Fix problems with memoryview object. There is still more to do to finish PEP 3118. The memory-view object needs to be fleshed out and the struct module needs to be modified.

4 files changed, 408 insertions, 389 deletions

diff --git a/Include/memoryobject.h b/Include/memoryobject.h
index 4426cd8..8709da5 100644
--- a/Include/memoryobject.h
+++ b/Include/memoryobject.h
@@ -8,9 +8,9 @@ extern "C" {
 #endif
 
 typedef struct {
-        PyObject_HEAD
-        PyObject *base;
-        Py_buffer view;
+	PyObject_HEAD
+	PyObject *base;
+	Py_buffer view;
 } PyMemoryViewObject;
 
 
@@ -21,39 +21,40 @@ PyAPI_DATA(PyTypeObject) PyMemoryView_Type;
 
 #define Py_END_OF_MEMORY	(-1)
 
-PyAPI_FUNC(PyObject *) PyMemoryView_GetContiguous(PyObject *base, int buffertype, 
-                                                  char fort);
+PyAPI_FUNC(PyObject *) PyMemoryView_GetContiguous(PyObject *base, 
+						  int buffertype, 
+						  char fort);
 
 	/* Return a contiguous chunk of memory representing the buffer
 	   from an object in a memory view object.  If a copy is made then the
-           base object for the memory view will be a *new* bytes object. 
-           
-           Otherwise, the base-object will be the object itself and no 
-           data-copying will be done. 
+	   base object for the memory view will be a *new* bytes object. 
+	   
+	   Otherwise, the base-object will be the object itself and no 
+	   data-copying will be done. 
 
-           The buffertype argument can be PyBUF_READ, PyBUF_WRITE,
-           PyBUF_UPDATEIFCOPY to determine whether the returned buffer
-           should be READONLY, WRITABLE, or set to update the
-           original buffer if a copy must be made.  If buffertype is
-           PyBUF_WRITE and the buffer is not contiguous an error will
-           be raised.  In this circumstance, the user can use
-           PyBUF_UPDATEIFCOPY to ensure that a a writable temporary
-           contiguous buffer is returned.  The contents of this
-           contiguous buffer will be copied back into the original
-           object after the memoryview object is deleted as long as
-           the original object is writable and allows setting its
-           memory to "readonly".  If this is not allowed by the
-           original object, then a BufferError is raised.
+	   The buffertype argument can be PyBUF_READ, PyBUF_WRITE,
+	   PyBUF_SHADOW to determine whether the returned buffer
+	   should be READONLY, WRITABLE, or set to update the
+	   original buffer if a copy must be made.  If buffertype is
+	   PyBUF_WRITE and the buffer is not contiguous an error will
+	   be raised.  In this circumstance, the user can use
+	   PyBUF_SHADOW to ensure that a a writable temporary
+	   contiguous buffer is returned.  The contents of this
+	   contiguous buffer will be copied back into the original
+	   object after the memoryview object is deleted as long as
+	   the original object is writable and allows setting an
+	   exclusive write lock. If this is not allowed by the
+	   original object, then a BufferError is raised.
 	   
-           If the object is multi-dimensional and if fortran is 'F',
-           the first dimension of the underlying array will vary the
-           fastest in the buffer.  If fortran is 'C', then the last
-           dimension will vary the fastest (C-style contiguous).  If
-           fortran is 'A', then it does not matter and you will get
-           whatever the object decides is more efficient.  
+	   If the object is multi-dimensional and if fortran is 'F',
+	   the first dimension of the underlying array will vary the
+	   fastest in the buffer.  If fortran is 'C', then the last
+	   dimension will vary the fastest (C-style contiguous).  If
+	   fortran is 'A', then it does not matter and you will get
+	   whatever the object decides is more efficient.  
 
-           A new reference is returned that must be DECREF'd when finished.
-        */
+	   A new reference is returned that must be DECREF'd when finished.
+	*/
 
 PyAPI_FUNC(PyObject *) PyMemoryView_FromObject(PyObject *base);
 
diff --git a/Include/object.h b/Include/object.h
index 88a3b84..c9d2217 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -164,7 +164,7 @@ typedef void (*releasebufferproc)(PyObject *, Py_buffer *);
 #define PyBUF_WRITABLE 0x0002
 /*  we used to include an E, backwards compatible alias  */
 #define PyBUF_WRITEABLE PyBUF_WRITABLE
-#define PyBUF_LOCKDATA 0x0004
+#define PyBUF_LOCK 0x0004
 #define PyBUF_FORMAT 0x0008
 #define PyBUF_ND 0x0010
 #define PyBUF_STRIDES (0x0020 | PyBUF_ND)
@@ -175,19 +175,25 @@ typedef void (*releasebufferproc)(PyObject *, Py_buffer *);
 
 #define PyBUF_CONTIG (PyBUF_ND | PyBUF_WRITABLE)
 #define PyBUF_CONTIG_RO (PyBUF_ND)
-#define PyBUF_CONTIG_LCK (PyBUF_ND | PyBUF_LOCKDATA)
+#define PyBUF_CONTIG_LCK (PyBUF_ND | PyBUF_LOCK)
+#define PyBUF_CONTIG_XLCK (PyBUF_ND | PyBUF_LOCK | PyBUF_WRITABLE)
 
 #define PyBUF_STRIDED (PyBUF_STRIDES | PyBUF_WRITABLE)
 #define PyBUF_STRIDED_RO (PyBUF_STRIDES)
-#define PyBUF_STRIDED_LCK (PyBUF_STRIDES | PyBUF_LOCKDATA)
+#define PyBUF_STRIDED_LCK (PyBUF_STRIDES | PyBUF_LOCK)
+#define PyBUF_STRIDED_XLCK (PyBUF_STRIDES | PyBUF_LOCK | PyBUF_WRITABLE)
 
