+++ /dev/null
-
-/* Buffer object implementation */
-
-#include "Python.h"
-
-
-typedef struct {
- PyObject_HEAD
- PyObject *b_base;
- void *b_ptr;
- Py_ssize_t b_size;
- Py_ssize_t b_offset;
- int b_readonly;
- long b_hash;
-} PyBufferObject;
-
-
-static int
-get_buf(PyBufferObject *self, Py_buffer *view, int flags)
-{
- if (self->b_base == NULL) {
- view->buf = self->b_ptr;
- view->len = self->b_size;
- view->readonly = 0;
- }
- else {
- Py_ssize_t count, offset;
- PyBufferProcs *bp = self->b_base->ob_type->tp_as_buffer;
- 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;
- view->buf = (char*)view->buf + offset;
- if (self->b_size == Py_END_OF_BUFFER)
- view->len = count;
- else
- view->len = self->b_size;
- if (offset + view->len > count)
- view->len = count - offset;
- }
- return 1;
-}
-
-
-static int
-buffer_getbuf(PyBufferObject *self, Py_buffer *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, Py_buffer *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);
- }
- }
-}
-
-static PyObject *
-buffer_from_memory(PyObject *base, Py_ssize_t size, Py_ssize_t offset,
- void *ptr, int readonly)
-{
- PyBufferObject * b;
-
- if (size < 0 && size != Py_END_OF_BUFFER) {
- PyErr_SetString(PyExc_ValueError,
- "size must be zero or positive");
- return NULL;
- }
- if (offset < 0) {
- PyErr_SetString(PyExc_ValueError,
- "offset must be zero or positive");
- return NULL;
- }
-
- b = PyObject_NEW(PyBufferObject, &PyBuffer_Type);
- if (b == NULL)
- return NULL;
-
- Py_XINCREF(base);
- b->b_base = base;
- b->b_ptr = ptr;
- b->b_size = size;
- b->b_offset = offset;
- b->b_readonly = readonly;
- b->b_hash = -1;
-
- return (PyObject *) b;
-}
-
-static PyObject *
-buffer_from_object(PyObject *base, Py_ssize_t size, Py_ssize_t offset,
- int readonly)
-{
- if (offset < 0) {
- PyErr_SetString(PyExc_ValueError,
- "offset must be zero or positive");
- return NULL;
- }
- if (PyBuffer_Check(base) && (((PyBufferObject *)base)->b_base)) {
- /* another buffer, refer to the base object */
- PyBufferObject *b = (PyBufferObject *)base;
- if (b->b_size != Py_END_OF_BUFFER) {
- Py_ssize_t base_size = b->b_size - offset;
- if (base_size < 0)
- base_size = 0;
- if (size == Py_END_OF_BUFFER || size > base_size)
- size = base_size;
- }
- offset += b->b_offset;
- base = b->b_base;
- }
- return buffer_from_memory(base, size, offset, NULL, readonly);
-}
-
-
-PyObject *
-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_getbuffer == NULL) {
- PyErr_SetString(PyExc_TypeError, "buffer object expected");
- return NULL;
- }
-
- return buffer_from_object(base, size, offset, 1);
-}
-
-PyObject *
-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_getbuffer == NULL) {
- PyErr_SetString(PyExc_TypeError, "buffer object expected");
- return NULL;
- }
-
- return buffer_from_object(base, size, offset, 0);
-}
-
-PyObject *
-PyBuffer_FromMemory(void *ptr, Py_ssize_t size)
-{
- return buffer_from_memory(NULL, size, 0, ptr, 1);
-}
-
-PyObject *
-PyBuffer_FromReadWriteMemory(void *ptr, Py_ssize_t size)
-{
- return buffer_from_memory(NULL, size, 0, ptr, 0);
-}
-
-PyObject *
-PyBuffer_New(Py_ssize_t size)
-{
- PyObject *o;
- PyBufferObject * b;
-
- if (size < 0) {
- PyErr_SetString(PyExc_ValueError,
- "size must be zero or positive");
- return NULL;
- }
- /* XXX: check for overflow in multiply */
- /* Inline PyObject_New */
- o = (PyObject *)PyObject_MALLOC(sizeof(*b) + size);
- if (o == NULL)
- return PyErr_NoMemory();
- b = (PyBufferObject *) PyObject_INIT(o, &PyBuffer_Type);
-
- b->b_base = NULL;
- b->b_ptr = (void *)(b + 1);
- b->b_size = size;
- b->b_offset = 0;
- b->b_readonly = 0;
- b->b_hash = -1;
-
- return o;
-}
-
-/* Methods */
-
-static PyObject *
-buffer_new(PyTypeObject *type, PyObject *args, PyObject *kw)
