Issue #29300: Convert _struct module to Argument Clinic

* The struct module now requires contiguous buffers.
* Convert most functions and methods of the _struct module to Argument Clinic
* Use "Py_buffer" type for the "buffer" argument. Argument Clinic is
  responsible to create and release the Py_buffer object.
* Use "PyStructObject *" type for self to avoid explicit conversions.
* Add an unit test on the _struct.Struct.unpack_from() method to test passing
  arguments as keywords.
* Rephrase docstrings.
* Rename "fmt" argument to "format" in docstrings and the documentation.

As a side effect, functions and methods which used METH_VARARGS calling
convention like struct.pack() now use the METH_FASTCALL calling convention
which avoids the creation of temporary tuple to pass positional arguments and
so is faster. For example, struct.pack("i", 1) becomes 1.56x faster (-36%)::

    $ ./python -m perf timeit \
        -s 'import struct; pack=struct.pack' 'pack("i", 1)' \
        --compare-to=../default-ref/python
    Median +- std dev: 119 ns +- 1 ns -> 76.8 ns +- 0.4 ns: 1.56x faster (-36%)
    Significant (t=295.91)

Patch co-written with Serhiy Storchaka.
This commit is contained in:
Victor Stinner 2017-02-02 12:09:30 +01:00
parent fd6d0d2a18
commit 3f2d10132d
4 changed files with 540 additions and 239 deletions

View File

@ -48,40 +48,40 @@ The module defines the following exception and functions:
is wrong.
.. function:: pack(fmt, v1, v2, ...)
.. function:: pack(format, v1, v2, ...)
Return a bytes object containing the values *v1*, *v2*, ... packed according
to the format string *fmt*. The arguments must match the values required by
to the format string *format*. The arguments must match the values required by
the format exactly.
.. function:: pack_into(fmt, buffer, offset, v1, v2, ...)
.. function:: pack_into(format, buffer, offset, v1, v2, ...)
Pack the values *v1*, *v2*, ... according to the format string *fmt* and
Pack the values *v1*, *v2*, ... according to the format string *format* and
write the packed bytes into the writable buffer *buffer* starting at
position *offset*. Note that *offset* is a required argument.
.. function:: unpack(fmt, buffer)
.. function:: unpack(format, buffer)
Unpack from the buffer *buffer* (presumably packed by ``pack(fmt, ...)``)
according to the format string *fmt*. The result is a tuple even if it
Unpack from the buffer *buffer* (presumably packed by ``pack(format, ...)``)
according to the format string *format*. The result is a tuple even if it
contains exactly one item. The buffer's size in bytes must match the
size required by the format, as reflected by :func:`calcsize`.
.. function:: unpack_from(fmt, buffer, offset=0)
.. function:: unpack_from(format, buffer, offset=0)
Unpack from *buffer* starting at position *offset*, according to the format
string *fmt*. The result is a tuple even if it contains exactly one
string *format*. The result is a tuple even if it contains exactly one
item. The buffer's size in bytes, minus *offset*, must be at least
the size required by the format, as reflected by :func:`calcsize`.
.. function:: iter_unpack(fmt, buffer)
.. function:: iter_unpack(format, buffer)
Iteratively unpack from the buffer *buffer* according to the format
string *fmt*. This function returns an iterator which will read
string *format*. This function returns an iterator which will read
equally-sized chunks from the buffer until all its contents have been
consumed. The buffer's size in bytes must be a multiple of the size
required by the format, as reflected by :func:`calcsize`.
@ -91,10 +91,11 @@ The module defines the following exception and functions:
.. versionadded:: 3.4
.. function:: calcsize(fmt)
.. function:: calcsize(format)
Return the size of the struct (and hence of the bytes object produced by
``pack(fmt, ...)``) corresponding to the format string *fmt*.
``pack(format, ...)``) corresponding to the format string *format*.
.. _struct-format-strings:

View File

@ -412,6 +412,10 @@ class StructTest(unittest.TestCase):
for i in range(6, len(test_string) + 1):
self.assertRaises(struct.error, struct.unpack_from, fmt, data, i)
# keyword arguments
self.assertEqual(s.unpack_from(buffer=test_string, offset=2),
(b'cd01',))
def test_pack_into(self):
test_string = b'Reykjavik rocks, eow!'
writable_buf = array.array('b', b' '*100)

View File

@ -9,6 +9,11 @@
#include "structmember.h"
#include <ctype.h>
/*[clinic input]
class Struct "PyStructObject *" "&PyStructType"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=9b032058a83ed7c3]*/
static PyTypeObject PyStructType;
/* The translation function for each format character is table driven */
@ -80,6 +85,8 @@ typedef struct { char c; long long x; } s_long_long;
#pragma options align=reset
#endif
#include "clinic/_struct.c.h"
/* Helper for integer format codes: converts an arbitrary Python object to a
PyLongObject if possible, otherwise fails. Caller should decref. */
@ -1429,41 +1436,46 @@ s_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
return self;
}
/*[clinic input]
Struct.__init__
format: object
Create a compiled struct object.