 #define PyBUF_RECORDS (PyBUF_STRIDES | PyBUF_WRITABLE | PyBUF_FORMAT)
 #define PyBUF_RECORDS_RO (PyBUF_STRIDES | PyBUF_FORMAT)
-#define PyBUF_RECORDS_LCK (PyBUF_STRIDES | PyBUF_LOCKDATA | PyBUF_FORMAT)
+#define PyBUF_RECORDS_LCK (PyBUF_STRIDES | PyBUF_LOCK | PyBUF_FORMAT)
+#define PyBUF_RECORDS_XLCK (PyBUF_STRIDES | PyBUF_LOCK | PyBUF_WRITABLE \
+			    | PyBUF_FORMAT)
 
 #define PyBUF_FULL (PyBUF_INDIRECT | PyBUF_WRITABLE | PyBUF_FORMAT)
 #define PyBUF_FULL_RO (PyBUF_INDIRECT | PyBUF_FORMAT)
-#define PyBUF_FULL_LCK (PyBUF_INDIRECT | PyBUF_LOCKDATA | PyBUF_FORMAT)
+#define PyBUF_FULL_LCK (PyBUF_INDIRECT | PyBUF_LOCK | PyBUF_FORMAT)
+#define PyBUF_FULL_XLCK (PyBUF_INDIRECT | PyBUF_LOCK | PyBUF_WRITABLE \
+			 | PyBUF_FORMAT)
 
 
 #define PyBUF_READ  0x100
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 141996d..3d736d1 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -220,11 +220,11 @@ PyObject_DelItemString(PyObject *o, char *key)
  */
 int
 PyObject_AsCharBuffer(PyObject *obj,
-                      const char **buffer,
-                      Py_ssize_t *buffer_len)
+		      const char **buffer,
+		      Py_ssize_t *buffer_len)
 {
 	PyBufferProcs *pb;
-        Py_buffer view;
+	Py_buffer view;
 
 	if (obj == NULL || buffer == NULL || buffer_len == NULL) {
 		null_error();
@@ -235,30 +235,30 @@ PyObject_AsCharBuffer(PyObject *obj,
 		PyErr_SetString(PyExc_TypeError,
 				"expected an object with the buffer interface");
 		return -1;
-        }
-        if ((*pb->bf_getbuffer)(obj, &view, PyBUF_CHARACTER)) return -1;
+	}
+	if ((*pb->bf_getbuffer)(obj, &view, PyBUF_CHARACTER)) return -1;
 
 	*buffer = view.buf;
 	*buffer_len = view.len;
-        if (pb->bf_releasebuffer != NULL)
-                (*pb->bf_releasebuffer)(obj, &view);
+	if (pb->bf_releasebuffer != NULL)
+		(*pb->bf_releasebuffer)(obj, &view);
 	return 0;
 }
 
 int
 PyObject_CheckReadBuffer(PyObject *obj)
 {
-	PyBufferProcs *pb = obj->ob_type->tp_as_buffer;                
+	PyBufferProcs *pb = obj->ob_type->tp_as_buffer;		       
 
 	if (pb == NULL ||
 	    pb->bf_getbuffer == NULL)
-                return 0;
-        if ((*pb->bf_getbuffer)(obj, NULL, PyBUF_SIMPLE) == -1) {
-                PyErr_Clear();
-                return 0;
-        }
-        if (*pb->bf_releasebuffer != NULL)
-                (*pb->bf_releasebuffer)(obj, NULL);
+		return 0;
+	if ((*pb->bf_getbuffer)(obj, NULL, PyBUF_SIMPLE) == -1) {
+		PyErr_Clear();
+		return 0;
+	}
+	if (*pb->bf_releasebuffer != NULL)
+		(*pb->bf_releasebuffer)(obj, NULL);
 	return 1;
 }
 
@@ -267,7 +267,7 @@ int PyObject_AsReadBuffer(PyObject *obj,
 			  Py_ssize_t *buffer_len)
 {
 	PyBufferProcs *pb;
-        Py_buffer view;
+	Py_buffer view;
 
 	if (obj == NULL || buffer == NULL || buffer_len == NULL) {
 		null_error();
@@ -275,18 +275,18 @@ int PyObject_AsReadBuffer(PyObject *obj,
 	}
 	pb = obj->ob_type->tp_as_buffer;
 	if (pb == NULL ||
-            pb->bf_getbuffer == NULL) {
+	    pb->bf_getbuffer == NULL) {
 		PyErr_SetString(PyExc_TypeError,
 				"expected an object with a buffer interface");
 		return -1;
 	}
 
-        if ((*pb->bf_getbuffer)(obj, &view, PyBUF_SIMPLE)) return -1;
+	if ((*pb->bf_getbuffer)(obj, &view, PyBUF_SIMPLE)) return -1;
 
 	*buffer = view.buf;
 	*buffer_len = view.len;
-        if (pb->bf_releasebuffer != NULL)
-                (*pb->bf_releasebuffer)(obj, &view);
+	if (pb->bf_releasebuffer != NULL)
+		(*pb->bf_releasebuffer)(obj, &view);
 	return 0;
 }
 
@@ -295,7 +295,7 @@ int PyObject_AsWriteBuffer(PyObject *obj,
 			   Py_ssize_t *buffer_len)
 {
 	PyBufferProcs *pb;
-        Py_buffer view;
+	Py_buffer view;
 
 	if (obj == NULL || buffer == NULL || buffer_len == NULL) {
 		null_error();
@@ -303,17 +303,17 @@ int PyObject_AsWriteBuffer(PyObject *obj,
 	}
 	pb = obj->ob_type->tp_as_buffer;
 	if (pb == NULL ||
-            pb->bf_getbuffer == NULL ||
-            ((*pb->bf_getbuffer)(obj, &view, PyBUF_WRITABLE) != 0)) {
+	    pb->bf_getbuffer == NULL ||
+	    ((*pb->bf_getbuffer)(obj, &view, PyBUF_WRITABLE) != 0)) {
 		PyErr_SetString(PyExc_TypeError, 
-                                "expected an object with a writable buffer interface");
+				"expected an object with a writable buffer interface");
 		return -1;
 	}
 
