mirror of https://github.com/python/cpython
Implement extended slicing in bytes objects.
This commit is contained in:
Thomas Wouters
parent
5672904eff
commit
376446dd4e
|
|
@ -163,6 +163,17 @@ class BytesTest(unittest.TestCase):
|
|||
self.assertEqual(b[-5:100], by("world"))
|
||||
self.assertEqual(b[-100:5], by("Hello"))
|
||||
|
||||
def test_extended_getslice(self):
|
||||
# Test extended slicing by comparing with list slicing.
|
||||
L = list(range(255))
|
||||
b = bytes(L)
|
||||
indices = (0, None, 1, 3, 19, 100, -1, -2, -31, -100)
|
||||
for start in indices:
|
||||
for stop in indices:
|
||||
# Skip step 0 (invalid)
|
||||
for step in indices[1:]:
|
||||
self.assertEqual(b[start:stop:step], bytes(L[start:stop:step]))
|
||||
|
||||
def test_regexps(self):
|
||||
def by(s):
|
||||
return bytes(map(ord, s))
|
||||
|
|
@ -239,6 +250,26 @@ class BytesTest(unittest.TestCase):
|
|||
b[3:0] = [42, 42, 42]
|
||||
self.assertEqual(b, bytes([0, 1, 2, 42, 42, 42, 3, 4, 5, 6, 7, 8, 9]))
|
||||
|
||||
def test_extended_set_del_slice(self):
|
||||
indices = (0, None, 1, 3, 19, 300, -1, -2, -31, -300)
|
||||
for start in indices:
|
||||
for stop in indices:
|
||||
# Skip invalid step 0
|
||||
for step in indices[1:]:
|
||||
L = list(range(255))
|
||||
b = bytes(L)
|
||||
# Make sure we have a slice of exactly the right length,
|
||||
# but with different data.
|
||||
data = L[start:stop:step]
|
||||
data.reverse()
|
||||
L[start:stop:step] = data
|
||||
b[start:stop:step] = data
|
||||
self.assertEquals(b, bytes(L))
|
||||
|
||||
del L[start:stop:step]
|
||||
del b[start:stop:step]
|
||||
self.assertEquals(b, bytes(L))
|
||||
|
||||
def test_setslice_trap(self):
|
||||
# This test verifies that we correctly handle assigning self
|
||||
# to a slice of self (the old Lambert Meertens trap).
|
||||
|
|
|
|||
|
|
@ -269,19 +269,62 @@ bytes_getitem(PyBytesObject *self, Py_ssize_t i)
|
|||
}
|
||||
|
||||
static PyObject *
|
||||
bytes_getslice(PyBytesObject *self, Py_ssize_t lo, Py_ssize_t hi)
|
||||
bytes_subscript(PyBytesObject *self, PyObject *item)
|
||||
{
|
||||
if (lo < 0)
|
||||
lo = 0;
|
||||
if (hi > self->ob_size)
|
||||
hi = self->ob_size;
|
||||
if (lo >= hi)
|
||||
lo = hi = 0;
|
||||
return PyBytes_FromStringAndSize(self->ob_bytes + lo, hi - lo);
|
||||
}
|
||||
if (PyIndex_Check(item)) {
|
||||
Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);
|
||||
|
||||
if (i == -1 && PyErr_Occurred())
|
||||
return NULL;
|
||||
|
||||
if (i < 0)
|
||||
i += PyBytes_GET_SIZE(self);
|
||||
|
||||
if (i < 0 || i >= self->ob_size) {
|
||||
PyErr_SetString(PyExc_IndexError, "bytes index out of range");
|
||||
return NULL;
|
||||
}
|
||||
return PyInt_FromLong((unsigned char)(self->ob_bytes[i]));
|
||||
}
|
||||
else if (PySlice_Check(item)) {
|
||||
Py_ssize_t start, stop, step, slicelength, cur, i;
|
||||
if (PySlice_GetIndicesEx((PySliceObject *)item,
|
||||
PyBytes_GET_SIZE(self),
|
||||
&start, &stop, &step, &slicelength) < 0) {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
if (slicelength <= 0)
|
||||
return PyBytes_FromStringAndSize("", 0);
|
||||
else if (step == 1) {
|
||||
return PyBytes_FromStringAndSize(self->ob_bytes + start,
|
||||
slicelength);
|
||||
}
|
||||
else {
|
||||
char *source_buf = PyBytes_AS_STRING(self);
|
||||
char *result_buf = (char *)PyMem_Malloc(slicelength);
|
||||
PyObject *result;
|
||||
|
||||
if (result_buf == NULL)
|
||||
return PyErr_NoMemory();
|
||||
|
||||
for (cur = start, i = 0; i < slicelength;
|
||||