Return a new Struct object which writes and reads binary data according to
the format string.
See help(struct) for more on format strings.
[clinic start generated code]*/
static int
s_init(PyObject *self, PyObject *args, PyObject *kwds)
Struct___init___impl(PyStructObject *self, PyObject *format)
/*[clinic end generated code: output=b8e80862444e92d0 input=192a4575a3dde802]*/
{
PyStructObject *soself = (PyStructObject *)self;
PyObject *o_format = NULL;
int ret = 0;
static char *kwlist[] = {"format", 0};
assert(PyStruct_Check(self));
if (!PyArg_ParseTupleAndKeywords(args, kwds, "O:Struct", kwlist,
&o_format))
return -1;
if (PyUnicode_Check(o_format)) {
o_format = PyUnicode_AsASCIIString(o_format);
if (o_format == NULL)
if (PyUnicode_Check(format)) {
format = PyUnicode_AsASCIIString(format);
if (format == NULL)
return -1;
}
/* XXX support buffer interface, too */
else {
Py_INCREF(o_format);
Py_INCREF(format);
}
if (!PyBytes_Check(o_format)) {
Py_DECREF(o_format);
if (!PyBytes_Check(format)) {
Py_DECREF(format);
PyErr_Format(PyExc_TypeError,
"Struct() argument 1 must be a bytes object, not %.200s",
Py_TYPE(o_format)->tp_name);
Py_TYPE(format)->tp_name);
return -1;
}
Py_XSETREF(soself->s_format, o_format);
Py_XSETREF(self->s_format, format);
ret = prepare_s(soself);
ret = prepare_s(self);
return ret;
}
@ -1517,78 +1529,69 @@ fail:
}
PyDoc_STRVAR(s_unpack__doc__,
"S.unpack(buffer) -> (v1, v2, ...)\n\
\n\
Return a tuple containing values unpacked according to the format\n\
string S.format. The buffer's size in bytes must be S.size. See\n\
help(struct) for more on format strings.");
/*[clinic input]
Struct.unpack
buffer: Py_buffer
/
Return a tuple containing unpacked values.
Unpack according to the format string Struct.format. The buffer's size
in bytes must be Struct.size.
See help(struct) for more on format strings.
[clinic start generated code]*/
static PyObject *
s_unpack(PyObject *self, PyObject *input)
Struct_unpack_impl(PyStructObject *self, Py_buffer *buffer)
/*[clinic end generated code: output=873a24faf02e848a input=3113f8e7038b2f6c]*/
{
Py_buffer vbuf;
PyObject *result;
PyStructObject *soself = (PyStructObject *)self;
assert(PyStruct_Check(self));
assert(soself->s_codes != NULL);
if (PyObject_GetBuffer(input, &vbuf, PyBUF_SIMPLE) < 0)
return NULL;
if (vbuf.len != soself->s_size) {
assert(self->s_codes != NULL);
if (buffer->len != self->s_size) {
PyErr_Format(StructError,
"unpack requires a bytes object of length %zd",
soself->s_size);
PyBuffer_Release(&vbuf);
self->s_size);
return NULL;
}
result = s_unpack_internal(soself, vbuf.buf);
PyBuffer_Release(&vbuf);
return result;
return s_unpack_internal(self, buffer->buf);
}
PyDoc_STRVAR(s_unpack_from__doc__,
"S.unpack_from(buffer, offset=0) -> (v1, v2, ...)\n\
\n\
Return a tuple containing values unpacked according to the format\n\
string S.format. The buffer's size in bytes, minus offset, must be at\n\
least S.size. See help(struct) for more on format strings.");
/*[clinic input]
Struct.unpack_from
buffer: Py_buffer
offset: Py_ssize_t = 0
Return a tuple containing unpacked values.
Values are unpacked according to the format string Struct.format.
The buffer's size in bytes, minus offset, must be at least Struct.size.
See help(struct) for more on format strings.