 	*buffer = view.buf;
 	*buffer_len = view.len;
-        if (pb->bf_releasebuffer != NULL)
-                (*pb->bf_releasebuffer)(obj, &view);
+	if (pb->bf_releasebuffer != NULL)
+		(*pb->bf_releasebuffer)(obj, &view);
 	return 0;
 }
 
@@ -322,128 +322,128 @@ int PyObject_AsWriteBuffer(PyObject *obj,
 int
 PyObject_GetBuffer(PyObject *obj, Py_buffer *view, int flags)
 {
-        if (!PyObject_CheckBuffer(obj)) {
-                PyErr_SetString(PyExc_TypeError,
-                                "object does not have the buffer interface");
-                return -1;
-        }
-        return (*(obj->ob_type->tp_as_buffer->bf_getbuffer))(obj, view, flags);
+	if (!PyObject_CheckBuffer(obj)) {
+		PyErr_SetString(PyExc_TypeError,
+				"object does not have the buffer interface");
+		return -1;
+	}
+	return (*(obj->ob_type->tp_as_buffer->bf_getbuffer))(obj, view, flags);
 }
 
 void
 PyObject_ReleaseBuffer(PyObject *obj, Py_buffer *view)
 {
-        if (obj->ob_type->tp_as_buffer != NULL && 
-            obj->ob_type->tp_as_buffer->bf_releasebuffer != NULL) {
-                (*(obj->ob_type->tp_as_buffer->bf_releasebuffer))(obj, view);
-        }
+	if (obj->ob_type->tp_as_buffer != NULL && 
+	    obj->ob_type->tp_as_buffer->bf_releasebuffer != NULL) {
+		(*(obj->ob_type->tp_as_buffer->bf_releasebuffer))(obj, view);
+	}
 }
 
 
 static int
 _IsFortranContiguous(Py_buffer *view)
 {
-        Py_ssize_t sd, dim;
-        int i;
-        
-        if (view->ndim == 0) return 1;
-        if (view->strides == NULL) return (view->ndim == 1);
-
-        sd = view->itemsize;
-        if (view->ndim == 1) return (view->shape[0] == 1 ||
-                                   sd == view->strides[0]);
-        for (i=0; i<view->ndim; i++) {
-                dim = view->shape[i];
-                if (dim == 0) return 1;
-                if (view->strides[i] != sd) return 0;
-                sd *= dim;
-        }
-        return 1;
+	Py_ssize_t sd, dim;
+	int i;
+	
+	if (view->ndim == 0) return 1;
+	if (view->strides == NULL) return (view->ndim == 1);
+
+	sd = view->itemsize;
+	if (view->ndim == 1) return (view->shape[0] == 1 ||
+				   sd == view->strides[0]);
+	for (i=0; i<view->ndim; i++) {
+		dim = view->shape[i];
+		if (dim == 0) return 1;
+		if (view->strides[i] != sd) return 0;
+		sd *= dim;
+	}
+	return 1;
 }
 
 static int
 _IsCContiguous(Py_buffer *view)
 {
-        Py_ssize_t sd, dim;
-        int i;
-        
-        if (view->ndim == 0) return 1;
-        if (view->strides == NULL) return 1;
+	Py_ssize_t sd, dim;
+	int i;
+	
+	if (view->ndim == 0) return 1;
+	if (view->strides == NULL) return 1;
 
-        sd = view->itemsize;
-        if (view->ndim == 1) return (view->shape[0] == 1 ||
-                                   sd == view->strides[0]);
-        for (i=view->ndim-1; i>=0; i--) {
-                dim = view->shape[i];
-                if (dim == 0) return 1;
-                if (view->strides[i] != sd) return 0;
-                sd *= dim;
-        }
-        return 1;        
+	sd = view->itemsize;
+	if (view->ndim == 1) return (view->shape[0] == 1 ||
+				   sd == view->strides[0]);
+	for (i=view->ndim-1; i>=0; i--) {
+		dim = view->shape[i];
+		if (dim == 0) return 1;
+		if (view->strides[i] != sd) return 0;
+		sd *= dim;
+	}
+	return 1;	 
 }
 
 int
 PyBuffer_IsContiguous(Py_buffer *view, char fort)
 {
 
-        if (view->suboffsets != NULL) return 0;
+	if (view->suboffsets != NULL) return 0;
 
-        if (fort == 'C')
-                return _IsCContiguous(view);
-        else if (fort == 'F') 
-                return _IsFortranContiguous(view);
-        else if (fort == 'A')
-                return (_IsCContiguous(view) || _IsFortranContiguous(view));
-        return 0;
+	if (fort == 'C')
+		return _IsCContiguous(view);
+	else if (fort == 'F') 
+		return _IsFortranContiguous(view);
+	else if (fort == 'A')
+		return (_IsCContiguous(view) || _IsFortranContiguous(view));
+	return 0;
 }
 
 
 void* 
 PyBuffer_GetPointer(Py_buffer *view, Py_ssize_t *indices)
 {
-        char* pointer;
-        int i;
-        pointer = (char *)view->buf;
-        for (i = 0; i < view->ndim; i++) {
-                pointer += view->strides[i]*indices[i];
-                if ((view->suboffsets != NULL) && (view->suboffsets[i] >= 0)) {
-                        pointer = *((char**)pointer) + view->suboffsets[i];
-                }
-        }
-        return (void*)pointer;
+	char* pointer;
+	int i;
+	pointer = (char *)view->buf;
+	for (i = 0; i < view->ndim; i++) {
+		pointer += view->strides[i]*indices[i];
+		if ((view->suboffsets != NULL) && (view->suboffsets[i] >= 0)) {
+			pointer = *((char**)pointer) + view->suboffsets[i];
+		}
+	}
+	return (void*)pointer;
 }
 
