Stowage/cpython
2
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2026-01-06 15:32:22 +00:00
Code Issues Projects Releases Packages Wiki Activity

String interning.

Browse source
This commit is contained in:
Guido van Rossum 1997-01-18 07:55:05 +00:00
parent ee5cf9b672
commit 2a61e7428d
3 changed files with 287 additions and 34 deletions
Download patch file Download diff file Expand all files Collapse all files

75
Objects/stringobject.c
View file

@ -97,6 +97,9 @@ newsizedstringobject(str, size)
op->ob_size = size;
#ifdef CACHE_HASH
op->ob_shash = -1;
#endif
#ifdef INTERN_STRINGS
op->ob_sinterned = NULL;
#endif
NEWREF(op);
if (str != NULL)
@ -144,6 +147,9 @@ newstringobject(str)
op->ob_size = size;
#ifdef CACHE_HASH
op->ob_shash = -1;
#endif
#ifdef INTERN_STRINGS
op->ob_sinterned = NULL;
#endif
NEWREF(op);
strcpy(op->ob_sval, str);
@ -303,6 +309,9 @@ string_concat(a, bb)
op->ob_size = size;
#ifdef CACHE_HASH
op->ob_shash = -1;
#endif
#ifdef INTERN_STRINGS
op->ob_sinterned = NULL;
#endif
NEWREF(op);
memcpy(op->ob_sval, a->ob_sval, (int) a->ob_size);
@ -335,6 +344,9 @@ string_repeat(a, n)
op->ob_size = size;
#ifdef CACHE_HASH
op->ob_shash = -1;
#endif
#ifdef INTERN_STRINGS
op->ob_sinterned = NULL;
#endif
NEWREF(op);
for (i = 0; i < size; i += a->ob_size)
@ -462,6 +474,13 @@ typeobject Stringtype = {
&string_as_sequence, /*tp_as_sequence*/
0, /*tp_as_mapping*/
(hashfunc)string_hash, /*tp_hash*/
0, /*tp_call*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_xxx3*/
0, /*tp_xxx4*/
0, /*tp_doc*/
};
void
@ -928,3 +947,59 @@ formatstring(format, args)
DECREF(args);
return NULL;
}
#ifdef INTERN_STRINGS
static PyObject *interned;
void
PyString_InternInPlace(p)
PyObject **p;
{
register PyStringObject *s = (PyStringObject *)(*p);
PyObject *t;
if (s == NULL || !PyString_Check(s))
Py_FatalError("PyString_InternInPlace: strings only please!");
if ((t = s->ob_sinterned) != NULL) {
if (t == (PyObject *)s)
return;
Py_INCREF(t);
*p = t;
Py_DECREF(s);
return;
}
if (interned == NULL) {
interned = PyDict_New();
if (interned == NULL)
return;
/* Force slow lookups: */
PyDict_SetItem(interned, Py_None, Py_None);
}
if ((t = PyDict_GetItem(interned, (PyObject *)s)) != NULL) {
Py_INCREF(t);
*p = s->ob_sinterned = t;
Py_DECREF(s);
return;
}
t = (PyObject *)s;
if (PyDict_SetItem(interned, t, t) == 0) {
s->ob_sinterned = t;
return;
}
PyErr_Clear();
}
PyObject *
PyString_InternFromString(cp)
const char *cp;
{
PyObject *s = PyString_FromString(cp);
if (s == NULL)
return NULL;
PyString_InternInPlace(&s);
return s;
}
#endif