[clinic start generated code]*/
static PyObject *
s_unpack_from(PyObject *self, PyObject *args, PyObject *kwds)
Struct_unpack_from_impl(PyStructObject *self, Py_buffer *buffer,
Py_ssize_t offset)
/*[clinic end generated code: output=57fac875e0977316 input=97ade52422f8962f]*/
{
static char *kwlist[] = {"buffer", "offset", 0};
assert(self->s_codes != NULL);
PyObject *input;
Py_ssize_t offset = 0;
Py_buffer vbuf;
PyObject *result;
PyStructObject *soself = (PyStructObject *)self;
assert(PyStruct_Check(self));
assert(soself->s_codes != NULL);
if (!PyArg_ParseTupleAndKeywords(args, kwds,
"O|n:unpack_from", kwlist,
&input, &offset))
return NULL;
if (PyObject_GetBuffer(input, &vbuf, PyBUF_SIMPLE) < 0)
return NULL;
if (offset < 0)
offset += vbuf.len;
if (offset < 0 || vbuf.len - offset < soself->s_size) {
offset += buffer->len;
if (offset < 0 || buffer->len - offset < self->s_size) {
PyErr_Format(StructError,
"unpack_from requires a buffer of at least %zd bytes",
soself->s_size);
PyBuffer_Release(&vbuf);
self->s_size);
return NULL;
}
result = s_unpack_internal(soself, (char*)vbuf.buf + offset);
PyBuffer_Release(&vbuf);
return result;
return s_unpack_internal(self, (char*)buffer->buf + offset);
}
/* Unpack iterator type */
typedef struct {
@ -1680,48 +1683,54 @@ static PyTypeObject unpackiter_type = {
unpackiter_methods /* tp_methods */
};
PyDoc_STRVAR(s_iter_unpack__doc__,
"S.iter_unpack(buffer) -> iterator(v1, v2, ...)\n\
\n\
Return an iterator yielding tuples unpacked from the given bytes\n\
source, like a repeated invocation of unpack_from(). Requires\n\
that the bytes length be a multiple of the struct size.");
/*[clinic input]
Struct.iter_unpack
buffer: object
/
Return an iterator yielding tuples.
Tuples are unpacked from the given bytes source, like a repeated
invocation of unpack_from().
Requires that the bytes length be a multiple of the struct size.
[clinic start generated code]*/
static PyObject *
s_iter_unpack(PyObject *_so, PyObject *input)
Struct_iter_unpack(PyStructObject *self, PyObject *buffer)
/*[clinic end generated code: output=172d83d0cd15dbab input=6d65b3f3107dbc99]*/
{
PyStructObject *so = (PyStructObject *) _so;
unpackiterobject *self;
unpackiterobject *iter;
assert(PyStruct_Check(_so));
assert(so->s_codes != NULL);
assert(self->s_codes != NULL);
if (so->s_size == 0) {
if (self->s_size == 0) {
PyErr_Format(StructError,
"cannot iteratively unpack with a struct of length 0");
return NULL;
}
self = (unpackiterobject *) PyType_GenericAlloc(&unpackiter_type, 0);
if (self == NULL)
iter = (unpackiterobject *) PyType_GenericAlloc(&unpackiter_type, 0);
if (iter == NULL)
return NULL;
if (PyObject_GetBuffer(input, &self->buf, PyBUF_SIMPLE) < 0) {
Py_DECREF(self);
if (PyObject_GetBuffer(buffer, &iter->buf, PyBUF_SIMPLE) < 0) {
Py_DECREF(iter);
return NULL;
}
if (self->buf.len % so->s_size != 0) {
if (iter->buf.len % self->s_size != 0) {
PyErr_Format(StructError,
"iterative unpacking requires a bytes length "
"multiple of %zd",
so->s_size);
Py_DECREF(self);
self->s_size);
Py_DECREF(iter);
return NULL;
}
Py_INCREF(so);
self->so = so;
self->index = 0;
return (PyObject *) self;
Py_INCREF(self);
iter->so = self;
iter->index = 0;
return (PyObject *)iter;
}
@ -1736,7 +1745,7 @@ s_iter_unpack(PyObject *_so, PyObject *input)
*
*/
static int
s_pack_internal(PyStructObject *soself, PyObject *args, int offset, char* buf)
s_pack_internal(PyStructObject *soself, PyObject **args, int offset, char* buf)
{
formatcode *code;
/* XXX(nnorwitz): why does i need to be a local? can we use
@ -1750,7 +1759,7 @@ s_pack_internal(PyStructObject *soself, PyObject *args, int offset, char* buf)
char *res = buf + code->offset;
Py_ssize_t j = code->repeat;
while (j--) {
PyObject *v = PyTuple_GET_ITEM(args, i++);
PyObject *v = args[i++];
if (e->format == 's') {
Py_ssize_t n;
int isstring;
@ -1823,7 +1832,7 @@ to the format string S.format. See help(struct) for more on format\n\
strings.");
static PyObject *
s_pack(PyObject *self, PyObject *args)
s_pack(PyObject *self, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
{
PyStructObject *soself;
PyObject *result;
@ -1832,10 +1841,13 @@ s_pack(PyObject *self, PyObject *args)
soself = (PyStructObject *)self;
assert(PyStruct_Check(self));