 
 void 
 _add_one_to_index_F(int nd, Py_ssize_t *index, Py_ssize_t *shape)
 {
-        int k;
-        
-        for (k=0; k<nd; k++) {
-                if (index[k] < shape[k]-1) {
-                        index[k]++;
-                        break;
-                }
-                else {
-                        index[k] = 0;
-                }
-        }
+	int k;
+	
+	for (k=0; k<nd; k++) {
+		if (index[k] < shape[k]-1) {
+			index[k]++;
+			break;
+		}
+		else {
+			index[k] = 0;
+		}
+	}
 }
 
 void 
 _add_one_to_index_C(int nd, Py_ssize_t *index, Py_ssize_t *shape)
 {
-        int k;
+	int k;
 
-        for (k=nd-1; k>=0; k--) {
-                if (index[k] < shape[k]-1) {
-                        index[k]++;
-                        break;
-                }
-                else {
-                        index[k] = 0;
-                }
-        }
+	for (k=nd-1; k>=0; k--) {
+		if (index[k] < shape[k]-1) {
+			index[k]++;
+			break;
+		}
+		else {
+			index[k] = 0;
+		}
+	}
 }
 
   /* view is not checked for consistency in either of these.  It is
@@ -454,235 +454,235 @@ _add_one_to_index_C(int nd, Py_ssize_t *index, Py_ssize_t *shape)
 int 
 PyBuffer_ToContiguous(void *buf, Py_buffer *view, Py_ssize_t len, char fort)
 {
-        int k;
-        void (*addone)(int, Py_ssize_t *, Py_ssize_t *);
-        Py_ssize_t *indices, elements;
-        char *dest, *ptr;
-
-        if (len > view->len) {
-                len = view->len;
-        }
-        
-        if (PyBuffer_IsContiguous(view, fort)) {
-                /* simplest copy is all that is needed */
-                memcpy(buf, view->buf, len);
-                return 0;
-        }
-
-        /* Otherwise a more elaborate scheme is needed */
-        
+	int k;
+	void (*addone)(int, Py_ssize_t *, Py_ssize_t *);
+	Py_ssize_t *indices, elements;
+	char *dest, *ptr;
+
+	if (len > view->len) {
+		len = view->len;
+	}
+	
+	if (PyBuffer_IsContiguous(view, fort)) {
+		/* simplest copy is all that is needed */
+		memcpy(buf, view->buf, len);
+		return 0;
+	}
+
+	/* Otherwise a more elaborate scheme is needed */
+	
 	/* XXX(nnorwitz): need to check for overflow! */
-        indices = (Py_ssize_t *)PyMem_Malloc(sizeof(Py_ssize_t)*(view->ndim));
-        if (indices == NULL) {
-                PyErr_NoMemory();
-                return -1;
-        }
-        for (k=0; k<view->ndim;k++) {
-                indices[k] = 0;
-        }
-        
-        if (fort == 'F') {
-                addone = _add_one_to_index_F;
-        }
-        else {
-                addone = _add_one_to_index_C;
-        }
-        dest = buf;
-        /* XXX : This is not going to be the fastest code in the world
-                 several optimizations are possible. 
-         */
-        elements = len / view->itemsize;
-        while (elements--) {
-                addone(view->ndim, indices, view->shape);
-                ptr = PyBuffer_GetPointer(view, indices);
-                memcpy(dest, ptr, view->itemsize);
-                dest += view->itemsize;
-        }                
-        PyMem_Free(indices);
-        return 0;
+	indices = (Py_ssize_t *)PyMem_Malloc(sizeof(Py_ssize_t)*(view->ndim));
+	if (indices == NULL) {
+		PyErr_NoMemory();
+		return -1;
+	}
+	for (k=0; k<view->ndim;k++) {
+		indices[k] = 0;
+	}
+	
+	if (fort == 'F') {
+		addone = _add_one_to_index_F;
+	}
+	else {
+		addone = _add_one_to_index_C;
+	}
+	dest = buf;
+	/* XXX : This is not going to be the fastest code in the world
+		 several optimizations are possible. 
+	 */
+	elements = len / view->itemsize;
+	while (elements--) {
+		addone(view->ndim, indices, view->shape);
+		ptr = PyBuffer_GetPointer(view, indices);
+		memcpy(dest, ptr, view->itemsize);
+		dest += view->itemsize;
+	}		 
+	PyMem_Free(indices);
+	return 0;
 }
 
 int
 PyBuffer_FromContiguous(Py_buffer *view, void *buf, Py_ssize_t len, char fort)
 {
-        int k;
-        void (*addone)(int, Py_ssize_t *, Py_ssize_t *);
-        Py_ssize_t *indices, elements;
-        char *src, *ptr;
+	int k;
+	void (*addone)(int, Py_ssize_t *, Py_ssize_t *);
+	Py_ssize_t *indices, elements;
+	char *src, *ptr;
 
-        if (len > view->len) {
-                len = view->len;
-        }
+	if (len > view->len) {
+		len = view->len;
+	}
 
-        if (PyBuffer_IsContiguous(view, fort)) {
-                /* simplest copy is all that is needed */
-                memcpy(view->buf, buf, len);
-                return 0;
-        }
+	if (PyBuffer_IsContiguous(view, fort)) {
+		/* simplest copy is all that is needed */
+		memcpy(view->buf, buf, len);
+		return 0;
+	}
 
