Merged in py3k-buffer branch to main line. All objects now use the buffer protocol in PEP 3118.

8 files changed, 1305 insertions, 521 deletions

diff --git a/Objects/abstract.c b/Objects/abstract.c
index d43bb6a..a48d5dc 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -215,50 +215,50 @@ PyObject_DelItemString(PyObject *o, char *key)
 	return ret;
 }
 
+/* We release the buffer right after use of this function which could
+   cause issues later on.  Don't use these functions in new code. 
+ */
 int
 PyObject_AsCharBuffer(PyObject *obj,
-			  const char **buffer,
-			  Py_ssize_t *buffer_len)
+                      const char **buffer,
+                      Py_ssize_t *buffer_len)
 {
 	PyBufferProcs *pb;
-	char *pp;
-	Py_ssize_t len;
+        PyBuffer view;
 
 	if (obj == NULL || buffer == NULL || buffer_len == NULL) {
 		null_error();
 		return -1;
 	}
 	pb = obj->ob_type->tp_as_buffer;
-	if (pb == NULL ||
-	     pb->bf_getcharbuffer == NULL ||
-	     pb->bf_getsegcount == NULL) {
+	if (pb == NULL || pb->bf_getbuffer == NULL) {
 		PyErr_SetString(PyExc_TypeError,
-				"expected a character buffer object");
+				"expected an object with the buffer interface");
 		return -1;
-	}
-	if ((*pb->bf_getsegcount)(obj,NULL) != 1) {
-		PyErr_SetString(PyExc_TypeError,
-				"expected a single-segment buffer object");
-		return -1;
-	}
-	len = (*pb->bf_getcharbuffer)(obj, 0, &pp);
-	if (len < 0)
-		return -1;
-	*buffer = pp;
-	*buffer_len = len;
+        }
+        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);
 	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_getreadbuffer == NULL ||
-	    pb->bf_getsegcount == NULL ||
-	    (*pb->bf_getsegcount)(obj, NULL) != 1)
-		return 0;
+	    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 1;
 }
 
@@ -267,8 +267,7 @@ int PyObject_AsReadBuffer(PyObject *obj,
 			  Py_ssize_t *buffer_len)
 {
 	PyBufferProcs *pb;
-	void *pp;
-	Py_ssize_t len;
+        PyBuffer view;
 
 	if (obj == NULL || buffer == NULL || buffer_len == NULL) {
 		null_error();
@@ -276,22 +275,18 @@ int PyObject_AsReadBuffer(PyObject *obj,
 	}
 	pb = obj->ob_type->tp_as_buffer;
 	if (pb == NULL ||
-	     pb->bf_getreadbuffer == NULL ||
-	     pb->bf_getsegcount == NULL) {
-		PyErr_SetString(PyExc_TypeError,
-				"expected a readable buffer object");
-		return -1;
-	}
-	if ((*pb->bf_getsegcount)(obj, NULL) != 1) {
+            pb->bf_getbuffer == NULL) {
 		PyErr_SetString(PyExc_TypeError,
-				"expected a single-segment buffer object");
+				"expected an object with a buffer interface");
 		return -1;
 	}
-	len = (*pb->bf_getreadbuffer)(obj, 0, &pp);
-	if (len < 0)
-		return -1;
-	*buffer = pp;
-	*buffer_len = len;
+
+        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);
 	return 0;
 }
 
@@ -300,8 +295,7 @@ int PyObject_AsWriteBuffer(PyObject *obj,
 			   Py_ssize_t *buffer_len)
 {
 	PyBufferProcs *pb;
-	void*pp;
-	Py_ssize_t len;
+        PyBuffer view;
 
 	if (obj == NULL || buffer == NULL || buffer_len == NULL) {
 		null_error();
@@ -309,25 +303,384 @@ int PyObject_AsWriteBuffer(PyObject *obj,
 	}
 	pb = obj->ob_type->tp_as_buffer;
 	if (pb == NULL ||
-	     pb->bf_getwritebuffer == NULL ||
-	     pb->bf_getsegcount == NULL) {
-		PyErr_SetString(PyExc_TypeError,
-				"expected a writeable buffer object");
+            pb->bf_getbuffer == NULL ||
+            ((*pb->bf_getbuffer)(obj, &view, PyBUF_WRITEABLE) != 0)) {
+		PyErr_SetString(PyExc_TypeError, 
+                                "expected an object with a writeable buffer interface");
 		return -1;
 	}
-	if ((*pb->bf_getsegcount)(obj, NULL) != 1) {
-		PyErr_SetString(PyExc_TypeError,
-				"expected a single-segment buffer object");
-		return -1;
-	}
-	len = (*pb->bf_getwritebuffer)(obj,0,&pp);
-	if (len < 0)
-		return -1;
-	*buffer = pp;
-	*buffer_len = len;
+
+	*buffer = view.buf;
+	*buffer_len = view.len;
+        if (pb->bf_releasebuffer != NULL)
+                (*pb->bf_releasebuffer)(obj, &view);
 	return 0;
 }
 
+/* Buffer C-API for Python 3.0 */
+
+int
+PyObject_GetBuffer(PyObject *obj, PyBuffer *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);
+}
+
+void
+PyObject_ReleaseBuffer(PyObject *obj, PyBuffer *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(PyBuffer *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;
+}
+
+static int
+_IsCContiguous(PyBuffer *view)
+{
+        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;        
+}
+
+int
+PyBuffer_IsContiguous(PyBuffer *view, char fort)
+{
+
+        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;
+}
+
+
+void* 
+PyBuffer_GetPointer(PyBuffer *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;
+}
+
+
+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;
+                }
+        }
+}
+
+void 
+_add_one_to_index_C(int nd, Py_ssize_t *index, Py_ssize_t *shape)
+{
+        int k;
+
+        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
+     assumed that the size of the buffer is view->len in 
+     view->len / view->itemsize elements.
+  */
+
+int 
+PyBuffer_ToContiguous(void *buf, PyBuffer *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 */
+        
+        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(PyBuffer *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;
+
+        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;
+        }
+
+        /* Otherwise a more elaborate scheme is needed */
+        
+        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) 
+{
+        PyBuffer 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 */
+        
+        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++) {
+                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;
+}
+
+int
+PyBuffer_FillInfo(PyBuffer *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_WRITEABLE) == PyBUF_WRITEABLE) &&
+            readonly == 1) {
+                PyErr_SetString(PyExc_BufferError,
+                                "Object is not writeable.");
+                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 */
 
 int
diff --git a/Objects/bufferobject.c b/Objects/bufferobject.c
index 64b11a9..a8bbd15 100644
--- a/Objects/bufferobject.c
+++ b/Objects/bufferobject.c
@@ -15,80 +15,58 @@ typedef struct {
 } PyBufferObject;
 
 
-enum buffer_t {
-    READ_BUFFER,
-    WRITE_BUFFER,
-    CHAR_BUFFER,
-    ANY_BUFFER
-};
-
 static int
-get_buf(PyBufferObject *self, void **ptr, Py_ssize_t *size,
-	enum buffer_t buffer_type)
+get_buf(PyBufferObject *self, PyBuffer *view, int flags)
 {
 	if (self->b_base == NULL) {
-		assert (ptr != NULL);
-		*ptr = self->b_ptr;
-		*size = self->b_size;
+		view->buf = self->b_ptr;
+		view->len = self->b_size;
 	}
 	else {
 		Py_ssize_t count, offset;
-		readbufferproc proc = 0;
 		PyBufferProcs *bp = self->b_base->ob_type->tp_as_buffer;
-		if ((*bp->bf_getsegcount)(self->b_base, NULL) != 1) {
-			PyErr_SetString(PyExc_TypeError,
-				"single-segment buffer object expected");
-			return 0;
-		}
-		if ((buffer_type == READ_BUFFER) ||
-			((buffer_type == ANY_BUFFER) && self->b_readonly))
-		    proc = bp->bf_getreadbuffer;
-		else if ((buffer_type == WRITE_BUFFER) ||
-			(buffer_type == ANY_BUFFER))
-    		    proc = (readbufferproc)bp->bf_getwritebuffer;
-		else if (buffer_type == CHAR_BUFFER) {
-		    proc = (readbufferproc)bp->bf_getcharbuffer;
-		}
-		if (!proc) {
-		    char *buffer_type_name;
-		    switch (buffer_type) {
-			case READ_BUFFER:
-			    buffer_type_name = "read";
-			    break;
-			case WRITE_BUFFER:
-			    buffer_type_name = "write";
-			    break;
-			case CHAR_BUFFER:
-			    buffer_type_name = "char";
-			    break;
-			default:
-			    buffer_type_name = "no";
-			    break;
-		    }
-		    PyErr_Format(PyExc_TypeError,
-			    "%s buffer type not available",
-			    buffer_type_name);
-		    return 0;
-		}
-		if ((count = (*proc)(self->b_base, 0, ptr)) < 0)
-			return 0;
+                if ((*bp->bf_getbuffer)(self->b_base, view, flags) < 0) return 0;
+                count = view->len;
 		/* apply constraints to the start/end */
 		if (self->b_offset > count)
 			offset = count;
 		else
 			offset = self->b_offset;
-		*(char **)ptr = *(char **)ptr + offset;
+                view->buf = (char*)view->buf + offset;
 		if (self->b_size == Py_END_OF_BUFFER)
-			*size = count;
+			view->len = count;
 		else
-			*size = self->b_size;
-		if (offset + *size > count)
-			*size = count - offset;
+			view->len = self->b_size;
+		if (offset + view->len > count)
+			view->len = count - offset;
 	}
 	return 1;
 }
 