assert(soself->s_codes != NULL);
if (PyTuple_GET_SIZE(args) != soself->s_len)
if (nargs != soself->s_len)
{
PyErr_Format(StructError,
"pack expected %zd items for packing (got %zd)", soself->s_len, PyTuple_GET_SIZE(args));
"pack expected %zd items for packing (got %zd)", soself->s_len, nargs);
return NULL;
}
if (!_PyArg_NoStackKeywords("pack", kwnames)) {
return NULL;
}
@ -1862,7 +1874,7 @@ offset. Note that the offset is a required argument. See\n\
help(struct) for more on format strings.");
static PyObject *
s_pack_into(PyObject *self, PyObject *args)
s_pack_into(PyObject *self, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
{
PyStructObject *soself;
Py_buffer buffer;
@ -1872,31 +1884,34 @@ s_pack_into(PyObject *self, PyObject *args)
soself = (PyStructObject *)self;
assert(PyStruct_Check(self));
assert(soself->s_codes != NULL);
if (PyTuple_GET_SIZE(args) != (soself->s_len + 2))
if (nargs != (soself->s_len + 2))
{
if (PyTuple_GET_SIZE(args) == 0) {
if (nargs == 0) {
PyErr_Format(StructError,
"pack_into expected buffer argument");
}
else if (PyTuple_GET_SIZE(args) == 1) {
else if (nargs == 1) {
PyErr_Format(StructError,
"pack_into expected offset argument");
}
else {
PyErr_Format(StructError,
"pack_into expected %zd items for packing (got %zd)",
soself->s_len, (PyTuple_GET_SIZE(args) - 2));
soself->s_len, (nargs - 2));
}
return NULL;
}
if (!_PyArg_NoStackKeywords("pack_into", kwnames)) {
return NULL;
}
/* Extract a writable memory buffer from the first argument */
if (!PyArg_Parse(PyTuple_GET_ITEM(args, 0), "w*", &buffer))
if (!PyArg_Parse(args[0], "w*", &buffer))
return NULL;
assert(buffer.len >= 0);
/* Extract the offset from the first argument */
offset = PyNumber_AsSsize_t(PyTuple_GET_ITEM(args, 1), PyExc_IndexError);
offset = PyNumber_AsSsize_t(args[1], PyExc_IndexError);
if (offset == -1 && PyErr_Occurred()) {
PyBuffer_Release(&buffer);
return NULL;
@ -1956,22 +1971,15 @@ s_sizeof(PyStructObject *self, void *unused)
/* List of functions */
static struct PyMethodDef s_methods[] = {
{"iter_unpack", s_iter_unpack, METH_O, s_iter_unpack__doc__},
{"pack", s_pack, METH_VARARGS, s_pack__doc__},
{"pack_into", s_pack_into, METH_VARARGS, s_pack_into__doc__},
{"unpack", s_unpack, METH_O, s_unpack__doc__},
{"unpack_from", (PyCFunction)s_unpack_from, METH_VARARGS|METH_KEYWORDS,
s_unpack_from__doc__},
STRUCT_ITER_UNPACK_METHODDEF
{"pack", (PyCFunction)s_pack, METH_FASTCALL, s_pack__doc__},
{"pack_into", (PyCFunction)s_pack_into, METH_FASTCALL, s_pack_into__doc__},
STRUCT_UNPACK_METHODDEF
STRUCT_UNPACK_FROM_METHODDEF
{"__sizeof__", (PyCFunction)s_sizeof, METH_NOARGS, s_sizeof__doc__},
{NULL, NULL} /* sentinel */
};
PyDoc_STRVAR(s__doc__,
"Struct(fmt) --> compiled struct object\n"
"\n"
"Return a new Struct object which writes and reads binary data according to\n"
"the format string fmt. See help(struct) for more on format strings.");
#define OFF(x) offsetof(PyStructObject, x)
static PyGetSetDef s_getsetlist[] = {
@ -2002,7 +2010,7 @@ PyTypeObject PyStructType = {
PyObject_GenericSetAttr, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
s__doc__, /* tp_doc */
Struct___init____doc__, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
@ -2017,8 +2025,8 @@ PyTypeObject PyStructType = {
0, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
s_init, /* tp_init */
PyType_GenericAlloc,/* tp_alloc */
Struct___init__, /* tp_init */
PyType_GenericAlloc, /* tp_alloc */
s_new, /* tp_new */
PyObject_Del, /* tp_free */
};
@ -2029,7 +2037,7 @@ PyTypeObject PyStructType = {
#define MAXCACHE 100
static PyObject *cache = NULL;
static PyObject *
static PyStructObject *
cache_struct(PyObject *fmt)
{
PyObject * s_object;
@ -2043,7 +2051,7 @@ cache_struct(PyObject *fmt)
s_object = PyDict_GetItem(cache, fmt);
if (s_object != NULL) {
Py_INCREF(s_object);
return s_object;
return (PyStructObject *)s_object;
}
s_object = PyObject_CallFunctionObjArgs((PyObject *)(&PyStructType), fmt, NULL);
@ -2054,191 +2062,203 @@ cache_struct(PyObject *fmt)
if (PyDict_SetItem(cache, fmt, s_object) == -1)
PyErr_Clear();
}
return s_object;
return (PyStructObject *)s_object;
}
PyDoc_STRVAR(clearcache_doc,
"Clear the internal cache.");
/*[clinic input]
_clearcache
Clear the internal cache.