-        /* Otherwise a more elaborate scheme is needed */
-        
+	/* Otherwise a more elaborate scheme is needed */
+	
 	/* XXX(nnorwitz): need to check for overflow! */
-        indices = (Py_ssize_t *)PyMem_Malloc(sizeof(Py_ssize_t)*(view->ndim));
-        if (indices == NULL) {
-                PyErr_NoMemory();
-                return -1;
-        }
-        for (k=0; k<view->ndim;k++) {
-                indices[k] = 0;
-        }
-        
-        if (fort == 'F') {
-                addone = _add_one_to_index_F;
-        }
-        else {
-                addone = _add_one_to_index_C;
-        }
-        src = buf;
-        /* XXX : This is not going to be the fastest code in the world
-                 several optimizations are possible. 
-         */
-        elements = len / view->itemsize;
-        while (elements--) {
-                addone(view->ndim, indices, view->shape);
-                ptr = PyBuffer_GetPointer(view, indices);
-                memcpy(ptr, src, view->itemsize);
-                src += view->itemsize;
-        }
-                
-        PyMem_Free(indices);
-        return 0;
+	indices = (Py_ssize_t *)PyMem_Malloc(sizeof(Py_ssize_t)*(view->ndim));
+	if (indices == NULL) {
+		PyErr_NoMemory();
+		return -1;
+	}
+	for (k=0; k<view->ndim;k++) {
+		indices[k] = 0;
+	}
+	
+	if (fort == 'F') {
+		addone = _add_one_to_index_F;
+	}
+	else {
+		addone = _add_one_to_index_C;
+	}
+	src = buf;
+	/* XXX : This is not going to be the fastest code in the world
+		 several optimizations are possible. 
+	 */
+	elements = len / view->itemsize;
+	while (elements--) {
+		addone(view->ndim, indices, view->shape);
+		ptr = PyBuffer_GetPointer(view, indices);
+		memcpy(ptr, src, view->itemsize);
+		src += view->itemsize;
+	}
+		
+	PyMem_Free(indices);
+	return 0;
 }
 
 int PyObject_CopyData(PyObject *dest, PyObject *src) 
 {
-        Py_buffer view_dest, view_src;
-        int k;
-        Py_ssize_t *indices, elements;
-        char *dptr, *sptr;
-
-        if (!PyObject_CheckBuffer(dest) ||
-            !PyObject_CheckBuffer(src)) {
-                PyErr_SetString(PyExc_TypeError,
-                                "both destination and source must have the "\
-                                "buffer interface");
-                return -1;
-        }
-
-        if (PyObject_GetBuffer(dest, &view_dest, PyBUF_FULL) != 0) return -1;
-        if (PyObject_GetBuffer(src, &view_src, PyBUF_FULL_RO) != 0) {
-                PyObject_ReleaseBuffer(dest, &view_dest);
-                return -1;
-        }
-
-        if (view_dest.len < view_src.len) {
-                PyErr_SetString(PyExc_BufferError, 
-                                "destination is too small to receive data from source");
-                PyObject_ReleaseBuffer(dest, &view_dest);
-                PyObject_ReleaseBuffer(src, &view_src);
-                return -1;
-        }
-
-        if ((PyBuffer_IsContiguous(&view_dest, 'C') && 
-             PyBuffer_IsContiguous(&view_src, 'C')) ||
-            (PyBuffer_IsContiguous(&view_dest, 'F') && 
-             PyBuffer_IsContiguous(&view_src, 'F'))) {
-                /* simplest copy is all that is needed */
-                memcpy(view_dest.buf, view_src.buf, view_src.len);
-                PyObject_ReleaseBuffer(dest, &view_dest);
-                PyObject_ReleaseBuffer(src, &view_src);
-                return 0;
-        }
-
-        /* Otherwise a more elaborate copy scheme is needed */
-        
+	Py_buffer view_dest, view_src;
+	int k;
+	Py_ssize_t *indices, elements;
+	char *dptr, *sptr;
+
+	if (!PyObject_CheckBuffer(dest) ||
+	    !PyObject_CheckBuffer(src)) {
+		PyErr_SetString(PyExc_TypeError,
+				"both destination and source must have the "\
+				"buffer interface");
+		return -1;
+	}
+
+	if (PyObject_GetBuffer(dest, &view_dest, PyBUF_FULL) != 0) return -1;
+	if (PyObject_GetBuffer(src, &view_src, PyBUF_FULL_RO) != 0) {
+		PyObject_ReleaseBuffer(dest, &view_dest);
+		return -1;
+	}
+
+	if (view_dest.len < view_src.len) {
+		PyErr_SetString(PyExc_BufferError, 
+				"destination is too small to receive data from source");
+		PyObject_ReleaseBuffer(dest, &view_dest);
+		PyObject_ReleaseBuffer(src, &view_src);
+		return -1;
+	}
+
+	if ((PyBuffer_IsContiguous(&view_dest, 'C') && 
+	     PyBuffer_IsContiguous(&view_src, 'C')) ||
+	    (PyBuffer_IsContiguous(&view_dest, 'F') && 
+	     PyBuffer_IsContiguous(&view_src, 'F'))) {
+		/* simplest copy is all that is needed */
+		memcpy(view_dest.buf, view_src.buf, view_src.len);
+		PyObject_ReleaseBuffer(dest, &view_dest);
+		PyObject_ReleaseBuffer(src, &view_src);
+		return 0;
+	}
+
+	/* Otherwise a more elaborate copy scheme is needed */
+	
 	/* XXX(nnorwitz): need to check for overflow! */
-        indices = (Py_ssize_t *)PyMem_Malloc(sizeof(Py_ssize_t)*view_src.ndim);
-        if (indices == NULL) {
-                PyErr_NoMemory();
-                PyObject_ReleaseBuffer(dest, &view_dest);
-                PyObject_ReleaseBuffer(src, &view_src);
-                return -1;
-        }
-        for (k=0; k<view_src.ndim;k++) {
-                indices[k] = 0;
-        }        
-        elements = 1;
-        for (k=0; k<view_src.ndim; k++) {
+	indices = (Py_ssize_t *)PyMem_Malloc(sizeof(Py_ssize_t)*view_src.ndim);
+	if (indices == NULL) {
+		PyErr_NoMemory();
+		PyObject_ReleaseBuffer(dest, &view_dest);
+		PyObject_ReleaseBuffer(src, &view_src);
+		return -1;
+	}
+	for (k=0; k<view_src.ndim;k++) {
+		indices[k] = 0;
+	}	 
+	elements = 1;
+	for (k=0; k<view_src.ndim; k++) {
 		/* XXX(nnorwitz): can this overflow? */
-                elements *= view_src.shape[k];
-        }
-        while (elements--) {
-                _add_one_to_index_C(view_src.ndim, indices, view_src.shape);
-                dptr = PyBuffer_GetPointer(&view_dest, indices);
-                sptr = PyBuffer_GetPointer(&view_src, indices);
-                memcpy(dptr, sptr, view_src.itemsize);
-        }                
-        PyMem_Free(indices);
-        PyObject_ReleaseBuffer(dest, &view_dest);
-        PyObject_ReleaseBuffer(src, &view_src);
-        return 0;
+		elements *= view_src.shape[k];
+	}
+	while (elements--) {
+		_add_one_to_index_C(view_src.ndim, indices, view_src.shape);
+		dptr = PyBuffer_GetPointer(&view_dest, indices);
+		sptr = PyBuffer_GetPointer(&view_src, indices);
+		memcpy(dptr, sptr, view_src.itemsize);
+	}		 
+	PyMem_Free(indices);
+	PyObject_ReleaseBuffer(dest, &view_dest);
+	PyObject_ReleaseBuffer(src, &view_src);
+	return 0;
 }
 
