diff options
Diffstat (limited to 'Objects/bufferobject.c')
| -rw-r--r-- | Objects/bufferobject.c | 153 |
1 files changed, 152 insertions, 1 deletions
diff --git a/Objects/bufferobject.c b/Objects/bufferobject.c index c415013..e307aab 100644 --- a/Objects/bufferobject.c +++ b/Objects/bufferobject.c @@ -482,6 +482,75 @@ buffer_slice(PyBufferObject *self, Py_ssize_t left, Py_ssize_t right) return ob; } +static PyObject * +buffer_subscript(PyBufferObject *self, PyObject *item) +{ + PyBuffer 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) { @@ -587,6 +656,82 @@ buffer_ass_slice(PyBufferObject *self, Py_ssize_t left, Py_ssize_t right, PyObje return 0; } +static int +buffer_ass_subscript(PyBufferObject *self, PyObject *item, PyObject *value) +{ + PyBuffer 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; + PyBuffer 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 = { @@ -599,6 +744,12 @@ static PySequenceMethods buffer_as_sequence = { (ssizessizeobjargproc)buffer_ass_slice, /*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, @@ -617,7 +768,7 @@ PyTypeObject PyBuffer_Type = { (reprfunc)buffer_repr, /* tp_repr */ 0, /* tp_as_number */ &buffer_as_sequence, /* tp_as_sequence */ - 0, /* tp_as_mapping */ + &buffer_as_mapping, /* tp_as_mapping */ (hashfunc)buffer_hash, /* tp_hash */ 0, /* tp_call */ (reprfunc)buffer_str, /* tp_str */ |