[clinic start generated code]*/
static PyObject *
clearcache(PyObject *self)
_clearcache_impl(PyObject *module)
/*[clinic end generated code: output=ce4fb8a7bf7cb523 input=463eaae04bab3211]*/
{
Py_CLEAR(cache);
Py_RETURN_NONE;
}
PyDoc_STRVAR(calcsize_doc,
"calcsize(fmt) -> integer\n\
\n\
Return size in bytes of the struct described by the format string fmt.");
/*[clinic input]
calcsize
format: object
/
Return size in bytes of the struct described by the format string.
[clinic start generated code]*/
static PyObject *
calcsize(PyObject *self, PyObject *fmt)
calcsize(PyObject *module, PyObject *format)
/*[clinic end generated code: output=90fbcf191fe9470a input=55488303a06777fa]*/
{
Py_ssize_t n;
PyObject *s_object = cache_struct(fmt);
PyStructObject *s_object = cache_struct(format);
if (s_object == NULL)
return NULL;
n = ((PyStructObject *)s_object)->s_size;
n = s_object->s_size;
Py_DECREF(s_object);
return PyLong_FromSsize_t(n);
}
PyDoc_STRVAR(pack_doc,
"pack(fmt, v1, v2, ...) -> bytes\n\
"pack(format, v1, v2, ...) -> bytes\n\
\n\
Return a bytes object containing the values v1, v2, ... packed according\n\
to the format string fmt. See help(struct) for more on format strings.");
to the format string. See help(struct) for more on format strings.");
static PyObject *
pack(PyObject *self, PyObject *args)
pack(PyObject *self, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
{
PyObject *s_object, *fmt, *newargs, *result;
Py_ssize_t n = PyTuple_GET_SIZE(args);
PyStructObject *s_object;
PyObject *format, *result;
if (n == 0) {
if (nargs == 0) {
PyErr_SetString(PyExc_TypeError, "missing format argument");
return NULL;
}
fmt = PyTuple_GET_ITEM(args, 0);
newargs = PyTuple_GetSlice(args, 1, n);
if (newargs == NULL)
return NULL;
format = args[0];
s_object = cache_struct(fmt);
s_object = cache_struct(format);
if (s_object == NULL) {
Py_DECREF(newargs);
return NULL;
}
result = s_pack(s_object, newargs);
Py_DECREF(newargs);
result = s_pack((PyObject *)s_object, args + 1, nargs - 1, kwnames);
Py_DECREF(s_object);
return result;
}
PyDoc_STRVAR(pack_into_doc,
"pack_into(fmt, buffer, offset, v1, v2, ...)\n\
"pack_into(format, buffer, offset, v1, v2, ...)\n\
\n\
Pack the values v1, v2, ... according to the format string fmt and write\n\
Pack the values v1, v2, ... according to the format string and write\n\
the packed bytes into the writable buffer buf starting at offset. Note\n\
that the offset is a required argument. See help(struct) for more\n\
on format strings.");
static PyObject *
pack_into(PyObject *self, PyObject *args)
pack_into(PyObject *self, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
{
PyObject *s_object, *fmt, *newargs, *result;
Py_ssize_t n = PyTuple_GET_SIZE(args);
PyStructObject *s_object;
PyObject *format, *result;
if (n == 0) {
if (nargs == 0) {
PyErr_SetString(PyExc_TypeError, "missing format argument");
return NULL;
}
fmt = PyTuple_GET_ITEM(args, 0);
newargs = PyTuple_GetSlice(args, 1, n);
if (newargs == NULL)
return NULL;
format = args[0];
s_object = cache_struct(fmt);
s_object = cache_struct(format);
if (s_object == NULL) {
Py_DECREF(newargs);
return NULL;
}
result = s_pack_into(s_object, newargs);
Py_DECREF(newargs);
result = s_pack_into((PyObject *)s_object, args + 1, nargs - 1, kwnames);
Py_DECREF(s_object);
return result;
}
PyDoc_STRVAR(unpack_doc,
"unpack(fmt, buffer) -> (v1, v2, ...)\n\
\n\
Return a tuple containing values unpacked according to the format string\n\
fmt. The buffer's size in bytes must be calcsize(fmt). See help(struct)\n\
for more on format strings.");
/*[clinic input]
unpack
format: object
inputstr: object
/
Return a tuple containing values unpacked according to the format string.