 void
 PyBuffer_FillContiguousStrides(int nd, Py_ssize_t *shape,
-                               Py_ssize_t *strides, int itemsize,
-                               char fort)
-{
-        int k;
-        Py_ssize_t sd;
-        
-        sd = itemsize;
-        if (fort == 'F') {
-                for (k=0; k<nd; k++) {
-                        strides[k] = sd;
-                        sd *= shape[k];
-                }                                      
-        }
-        else {
-                for (k=nd-1; k>=0; k--) {
-                        strides[k] = sd;
-                        sd *= shape[k];
-                }
-        }
-        return;
+			       Py_ssize_t *strides, int itemsize,
+			       char fort)
+{
+	int k;
+	Py_ssize_t sd;
+	
+	sd = itemsize;
+	if (fort == 'F') {
+		for (k=0; k<nd; k++) {
+			strides[k] = sd;
+			sd *= shape[k];
+		}				       
+	}
+	else {
+		for (k=nd-1; k>=0; k--) {
+			strides[k] = sd;
+			sd *= shape[k];
+		}
+	}
+	return;
 }
 
 int
 PyBuffer_FillInfo(Py_buffer *view, void *buf, Py_ssize_t len,
-              int readonly, int flags)
-{        
-        if (view == NULL) return 0;
-        if (((flags & PyBUF_LOCKDATA) == PyBUF_LOCKDATA) && 
-            readonly != -1) {
-                PyErr_SetString(PyExc_BufferError, 
-                                "Cannot make this object read-only.");
-                return -1;
-        }
-        if (((flags & PyBUF_WRITABLE) == PyBUF_WRITABLE) &&
-            readonly == 1) {
-                PyErr_SetString(PyExc_BufferError,
-                                "Object is not writable.");
-                return -1;
-        }
-        
-        view->buf = buf;
-        view->len = len;
-        view->readonly = readonly;
-        view->itemsize = 1;
-        view->format = NULL;
-        if ((flags & PyBUF_FORMAT) == PyBUF_FORMAT) 
-                view->format = "B";
-        view->ndim = 1;
-        view->shape = NULL;
-        if ((flags & PyBUF_ND) == PyBUF_ND)
-                view->shape = &(view->len);
-        view->strides = NULL;
-        if ((flags & PyBUF_STRIDES) == PyBUF_STRIDES)
-                view->strides = &(view->itemsize);
-        view->suboffsets = NULL;
-        view->internal = NULL;
-        return 0;
+	      int readonly, int flags)
+{	 
+	if (view == NULL) return 0;
+	if (((flags & PyBUF_LOCK) == PyBUF_LOCK) && 
+	    readonly >= 0) {
+		PyErr_SetString(PyExc_BufferError, 
+				"Cannot lock this object.");
+		return -1;
+	}
+	if (((flags & PyBUF_WRITABLE) == PyBUF_WRITABLE) &&
+	    (readonly == 1)) {
+		PyErr_SetString(PyExc_BufferError,
+				"Object is not writable.");
+		return -1;
+	}
+	
+	view->buf = buf;
+	view->len = len;
+	view->readonly = readonly;
+	view->itemsize = 1;
+	view->format = NULL;
+	if ((flags & PyBUF_FORMAT) == PyBUF_FORMAT) 
+		view->format = "B";
+	view->ndim = 1;
+	view->shape = NULL;
+	if ((flags & PyBUF_ND) == PyBUF_ND)
+		view->shape = &(view->len);
+	view->strides = NULL;
+	if ((flags & PyBUF_STRIDES) == PyBUF_STRIDES)
+		view->strides = &(view->itemsize);
+	view->suboffsets = NULL;
+	view->internal = NULL;
+	return 0;
 }
 