 
+static int
+buffer_getbuf(PyBufferObject *self, PyBuffer *view, int flags)
+{
+        if (view == NULL) return 0;
+        if (!get_buf(self, view, flags))
+                return -1;
+        return PyBuffer_FillInfo(view, view->buf, view->len, self->b_readonly, flags);
+}
+
+
+static void
+buffer_releasebuf(PyBufferObject *self, PyBuffer *view) 
+{
+        /* No-op if there is no self->b_base */
+	if (self->b_base != NULL) {
+		PyBufferProcs *bp = self->b_base->ob_type->tp_as_buffer;
+                if (bp->bf_releasebuffer != NULL) {
+                        (*bp->bf_releasebuffer)(self->b_base, view);
+                }
+        }
+        return;
+}
+
 static PyObject *
 buffer_from_memory(PyObject *base, Py_ssize_t size, Py_ssize_t offset, void *ptr,
 		   int readonly)
@@ -152,10 +130,8 @@ PyBuffer_FromObject(PyObject *base, Py_ssize_t offset, Py_ssize_t size)
 	PyBufferProcs *pb = base->ob_type->tp_as_buffer;
 
 	if ( pb == NULL ||
-	     pb->bf_getreadbuffer == NULL ||
-	     pb->bf_getsegcount == NULL )
-	{
-		PyErr_SetString(PyExc_TypeError, "buffer object expected");
+	     pb->bf_getbuffer == NULL) {
+                PyErr_SetString(PyExc_TypeError, "buffer object expected");
 		return NULL;
 	}
 
@@ -168,9 +144,7 @@ PyBuffer_FromReadWriteObject(PyObject *base, Py_ssize_t offset, Py_ssize_t size)
 	PyBufferProcs *pb = base->ob_type->tp_as_buffer;
 
 	if ( pb == NULL ||
-	     pb->bf_getwritebuffer == NULL ||
-	     pb->bf_getsegcount == NULL )
-	{
+	     pb->bf_getbuffer == NULL) {
 		PyErr_SetString(PyExc_TypeError, "buffer object expected");
 		return NULL;
 	}
@@ -252,12 +226,12 @@ buffer_dealloc(PyBufferObject *self)
 }
 
 static int
-get_bufx(PyObject *obj, void **ptr, Py_ssize_t *size)
+get_bufx(PyObject *obj, PyBuffer *view, int flags)
 {
 	PyBufferProcs *bp;
 
 	if (PyBuffer_Check(obj)) {
-		if (!get_buf((PyBufferObject *)obj, ptr, size, ANY_BUFFER)) {
+		if (!get_buf((PyBufferObject *)obj, view, flags)) {
 			PyErr_Clear();
 			return 0;
 		}
@@ -266,17 +240,11 @@ get_bufx(PyObject *obj, void **ptr, Py_ssize_t *size)
 	}
 	bp = obj->ob_type->tp_as_buffer;
 	if (bp == NULL ||
-	    bp->bf_getreadbuffer == NULL ||
-	    bp->bf_getsegcount == NULL)
-		return 0;
-	if ((*bp->bf_getsegcount)(obj, NULL) != 1)
+	    bp->bf_getbuffer == NULL)
 		return 0;
-	*size = (*bp->bf_getreadbuffer)(obj, 0, ptr);
-	if (*size < 0) {
-		PyErr_Clear();
+	if ((*bp->bf_getbuffer)(obj, view, PyBUF_SIMPLE) < 0)
 		return 0;
-	}
-	return 1;
+        return 1;
 }
 
 static PyObject *
@@ -285,12 +253,15 @@ buffer_richcompare(PyObject *self, PyObject *other, int op)
 	void *p1, *p2;
 	Py_ssize_t len1, len2, min_len;
 	int cmp, ok;
+        PyBuffer v1, v2;
 
 	ok = 1;
-	if (!get_bufx(self, &p1, &len1))
+	if (!get_bufx(self, &v1, PyBUF_SIMPLE))
 		ok = 0;
-	if (!get_bufx(other, &p2, &len2))
+	if (!get_bufx(other, &v2, PyBUF_SIMPLE)) {
+                if (ok) PyObject_ReleaseBuffer((PyObject *)self, &v1);
 		ok = 0;
+        }
 	if (!ok) {
 		/* If we can't get the buffers,
 		   == and != are still defined
@@ -305,11 +276,17 @@ buffer_richcompare(PyObject *self, PyObject *other, int op)
 		Py_INCREF(result);
 		return result;
 	}
+        len1 = v1.len;
+        len2 = v2.len;
+        p1 = v1.buf;
+        p2 = v2.buf;
 	min_len = (len1 < len2) ? len1 : len2;
 	cmp = memcmp(p1, p2, min_len);
 	if (cmp == 0)
 		cmp = (len1 < len2) ? -1 :
 		      (len1 > len2) ? 1 : 0;
+        PyObject_ReleaseBuffer((PyObject *)self, &v1);
+        PyObject_ReleaseBuffer(other, &v2);
 	return Py_CmpToRich(op, cmp);
 }
 
@@ -337,8 +314,7 @@ buffer_repr(PyBufferObject *self)
 static long
 buffer_hash(PyBufferObject *self)
 {
-	void *ptr;
-	Py_ssize_t size;
+        PyBuffer view;
 	register Py_ssize_t len;
 	register unsigned char *p;
 	register long x;
@@ -346,42 +322,39 @@ buffer_hash(PyBufferObject *self)
 	if ( self->b_hash != -1 )
 		return self->b_hash;
 
-	/* XXX potential bugs here, a readonly buffer does not imply that the
-	 * underlying memory is immutable.  b_readonly is a necessary but not
-	 * sufficient condition for a buffer to be hashable.  Perhaps it would
-	 * be better to only allow hashing if the underlying object is known to
-	 * be immutable (e.g. PyString_Check() is true).  Another idea would
-	 * be to call tp_hash on the underlying object and see if it raises
-	 * an error. */
-	if ( !self->b_readonly )
-	{
-		PyErr_SetString(PyExc_TypeError,
-				"writable buffers are not hashable");
+        if (!get_buf(self, &view, PyBUF_SIMPLE))
 		return -1;
-	}
-
-	if (!get_buf(self, &ptr, &size, ANY_BUFFER))
+        if (!(self->b_readonly)) {
+                PyErr_SetString(PyExc_TypeError,
+                                "writable buffers are not hashable");
+                PyObject_ReleaseBuffer((PyObject *)self, &view);
 		return -1;
-	p = (unsigned char *) ptr;
-	len = size;
+	}
+                
+	p = (unsigned char *) view.buf;
+	len = view.len;
 	x = *p << 7;
 	while (--len >= 0)
 		x = (1000003*x) ^ *p++;
-	x ^= size;
+	x ^= view.len;
 	if (x == -1)
 		x = -2;
 	self->b_hash = x;
+        PyObject_ReleaseBuffer((PyObject *)self, &view);
 	return x;
 }
 
 static PyObject *
 buffer_str(PyBufferObject *self)
 {
-	void *ptr;
-	Py_ssize_t size;
-	if (!get_buf(self, &ptr, &size, ANY_BUFFER))
+        PyBuffer view;
+        PyObject *res;
+
+	if (!get_buf(self, &view, PyBUF_SIMPLE))
 		return NULL;
-	return PyString_FromStringAndSize((const char *)ptr, size);
+	res = PyString_FromStringAndSize((const char *)view.buf, view.len);
+        PyObject_ReleaseBuffer((PyObject *)self, &view);
+        return res;
 }
 
 /* Sequence methods */
@@ -389,71 +362,58 @@ buffer_str(PyBufferObject *self)
 static Py_ssize_t
 buffer_length(PyBufferObject *self)
 {
-	void *ptr;
-	Py_ssize_t size;
-	if (!get_buf(self, &ptr, &size, ANY_BUFFER))
+        PyBuffer view;
+
+	if (!get_buf(self, &view, PyBUF_SIMPLE))
 		return -1;
-	return size;
+        PyObject_ReleaseBuffer((PyObject *)self, &view);
+	return view.len;
 }
 
 static PyObject *
 buffer_concat(PyBufferObject *self, PyObject *other)
 {
 	PyBufferProcs *pb = other->ob_type->tp_as_buffer;
-	void *ptr1, *ptr2;
 	char *p;
 	PyObject *ob;
-	Py_ssize_t size, count;
+        PyBuffer view, view2;
 
 	if ( pb == NULL ||
-	     pb->bf_getreadbuffer == NULL ||
-	     pb->bf_getsegcount == NULL )
+	     pb->bf_getbuffer == NULL)
 	{
 		PyErr_BadArgument();
 		return NULL;
 	}
-	if ( (*pb->bf_getsegcount)(other, NULL) != 1 )
-	{
-		/* ### use a different exception type/message? */
-		PyErr_SetString(PyExc_TypeError,
-				"single-segment buffer object expected");
-		return NULL;
-	}
 