The buffer's size in bytes must be calcsize(format).
See help(struct) for more on format strings.
[clinic start generated code]*/
static PyObject *
unpack(PyObject *self, PyObject *args)
unpack_impl(PyObject *module, PyObject *format, PyObject *inputstr)
/*[clinic end generated code: output=06951d66eae6d63b input=4b81d54988890f5e]*/
{
PyObject *s_object, *fmt, *inputstr, *result;
PyStructObject *s_object;
PyObject *result;
if (!PyArg_UnpackTuple(args, "unpack", 2, 2, &fmt, &inputstr))
return NULL;
s_object = cache_struct(fmt);
s_object = cache_struct(format);
if (s_object == NULL)
return NULL;
result = s_unpack(s_object, inputstr);
result = Struct_unpack(s_object, inputstr);
Py_DECREF(s_object);
return result;
}
PyDoc_STRVAR(unpack_from_doc,
"unpack_from(fmt, buffer, offset=0) -> (v1, v2, ...)\n\
\n\
Return a tuple containing values unpacked according to the format string\n\
fmt. The buffer's size, minus offset, must be at least calcsize(fmt).\n\
See help(struct) for more on format strings.");
/*[clinic input]
unpack_from
format: object
/
buffer: Py_buffer
offset: Py_ssize_t = 0
Return a tuple containing values unpacked according to the format string.
The buffer's size, minus offset, must be at least calcsize(format).
See help(struct) for more on format strings.
[clinic start generated code]*/
static PyObject *
unpack_from(PyObject *self, PyObject *args, PyObject *kwds)
unpack_from_impl(PyObject *module, PyObject *format, Py_buffer *buffer,
Py_ssize_t offset)
/*[clinic end generated code: output=2492f0c3a0b82577 input=9ead76c6ac7164f7]*/
{
PyObject *s_object, *fmt, *newargs, *result;
Py_ssize_t n = PyTuple_GET_SIZE(args);
PyStructObject *s_object;
PyObject *result;
if (n == 0) {
PyErr_SetString(PyExc_TypeError, "missing format argument");
return NULL;
}
fmt = PyTuple_GET_ITEM(args, 0);
newargs = PyTuple_GetSlice(args, 1, n);
if (newargs == NULL)
return NULL;
s_object = cache_struct(fmt);
s_object = cache_struct(format);
if (s_object == NULL) {
Py_DECREF(newargs);
return NULL;
}
result = s_unpack_from(s_object, newargs, kwds);
Py_DECREF(newargs);
result = Struct_unpack_from_impl(s_object, buffer, offset);
Py_DECREF(s_object);
return result;
}
PyDoc_STRVAR(iter_unpack_doc,
"iter_unpack(fmt, buffer) -> iterator(v1, v2, ...)\n\
\n\
Return an iterator yielding tuples unpacked from the given bytes\n\
source according to the format string, like a repeated invocation of\n\
unpack_from(). Requires that the bytes length be a multiple of the\n\
format struct size.");
/*[clinic input]
iter_unpack
format: object
buffer: object
/
Return an iterator yielding tuples unpacked from the given bytes.
The bytes are unpacked according to the format string, like
a repeated invocation of unpack_from().
Requires that the bytes length be a multiple of the format struct size.
