Fix GetBuffer throwing ArgumentOutOfRangeException (#2120)

legomanww · web-flow · commit 131b466dcaa9 · 2023-03-12T14:01:52.000-07:00
* fix: incorrect length for buffer copy

* test: add PyBuffer test for strides

* docs: update `CHANGELOG` and `AUTHORS`
diff --git a/AUTHORS.md b/AUTHORS.md
@@ -85,3 +85,4 @@
 -   ([@alxnull](https://github.com/alxnull))
 -   ([@gpetrou](https://github.com/gpetrou))
 -   Ehsan Iran-Nejad ([@eirannejad](https://github.com/eirannejad))
+-   ([@legomanww](https://github.com/legomanww))
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -17,6 +17,7 @@ This document follows the conventions laid out in [Keep a CHANGELOG][].
 -   Make a second call to `pythonnet.load` a no-op, as it was intended.
 
 - Added support for multiple inheritance when inheriting from a class and/or multiple interfaces.
+- Fixed error occuring when calling `GetBuffer` for anything other than `PyBUF.SIMPLE` 
 
 ## [3.0.1](https://github.com/pythonnet/pythonnet/releases/tag/v3.0.1) - 2022-11-03
 
diff --git a/src/embed_tests/TestPyBuffer.cs b/src/embed_tests/TestPyBuffer.cs
@@ -110,6 +110,26 @@ public void Finalization()
             Assert.AreEqual(1, arr.Refcount);
         }
 
+        [Test]
+        public void MultidimensionalNumPyArray()
+        {
+            var ndarray = np.arange(24).reshape(1,2,3,4).T;
+            PyObject ndim = ndarray.ndim;
+            PyObject shape = ndarray.shape;
+            PyObject strides = ndarray.strides;
+            PyObject contiguous = ndarray.flags["C_CONTIGUOUS"];
+
+            using PyBuffer buf = ndarray.GetBuffer(PyBUF.STRIDED);
+
+            Assert.Multiple(() =>
+            {
+                Assert.That(buf.Dimensions, Is.EqualTo(ndim.As<int>()));
+                Assert.That(buf.Shape, Is.EqualTo(shape.As<long[]>()));
+                Assert.That(buf.Strides, Is.EqualTo(strides.As<long[]>()));
+                Assert.That(buf.IsContiguous(BufferOrderStyle.C), Is.EqualTo(contiguous.As<bool>()));
+            });
+        }
+
         [MethodImpl(MethodImplOptions.NoInlining)]
         static void MakeBufAndLeak(PyObject bufProvider)
         {
@@ -121,5 +141,21 @@ static PyObject ByteArrayFromAsciiString(string str)
             using var scope = Py.CreateScope();
             return Runtime.Runtime.PyByteArray_FromStringAndSize(str).MoveToPyObject();
         }
+
+        dynamic np
+        {
+            get
+            {
+                try
+                {
+                    return Py.Import("numpy");
+                }
+                catch (PythonException)
+                {
+                    Assert.Inconclusive("Numpy or dependency not installed");
+                    return null;
+                }
+            }
+        }
     }
 }
diff --git a/src/runtime/PythonTypes/PyBuffer.cs b/src/runtime/PythonTypes/PyBuffer.cs
@@ -11,7 +11,7 @@ public sealed class PyBuffer : IDisposable
         private PyObject _exporter;
         private Py_buffer _view;
 
-        unsafe internal PyBuffer(PyObject exporter, PyBUF flags)
+        internal PyBuffer(PyObject exporter, PyBUF flags)
         {
             _view = new Py_buffer();
 
@@ -25,17 +25,17 @@ unsafe internal PyBuffer(PyObject exporter, PyBUF flags)
             var intPtrBuf = new IntPtr[_view.ndim];
             if (_view.shape != IntPtr.Zero)
             {
-                Marshal.Copy(_view.shape, intPtrBuf, 0, (int)_view.len * sizeof(IntPtr));
+                Marshal.Copy(_view.shape, intPtrBuf, 0, _view.ndim);
                 Shape = intPtrBuf.Select(x => (long)x).ToArray();
             }
 
             if (_view.strides != IntPtr.Zero) {
-                Marshal.Copy(_view.strides, intPtrBuf, 0, (int)_view.len * sizeof(IntPtr));
+                Marshal.Copy(_view.strides, intPtrBuf, 0, _view.ndim);
                 Strides = intPtrBuf.Select(x => (long)x).ToArray();
             }
 
             if (_view.suboffsets != IntPtr.Zero) {
-                Marshal.Copy(_view.suboffsets, intPtrBuf, 0, (int)_view.len * sizeof(IntPtr));
+                Marshal.Copy(_view.suboffsets, intPtrBuf, 0, _view.ndim);
                 SubOffsets = intPtrBuf.Select(x => (long)x).ToArray();
             }
         }

Original file line number	Diff line number	Diff line change
`@@ -11,7 +11,7 @@ public sealed class PyBuffer : IDisposable`
`11`	`11`	`private PyObject _exporter;`
`12`	`12`	`private Py_buffer _view;`
`13`	`13`
`14`		`- unsafe internal PyBuffer(PyObject exporter, PyBUF flags)`
	`14`	`+ internal PyBuffer(PyObject exporter, PyBUF flags)`
`15`	`15`	`{`
`16`	`16`	`_view = new Py_buffer();`
`17`	`17`
`@@ -25,17 +25,17 @@ unsafe internal PyBuffer(PyObject exporter, PyBUF flags)`
`25`	`25`	`var intPtrBuf = new IntPtr[_view.ndim];`
`26`	`26`	`if (_view.shape != IntPtr.Zero)`
`27`	`27`	`{`
`28`		`- Marshal.Copy(_view.shape, intPtrBuf, 0, (int)_view.len * sizeof(IntPtr));`
	`28`	`+ Marshal.Copy(_view.shape, intPtrBuf, 0, _view.ndim);`
`29`	`29`	`Shape = intPtrBuf.Select(x => (long)x).ToArray();`
`30`	`30`	`}`
`31`	`31`
`32`	`32`	`if (_view.strides != IntPtr.Zero) {`
`33`		`- Marshal.Copy(_view.strides, intPtrBuf, 0, (int)_view.len * sizeof(IntPtr));`
	`33`	`+ Marshal.Copy(_view.strides, intPtrBuf, 0, _view.ndim);`
`34`	`34`	`Strides = intPtrBuf.Select(x => (long)x).ToArray();`
`35`	`35`	`}`
`36`	`36`
`37`	`37`	`if (_view.suboffsets != IntPtr.Zero) {`
`38`		`- Marshal.Copy(_view.suboffsets, intPtrBuf, 0, (int)_view.len * sizeof(IntPtr));`
	`38`	`+ Marshal.Copy(_view.suboffsets, intPtrBuf, 0, _view.ndim);`
`39`	`39`	`SubOffsets = intPtrBuf.Select(x => (long)x).ToArray();`
`40`	`40`	`}`
`41`	`41`	`}`