- 	if (!get_buf(self, &ptr1, &size, ANY_BUFFER))
+ 	if (!get_buf(self, &view, PyBUF_SIMPLE))
  		return NULL;
  
 	/* optimize special case */
         /* XXX bad idea type-wise */
-	if ( size == 0 )
-	{
-	    Py_INCREF(other);
-	    return other;
+	if ( view.len == 0 ) {
+                PyObject_ReleaseBuffer((PyObject *)self, &view);
+                Py_INCREF(other);
+                return other;
 	}
 
-        if (PyUnicode_Check(other)) {
-		/* XXX HACK */
-		if ( (count = (*pb->bf_getcharbuffer)(other, 0,
-                                                      (char **)&ptr2)) < 0 )
-			return NULL;
-	}
-	else {
-		if ( (count = (*pb->bf_getreadbuffer)(other, 0, &ptr2)) < 0 )
-			return NULL;
-	}
+        if (PyObject_GetBuffer((PyObject *)other, &view2, PyBUF_SIMPLE) < 0) {
+                PyObject_ReleaseBuffer((PyObject *)self, &view);
+                return NULL;
+        }
 
-        /* XXX Should return a bytes object, really */
- 	ob = PyString_FromStringAndSize(NULL, size + count);
-	if ( ob == NULL )
+ 	ob = PyBytes_FromStringAndSize(NULL, view.len+view2.len);
+	if ( ob == NULL ) {
+                PyObject_ReleaseBuffer((PyObject *)self, &view);
+                PyObject_ReleaseBuffer(other, &view2);
 		return NULL;
- 	p = PyString_AS_STRING(ob);
- 	memcpy(p, ptr1, size);
- 	memcpy(p + size, ptr2, count);
-
-	/* there is an extra byte in the string object, so this is safe */
-	p[size + count] = '\0';
-
-	return ob;
+        }
+ 	p = PyBytes_AS_STRING(ob);
+ 	memcpy(p, view.buf, view.len);
+ 	memcpy(p + view.len, view2.buf, view2.len);
+
+        PyObject_ReleaseBuffer((PyObject *)self, &view);
+        PyObject_ReleaseBuffer(other, &view2);
+        return ob;
 }
 
 static PyObject *
@@ -461,81 +421,83 @@ buffer_repeat(PyBufferObject *self, Py_ssize_t count)
 {
 	PyObject *ob;
 	register char *p;
-	void *ptr;
-	Py_ssize_t size;
+        PyBuffer view;
 
 	if ( count < 0 )
 		count = 0;
-	if (!get_buf(self, &ptr, &size, ANY_BUFFER))
+	if (!get_buf(self, &view, PyBUF_SIMPLE))
 		return NULL;
-	ob = PyString_FromStringAndSize(NULL, size * count);
+	ob = PyBytes_FromStringAndSize(NULL, view.len * count);
 	if ( ob == NULL )
 		return NULL;
 
-	p = PyString_AS_STRING(ob);
+	p = PyBytes_AS_STRING(ob);
 	while ( count-- )
 	{
-	    memcpy(p, ptr, size);
-	    p += size;
+	    memcpy(p, view.buf, view.len);
+	    p += view.len;
 	}
 
-	/* there is an extra byte in the string object, so this is safe */
-	*p = '\0';
-
+        PyObject_ReleaseBuffer((PyObject *)self, &view);
 	return ob;
 }
 
 static PyObject *
 buffer_item(PyBufferObject *self, Py_ssize_t idx)
 {
-	void *ptr;
-	Py_ssize_t size;
-	if (!get_buf(self, &ptr, &size, ANY_BUFFER))
+        PyBuffer view;
+        PyObject *ob;
+
+	if (!get_buf(self, &view, PyBUF_SIMPLE))
 		return NULL;
-	if ( idx < 0 || idx >= size ) {
+	if ( idx < 0 || idx >= view.len ) {
 		PyErr_SetString(PyExc_IndexError, "buffer index out of range");
 		return NULL;
 	}
-	return PyString_FromStringAndSize((char *)ptr + idx, 1);
+	ob = PyBytes_FromStringAndSize((char *)view.buf + idx, 1);
+        PyObject_ReleaseBuffer((PyObject *)self, &view);
+        return ob;
 }
 
 static PyObject *
 buffer_slice(PyBufferObject *self, Py_ssize_t left, Py_ssize_t right)
 {
-	void *ptr;
-	Py_ssize_t size;
-	if (!get_buf(self, &ptr, &size, ANY_BUFFER))
+        PyObject *ob;
+        PyBuffer view;
+	if (!get_buf(self, &view, PyBUF_SIMPLE))
 		return NULL;
 	if ( left < 0 )
 		left = 0;
 	if ( right < 0 )
 		right = 0;
-	if ( right > size )
-		right = size;
+	if ( right > view.len )
+		right = view.len;
 	if ( right < left )
 		right = left;
-	return PyString_FromStringAndSize((char *)ptr + left,
-					  right - left);
+	ob = PyBytes_FromStringAndSize((char *)view.buf + left,
+                                       right - left);
+        PyObject_ReleaseBuffer((PyObject *)self, &view);
+        return ob;
 }
 
 static int
 buffer_ass_item(PyBufferObject *self, Py_ssize_t idx, PyObject *other)
 {
 	PyBufferProcs *pb;
-	void *ptr1, *ptr2;
-	Py_ssize_t size;
-	Py_ssize_t count;
+        PyBuffer view, view2;
 
-	if ( self->b_readonly ) {
+	if (!get_buf(self, &view, PyBUF_SIMPLE))
+		return -1;
+        
+	if ( self->b_readonly || view.readonly ) {
 		PyErr_SetString(PyExc_TypeError,
 				"buffer is read-only");
+                PyObject_ReleaseBuffer((PyObject *)self, &view);
 		return -1;
 	}
 
-	if (!get_buf(self, &ptr1, &size, ANY_BUFFER))
-		return -1;
-
-	if (idx < 0 || idx >= size) {
+	if (idx < 0 || idx >= view.len) {
+                PyObject_ReleaseBuffer((PyObject *)self, &view);
 		PyErr_SetString(PyExc_IndexError,
 				"buffer assignment index out of range");
 		return -1;
@@ -543,29 +505,27 @@ buffer_ass_item(PyBufferObject *self, Py_ssize_t idx, PyObject *other)
 
 	pb = other ? other->ob_type->tp_as_buffer : NULL;
 	if ( pb == NULL ||
-	     pb->bf_getreadbuffer == NULL ||
-	     pb->bf_getsegcount == NULL )
-	{
+	     pb->bf_getbuffer == NULL) {
 		PyErr_BadArgument();
+                PyObject_ReleaseBuffer((PyObject *)self, &view);
 		return -1;
 	}
-	if ( (*pb->bf_getsegcount)(other, NULL) != 1 )
-	{
-		/* ### use a different exception type/message? */
-		PyErr_SetString(PyExc_TypeError,
-				"single-segment buffer object expected");
-		return -1;
-	}
-
-	if ( (count = (*pb->bf_getreadbuffer)(other, 0, &ptr2)) < 0 )
-		return -1;
-	if ( count != 1 ) {
+        
+        if (PyObject_GetBuffer(other, &view2, PyBUF_SIMPLE) < 0) {
+                PyObject_ReleaseBuffer((PyObject *)self, &view);
+                return -1;
+        }
+	if ( view.len != 1 ) {
+                PyObject_ReleaseBuffer((PyObject *)self, &view);
+                PyObject_ReleaseBuffer(other, &view2);
 		PyErr_SetString(PyExc_TypeError,
 				"right operand must be a single byte");
 		return -1;
 	}
 
-	((char *)ptr1)[idx] = *(char *)ptr2;
+	((char *)(view.buf))[idx] = *((char *)(view2.buf));
+        PyObject_ReleaseBuffer((PyObject *)self, &view);
+        PyObject_ReleaseBuffer(other, &view2);
 	return 0;
 }
 
@@ -573,125 +533,60 @@ static int
 buffer_ass_slice(PyBufferObject *self, Py_ssize_t left, Py_ssize_t right, PyObject *other)
 {
 	PyBufferProcs *pb;
-	void *ptr1, *ptr2;
-	Py_ssize_t size;
+        PyBuffer v1, v2;
 	Py_ssize_t slice_len;
-	Py_ssize_t count;
-
-	if ( self->b_readonly ) {
-		PyErr_SetString(PyExc_TypeError,
-				"buffer is read-only");
-		return -1;
-	}
 
 	pb = other ? other->ob_type->tp_as_buffer : NULL;
 	if ( pb == NULL ||
-	     pb->bf_getreadbuffer == NULL ||
-	     pb->bf_getsegcount == NULL )
+	     pb->bf_getbuffer == NULL)
 	{
 		PyErr_BadArgument();
 		return -1;
 	}
-	if ( (*pb->bf_getsegcount)(other, NULL) != 1 )
-	{
-		/* ### use a different exception type/message? */
+	if (!get_buf(self, &v1, PyBUF_SIMPLE))
+                return -1;
+
+	if ( self->b_readonly || v1.readonly) {
 		PyErr_SetString(PyExc_TypeError,
-				"single-segment buffer object expected");
+				"buffer is read-only");
+                PyObject_ReleaseBuffer((PyObject *)self, &v1);
 		return -1;
 	}
-	if (!get_buf(self, &ptr1, &size, ANY_BUFFER))
-		return -1;
-	if ( (count = (*pb->bf_getreadbuffer)(other, 0, &ptr2)) < 0 )
-		return -1;
+
+        if ((*pb->bf_getbuffer)(other, &v2, PyBUF_SIMPLE) < 0) {
+                PyObject_ReleaseBuffer((PyObject *)self, &v1);
+                return -1;
+        }
 
 	if ( left < 0 )
 		left = 0;
-	else if ( left > size )
-		left = size;
+	else if ( left > v1.len )
+		left = v1.len;
 	if ( right < left )
 		right = left;
-	else if ( right > size )
-		right = size;
+	else if ( right > v1.len )
+		right = v1.len;
 	slice_len = right - left;
 