cur += step, i++) {
|
||||
result_buf[i] = source_buf[cur];
|
||||
}
|
||||
result = PyBytes_FromStringAndSize(result_buf, slicelength);
|
||||
PyMem_Free(result_buf);
|
||||
return result;
|
||||
}
|
||||
}
|
||||
else {
|
||||
PyErr_SetString(PyExc_TypeError, "bytes indices must be integers");
|
||||
return NULL;
|
||||
}
|
||||
}
|
||||
|
||||
static int
|
||||
bytes_setslice(PyBytesObject *self, Py_ssize_t lo, Py_ssize_t hi,
|
||||
bytes_setslice(PyBytesObject *self, Py_ssize_t lo, Py_ssize_t hi,
|
||||
PyObject *values)
|
||||
{
|
||||
int avail;
|
||||
|
|
@ -330,7 +373,7 @@ bytes_setslice(PyBytesObject *self, Py_ssize_t lo, Py_ssize_t hi,
|
|||
memmove(self->ob_bytes + lo + needed, self->ob_bytes + hi,
|
||||
self->ob_size - hi);
|
||||
}
|
||||
if (PyBytes_Resize((PyObject *)self,
|
||||
if (PyBytes_Resize((PyObject *)self,
|
||||
self->ob_size + needed - avail) < 0)
|
||||
return -1;
|
||||
if (avail < needed) {
|
||||
|
|
@ -380,6 +423,164 @@ bytes_setitem(PyBytesObject *self, Py_ssize_t i, PyObject *value)
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int
|
||||
bytes_ass_subscript(PyBytesObject *self, PyObject *item, PyObject *values)
|
||||
{
|
||||
Py_ssize_t start, stop, step, slicelen, needed;
|
||||
char *bytes;
|
||||
|
||||
if (PyIndex_Check(item)) {
|
||||
Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);
|
||||
|
||||
if (i == -1 && PyErr_Occurred())
|
||||
return -1;
|
||||
|
||||
if (i < 0)
|
||||
i += PyBytes_GET_SIZE(self);
|
||||
|
||||
if (i < 0 || i >= self->ob_size) {
|
||||
PyErr_SetString(PyExc_IndexError, "bytes index out of range");
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (values == NULL) {
|
||||
/* Fall through to slice assignment */
|
||||
start = i;
|
||||
stop = i + 1;
|
||||
step = 1;
|
||||
slicelen = 1;
|
||||
}
|
||||
else {
|
||||
Py_ssize_t ival = PyNumber_AsSsize_t(values, PyExc_ValueError);
|
||||
if (ival == -1 && PyErr_Occurred())
|
||||
return -1;
|
||||
if (ival < 0 || ival >= 256) {
|
||||
PyErr_SetString(PyExc_ValueError,
|
||||
"byte must be in range(0, 256)");
|
||||
return -1;
|
||||
}
|
||||
self->ob_bytes[i] = (char)ival;
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
else if (PySlice_Check(item)) {
|
||||
if (PySlice_GetIndicesEx((PySliceObject *)item,
|
||||
PyBytes_GET_SIZE(self),
|
||||
&start, &stop, &step, &slicelen) < 0) {
|
||||
return -1;
|
||||
}
|
||||
}
|
||||
else {
|
||||
PyErr_SetString(PyExc_TypeError, "bytes indices must be integer");
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (values == NULL) {
|
||||
bytes = NULL;
|
||||
needed = 0;
|
||||
}
|
||||
else if (values == (PyObject *)self || !PyBytes_Check(values)) {
|
||||
/* Make a copy an call this function recursively */
|
||||
int err;
|
||||
values = PyBytes_FromObject(values);
|
||||
if (values == NULL)
|
||||
return -1;
|
||||
err = bytes_ass_subscript(self, item, values);
|
||||
Py_DECREF(values);
|
||||
return err;
|
||||
}
|
||||
else {
|
||||
assert(PyBytes_Check(values));
|
||||
bytes = ((PyBytesObject *)values)->ob_bytes;
|
||||
needed = ((PyBytesObject *)values)->ob_size;
|
||||
}
|
||||
/* Make sure b[5:2] = ... inserts before 5, not before 2. */
|
||||
if ((step < 0 && start < stop) ||
|
||||
(step > 0 && start > stop))
|
||||
stop = start;
|
||||
if (step == 1) {
|
||||
if (slicelen != needed) {
|
||||
if (slicelen > needed) {
|
||||
/*
|
||||
0 start stop old_size
|
||||
| |<---slicelen--->|<-----tomove------>|
|
||||
| |<-needed->|<-----tomove------>|
|
||||
0 lo new_hi new_size