-{
- PyObject *ob;
- Py_ssize_t offset = 0;
- Py_ssize_t size = Py_END_OF_BUFFER;
-
- if (!_PyArg_NoKeywords("buffer()", kw))
- return NULL;
-
- if (!PyArg_ParseTuple(args, "O|nn:buffer", &ob, &offset, &size))
- return NULL;
- return PyBuffer_FromObject(ob, offset, size);
-}
-
-PyDoc_STRVAR(buffer_doc,
-"buffer(object [, offset[, size]])\n\
-\n\
-Create a new buffer object which references the given object.\n\
-The buffer will reference a slice of the target object from the\n\
-start of the object (or at the specified offset). The slice will\n\
-extend to the end of the target object (or with the specified size).");
-
-
-static void
-buffer_dealloc(PyBufferObject *self)
-{
- Py_XDECREF(self->b_base);
- PyObject_DEL(self);
-}
-
-static int
-get_bufx(PyObject *obj, Py_buffer *view, int flags)
-{
- PyBufferProcs *bp;
-
- if (PyBuffer_Check(obj)) {
- if (!get_buf((PyBufferObject *)obj, view, flags)) {
- PyErr_Clear();
- return 0;
- }
- else
- return 1;
- }
- bp = obj->ob_type->tp_as_buffer;
- if (bp == NULL ||
- bp->bf_getbuffer == NULL)
- return 0;
- if ((*bp->bf_getbuffer)(obj, view, PyBUF_SIMPLE) < 0)
- return 0;
- return 1;
-}
-
-static PyObject *
-buffer_richcompare(PyObject *self, PyObject *other, int op)
-{
- void *p1, *p2;
- Py_ssize_t len1, len2, min_len;
- int cmp, ok;
- Py_buffer v1, v2;
-
- ok = 1;
- if (!get_bufx(self, &v1, PyBUF_SIMPLE))
- ok = 0;
- 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
- (and the objects are unequal) */
- PyObject *result;
- if (op == Py_EQ)
- result = Py_False;
- else if (op == Py_NE)
- result = Py_True;
- else
- result = Py_NotImplemented;
- 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);
-}
-
-static PyObject *
-buffer_repr(PyBufferObject *self)
-{
- const char *status = self->b_readonly ? "read-only" : "read-write";
-
- if (self->b_base == NULL)
- return PyUnicode_FromFormat(
- "<%s buffer ptr %p, size %zd at %p>",
- status,
- self->b_ptr,
- self->b_size,
- self);
- else
- return PyUnicode_FromFormat(
- "<%s buffer for %p, size %zd, offset %zd at %p>",
- status,
- self->b_base,
- self->b_size,
- self->b_offset,
- self);
-}
-
-static long
-buffer_hash(PyBufferObject *self)
-{
- Py_buffer view;
- register Py_ssize_t len;
- register unsigned char *p;
- register long x;
-
- if (self->b_hash != -1)
- return self->b_hash;
-
- if (!get_buf(self, &view, PyBUF_SIMPLE))
- return -1;
- if (!(self->b_readonly)) {
- PyErr_SetString(PyExc_TypeError,
- "writable buffers are not hashable");
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return -1;
- }
-
- p = (unsigned char *) view.buf;
- len = view.len;
- x = *p << 7;
- while (--len >= 0)
- x = (1000003*x) ^ *p++;
- 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)
-{
- Py_buffer view;
- PyObject *res;
-
- if (!get_buf(self, &view, PyBUF_SIMPLE))
- return NULL;
- res = PyString_FromStringAndSize((const char *)view.buf, view.len);
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return res;
-}
-
-/* Sequence methods */
-
-static Py_ssize_t
-buffer_length(PyBufferObject *self)
-{
- Py_buffer view;
-
- if (!get_buf(self, &view, PyBUF_SIMPLE))
- return -1;
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return view.len;
-}
-
-static PyObject *
-buffer_concat(PyBufferObject *self, PyObject *other)
-{
- PyBufferProcs *pb = other->ob_type->tp_as_buffer;
- char *p;
- PyObject *ob;
- Py_buffer view, view2;
-
- if (pb == NULL ||
- pb->bf_getbuffer == NULL)
- {
- PyErr_BadArgument();
- return NULL;
- }
-
- if (!get_buf(self, &view, PyBUF_SIMPLE))
- return NULL;
-
- /* optimize special case */
- /* XXX bad idea type-wise */
- if (view.len == 0) {
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- Py_INCREF(other);
- return other;