-	if ( count != slice_len ) {
+	if ( v2.len != slice_len ) {
 		PyErr_SetString(
 			PyExc_TypeError,
 			"right operand length must match slice length");
+                PyObject_ReleaseBuffer((PyObject *)self, &v1);
+                PyObject_ReleaseBuffer(other, &v2);
 		return -1;
 	}
 
 	if ( slice_len )
-	    memcpy((char *)ptr1 + left, ptr2, slice_len);
+	    memcpy((char *)v1.buf + left, v2.buf, slice_len);
 
+        PyObject_ReleaseBuffer((PyObject *)self, &v1);
+        PyObject_ReleaseBuffer(other, &v2);        
 	return 0;
 }
 
 /* Buffer methods */
 
-static Py_ssize_t
-buffer_getreadbuf(PyBufferObject *self, Py_ssize_t idx, void **pp)
-{
-	Py_ssize_t size;
-	if ( idx != 0 ) {
-		PyErr_SetString(PyExc_SystemError,
-				"accessing non-existent buffer segment");
-		return -1;
-	}
-	if (!get_buf(self, pp, &size, READ_BUFFER))
-		return -1;
-	return size;
-}
-
-static Py_ssize_t
-buffer_getwritebuf(PyBufferObject *self, Py_ssize_t idx, void **pp)
-{
-	Py_ssize_t size;
-
-	if ( self->b_readonly )
-	{
-		PyErr_SetString(PyExc_TypeError, "buffer is read-only");
-		return -1;
-	}
-
-	if ( idx != 0 ) {
-		PyErr_SetString(PyExc_SystemError,
-				"accessing non-existent buffer segment");
-		return -1;
-	}
-	if (!get_buf(self, pp, &size, WRITE_BUFFER))
-		return -1;
-	return size;
-}
-
-static Py_ssize_t
-buffer_getsegcount(PyBufferObject *self, Py_ssize_t *lenp)
-{
-	void *ptr;
-	Py_ssize_t size;
-	if (!get_buf(self, &ptr, &size, ANY_BUFFER))
-		return -1;
-	if (lenp)
-		*lenp = size;
-	return 1;
-}
-
-static Py_ssize_t
-buffer_getcharbuf(PyBufferObject *self, Py_ssize_t idx, const char **pp)
-{
-	void *ptr;
-	Py_ssize_t size;
-	if ( idx != 0 ) {
-		PyErr_SetString(PyExc_SystemError,
-				"accessing non-existent buffer segment");
-		return -1;
-	}
-	if (!get_buf(self, &ptr, &size, CHAR_BUFFER))
-		return -1;
-	*pp = (const char *)ptr;
-	return size;
-}
-
 static PySequenceMethods buffer_as_sequence = {
 	(lenfunc)buffer_length, /*sq_length*/
 	(binaryfunc)buffer_concat, /*sq_concat*/
@@ -703,10 +598,8 @@ static PySequenceMethods buffer_as_sequence = {
 };
 
 static PyBufferProcs buffer_as_buffer = {
-	(readbufferproc)buffer_getreadbuf,
-	(writebufferproc)buffer_getwritebuf,
-	(segcountproc)buffer_getsegcount,
-	(charbufferproc)buffer_getcharbuf,
+	(getbufferproc)buffer_getbuf,
+        (releasebufferproc)buffer_releasebuf,
 };
 
 PyTypeObject PyBuffer_Type = {
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index b409a28..5a03beb 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -26,6 +26,7 @@ PyBytes_Init(void)
         return 0;
     nullbytes->ob_bytes = NULL;
     Py_Size(nullbytes) = nullbytes->ob_alloc = 0;
+    nullbytes->ob_exports = 0;
     return 1;
 }
 
@@ -48,22 +49,44 @@ _getbytevalue(PyObject* arg, int *value)
     return 1;
 }
 
+static int
+bytes_getbuffer(PyBytesObject *obj, PyBuffer *view, int flags)
+{        
+        int ret;
+        void *ptr;
+        if (view == NULL) {
+                obj->ob_exports++;
+                return 0;
+        }
+        if (obj->ob_bytes == NULL) 
+                ptr = "";
+        else
+                ptr = obj->ob_bytes;
+        ret = PyBuffer_FillInfo(view, ptr, Py_Size(obj), 0, flags);
+        if (ret >= 0) {
+                obj->ob_exports++;
+        }
+        return ret;
+}
+
+static void
+bytes_releasebuffer(PyBytesObject *obj, PyBuffer *view)
+{
+        obj->ob_exports--;
+}
+
 Py_ssize_t
-_getbuffer(PyObject *obj, void **ptr)
+_getbuffer(PyObject *obj, PyBuffer *view)
 {
     PyBufferProcs *buffer = Py_Type(obj)->tp_as_buffer;
 
     if (buffer == NULL ||
         PyUnicode_Check(obj) ||
-        buffer->bf_getreadbuffer == NULL ||
-        buffer->bf_getsegcount == NULL ||
-        buffer->bf_getsegcount(obj, NULL) != 1)
-    {
-        *ptr = NULL;
-        return -1;
-    }
+        buffer->bf_getbuffer == NULL) return -1;
 
-    return buffer->bf_getreadbuffer(obj, 0, ptr);
+    if (buffer->bf_getbuffer(obj, view, PyBUF_SIMPLE) < 0)
+            return -1;
+    return view->len;
 }
 
 /* Direct API functions */
@@ -104,6 +127,7 @@ PyBytes_FromStringAndSize(const char *bytes, Py_ssize_t size)
     }
     Py_Size(new) = size;
     new->ob_alloc = alloc;
+    new->ob_exports = 0;
 
     return (PyObject *)new;
 }
@@ -155,6 +179,15 @@ PyBytes_Resize(PyObject *self, Py_ssize_t size)
         alloc = size + 1;
     }
 
+    if (((PyBytesObject *)self)->ob_exports > 0) {
+            /*
+            fprintf(stderr, "%d: %s", ((PyBytesObject *)self)->ob_exports, ((PyBytesObject *)self)->ob_bytes);
+            */
+            PyErr_SetString(PyExc_BufferError,
+                            "Existing exports of data: object cannot be re-sized");
+            return -1;
+    }
+
     sval = PyMem_Realloc(((PyBytesObject *)self)->ob_bytes, alloc);
     if (sval == NULL) {
         PyErr_NoMemory();
@@ -172,27 +205,38 @@ PyBytes_Resize(PyObject *self, Py_ssize_t size)
 PyObject *
 PyBytes_Concat(PyObject *a, PyObject *b)
 {
-    Py_ssize_t asize, bsize, size;
-    void *aptr, *bptr;
+    Py_ssize_t size;
+    PyBuffer va, vb;
     PyBytesObject *result;
 
-    asize = _getbuffer(a, &aptr);
-    bsize = _getbuffer(b, &bptr);
-    if (asize < 0 || bsize < 0) {
-        PyErr_Format(PyExc_TypeError, "can't concat %.100s to %.100s",
-                     Py_Type(a)->tp_name, Py_Type(b)->tp_name);
-        return NULL;
+    va.len = -1;
+    vb.len = -1;
+    if (_getbuffer(a, &va) < 0  ||
+        _getbuffer(b, &vb) < 0) {
+            if (va.len != -1) 
+                    PyObject_ReleaseBuffer(a, &va);
+            if (vb.len != -1)
+                    PyObject_ReleaseBuffer(b, &vb);
+            PyErr_Format(PyExc_TypeError, "can't concat %.100s to %.100s",
+                         Py_Type(a)->tp_name, Py_Type(b)->tp_name);
+            return NULL;
     }
 
-    size = asize + bsize;
-    if (size < 0)
-        return PyErr_NoMemory();
+    size = va.len + vb.len;
+    if (size < 0) {
+            PyObject_ReleaseBuffer(a, &va);
+            PyObject_ReleaseBuffer(b, &vb);
+            return PyErr_NoMemory();
+    }
 
     result = (PyBytesObject *) PyBytes_FromStringAndSize(NULL, size);
     if (result != NULL) {
-        memcpy(result->ob_bytes, aptr, asize);
-        memcpy(result->ob_bytes + asize, bptr, bsize);
+        memcpy(result->ob_bytes, va.buf, va.len);
+        memcpy(result->ob_bytes + va.len, vb.buf, vb.len);
     }
+    
+    PyObject_ReleaseBuffer(a, &va);
+    PyObject_ReleaseBuffer(b, &vb);
     return (PyObject *)result;
 }
 
