Repository navigation
Expand file tree
/
Copy pathconstructorbinder.cs
More file actions
96 lines (85 loc) · 4.56 KB
/
Copy pathconstructorbinder.cs
File metadata and controls
96 lines (85 loc) · 4.56 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
// ==========================================================================
// 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.Reflection;
namespace Python.Runtime {
//========================================================================
// A ConstructorBinder encapsulates information about one or more managed
// constructors, and is responsible for selecting the right constructor
// given a set of Python arguments. This is slightly different than the
// standard MethodBinder because of a difference in invoking constructors
// using reflection (which is seems to be a CLR bug).
//========================================================================
internal class ConstructorBinder : MethodBinder {
internal ConstructorBinder () : base() {}
//====================================================================
// Constructors get invoked when an instance of a wrapped managed
// class or a subclass of a managed class is created. This differs
// from the MethodBinder implementation in that we return the raw
// result of the constructor rather than wrapping it as a Python
// object - the reason is that only the caller knows the correct
// Python type to use when wrapping the result (may be a subclass).
//====================================================================
internal object InvokeRaw(IntPtr inst, IntPtr args, IntPtr kw) {
return this.InvokeRaw(inst, args, kw, null);
}
/// <summary>
/// Allows ctor selection to be limited to a single attempt at a
/// match by providing the MethodBase to use instead of searching
/// the entire MethodBinder.list (generic ArrayList)
/// </summary>
/// <param name="inst"> (possibly null) instance </param>
/// <param name="args"> PyObject* to the arg tuple </param>
/// <param name="kw"> PyObject* to the keyword args dict </param>
/// <param name="info"> The sole ContructorInfo to use or null </param>
/// <returns> The result of the constructor call with converted params </returns>
/// <remarks>
/// 2010-07-24 BC: I added the info parameter to the call to Bind()
/// Binding binding = this.Bind(inst, args, kw, info);
/// to take advantage of Bind()'s ability to use a single MethodBase (CI or MI).
/// </remarks>
internal object InvokeRaw(IntPtr inst, IntPtr args, IntPtr kw,
MethodBase info) {
Binding binding = this.Bind(inst, args, kw, info);
Object result;
if (binding == null) {
// It is possible for __new__ to be invoked on construction
// of a Python subclass of a managed class, so args may
// reflect more args than are required to instantiate the
// class. So if we cant find a ctor that matches, we'll see
// if there is a default constructor and, if so, assume that
// any extra args are intended for the subclass' __init__.
IntPtr eargs = Runtime.PyTuple_New(0);
binding = this.Bind(inst, eargs, kw);
Runtime.Decref(eargs);
if (binding == null) {
Exceptions.SetError(Exceptions.TypeError,
"no constructor matches given arguments"
);
return null;
}
}
// Fire the selected ctor and catch errors...
ConstructorInfo ci = (ConstructorInfo)binding.info;
// Object construction is presumed to be non-blocking and fast
// enough that we shouldn't really need to release the GIL.
try {
result = ci.Invoke(binding.args);
}
catch (Exception e) {
if (e.InnerException != null) {
e = e.InnerException;
}
Exceptions.SetError(e);
return null;
}
return result;
}
}
}