[clinic start generated code]*/
static PyObject *
iter_unpack(PyObject *self, PyObject *args)
iter_unpack_impl(PyObject *module, PyObject *format, PyObject *buffer)
/*[clinic end generated code: output=b1291e97a6d4cf3c input=8674dfd2f0dae416]*/
{
PyObject *s_object, *fmt, *input, *result;
PyStructObject *s_object;
PyObject *result;
if (!PyArg_ParseTuple(args, "OO:iter_unpack", &fmt, &input))
return NULL;
s_object = cache_struct(fmt);
s_object = cache_struct(format);
if (s_object == NULL)
return NULL;
result = s_iter_unpack(s_object, input);
result = Struct_iter_unpack(s_object, buffer);
Py_DECREF(s_object);
return result;
}
static struct PyMethodDef module_functions[] = {
{"_clearcache", (PyCFunction)clearcache, METH_NOARGS, clearcache_doc},
{"calcsize", calcsize, METH_O, calcsize_doc},
{"iter_unpack", iter_unpack, METH_VARARGS, iter_unpack_doc},
{"pack", pack, METH_VARARGS, pack_doc},
{"pack_into", pack_into, METH_VARARGS, pack_into_doc},
{"unpack", unpack, METH_VARARGS, unpack_doc},
{"unpack_from", (PyCFunction)unpack_from,
METH_VARARGS|METH_KEYWORDS, unpack_from_doc},
_CLEARCACHE_METHODDEF
CALCSIZE_METHODDEF
ITER_UNPACK_METHODDEF
{"pack", (PyCFunction)pack, METH_FASTCALL, pack_doc},
{"pack_into", (PyCFunction)pack_into, METH_FASTCALL, pack_into_doc},
UNPACK_METHODDEF
UNPACK_FROM_METHODDEF
{NULL, NULL} /* sentinel */
};

276
Modules/clinic/_struct.c.h Normal file
View File

@ -0,0 +1,276 @@
/*[clinic input]
preserve
[clinic start generated code]*/
PyDoc_STRVAR(Struct___init____doc__,
"Struct(format)\n"
"--\n"
"\n"
"Create a compiled struct object.\n"
"\n"
"Return a new Struct object which writes and reads binary data according to\n"
"the format string.\n"
"\n"
"See help(struct) for more on format strings.");
static int
Struct___init___impl(PyStructObject *self, PyObject *format);
static int
Struct___init__(PyObject *self, PyObject *args, PyObject *kwargs)
{
int return_value = -1;
static const char * const _keywords[] = {"format", NULL};
static _PyArg_Parser _parser = {"O:Struct", _keywords, 0};
PyObject *format;
if (!_PyArg_ParseTupleAndKeywordsFast(args, kwargs, &_parser,
&format)) {
goto exit;
}
return_value = Struct___init___impl((PyStructObject *)self, format);
exit:
return return_value;
}
PyDoc_STRVAR(Struct_unpack__doc__,
"unpack($self, buffer, /)\n"
"--\n"
"\n"
"Return a tuple containing unpacked values.\n"
"\n"
"Unpack according to the format string Struct.format. The buffer\'s size\n"
"in bytes must be Struct.size.\n"
"\n"
"See help(struct) for more on format strings.");
#define STRUCT_UNPACK_METHODDEF \
{"unpack", (PyCFunction)Struct_unpack, METH_O, Struct_unpack__doc__},
static PyObject *
Struct_unpack_impl(PyStructObject *self, Py_buffer *buffer);
static PyObject *
Struct_unpack(PyStructObject *self, PyObject *arg)
{
PyObject *return_value = NULL;
Py_buffer buffer = {NULL, NULL};
if (!PyArg_Parse(arg, "y*:unpack", &buffer)) {
goto exit;
}
return_value = Struct_unpack_impl(self, &buffer);
exit:
/* Cleanup for buffer */
if (buffer.obj) {
PyBuffer_Release(&buffer);
}
return return_value;
}
PyDoc_STRVAR(Struct_unpack_from__doc__,
"unpack_from($self, /, buffer, offset=0)\n"
"--\n"
"\n"
"Return a tuple containing unpacked values.\n"
"\n"
"Values are unpacked according to the format string Struct.format.\n"
"\n"
"The buffer\'s size in bytes, minus offset, must be at least Struct.size.\n"
"\n"
"See help(struct) for more on format strings.");
#define STRUCT_UNPACK_FROM_METHODDEF \
{"unpack_from", (PyCFunction)Struct_unpack_from, METH_FASTCALL, Struct_unpack_from__doc__},
static PyObject *
Struct_unpack_from_impl(PyStructObject *self, Py_buffer *buffer,
Py_ssize_t offset);
static PyObject *
Struct_unpack_from(PyStructObject *self, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
{
PyObject *return_value = NULL;
static const char * const _keywords[] = {"buffer", "offset", NULL};
static _PyArg_Parser _parser = {"y*|n:unpack_from", _keywords, 0};
Py_buffer buffer = {NULL, NULL};
Py_ssize_t offset = 0;
if (!_PyArg_ParseStackAndKeywords(args, nargs, kwnames, &_parser,
&buffer, &offset)) {
goto exit;
}
return_value = Struct_unpack_from_impl(self, &buffer, offset);
exit:
/* Cleanup for buffer */
