtr.Zero)
{
}
///
/// Implement binding of generic methods using the subscript syntax [].
///
public static IntPtr mp_subscript(IntPtr tp, IntPtr idx)
{
var self = (MethodBinding)GetManagedObject(tp);
Type[] types = Runtime.PythonArgsToTypeArray(idx);
if (types == null)
{
return Exceptions.RaiseTypeError("type(s) expected");
}
MethodInfo mi = MethodBinder.MatchParameters(self.m.info, types);
if (mi == null)
{
return Exceptions.RaiseTypeError("No match found for given type params");
}
var mb = new MethodBinding(self.m, self.target) { info = mi };
return mb.pyHandle;
}
///
/// MethodBinding __getattribute__ implementation.
///
public static IntPtr tp_getattro(IntPtr ob, IntPtr key)
{
var self = (MethodBinding)GetManagedObject(ob);
if (!Runtime.PyString_Check(key))
{
Exceptions.SetError(Exceptions.TypeError, "string expected");
return IntPtr.Zero;
}
string name = Runtime.GetManagedString(key);
switch (name)
{
case "__doc__":
IntPtr doc = self.m.GetDocString();
Runtime.XIncref(doc);
return doc;
// FIXME: deprecate __overloads__ soon...
case "__overloads__":
case "Overloads":
var om = new OverloadMapper(self.m, self.target);
return om.pyHandle;
default:
return Runtime.PyObject_GenericGetAttr(ob, key);
}
}
///
/// MethodBinding __call__ implementation.
///
public static IntPtr tp_call(IntPtr ob, IntPtr args, IntPtr kw)
{
var self = (MethodBinding)GetManagedObject(ob);
// This works around a situation where the wrong generic method is picked,
// for example this method in the tests: string Overloaded(int arg1, int arg2, string arg3)
if (self.info != null)
{
if (self.info.IsGenericMethod)
{
var len = Runtime.PyTuple_Size(args); //FIXME: Never used
Type[] sigTp = Runtime.PythonArgsToTypeArray(args, true);
if (sigTp != null)
{
Type[] genericTp = self.info.GetGenericArguments();
MethodInfo betterMatch = MethodBinder.MatchSignatureAndParameters(self.m.info, genericTp, sigTp);
if (betterMatch != null)
{
self.info = betterMatch;
}
}
}
}
// This supports calling a method 'unbound', passing the instance
// as the first argument. Note that this is not supported if any
// of the overloads are static since we can't know if the intent
// was to call the static method or the unbound instance method.
var disposeList = new List();
try
{
IntPtr target = self.target;
if (target == IntPtr.Zero && !self.m.IsStatic())
{
var len = Runtime.PyTuple_Size(args);
if (len < 1)
{
Exceptions.SetError(Exceptions.TypeError, "not enough arguments");
return IntPtr.Zero;
}
target = Runtime.PyTuple_GetItem(args, 0);
Runtime.XIncref(target);
disposeList.Add(target);
args = Runtime.PyTuple_GetSlice(args, 1, len);
disposeList.Add(args);
}
// if the class is a IPythonDerivedClass and target is not the same as self.targetType
// (eg if calling the base class method) then call the original base class method instead
// of the target method.
IntPtr superType = IntPtr.Zero;
if (Runtime.PyObject_TYPE(target) != self.targetType)
{
var inst = GetManagedObject(target) as CLRObject;
if (inst?.inst is IPythonDerivedType)
{
var baseType = GetManagedObject(self.targetType) as ClassBase;
if (baseType != null)
{
string baseMethodName = "_" + baseType.type.Name + "__" + self.m.name;
IntPtr baseMethod = Runtime.PyObject_GetAttrString(target, baseMethodName);
if (baseMethod != IntPtr.Zero)
{
var baseSelf = GetManagedObject(baseMethod) as MethodBinding;
if (baseSelf != null)
{
self = baseSelf;
}
Runtime.XDecref(baseMethod);
}
else
{
Runtime.PyErr_Clear();
}
}
}
}
return self.m.Invoke(target, args, kw, self.info);
}
finally
{
foreach (IntPtr ptr in disposeList)
{
Runtime.XDecref(ptr);
}
}
}
///
/// MethodBinding __hash__ implementation.
///
public static IntPtr tp_hash(IntPtr ob)
{
var self = (MethodBinding)GetManagedObject(ob);
long x = 0;
long y = 0;
if (self.target != IntPtr.Zero)
{
x = Runtime.PyObject_Hash(self.target).ToInt64();
if (x == -1)
{
return new IntPtr(-1);
}
}
y = Runtime.PyObject_Hash(self.m.pyHandle).ToInt64();
if (y == -1)
{
return new IntPtr(-1);
}
x ^= y;
if (x == -1)
{
x = -1;
}
return new IntPtr(x);
}
///
/// MethodBinding __repr__ implementation.
///
public static IntPtr tp_repr(IntPtr ob)
{
var self = (MethodBinding)GetManagedObject(ob);
string type = self.target == IntPtr.Zero ? "unbound" : "bound";
string name = self.m.name;
return Runtime.PyString_FromString($"<{type} method '{name}'>");
}
///
/// MethodBinding dealloc implementation.
///
public new static void tp_dealloc(IntPtr ob)
{
var self = (MethodBinding)GetManagedObject(ob);
Runtime.XDecref(self.target);
Runtime.XDecref(self.targetType);
FinalizeObject(self);
}
}
}