@@ -213,30 +257,32 @@ bytes_concat(PyBytesObject *self, PyObject *other)
 static PyObject *
 bytes_iconcat(PyBytesObject *self, PyObject *other)
 {
-    void *optr;
-    Py_ssize_t osize;
     Py_ssize_t mysize;
     Py_ssize_t size;
+    PyBuffer vo;
 
-    /* XXX What if other == self? */
-    osize = _getbuffer(other, &optr);
-    if (osize < 0) {
-        PyErr_Format(PyExc_TypeError,
-                     "can't concat bytes to %.100s", Py_Type(other)->tp_name);
-        return NULL;
+    if (_getbuffer(other, &vo) < 0) {
+            PyErr_Format(PyExc_TypeError,
+                         "can't concat bytes to %.100s", Py_Type(self)->tp_name);
+            return NULL;
     }
 
     mysize = Py_Size(self);
-    size = mysize + osize;
-    if (size < 0)
-        return PyErr_NoMemory();
+    size = mysize + vo.len;
+    if (size < 0) {
+            PyObject_ReleaseBuffer(other, &vo);
+            return PyErr_NoMemory();
+    }
     if (size < self->ob_alloc) {
-        Py_Size(self) = size;
-	self->ob_bytes[Py_Size(self)] = '\0'; /* Trailing null byte */
+            Py_Size(self) = size;
+            self->ob_bytes[Py_Size(self)] = '\0'; /* Trailing null byte */
     }
-    else if (PyBytes_Resize((PyObject *)self, size) < 0)
-        return NULL;
-    memcpy(self->ob_bytes + mysize, optr, osize);
+    else if (PyBytes_Resize((PyObject *)self, size) < 0) {
+            PyObject_ReleaseBuffer(other, &vo);
+            return NULL;
+    }
+    memcpy(self->ob_bytes + mysize, vo.buf, vo.len);
+    PyObject_ReleaseBuffer(other, &vo);
     Py_INCREF(self);
     return (PyObject *)self;
 }
@@ -409,9 +455,12 @@ bytes_setslice(PyBytesObject *self, Py_ssize_t lo, Py_ssize_t hi,
 {
     Py_ssize_t avail, needed;
     void *bytes;
+    PyBuffer vbytes;
+    int res = 0;
 
+    vbytes.len = -1;
     if (values == (PyObject *)self) {
-        /* Make a copy an call this function recursively */
+        /* Make a copy and call this function recursively */
         int err;
         values = PyBytes_FromObject(values);
         if (values == NULL)
@@ -426,13 +475,14 @@ bytes_setslice(PyBytesObject *self, Py_ssize_t lo, Py_ssize_t hi,
         needed = 0;
     }
     else {
-        needed = _getbuffer(values, &bytes);
-        if (needed < 0) {
-            PyErr_Format(PyExc_TypeError,
-                         "can't set bytes slice from %.100s",
-                         Py_Type(values)->tp_name);
-            return -1;
-        }
+            if (_getbuffer(values, &vbytes) < 0) {
+                    PyErr_Format(PyExc_TypeError,
+                                 "can't set bytes slice from %.100s",
+                                 Py_Type(values)->tp_name);
+                    return -1;
+            }
+            needed = vbytes.len;
+            bytes = vbytes.buf;
     }
 
     if (lo < 0)
@@ -458,8 +508,10 @@ bytes_setslice(PyBytesObject *self, Py_ssize_t lo, Py_ssize_t hi,
                     Py_Size(self) - hi);
         }
         if (PyBytes_Resize((PyObject *)self,
-                           Py_Size(self) + needed - avail) < 0)
-            return -1;
+                           Py_Size(self) + needed - avail) < 0) {
+                res = -1;
+                goto finish;
+        }
         if (avail < needed) {
             /*
               0   lo        hi               old_size
@@ -475,7 +527,11 @@ bytes_setslice(PyBytesObject *self, Py_ssize_t lo, Py_ssize_t hi,
     if (needed > 0)
         memcpy(self->ob_bytes + lo, bytes, needed);
 
-    return 0;
+    
+ finish:
+    if (vbytes.len != -1) 
+            PyObject_ReleaseBuffer(values, &vbytes);
+    return res;
 }
 
 static int
@@ -743,16 +799,22 @@ bytes_init(PyBytesObject *self, PyObject *args, PyObject *kwds)
         }
         return 0;
     }
-
-    if (PyObject_CheckReadBuffer(arg)) {
-        const void *bytes;
+    
+    /* Use the modern buffer interface */
+    if (PyObject_CheckBuffer(arg)) {
         Py_ssize_t size;
-        if (PyObject_AsReadBuffer(arg, &bytes, &size) < 0)
+        PyBuffer view;
+        if (PyObject_GetBuffer(arg, &view, PyBUF_FULL_RO) < 0)
             return -1;
-        if (PyBytes_Resize((PyObject *)self, size) < 0)
-            return -1;
-        memcpy(self->ob_bytes, bytes, size);
+        size = view.len;
+        if (PyBytes_Resize((PyObject *)self, size) < 0) goto fail;
+        if (PyBuffer_ToContiguous(self->ob_bytes, &view, size, 'C') < 0)
+                goto fail;
+        PyObject_ReleaseBuffer(arg, &view);
         return 0;
+    fail:
+        PyObject_ReleaseBuffer(arg, &view);
+        return -1;
     }
 
     /* XXX Optimize this if the arguments is a list, tuple */
@@ -881,7 +943,7 @@ static PyObject *
 bytes_richcompare(PyObject *self, PyObject *other, int op)
 {
     Py_ssize_t self_size, other_size;
-    void *self_bytes, *other_bytes;
+    PyBuffer self_bytes, other_bytes;
     PyObject *res;
     Py_ssize_t minsize;
     int cmp;
@@ -897,6 +959,7 @@ bytes_richcompare(PyObject *self, PyObject *other, int op)
 
     other_size = _getbuffer(other, &other_bytes);
     if (other_size < 0) {
+        PyObject_ReleaseBuffer(self, &self_bytes);
         Py_INCREF(Py_NotImplemented);
         return Py_NotImplemented;
     }
@@ -910,7 +973,7 @@ bytes_richcompare(PyObject *self, PyObject *other, int op)
         if (other_size < minsize)
             minsize = other_size;
 
-        cmp = memcmp(self_bytes, other_bytes, minsize);
+        cmp = memcmp(self_bytes.buf, other_bytes.buf, minsize);
         /* In ISO C, memcmp() guarantees to use unsigned bytes! */
 
         if (cmp == 0) {
@@ -931,6 +994,8 @@ bytes_richcompare(PyObject *self, PyObject *other, int op)
     }
 
     res = cmp ? Py_True : Py_False;
+    PyObject_ReleaseBuffer(self, &self_bytes);
+    PyObject_ReleaseBuffer(other, &other_bytes);    
     Py_INCREF(res);
     return res;
 }
@@ -944,30 +1009,6 @@ bytes_dealloc(PyBytesObject *self)
     Py_Type(self)->tp_free((PyObject *)self);
 }
 
-static Py_ssize_t
-bytes_getbuffer(PyBytesObject *self, Py_ssize_t index, const void **ptr)
-{
-    if (index != 0) {
-        PyErr_SetString(PyExc_SystemError,
-                        "accessing non-existent bytes segment");
-        return -1;
-    }
-    if (self->ob_bytes == NULL)
-        *ptr = "";
-    else
-        *ptr = self->ob_bytes;
-    return Py_Size(self);
-}
-
-static Py_ssize_t
-bytes_getsegcount(PyStringObject *self, Py_ssize_t *lenp)
-{
-    if (lenp)
-        *lenp = Py_Size(self);
-    return 1;
-}
-
-
 
 /* -------------------------------------------------------------------- */
 /* Methods */
@@ -1018,6 +1059,7 @@ bytes_find_internal(PyBytesObject *self, PyObject *args, int dir)
         sub = PyBytes_AS_STRING(subobj);
         sub_len = PyBytes_GET_SIZE(subobj);
     }
+    /* XXX --> use the modern buffer interface */
     else if (PyObject_AsCharBuffer(subobj, &sub, &sub_len))
         /* XXX - the "expected a character buffer object" is pretty
            confusing for a non-expert.  remap to something else ? */
@@ -1075,6 +1117,7 @@ bytes_count(PyBytesObject *self, PyObject *args)
         sub = PyBytes_AS_STRING(sub_obj);
         sub_len = PyBytes_GET_SIZE(sub_obj);
     }
+    /* XXX --> use the modern buffer interface */
     else if (PyObject_AsCharBuffer(sub_obj, &sub, &sub_len))
         return NULL;
 