 /* Operations on numbers */
@@ -1025,7 +1025,7 @@ PyNumber_InPlaceAdd(PyObject *v, PyObject *w)
 		Py_DECREF(result);
 		if (m != NULL) {
 			binaryfunc f = NULL;
-                        f = m->sq_inplace_concat;
+			f = m->sq_inplace_concat;
 			if (f == NULL)
 				f = m->sq_concat;
 			if (f != NULL)
@@ -1304,8 +1304,8 @@ PyNumber_Float(PyObject *o)
 		PyObject *res = m->nb_float(o);
 		if (res && !PyFloat_Check(res)) {
 			PyErr_Format(PyExc_TypeError,
-		          "__float__ returned non-float (type %.200s)",
-		          res->ob_type->tp_name);
+			  "__float__ returned non-float (type %.200s)",
+			  res->ob_type->tp_name);
 			Py_DECREF(res);
 			return NULL;
 		}
@@ -1384,7 +1384,7 @@ PySequence_Concat(PyObject *s, PyObject *o)
 		return m->sq_concat(s, o);
 
 	/* Instances of user classes defining an __add__() method only
-	   have an nb_add slot, not an sq_concat slot.  So we fall back
+	   have an nb_add slot, not an sq_concat slot.	So we fall back
 	   to nb_add if both arguments appear to be sequences. */
 	if (PySequence_Check(s) && PySequence_Check(o)) {
 		PyObject *result = binary_op1(s, o, NB_SLOT(nb_add));
@@ -1629,7 +1629,7 @@ PyObject *
 PySequence_Tuple(PyObject *v)
 {
 	PyObject *it;  /* iter(v) */
-	Py_ssize_t n;         /* guess for result tuple size */
+	Py_ssize_t n;	      /* guess for result tuple size */
 	PyObject *result;
 	Py_ssize_t j;
 
@@ -1662,7 +1662,7 @@ PySequence_Tuple(PyObject *v)
 			return NULL;
 		}
 		PyErr_Clear();
-		n = 10;  /* arbitrary */
+		n = 10;	 /* arbitrary */
 	}
 	result = PyTuple_New(n);
 	if (result == NULL)
@@ -1718,7 +1718,7 @@ PyObject *
 PySequence_List(PyObject *v)
 {
 	PyObject *result;  /* result list */
-	PyObject *rv;      /* return value from PyList_Extend */
+	PyObject *rv;	   /* return value from PyList_Extend */
 
 	if (v == NULL)
 		return null_error();
@@ -1749,7 +1749,7 @@ PySequence_Fast(PyObject *v, const char *m)
 		return v;
 	}
 
- 	it = PyObject_GetIter(v);
+	it = PyObject_GetIter(v);
 	if (it == NULL) {
 		if (PyErr_ExceptionMatches(PyExc_TypeError))
 			PyErr_SetString(PyExc_TypeError, m);
@@ -1763,9 +1763,9 @@ PySequence_Fast(PyObject *v, const char *m)
 }
 
 /* Iterate over seq.  Result depends on the operation:
-   PY_ITERSEARCH_COUNT:  -1 if error, else # of times obj appears in seq.
-   PY_ITERSEARCH_INDEX:  0-based index of first occurence of obj in seq;
-   	set ValueError and return -1 if none found; also return -1 on error.
+   PY_ITERSEARCH_COUNT:	 -1 if error, else # of times obj appears in seq.
+   PY_ITERSEARCH_INDEX:	 0-based index of first occurence of obj in seq;
+	set ValueError and return -1 if none found; also return -1 on error.
    Py_ITERSEARCH_CONTAINS:  return 1 if obj in seq, else 0; -1 on error.
 */
 Py_ssize_t
@@ -1839,7 +1839,7 @@ _PySequence_IterSearch(PyObject *seq, PyObject *obj, int operation)
 		goto Done;
 
 	PyErr_SetString(PyExc_ValueError,
-		        "sequence.index(x): x not in sequence");
+			"sequence.index(x): x not in sequence");
 	/* fall into failure code */
 Fail:
 	n = -1;
@@ -1865,7 +1865,7 @@ PySequence_Contains(PyObject *seq, PyObject *ob)
 {
 	Py_ssize_t result;
 	PySequenceMethods *sqm = seq->ob_type->tp_as_sequence;
-        if (sqm != NULL && sqm->sq_contains != NULL)
+	if (sqm != NULL && sqm->sq_contains != NULL)
 		return (*sqm->sq_contains)(seq, ob);
 	result = _PySequence_IterSearch(seq, ob, PY_ITERSEARCH_CONTAINS);
 	return Py_SAFE_DOWNCAST(result, Py_ssize_t, int);
@@ -1890,7 +1890,7 @@ PySequence_Index(PyObject *s, PyObject *o)
 int
 PyMapping_Check(PyObject *o)
 {
-	return  o && o->ob_type->tp_as_mapping &&
+	return	o && o->ob_type->tp_as_mapping &&
 		o->ob_type->tp_as_mapping->mp_subscript;
 }
 
@@ -2044,7 +2044,7 @@ PyObject_CallObject(PyObject *o, PyObject *a)
 PyObject *
 PyObject_Call(PyObject *func, PyObject *arg, PyObject *kw)
 {
-        ternaryfunc call;
+	ternaryfunc call;
 
 	if ((call = func->ob_type->tp_call) != NULL) {
 		PyObject *result;
@@ -2308,7 +2308,7 @@ PyObject_CallFunctionObjArgs(PyObject *callable, ...)
  * produce exactly the same results: NULL is returned and no error is set.
  *
  * If some exception other than AttributeError is raised, then NULL is also
- * returned, but the exception is not cleared.  That's because we want the
+ * returned, but the exception is not cleared.	That's because we want the
  * exception to be propagated along.
  *
  * Callers are expected to test for PyErr_Occurred() when the return value
@@ -2336,7 +2336,7 @@ abstract_get_bases(PyObject *cls)
 		return NULL;
 	}
 	if (!PyTuple_Check(bases)) {
-	        Py_DECREF(bases);
+		Py_DECREF(bases);
 		return NULL;
 	}
 	return bases;
@@ -2428,18 +2428,18 @@ recursive_isinstance(PyObject *inst, PyObject *cls, int recursion_depth)
 	else if (PyTuple_Check(cls)) {
 		Py_ssize_t i, n;
 