- }
-
- if (PyObject_GetBuffer((PyObject *)other, &view2, PyBUF_SIMPLE) < 0) {
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return NULL;
- }
-
- /* XXX(nnorwitz): need to check for overflow! */
- ob = PyBytes_FromStringAndSize(NULL, view.len+view2.len);
- if (ob == NULL) {
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- PyObject_ReleaseBuffer(other, &view2);
- return NULL;
- }
- 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 *
-buffer_repeat(PyBufferObject *self, Py_ssize_t count)
-{
- PyObject *ob;
- register char *p;
- Py_buffer view;
-
- if (count < 0)
- count = 0;
- if (!get_buf(self, &view, PyBUF_SIMPLE))
- return NULL;
- /* XXX(nnorwitz): need to check for overflow! */
- ob = PyBytes_FromStringAndSize(NULL, view.len * count);
- if (ob == NULL)
- return NULL;
-
- p = PyBytes_AS_STRING(ob);
- while (count--) {
- memcpy(p, view.buf, view.len);
- p += view.len;
- }
-
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return ob;
-}
-
-static PyObject *
-buffer_item(PyBufferObject *self, Py_ssize_t idx)
-{
- Py_buffer view;
- PyObject *ob;
-
- if (!get_buf(self, &view, PyBUF_SIMPLE))
- return NULL;
- if (idx < 0 || idx >= view.len) {
- PyErr_SetString(PyExc_IndexError, "buffer index out of range");
- return NULL;
- }
- ob = PyBytes_FromStringAndSize((char *)view.buf + idx, 1);
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return ob;
-}
-
-static PyObject *
-buffer_subscript(PyBufferObject *self, PyObject *item)
-{
- Py_buffer view;
- PyObject *ob;
-
- if (!get_buf(self, &view, PyBUF_SIMPLE))
- return NULL;
- if (PyIndex_Check(item)) {
- Py_ssize_t idx = PyNumber_AsSsize_t(item, PyExc_IndexError);
-
- if (idx == -1 && PyErr_Occurred())
- return NULL;
- if (idx < 0)
- idx += view.len;
- if (idx < 0 || idx >= view.len) {
- PyErr_SetString(PyExc_IndexError,
- "buffer index out of range");
- return NULL;
- }
- ob = PyBytes_FromStringAndSize((char *)view.buf + idx, 1);
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return ob;
- }
- else if (PySlice_Check(item)) {
- Py_ssize_t start, stop, step, slicelength, cur, i;
-
- if (PySlice_GetIndicesEx((PySliceObject*)item, view.len,
- &start, &stop, &step, &slicelength) < 0) {
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return NULL;
- }
-
- if (slicelength <= 0) {
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return PyBytes_FromStringAndSize("", 0);
- }
- else if (step == 1) {
- ob = PyBytes_FromStringAndSize((char *)view.buf +
- start, stop - start);
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return ob;
- }
- else {
- char *source_buf = (char *)view.buf;
- char *result_buf = (char *)PyMem_Malloc(slicelength);
-
- if (result_buf == NULL)
- return PyErr_NoMemory();
-
- for (cur = start, i = 0; i < slicelength;
- cur += step, i++) {
- result_buf[i] = source_buf[cur];
- }
-
- ob = PyBytes_FromStringAndSize(result_buf,
- slicelength);
- PyMem_Free(result_buf);
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return ob;
- }
- }
- else {
- PyErr_SetString(PyExc_TypeError,
- "sequence index must be integer");
- return NULL;
- }
-}
-
-static int
-buffer_ass_item(PyBufferObject *self, Py_ssize_t idx, PyObject *other)
-{
- PyBufferProcs *pb;
- Py_buffer view, view2;
-
- 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 (idx < 0 || idx >= view.len) {
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- PyErr_SetString(PyExc_IndexError,
- "buffer assignment index out of range");
- return -1;
- }
-
- pb = other ? other->ob_type->tp_as_buffer : NULL;
- if (pb == NULL ||
- pb->bf_getbuffer == NULL) {
- PyErr_BadArgument();
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- return -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 *)(view.buf))[idx] = *((char *)(view2.buf));