@@ -1162,6 +1205,7 @@ _bytes_tailmatch(PyBytesObject *self, PyObject *substr, Py_ssize_t start,
         sub = PyBytes_AS_STRING(substr);
         slen = PyBytes_GET_SIZE(substr);
     }
+    /* XXX --> Use the modern buffer interface */
     else if (PyObject_AsCharBuffer(substr, &sub, &slen))
         return -1;
     str = PyBytes_AS_STRING(self);
@@ -1297,6 +1341,7 @@ bytes_translate(PyBytesObject *self, PyObject *args)
         table1 = PyBytes_AS_STRING(tableobj);
         tablen = PyBytes_GET_SIZE(tableobj);
     }
+    /* XXX -> Use the modern buffer interface */
     else if (PyObject_AsCharBuffer(tableobj, &table1, &tablen))
         return NULL;
 
@@ -1311,6 +1356,7 @@ bytes_translate(PyBytesObject *self, PyObject *args)
             del_table = PyBytes_AS_STRING(delobj);
             dellen = PyBytes_GET_SIZE(delobj);
         }
+        /* XXX -> use the modern buffer interface */
         else if (PyObject_AsCharBuffer(delobj, &del_table, &dellen))
             return NULL;
     }
@@ -1973,9 +2019,11 @@ static PyObject *
 bytes_replace(PyBytesObject *self, PyObject *args)
 {
     Py_ssize_t count = -1;
-    PyObject *from, *to;
+    PyObject *from, *to, *res;
     const char *from_s, *to_s;
     Py_ssize_t from_len, to_len;
+    int relfrom=0, relto=0;
+    PyBuffer vfrom, vto;
 
     if (!PyArg_ParseTuple(args, "OO|n:replace", &from, &to, &count))
         return NULL;
@@ -1984,19 +2032,38 @@ bytes_replace(PyBytesObject *self, PyObject *args)
         from_s = PyBytes_AS_STRING(from);
         from_len = PyBytes_GET_SIZE(from);
     }
-    else if (PyObject_AsCharBuffer(from, &from_s, &from_len))
-        return NULL;
+    else {
+            if (PyObject_GetBuffer(from, &vfrom, PyBUF_CHARACTER) < 0) 
+                    return NULL;
+            from_s = vfrom.buf;
+            from_len = vfrom.len;
+            relfrom = 1;
+    }
 
     if (PyBytes_Check(to)) {
         to_s = PyBytes_AS_STRING(to);
         to_len = PyBytes_GET_SIZE(to);
     }
-    else if (PyObject_AsCharBuffer(to, &to_s, &to_len))
-        return NULL;
+    else {
+            if (PyObject_GetBuffer(to, &vto, PyBUF_CHARACTER) < 0) {
+                    if (relfrom)
+                            PyObject_ReleaseBuffer(from, &vfrom);
+                    return NULL;
+            }
+            to_s = vto.buf;
+            to_len = vto.len;
+            relto = 1;
+    }
 
-    return (PyObject *)replace((PyBytesObject *) self,
-                               from_s, from_len,
-                               to_s, to_len, count);
+    res = (PyObject *)replace((PyBytesObject *) self,
+                              from_s, from_len,
+                              to_s, to_len, count);
+
+    if (relfrom)
+            PyObject_ReleaseBuffer(from, &vfrom);
+    if (relto)
+            PyObject_ReleaseBuffer(to, &vto);
+    return res;
 }
 
 
@@ -2104,6 +2171,7 @@ bytes_split(PyBytesObject *self, PyObject *args)
         sub = PyBytes_AS_STRING(subobj);
         n = PyBytes_GET_SIZE(subobj);
     }
+    /* XXX -> use the modern buffer interface */
     else if (PyObject_AsCharBuffer(subobj, &sub, &n))
         return NULL;
 
@@ -2261,6 +2329,7 @@ bytes_rsplit(PyBytesObject *self, PyObject *args)
         sub = PyBytes_AS_STRING(subobj);
         n = PyBytes_GET_SIZE(subobj);
     }
+    /* XXX -> Use the modern buffer interface */
     else if (PyObject_AsCharBuffer(subobj, &sub, &n))
         return NULL;
 
@@ -2756,12 +2825,8 @@ static PyMappingMethods bytes_as_mapping = {
 };
 
 static PyBufferProcs bytes_as_buffer = {
-    (readbufferproc)bytes_getbuffer,
-    (writebufferproc)bytes_getbuffer,
-    (segcountproc)bytes_getsegcount,
-    /* XXX Bytes are not characters! But we need to implement
-       bf_getcharbuffer() so we can be used as 't#' argument to codecs. */
-    (charbufferproc)bytes_getbuffer,
+    (getbufferproc)bytes_getbuffer,
+    (releasebufferproc)bytes_releasebuffer,
 };
 
 static PyMethodDef
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index 2d096a7..710495f 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -1539,6 +1539,11 @@ SimpleExtendsException(PyExc_Exception, ReferenceError,
  */
 SimpleExtendsException(PyExc_Exception, MemoryError, "Out of memory.");
 
+/*
+ *    BufferError extends Exception
+ */
+SimpleExtendsException(PyExc_Exception, BufferError, "Buffer error.");
+
 
