[Python-checkins] r46268 - python/trunk/Objects/stringobject.c

[Neal Norwitz]

Why not use METH_O so the PyArgs_ParseTuple() call is not necessary?

n
--

On 5/25/06, fredrik.lundh <python-checkins at python.org> wrote:
> Author: fredrik.lundh
> Date: Fri May 26 01:27:53 2006
> New Revision: 46268
>
> Modified:
>    python/trunk/Objects/stringobject.c
> Log:
> needforspeed: partition for 8-bit strings.  for some simple tests,
> this is on par with a corresponding find, and nearly twice as fast
> as split(sep, 1)
>
> full tests, a unicode version, and documentation will follow to-
> morrow.
>
>
>
> Modified: python/trunk/Objects/stringobject.c
> ==============================================================================
> --- python/trunk/Objects/stringobject.c (original)
> +++ python/trunk/Objects/stringobject.c Fri May 26 01:27:53 2006
> @@ -799,8 +799,7 @@
>  #define FAST_SEARCH 1
>
>  LOCAL(Py_ssize_t)
> -       fastsearch(const char* s, Py_ssize_t n, const char* p,
> -                  Py_ssize_t m, int mode)
> +fastsearch(const char* s, Py_ssize_t n, const char* p, Py_ssize_t m, int mode)
>  {
>         long mask;
>         int skip, count = 0;
> @@ -860,10 +859,8 @@
>                         /* miss: check if next character is part of pattern */
>                         if (!(mask & (1 << (s[i+m] & 0x1F))))
>                                 i = i + m;
> -                       else {
> +                       else
>                                 i = i + skip;
> -                               continue;
> -                       }
>                 } else {
>                         /* skip: check if next character is part of pattern */
>                         if (!(mask & (1 << (s[i+m] & 0x1F))))
> @@ -1601,6 +1598,68 @@
>         return NULL;
>  }
>
> +PyDoc_STRVAR(partition__doc__,
> +"S.partition(sep) -> (head, sep, tail)\n\
> +\n\
> +Searches for the separator sep in S, and returns the part before it,\n\
> +the separator itself, and the part after it.  If the separator is not\n\
> +found, returns S and two empty strings.");
> +
> +static PyObject *
> +string_partition(PyStringObject *self, PyObject *args)
> +{
> +       Py_ssize_t len = PyString_GET_SIZE(self), sep_len, pos;
> +       const char *str = PyString_AS_STRING(self), *sep;
> +       PyObject *sepobj;
> +       PyObject * out;
> +
> +       if (!PyArg_ParseTuple(args, "O:partition", &sepobj))
> +               return NULL;
> +       if (PyString_Check(sepobj)) {
> +               sep = PyString_AS_STRING(sepobj);
> +               sep_len = PyString_GET_SIZE(sepobj);
> +       }
> +#ifdef Py_USING_UNICODE_NOTYET
> +       else if (PyUnicode_Check(sepobj))
> +               return PyUnicode_Partition((PyObject *)self, sepobj);
> +#endif
> +       else if (PyObject_AsCharBuffer(sepobj, &sep, &sep_len))
> +               return NULL;
> +
> +       if (sep_len == 0) {
> +               PyErr_SetString(PyExc_ValueError, "empty separator");
> +               return NULL;
> +       }
> +
> +       out = PyTuple_New(3);
> +       if (!out)
> +               return NULL;
> +
> +       pos = fastsearch(str, len, sep, sep_len, FAST_SEARCH);
> +       if (pos < 0) {
> +               Py_INCREF(self);
> +               PyTuple_SET_ITEM(out, 0, (PyObject*) self);
> +               Py_INCREF(nullstring);
> +               PyTuple_SET_ITEM(out, 1, (PyObject*) nullstring);
> +               Py_INCREF(nullstring);
> +               PyTuple_SET_ITEM(out, 2, (PyObject*) nullstring);
> +       } else {
> +               Py_INCREF(sepobj);
> +               PyTuple_SET_ITEM(out, 0, PyString_FromStringAndSize(str, pos));
> +               PyTuple_SET_ITEM(out, 1, sepobj);
> +               PyTuple_SET_ITEM(out, 2,
> +                       PyString_FromStringAndSize(str + sep_len + pos,
> +                                                  len - sep_len - pos)
> +                       );
> +               if (PyErr_Occurred()) {
> +                       Py_DECREF(out);
> +                       return NULL;
> +               }
> +       }
> +
> +       return out;
> +}
> +
>  static PyObject *
>  rsplit_whitespace(const char *s, Py_ssize_t len, Py_ssize_t maxsplit)
>  {
> @@ -3910,6 +3969,8 @@
>         {"count", (PyCFunction)string_count, METH_VARARGS, count__doc__},
>         {"endswith", (PyCFunction)string_endswith, METH_VARARGS,
>          endswith__doc__},
> +       {"partition", (PyCFunction)string_partition, METH_VARARGS,
> +        partition__doc__},
>         {"find", (PyCFunction)string_find, METH_VARARGS, find__doc__},
>         {"index", (PyCFunction)string_index, METH_VARARGS, index__doc__},
>         {"lstrip", (PyCFunction)string_lstrip, METH_VARARGS, lstrip__doc__},
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