- PyObject_ReleaseBuffer((PyObject *)self, &view);
- PyObject_ReleaseBuffer(other, &view2);
- return 0;
-}
-
-static int
-buffer_ass_subscript(PyBufferObject *self, PyObject *item, PyObject *value)
-{
- Py_buffer v1;
-
- if (!get_buf(self, &v1, PyBUF_SIMPLE))
- return -1;
- if (self->b_readonly || v1.readonly) {
- PyErr_SetString(PyExc_TypeError,
- "buffer is read-only");
- PyObject_ReleaseBuffer((PyObject *)self, &v1);
- return -1;
- }
- if (PyIndex_Check(item)) {
- Py_ssize_t idx = PyNumber_AsSsize_t(item, PyExc_IndexError);
- if (idx == -1 && PyErr_Occurred())
- return -1;
- if (idx < 0)
- idx += v1.len;
- PyObject_ReleaseBuffer((PyObject *)self, &v1);
- return buffer_ass_item(self, idx, value);
- }
- else if (PySlice_Check(item)) {
- Py_ssize_t start, stop, step, slicelength;
- Py_buffer v2;
- PyBufferProcs *pb;
-
- if (PySlice_GetIndicesEx((PySliceObject *)item, v1.len,
- &start, &stop, &step, &slicelength) < 0) {
- PyObject_ReleaseBuffer((PyObject *)self, &v1);
- return -1;
- }
-
- pb = value ? value->ob_type->tp_as_buffer : NULL;
- if (pb == NULL ||
- pb->bf_getbuffer == NULL) {
- PyObject_ReleaseBuffer((PyObject *)self, &v1);
- PyErr_BadArgument();
- return -1;
- }
- if ((*pb->bf_getbuffer)(value, &v2, PyBUF_SIMPLE) < 0) {
- PyObject_ReleaseBuffer((PyObject *)self, &v1);
- return -1;
- }
-
- if (v2.len != slicelength) {
- PyObject_ReleaseBuffer((PyObject *)self, &v1);
- PyObject_ReleaseBuffer(value, &v2);
- PyErr_SetString(PyExc_TypeError, "right operand"
- " length must match slice length");
- return -1;
- }
-
- if (slicelength == 0)
- /* nothing to do */;
- else if (step == 1)
- memcpy((char *)v1.buf + start, v2.buf, slicelength);
- else {
- Py_ssize_t cur, i;
-
- for (cur = start, i = 0; i < slicelength;
- cur += step, i++) {
- ((char *)v1.buf)[cur] = ((char *)v2.buf)[i];
- }
- }
- PyObject_ReleaseBuffer((PyObject *)self, &v1);
- PyObject_ReleaseBuffer(value, &v2);
- return 0;
- } else {
- PyErr_SetString(PyExc_TypeError,
- "buffer indices must be integers");
- PyObject_ReleaseBuffer((PyObject *)self, &v1);
- return -1;
- }
-}
-
-/* Buffer methods */
-
-static PySequenceMethods buffer_as_sequence = {
- (lenfunc)buffer_length, /*sq_length*/
- (binaryfunc)buffer_concat, /*sq_concat*/
- (ssizeargfunc)buffer_repeat, /*sq_repeat*/
- (ssizeargfunc)buffer_item, /*sq_item*/
- 0, /*sq_slice*/
- (ssizeobjargproc)buffer_ass_item, /*sq_ass_item*/
- 0, /*sq_ass_slice*/
-};
-
-static PyMappingMethods buffer_as_mapping = {
- (lenfunc)buffer_length,
- (binaryfunc)buffer_subscript,
- (objobjargproc)buffer_ass_subscript,
-};
-
-static PyBufferProcs buffer_as_buffer = {
- (getbufferproc)buffer_getbuf,
- (releasebufferproc)buffer_releasebuf,
-};
-
-PyTypeObject PyBuffer_Type = {
- PyVarObject_HEAD_INIT(&PyType_Type, 0)
- "buffer",
- sizeof(PyBufferObject),
- 0,
- (destructor)buffer_dealloc, /* tp_dealloc */
- 0, /* tp_print */
- 0, /* tp_getattr */
- 0, /* tp_setattr */
- 0, /* tp_compare */
- (reprfunc)buffer_repr, /* tp_repr */
- 0, /* tp_as_number */
- &buffer_as_sequence, /* tp_as_sequence */
- &buffer_as_mapping, /* tp_as_mapping */
- (hashfunc)buffer_hash, /* tp_hash */
- 0, /* tp_call */
- (reprfunc)buffer_str, /* tp_str */
- PyObject_GenericGetAttr, /* tp_getattro */
- 0, /* tp_setattro */
- &buffer_as_buffer, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT, /* tp_flags */
- buffer_doc, /* tp_doc */
- 0, /* tp_traverse */
- 0, /* tp_clear */
- buffer_richcompare, /* tp_richcompare */
- 0, /* tp_weaklistoffset */
- 0, /* tp_iter */
- 0, /* tp_iternext */
- 0, /* tp_methods */
- 0, /* tp_members */
- 0, /* 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 */
- buffer_new, /* tp_new */
-};
projects / python / commitdiff