 /* Warning category docstrings */
 
diff --git a/Objects/memoryobject.c b/Objects/memoryobject.c
new file mode 100644
index 0000000..efcb7ae
--- /dev/null
+++ b/Objects/memoryobject.c
@@ -0,0 +1,540 @@
+
+/* Memoryview object implementation */
+
+#include "Python.h"
+
+static int
+memory_getbuf(PyMemoryViewObject *self, PyBuffer *view, int flags)
+{
+        if (view != NULL) 
+                memcpy(view, &(self->view), sizeof(PyBuffer));
+        return self->base->ob_type->tp_as_buffer->bf_getbuffer(self->base, 
+                                                               NULL, PyBUF_FULL);
+}
+
+static void
+memory_releasebuf(PyMemoryViewObject *self, PyBuffer *view) 
+{
+        PyObject_ReleaseBuffer(self->base, NULL);
+}
+
+PyDoc_STRVAR(memory_doc,
+"memoryview(object)\n\
+\n\
+Create a new memoryview object which references the given object.");
+
+PyObject *
+PyMemoryView_FromMemory(PyBuffer *info)
+{
+        return NULL;
+}
+
+PyObject *
+PyMemoryView_FromObject(PyObject *base)
+{
+        PyMemoryViewObject *mview;
+
+        if (!PyObject_CheckBuffer(base)) {
+                PyErr_SetString(PyExc_TypeError, 
+                                "cannot make memory view because object does "\
+                                "not have the buffer interface");
+                return NULL;                               
+        }
+        
+        mview = (PyMemoryViewObject *)PyObject_New(PyMemoryViewObject, 
+                                                   &PyMemoryView_Type);
+        if (mview == NULL) return NULL;
+        
+        if (PyObject_GetBuffer(base, &(mview->view), PyBUF_FULL) < 0) {
+                PyObject_DEL(mview);
+                return NULL;
+        }
+
+        mview->base = base;
+        Py_INCREF(base);
+        return (PyObject *)mview;
+}
+
+static PyObject *
+memory_new(PyTypeObject *subtype, PyObject *args, PyObject *kwds)
+{
+        PyObject *obj;
+        if (!PyArg_ParseTuple(args, "O", &obj)) return NULL;
+
+        return PyMemoryView_FromObject(obj);        
+}
+
+
+static void
+_strided_copy_nd(char *dest, char *src, int nd, Py_ssize_t *shape, 
+                 Py_ssize_t *strides, int itemsize, char fort)
+{
+        int k;
+        Py_ssize_t outstride;
+
+        if (nd==0) {
+                memcpy(dest, src, itemsize);
+        }
+        else if (nd == 1) {
+                for (k = 0; k<shape[0]; k++) {
+                        memcpy(dest, src, itemsize);
+                        dest += itemsize;
+                        src += strides[0];
+                }
+        }
+        else {
+                if (fort == 'F') {
+                        /* Copy first dimension first, 
+                           second dimension second, etc...
+                           Set up the recursive loop backwards so that final
+                           dimension is actually copied last. 
+                        */
+                        outstride = itemsize;
+                        for (k=1; k<nd-1;k++) {
+                                outstride *= shape[k];
+                        }
+                        for (k=0; k<shape[nd-1]; k++) {
+                                _strided_copy_nd(dest, src, nd-1, shape, 
+                                                 strides, itemsize, fort);
+                                dest += outstride;
+                                src += strides[nd-1];
+                        }
+                }
+                
+                else {
+                        /* Copy last dimension first,
+                           second-to-last dimension second, etc.
+                           Set up the recursion so that the
+                           first dimension is copied last
+                        */
+                        outstride = itemsize;
+                        for (k=1; k < nd; k++) {
+                                outstride *= shape[k];
+                        }
+                        for (k=0; k<shape[0]; k++) {
+                                _strided_copy_nd(dest, src, nd-1, shape+1,
+                                                 strides+1, itemsize, 
+                                                 fort);
+                                dest += outstride;
+                                src += strides[0];
+                        }
+                }
+        }
+        return;
+}
+
+void _add_one_to_index_F(int nd, Py_ssize_t *index, Py_ssize_t *shape);
+void _add_one_to_index_C(int nd, Py_ssize_t *index, Py_ssize_t *shape);
+
+static int
+_indirect_copy_nd(char *dest, PyBuffer *view, char fort)
+{
+        Py_ssize_t *indices;
+        int k;
+        Py_ssize_t elements;
+        char *ptr;
+        void (*func)(int, Py_ssize_t *, Py_ssize_t *);
+        
+        
+        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;
+        }
+        
+        elements = 1;
+        for (k=0; k<view->ndim; k++) {
+                elements *= view->shape[k];
+        }
+        if (fort == 'F') {
+                func = _add_one_to_index_F;
+        }
+        else {
+                func = _add_one_to_index_C;
+        }
+        while (elements--) {
+                func(view->ndim, indices, view->shape);
+                ptr = PyBuffer_GetPointer(view, indices);
+                memcpy(dest, ptr, view->itemsize);
+                dest += view->itemsize;
+        }
+                
+        PyMem_Free(indices);
+        return 0;
+}
+
+/* 
+   Get a the data from an object as a contiguous chunk of memory (in
+   either 'C' or 'F'ortran order) even if it means copying it into a
+   separate memory area.
+
+   Returns a new reference to a Memory view object.  If no copy is needed,
+   the memory view object points to the original memory and holds a 
+   lock on the original.  If a copy is needed, then the memory view object
+   points to a brand-new Bytes object (and holds a memory lock on it). 
+
+   buffertype
+
+   PyBUF_READ  buffer only needs to be read-only
+   PyBUF_WRITE buffer needs to be writeable (give error if not contiguous)
+   PyBUF_SHADOW buffer needs to be writeable so shadow it with 
+                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.
+ */
+
+PyObject *
+PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char fort)
+{
+        PyMemoryViewObject *mem;
+        PyObject *bytes;
+        PyBuffer *view;
+        int flags;
+        char *dest;
+
+        if (!PyObject_CheckBuffer(obj)) {
+                PyErr_SetString(PyExc_TypeError,
+                                "object does not have the buffer interface");
+                return NULL;
+        }
+        
+        mem = PyObject_New(PyMemoryViewObject, &PyMemoryView_Type);
+        if (mem == NULL) return NULL;
+
+        view = &PyMemoryView(mem);
+        flags = PyBUF_FULL_RO;
+        switch(buffertype) {
+        case PyBUF_WRITE:
+                flags = PyBUF_FULL;
+                break;
+        case PyBUF_SHADOW:
+                flags = PyBUF_FULL_LCK;
+                break;
+        }
+
+        if (PyObject_GetBuffer(obj, view, flags) != 0) {
+                PyObject_DEL(mem);
+                return NULL;
+        }
+
+        if (PyBuffer_IsContiguous(view, fort)) {
+                /* no copy needed */
+                Py_INCREF(obj);
+                mem->base = obj;
+                return (PyObject *)mem;
+        }
+        /* otherwise a copy is needed */
+        if (buffertype == PyBUF_WRITE) {
+                PyObject_DEL(mem);
+                PyErr_SetString(PyExc_BufferError,
+                                "writeable contiguous buffer requested for a non-contiguous" \
+                                "object.");
+                return NULL;
+        }
+        bytes = PyBytes_FromStringAndSize(NULL, view->len);
+        if (bytes == NULL) {
+                PyObject_ReleaseBuffer(obj, view);
+                return NULL;
+        }
+        dest = PyBytes_AS_STRING(bytes);
+        /* different copying strategy depending on whether
+           or not any pointer de-referencing is needed
+        */
+        /* strided or in-direct copy */
+        if (view->suboffsets==NULL) {
+                _strided_copy_nd(dest, view->buf, view->ndim, view->shape, 
+                                 view->strides, view->itemsize, fort); 
+        }
+        else {
+                if (_indirect_copy_nd(dest, view, fort) < 0) {
+                        Py_DECREF(bytes);
+                        PyObject_ReleaseBuffer(obj, view);
+                        return NULL;
+                }                 
+        }
+        if (buffertype == PyBUF_SHADOW) {
+                /* return a shadowed memory-view object */
+                view->buf = dest;
+                mem->base = PyTuple_Pack(2, obj, bytes);
+                Py_DECREF(bytes);
+        }
+        else {
+                PyObject_ReleaseBuffer(obj, view);
+                /* steal the reference */
+                mem->base = bytes;
+        }
+        return (PyObject *)mem;
+}
+
+
+static PyObject *
+memory_format_get(PyMemoryViewObject *self)
+{
+        return PyUnicode_FromString(self->view.format);
+}
+
+static PyObject *
+memory_itemsize_get(PyMemoryViewObject *self)
+{
+        return PyInt_FromLong(self->view.itemsize);
+}
+
+static PyObject *
+_IntTupleFromSsizet(int len, Py_ssize_t *vals)
+{
+        int i;
+        PyObject *o;
+        PyObject *intTuple;
+
+        if (vals == NULL) {
+                Py_INCREF(Py_None);
+                return Py_None;
+        }
+        intTuple = PyTuple_New(len);
+        if (!intTuple) return NULL;
+        for(i=0; i<len; i++) {
+                o = PyInt_FromSsize_t(vals[i]);
+                if (!o) {
+                        Py_DECREF(intTuple);
+                        return NULL;
+                }
+                PyTuple_SET_ITEM(intTuple, i, o);
+        }
+        return intTuple;
+}
+
+static PyObject *
+memory_shape_get(PyMemoryViewObject *self)
+{
+        return _IntTupleFromSsizet(self->view.ndim, self->view.shape);
+}
+
+static PyObject *
+memory_strides_get(PyMemoryViewObject *self)
+{
+        return _IntTupleFromSsizet(self->view.ndim, self->view.strides);
+}
+
+static PyObject *
+memory_suboffsets_get(PyMemoryViewObject *self)
+{
+        return _IntTupleFromSsizet(self->view.ndim, self->view.suboffsets);
+}
+
+static PyObject *
+memory_size_get(PyMemoryViewObject *self)
+{
+        return PyInt_FromSsize_t(self->view.len);
+}
+
+static PyObject *
+memory_readonly_get(PyMemoryViewObject *self)
+{
+        return PyInt_FromLong(self->view.readonly);
+}
+
+static PyObject *
+memory_ndim_get(PyMemoryViewObject *self)
+{
+        return PyInt_FromLong(self->view.ndim);
+}
+
+static PyGetSetDef memory_getsetlist[] ={ 
+        {"format",
+         (getter)memory_format_get,
+         NULL, NULL},
+        {"itemsize",
+         (getter)memory_itemsize_get,
+         NULL, NULL},
+        {"shape",
+         (getter)memory_shape_get,
+         NULL, NULL},
+        {"strides",
+         (getter)memory_strides_get,
+         NULL, NULL},
+        {"suboffsets",
+         (getter)memory_suboffsets_get,
+         NULL, NULL},
+        {"size",
+         (getter)memory_size_get,
+         NULL, NULL},
+        {"readonly",
+         (getter)memory_readonly_get,
+         NULL, NULL},
+        {"ndim",
+         (getter)memory_ndim_get,
+         NULL, NULL},
+        {NULL, NULL, NULL, NULL},
+};
+
+
+static PyObject *
+memory_tobytes(PyMemoryViewObject *mem, PyObject *args)
+{
+        if (!PyArg_ParseTuple(args, "")) return NULL;
+        /* Create new Bytes object for data */
+        return PyBytes_FromObject((PyObject *)mem);
+}
+
+static PyObject *
+memory_tolist(PyMemoryViewObject *mem, PyObject *args)
+{
+        if (!PyArg_ParseTuple(args, "")) return NULL;        
+        Py_INCREF(Py_NotImplemented);
+        return Py_NotImplemented;
+}
+
+
+
+static PyMethodDef memory_methods[] = {
+        {"tobytes", (PyCFunction)memory_tobytes, 1, NULL},
+        {"tolist", (PyCFunction)memory_tolist, 1, NULL},
+        {NULL,          NULL}           /* sentinel */
+};
+
+
+static void
+memory_dealloc(PyMemoryViewObject *self)
+{
+
+        if (PyTuple_Check(self->base)) {
+                /* Special case when first element is generic object
+                   with buffer interface and the second element is a
+                   contiguous "shadow" that must be copied back into
+                   the data areay of the first tuple element before
+                   releasing the buffer on the first element.  
+                */
+                
+                PyObject_CopyData(PyTuple_GET_ITEM(self->base,0),
+                                  PyTuple_GET_ITEM(self->base,1));
+
+                /* The view member should have readonly == -1 in
+                   this instance indicating that the memory can
+                   be "locked" and was locked and will be unlocked
+                   again after this call. 
+                */
+                PyObject_ReleaseBuffer(PyTuple_GET_ITEM(self->base,0),
+                                       &(self->view));
+        }
+        else {
+                PyObject_ReleaseBuffer(self->base, &(self->view));
+        }
+        Py_DECREF(self->base);
+        PyObject_DEL(self);
+}
+
+static PyObject *
+memory_repr(PyMemoryViewObject *self)
+{
+
+	if ( self->base == NULL )
+		return PyUnicode_FromFormat("<memory at %p>",
+					   self);
+	else
+		return PyUnicode_FromFormat(
+			"<memory at %p>",
+			self);
+}
+
+
+static PyObject *
+memory_str(PyMemoryViewObject *self)
+{
+        PyBuffer view;
+        PyObject *res;
+
+        if (PyObject_GetBuffer((PyObject *)self, &view, PyBUF_FULL) < 0)
+                return NULL;
+        
+	res = PyBytes_FromStringAndSize(NULL, view.len);
+        PyBuffer_ToContiguous(PyBytes_AS_STRING(res), &view, view.len, 'C');
+        PyObject_ReleaseBuffer((PyObject *)self, &view);
+        return res;
+}
+
+/* Sequence methods */
+
+static Py_ssize_t
+memory_length(PyMemoryViewObject *self)
+{
+        PyBuffer view;
+
+        if (PyObject_GetBuffer((PyObject *)self, &view, PyBUF_FULL) < 0)
+                return -1;
+        PyObject_ReleaseBuffer((PyObject *)self, &view);
+	return view.len;
+}
+
+static PyObject *
+memory_subscript(PyMemoryViewObject *self, PyObject *key)
+{
+        Py_INCREF(Py_NotImplemented);
+        return Py_NotImplemented;
+}
+
+static int
+memory_ass_sub(PyMemoryViewObject *self, PyObject *key, PyObject *value)
+{
+        return 0;
+}
+
+/* As mapping */
+static PyMappingMethods memory_as_mapping = {
+	(lenfunc)memory_length, /*mp_length*/
+	(binaryfunc)memory_subscript, /*mp_subscript*/
+	(objobjargproc)memory_ass_sub, /*mp_ass_subscript*/
+};
+
+
+/* Buffer methods */
+
+static PyBufferProcs memory_as_buffer = {
+	(getbufferproc)memory_getbuf,         /* bf_getbuffer */
+        (releasebufferproc)memory_releasebuf, /* bf_releasebuffer */
+};
+
+
+PyTypeObject PyMemoryView_Type = {
+	PyVarObject_HEAD_INIT(&PyType_Type, 0)
+	"memoryview",
+	sizeof(PyMemoryViewObject),
+	0,
+	(destructor)memory_dealloc, 		/* tp_dealloc */
+	0,					/* tp_print */
+	0,					/* tp_getattr */
+	0,					/* tp_setattr */
+	0,					/* tp_compare */
+	(reprfunc)memory_repr,			/* tp_repr */
+	0,					/* tp_as_number */
+	0,			                /* tp_as_sequence */
+	&memory_as_mapping,	    	        /* tp_as_mapping */
+	0,		                        /* tp_hash */
+	0,					/* tp_call */
+	(reprfunc)memory_str,			/* tp_str */
+	PyObject_GenericGetAttr,		/* tp_getattro */
+	0,					/* tp_setattro */
+	&memory_as_buffer,			/* tp_as_buffer */
+	Py_TPFLAGS_DEFAULT,			/* tp_flags */
+	memory_doc,				/* tp_doc */
+	0,					/* tp_traverse */
+	0,					/* tp_clear */
+	0,		                	/* tp_richcompare */
+	0,					/* tp_weaklistoffset */
+	0,					/* tp_iter */
+	0,					/* tp_iternext */
+	memory_methods,	   		        /* tp_methods */	
+	0,	      		                /* tp_members */
+	memory_getsetlist,  		        /* tp_getset */
+	0,					/* tp_base */
+	0,					/* tp_dict */
+	0,					/* tp_descr_get */
+	0,					/* tp_descr_set */
+	0,					/* tp_dictoffset */
+	0,					/* tp_init */
+	0,					/* tp_alloc */
+	memory_new,				/* tp_new */
+};
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index b1d711d..fff4b45 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -1171,44 +1171,10 @@ string_subscript(PyStringObject* self, PyObject* item)
 	}
 }
 