|
||||
*/
|
||||
memmove(self->ob_bytes + start + needed, self->ob_bytes + stop,
|
||||
self->ob_size - stop);
|
||||
}
|
||||
if (PyBytes_Resize((PyObject *)self,
|
||||
self->ob_size + needed - slicelen) < 0)
|
||||
return -1;
|
||||
if (slicelen < needed) {
|
||||
/*
|
||||
0 lo hi old_size
|
||||
| |<-avail->|<-----tomove------>|
|
||||
| |<----needed---->|<-----tomove------>|
|
||||
0 lo new_hi new_size
|
||||
*/
|
||||
memmove(self->ob_bytes + start + needed, self->ob_bytes + stop,
|
||||
self->ob_size - start - needed);
|
||||
}
|
||||
}
|
||||
|
||||
if (needed > 0)
|
||||
memcpy(self->ob_bytes + start, bytes, needed);
|
||||
|
||||
return 0;
|
||||
}
|
||||
else {
|
||||
if (needed == 0) {
|
||||
/* Delete slice */
|
||||
Py_ssize_t cur, i;
|
||||
|
||||
if (step < 0) {
|
||||
stop = start + 1;
|
||||
start = stop + step * (slicelen - 1) - 1;
|
||||
step = -step;
|
||||
}
|
||||
for (cur = start, i = 0;
|
||||
i < slicelen; cur += step, i++) {
|
||||
Py_ssize_t lim = step - 1;
|
||||
|
||||
if (cur + step >= PyBytes_GET_SIZE(self))
|
||||
lim = PyBytes_GET_SIZE(self) - cur - 1;
|
||||
|
||||
memmove(self->ob_bytes + cur - i,
|
||||
self->ob_bytes + cur + 1, lim);
|
||||
}
|
||||
/* Move the tail of the bytes, in one chunk */
|
||||
cur = start + slicelen*step;
|
||||
if (cur < PyBytes_GET_SIZE(self)) {
|
||||
memmove(self->ob_bytes + cur - slicelen,
|
||||
self->ob_bytes + cur,
|
||||
PyBytes_GET_SIZE(self) - cur);
|
||||
}
|
||||
if (PyBytes_Resize((PyObject *)self,
|
||||
PyBytes_GET_SIZE(self) - slicelen) < 0)
|
||||
return -1;
|
||||
|
||||
return 0;
|
||||
}
|
||||
else {
|
||||
/* Assign slice */
|
||||
Py_ssize_t cur, i;
|
||||
|
||||
if (needed != slicelen) {
|
||||
PyErr_Format(PyExc_ValueError,
|
||||
"attempt to assign bytes of size %zd "
|
||||
"to extended slice of size %zd",
|
||||
needed, slicelen);
|
||||
return -1;
|
||||
}
|
||||
for (cur = start, i = 0; i < slicelen; cur += step, i++)
|
||||
self->ob_bytes[cur] = bytes[i];
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static int
|
||||
bytes_init(PyBytesObject *self, PyObject *args, PyObject *kwds)
|
||||
{
|
||||
|
|
@ -776,9 +977,9 @@ static PySequenceMethods bytes_as_sequence = {
|
|||
(binaryfunc)bytes_concat, /*sq_concat*/
|
||||
(ssizeargfunc)bytes_repeat, /*sq_repeat*/
|
||||
(ssizeargfunc)bytes_getitem, /*sq_item*/
|
||||
(ssizessizeargfunc)bytes_getslice, /*sq_slice*/
|
||||
0, /*sq_slice*/
|
||||
(ssizeobjargproc)bytes_setitem, /*sq_ass_item*/
|
||||
(ssizessizeobjargproc)bytes_setslice, /* sq_ass_slice */
|
||||
0, /* sq_ass_slice */
|
||||
(objobjproc)bytes_contains, /* sq_contains */
|
||||
(binaryfunc)bytes_iconcat, /* sq_inplace_concat */
|
||||
(ssizeargfunc)bytes_irepeat, /* sq_inplace_repeat */
|
||||
|
|
@ -786,8 +987,8 @@ static PySequenceMethods bytes_as_sequence = {
|
|||
|
||||
static PyMappingMethods bytes_as_mapping = {
|
||||
(lenfunc)bytes_length,
|
||||
(binaryfunc)0,
|
||||
0,
|
||||
(binaryfunc)bytes_subscript,
|
||||
(objobjargproc)bytes_ass_subscript,
|
||||
};
|
||||
|
||||
static PyBufferProcs bytes_as_buffer = {
|
||||
|
|
@ -833,7 +1034,7 @@ PyTypeObject PyBytes_Type = {
|
|||
PyObject_GenericGetAttr, /* tp_getattro */
|
||||
0, /* tp_setattro */
|
||||
&bytes_as_buffer, /* tp_as_buffer */
|
||||
Py_TPFLAGS_DEFAULT, /* tp_flags */
|
||||
Py_TPFLAGS_DEFAULT, /* tp_flags */
|
||||
/* bytes is 'final' or 'sealed' */
|
||||
bytes_doc, /* tp_doc */
|
||||
0, /* tp_traverse */
|
||||
|
|
|
|||
Loading…
Reference in New Issue