if (buffer.obj) {
PyBuffer_Release(&buffer);
}
return return_value;
}
PyDoc_STRVAR(Struct_iter_unpack__doc__,
"iter_unpack($self, buffer, /)\n"
"--\n"
"\n"
"Return an iterator yielding tuples.\n"
"\n"
"Tuples are unpacked from the given bytes source, like a repeated\n"
"invocation of unpack_from().\n"
"\n"
"Requires that the bytes length be a multiple of the struct size.");
#define STRUCT_ITER_UNPACK_METHODDEF \
{"iter_unpack", (PyCFunction)Struct_iter_unpack, METH_O, Struct_iter_unpack__doc__},
PyDoc_STRVAR(_clearcache__doc__,
"_clearcache($module, /)\n"
"--\n"
"\n"
"Clear the internal cache.");
#define _CLEARCACHE_METHODDEF \
{"_clearcache", (PyCFunction)_clearcache, METH_NOARGS, _clearcache__doc__},
static PyObject *
_clearcache_impl(PyObject *module);
static PyObject *
_clearcache(PyObject *module, PyObject *Py_UNUSED(ignored))
{
return _clearcache_impl(module);
}
PyDoc_STRVAR(calcsize__doc__,
"calcsize($module, format, /)\n"
"--\n"
"\n"
"Return size in bytes of the struct described by the format string.");
#define CALCSIZE_METHODDEF \
{"calcsize", (PyCFunction)calcsize, METH_O, calcsize__doc__},
PyDoc_STRVAR(unpack__doc__,
"unpack($module, format, inputstr, /)\n"
"--\n"
"\n"
"Return a tuple containing values unpacked according to the format string.\n"
"\n"
"The buffer\'s size in bytes must be calcsize(format).\n"
"\n"
"See help(struct) for more on format strings.");
#define UNPACK_METHODDEF \
{"unpack", (PyCFunction)unpack, METH_FASTCALL, unpack__doc__},
static PyObject *
unpack_impl(PyObject *module, PyObject *format, PyObject *inputstr);
static PyObject *
unpack(PyObject *module, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
{
PyObject *return_value = NULL;
PyObject *format;
PyObject *inputstr;
if (!_PyArg_UnpackStack(args, nargs, "unpack",
2, 2,
&format, &inputstr)) {
goto exit;
}
if (!_PyArg_NoStackKeywords("unpack", kwnames)) {
goto exit;
}
return_value = unpack_impl(module, format, inputstr);
exit:
return return_value;
}
PyDoc_STRVAR(unpack_from__doc__,
"unpack_from($module, format, /, buffer, offset=0)\n"
"--\n"
"\n"
"Return a tuple containing values unpacked according to the format string.\n"
"\n"
"The buffer\'s size, minus offset, must be at least calcsize(format).\n"
"\n"
"See help(struct) for more on format strings.");
#define UNPACK_FROM_METHODDEF \
{"unpack_from", (PyCFunction)unpack_from, METH_FASTCALL, unpack_from__doc__},
static PyObject *
unpack_from_impl(PyObject *module, PyObject *format, Py_buffer *buffer,
Py_ssize_t offset);
static PyObject *
unpack_from(PyObject *module, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
{
PyObject *return_value = NULL;
static const char * const _keywords[] = {"", "buffer", "offset", NULL};
static _PyArg_Parser _parser = {"Oy*|n:unpack_from", _keywords, 0};
PyObject *format;
Py_buffer buffer = {NULL, NULL};
Py_ssize_t offset = 0;
if (!_PyArg_ParseStackAndKeywords(args, nargs, kwnames, &_parser,
&format, &buffer, &offset)) {
goto exit;
}
return_value = unpack_from_impl(module, format, &buffer, offset);
exit:
/* Cleanup for buffer */
if (buffer.obj) {
PyBuffer_Release(&buffer);
}
return return_value;
}
PyDoc_STRVAR(iter_unpack__doc__,
"iter_unpack($module, format, buffer, /)\n"
"--\n"
"\n"
"Return an iterator yielding tuples unpacked from the given bytes.\n"
"\n"
"The bytes are unpacked according to the format string, like\n"
"a repeated invocation of unpack_from().\n"
"\n"
"Requires that the bytes length be a multiple of the format struct size.");
#define ITER_UNPACK_METHODDEF \
{"iter_unpack", (PyCFunction)iter_unpack, METH_FASTCALL, iter_unpack__doc__},
static PyObject *
iter_unpack_impl(PyObject *module, PyObject *format, PyObject *buffer);
static PyObject *
iter_unpack(PyObject *module, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
{
PyObject *return_value = NULL;
PyObject *format;
PyObject *buffer;
if (!_PyArg_UnpackStack(args, nargs, "iter_unpack",
2, 2,
&format, &buffer)) {
goto exit;
}
if (!_PyArg_NoStackKeywords("iter_unpack", kwnames)) {
goto exit;
}
return_value = iter_unpack_impl(module, format, buffer);
exit:
return return_value;
}
/*[clinic end generated code: output=db8152ad222fa3d0 input=a9049054013a1b77]*/