-static Py_ssize_t
-string_buffer_getreadbuf(PyStringObject *self, Py_ssize_t index, const void **ptr)
-{
-	if ( index != 0 ) {
-		PyErr_SetString(PyExc_SystemError,
-				"accessing non-existent string segment");
-		return -1;
-	}
-	*ptr = (void *)self->ob_sval;
-	return Py_Size(self);
-}
-
-static Py_ssize_t
-string_buffer_getwritebuf(PyStringObject *self, Py_ssize_t index, const void **ptr)
-{
-	PyErr_SetString(PyExc_TypeError,
-			"Cannot use string as modifiable buffer");
-	return -1;
-}
-
-static Py_ssize_t
-string_buffer_getsegcount(PyStringObject *self, Py_ssize_t *lenp)
-{
-	if ( lenp )
-		*lenp = Py_Size(self);
-	return 1;
-}
-
-static Py_ssize_t
-string_buffer_getcharbuf(PyStringObject *self, Py_ssize_t index, const char **ptr)
+static int
+string_buffer_getbuffer(PyStringObject *self, PyBuffer *view, int flags)
 {
-	if ( index != 0 ) {
-		PyErr_SetString(PyExc_SystemError,
-				"accessing non-existent string segment");
-		return -1;
-	}
-	*ptr = self->ob_sval;
-	return Py_Size(self);
+        return PyBuffer_FillInfo(view, (void *)self->ob_sval, Py_Size(self), 0, flags);
 }
 
 static PySequenceMethods string_as_sequence = {
@@ -1229,14 +1195,11 @@ static PyMappingMethods string_as_mapping = {
 };
 
 static PyBufferProcs string_as_buffer = {
-	(readbufferproc)string_buffer_getreadbuf,
-	(writebufferproc)string_buffer_getwritebuf,
-	(segcountproc)string_buffer_getsegcount,
-	(charbufferproc)string_buffer_getcharbuf,
+	(getbufferproc)string_buffer_getbuffer,
+        NULL,
 };
 
 
-
 #define LEFTSTRIP 0
 #define RIGHTSTRIP 1
 #define BOTHSTRIP 2
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 8cc5058..f042f4a 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -3251,10 +3251,8 @@ inherit_slots(PyTypeObject *type, PyTypeObject *base)
 		basebase = base->tp_base;
 		if (basebase->tp_as_buffer == NULL)
 			basebase = NULL;
-		COPYBUF(bf_getreadbuffer);
-		COPYBUF(bf_getwritebuffer);
-		COPYBUF(bf_getsegcount);
-		COPYBUF(bf_getcharbuffer);
+		COPYBUF(bf_getbuffer);
+		COPYBUF(bf_releasebuffer);
 	}
 
 	basebase = base->tp_base;
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 5ee3347..157ea1c 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -8108,57 +8108,26 @@ static PyMappingMethods unicode_as_mapping = {
     (objobjargproc)0,			/* mp_ass_subscript */
 };
 
-static Py_ssize_t
-unicode_buffer_getreadbuf(PyUnicodeObject *self,
-			  Py_ssize_t index,
-			  const void **ptr)
-{
-    if (index != 0) {
-        PyErr_SetString(PyExc_SystemError,
-			"accessing non-existent unicode segment");
-        return -1;
-    }
-    *ptr = (void *) self->str;
-    return PyUnicode_GET_DATA_SIZE(self);
-}
-
-static Py_ssize_t
-unicode_buffer_getwritebuf(PyUnicodeObject *self, Py_ssize_t index,
-			   const void **ptr)
-{
-    PyErr_SetString(PyExc_TypeError,
-		    "cannot use unicode as modifiable buffer");
-    return -1;
-}
 
 static int
-unicode_buffer_getsegcount(PyUnicodeObject *self,
-			   Py_ssize_t *lenp)
+unicode_buffer_getbuffer(PyUnicodeObject *self, PyBuffer *view, int flags)
 {
-    if (lenp)
-        *lenp = PyUnicode_GET_DATA_SIZE(self);
-    return 1;
-}
-
-static Py_ssize_t
-unicode_buffer_getcharbuf(PyUnicodeObject *self,
-			  Py_ssize_t index,
-			  const void **ptr)
-{
-    PyObject *str;
 
-    if (index != 0) {
-        PyErr_SetString(PyExc_SystemError,
-			"accessing non-existent unicode segment");
-        return -1;
+    if (flags & PyBUF_CHARACTER) {
+        PyObject *str;
+        
+        str = _PyUnicode_AsDefaultEncodedString((PyObject *)self, NULL);
+        if (str == NULL) return -1;
+        return PyBuffer_FillInfo(view, (void *)PyString_AS_STRING(str),
+                                 PyString_GET_SIZE(str), 1, flags);
+    }
+    else {
+        return PyBuffer_FillInfo(view, (void *)self->str, 
+                                 PyUnicode_GET_DATA_SIZE(self), 1, flags);
     }
-    str = _PyUnicode_AsDefaultEncodedString((PyObject *)self, NULL);
-    if (str == NULL)
-	return -1;
-    *ptr = (void *) PyString_AS_STRING(str);
-    return PyString_GET_SIZE(str);
 }
 
+
 /* Helpers for PyUnicode_Format() */
 
 static PyObject *
@@ -8853,10 +8822,8 @@ PyObject *PyUnicode_Format(PyObject *format,
 }
 
 static PyBufferProcs unicode_as_buffer = {
-    (readbufferproc) unicode_buffer_getreadbuf,
-    (writebufferproc) unicode_buffer_getwritebuf,
-    (segcountproc) unicode_buffer_getsegcount,
-    (charbufferproc) unicode_buffer_getcharbuf,
+    (getbufferproc) unicode_buffer_getbuffer,
+    NULL,
 };
 
 static PyObject *