-                if (!recursion_depth) {
-                    PyErr_SetString(PyExc_RuntimeError,
-                                    "nest level of tuple too deep");
-                    return -1;
-                }
+		if (!recursion_depth) {
+		    PyErr_SetString(PyExc_RuntimeError,
+				    "nest level of tuple too deep");
+		    return -1;
+		}
 
 		n = PyTuple_GET_SIZE(cls);
 		for (i = 0; i < n; i++) {
 			retval = recursive_isinstance(
-                                    inst,
-                                    PyTuple_GET_ITEM(cls, i),
-                                    recursion_depth-1);
+				    inst,
+				    PyTuple_GET_ITEM(cls, i),
+				    recursion_depth-1);
 			if (retval != 0)
 				break;
 		}
@@ -2490,12 +2490,12 @@ PyObject_IsInstance(PyObject *inst, PyObject *cls)
 	return recursive_isinstance(inst, cls, Py_GetRecursionLimit());
 }
 
-static  int
+static	int
 recursive_issubclass(PyObject *derived, PyObject *cls, int recursion_depth)
 {
 	int retval;
 
-        {
+	{
 		if (!check_class(derived,
 				 "issubclass() arg 1 must be a class"))
 			return -1;
@@ -2504,16 +2504,16 @@ recursive_issubclass(PyObject *derived, PyObject *cls, int recursion_depth)
 			Py_ssize_t i;
 			Py_ssize_t n = PyTuple_GET_SIZE(cls);
 
-                        if (!recursion_depth) {
-                            PyErr_SetString(PyExc_RuntimeError,
-                                            "nest level of tuple too deep");
-                            return -1;
-                        }
+			if (!recursion_depth) {
+			    PyErr_SetString(PyExc_RuntimeError,
+					    "nest level of tuple too deep");
+			    return -1;
+			}
 			for (i = 0; i < n; ++i) {
 				retval = recursive_issubclass(
-                                            derived,
-                                            PyTuple_GET_ITEM(cls, i),
-                                            recursion_depth-1);
+					    derived,
+					    PyTuple_GET_ITEM(cls, i),
+					    recursion_depth-1);
 				if (retval != 0) {
 					/* either found it, or got an error */
 					return retval;
@@ -2590,7 +2590,7 @@ PyObject_GetIter(PyObject *o)
  * If the iteration terminates normally, return NULL and clear the
  * PyExc_StopIteration exception (if it was set).  PyErr_Occurred()
  * will be false.
- * Else return the next object.  PyErr_Occurred() will be false.
+ * Else return the next object.	 PyErr_Occurred() will be false.
  */
 PyObject *
 PyIter_Next(PyObject *iter)
diff --git a/Objects/memoryobject.c b/Objects/memoryobject.c
index f2f7505..02f21ce 100644
--- a/Objects/memoryobject.c
+++ b/Objects/memoryobject.c
@@ -196,7 +196,9 @@ _indirect_copy_nd(char *dest, Py_buffer *view, char fort)
                 a contiguous buffer if it is not. The view will point to
                 the shadow buffer which can be written to and then
                 will be copied back into the other buffer when the memory
-                view is de-allocated.
+                view is de-allocated.  While the shadow buffer is 
+		being used, it will have an exclusive write lock on 
+		the original buffer. 
  */
 
 PyObject *
@@ -224,7 +226,7 @@ PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char fort)
                 flags = PyBUF_FULL;
                 break;
         case PyBUF_SHADOW:
-                flags = PyBUF_FULL_LCK;
+                flags = PyBUF_FULL_XLCK;
                 break;
         }
 
@@ -431,11 +433,7 @@ memory_dealloc(PyMemoryViewObject *self)
 static PyObject *
 memory_repr(PyMemoryViewObject *self)
 {
-	/* XXX(nnorwitz): the code should be different or remove condition. */
-	if (self->base == NULL)
-		return PyUnicode_FromFormat("<memory at %p>", self);
-	else
-		return PyUnicode_FromFormat("<memory at %p>", self);
+	return PyUnicode_FromFormat("<memory at %p>", self);
 }
 
 
@@ -502,6 +500,14 @@ memory_subscript(PyMemoryViewObject *self, PyObject *key)
 			/* Return a bytes object */
 			char *ptr;
 			ptr = (char *)view->buf;
+			if (result < 0) {
+				result += view->shape[0];
+			}
+			if ((result < 0) || (result > view->shape[0])) {
+				PyErr_SetString(PyExc_IndexError,
+						"index out of bounds");
+				return NULL;
+			}
 			if (view->strides == NULL)
 				ptr += view->itemsize * result;
 			else
@@ -517,14 +523,20 @@ memory_subscript(PyMemoryViewObject *self, PyObject *key)
 			/* Return a new memory-view object */
 			Py_buffer newview;
 			memset(&newview, 0, sizeof(newview));
+			/* XXX:  This needs to be fixed so it 
+			         actually returns a sub-view
+			*/
 			return PyMemoryView_FromMemory(&newview);
 		}
 	}
 
+	/* Need to support getting a sliced view */
         Py_INCREF(Py_NotImplemented);
         return Py_NotImplemented;
 }
 
+
+/* Need to support assigning memory if we can */
 static int
 memory_ass_sub(PyMemoryViewObject *self, PyObject *key, PyObject *value)
 {