String interning.
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index a8b18ef..a8767d7 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -87,6 +87,9 @@
int ma_fill;
int ma_used;
int ma_size;
+#ifdef INTERN_STRINGS
+ int ma_fast;
+#endif
mappingentry *ma_table;
} mappingobject;
@@ -106,6 +109,9 @@
mp->ma_table = NULL;
mp->ma_fill = 0;
mp->ma_used = 0;
+#ifdef INTERN_STRINGS
+ mp->ma_fast = 1;
+#endif
return (object *)mp;
}
@@ -163,17 +169,40 @@
unsigned long sum;
int incr;
int size;
+#ifdef INTERN_STRINGS
+ int fast;
+#endif
ep = &mp->ma_table[(unsigned long)hash%mp->ma_size];
ekey = ep->me_key;
if (ekey == NULL)
return ep;
+#ifdef INTERN_STRINGS
+ if ((fast = mp->ma_fast)) {
+ object *ikey;
+ if (!is_stringobject(key) ||
+ (ikey = ((stringobject *)key)->ob_sinterned) == NULL)
+ fast = 0;
+ else
+ key = ikey;
+ }
+#endif
if (ekey == dummy)
freeslot = ep;
- else if (ep->me_hash == hash && cmpobject(ekey, key) == 0)
- return ep;
- else
+ else {
+#ifdef INTERN_STRINGS
+ if (fast) {
+ if (ekey == key)
+ return ep;
+ }
+ else
+#endif
+ {
+ if (ep->me_hash == hash && cmpobject(ekey, key) == 0)
+ return ep;
+ }
freeslot = NULL;
+ }
size = mp->ma_size;
sum = hash;
@@ -184,6 +213,36 @@
end = mp->ma_table + size;
+#ifdef INTERN_STRINGS
+ if (fast) {
+ if (freeslot == NULL) {
+ for (;;) {
+ ep += incr;
+ if (ep >= end)
+ ep -= size;
+ ekey = ep->me_key;
+ if (ekey == NULL || ekey == key)
+ return ep;
+ if (ekey == dummy) {
+ freeslot = ep;
+ break;
+ }
+ }
+ }
+
+ for (;;) {
+ ep += incr;
+ if (ep >= end)
+ ep -= size;
+ ekey = ep->me_key;
+ if (ekey == NULL)
+ return freeslot;
+ if (ekey == key)
+ return ep;
+ }
+ }
+#endif
+
if (freeslot == NULL) {
for (;;) {
ep += incr;
@@ -339,13 +398,35 @@
err_badcall();
return -1;
}
-#ifdef CACHE_HASH
- if (!is_stringobject(key) || (hash = ((stringobject *) key)->ob_shash) == -1)
-#endif
- hash = hashobject(key);
- if (hash == -1)
- return -1;
mp = (mappingobject *)op;
+#ifdef CACHE_HASH
+ if (is_stringobject(key)) {
+#ifdef INTERN_STRINGS
+ if (((stringobject *)key)->ob_sinterned != NULL) {
+ key = ((stringobject *)key)->ob_sinterned;
+ hash = ((stringobject *)key)->ob_shash;
+ }
+ else
+#endif
+ {
+ hash = ((stringobject *)key)->ob_shash;
+ if (hash == -1)
+ hash = hashobject(key);
+#ifdef INTERN_STRINGS
+ mp->ma_fast = 0;
+#endif
+ }
+ }
+ else
+#endif
+ {
+ hash = hashobject(key);
+ if (hash == -1)
+ return -1;
+#ifdef INTERN_STRINGS
+ mp->ma_fast = 0;
+#endif
+ }
/* if fill >= 2/3 size, resize */
if (mp->ma_fill*3 >= mp->ma_size*2) {
if (mappingresize(mp) != 0) {
@@ -907,16 +988,22 @@
object *name;
object *value;
{
+ int err;
+ INCREF(name);
+ PyString_InternInPlace(&name);
if (v->ob_type->tp_setattro != NULL)
- return (*v->ob_type->tp_setattro)(v, name, value);
-
- if (name != last_name_object) {
- XDECREF(last_name_object);
- INCREF(name);
- last_name_object = name;
- last_name_char = getstringvalue(name);
+ err = (*v->ob_type->tp_setattro)(v, name, value);
+ else {
+ if (name != last_name_object) {
+ XDECREF(last_name_object);
+ INCREF(name);
+ last_name_object = name;
+ last_name_char = getstringvalue(name);
+ }
+ err = setattr(v, last_name_char, value);
}
- return setattr(v, last_name_char, value);
+ DECREF(name);
+ return err;
}
object *
@@ -931,6 +1018,7 @@
last_name_char = NULL;
return NULL;
}
+ PyString_InternInPlace(&last_name_object);
last_name_char = getstringvalue(last_name_object);
}
return mappinglookup(v, last_name_object);
@@ -949,6 +1037,7 @@
last_name_char = NULL;
return -1;
}
+ PyString_InternInPlace(&last_name_object);
last_name_char = getstringvalue(last_name_object);
}
return mappinginsert(v, last_name_object, item);
diff --git a/Objects/mappingobject.c b/Objects/mappingobject.c
index a8b18ef..a8767d7 100644
--- a/Objects/mappingobject.c
+++ b/Objects/mappingobject.c
@@ -87,6 +87,9 @@
int ma_fill;
int ma_used;
int ma_size;
+#ifdef INTERN_STRINGS
+ int ma_fast;
+#endif
mappingentry *ma_table;
} mappingobject;
@@ -106,6 +109,9 @@
mp->ma_table = NULL;
mp->ma_fill = 0;
mp->ma_used = 0;
+#ifdef INTERN_STRINGS
+ mp->ma_fast = 1;
+#endif
return (object *)mp;
}
@@ -163,17 +169,40 @@
unsigned long sum;
int incr;
int size;
+#ifdef INTERN_STRINGS
+ int fast;
+#endif
ep = &mp->ma_table[(unsigned long)hash%mp->ma_size];
ekey = ep->me_key;
if (ekey == NULL)
return ep;
+#ifdef INTERN_STRINGS
+ if ((fast = mp->ma_fast)) {
+ object *ikey;
+ if (!is_stringobject(key) ||
+ (ikey = ((stringobject *)key)->ob_sinterned) == NULL)
+ fast = 0;
+ else
+ key = ikey;
+ }
+#endif
if (ekey == dummy)
freeslot = ep;
- else if (ep->me_hash == hash && cmpobject(ekey, key) == 0)
- return ep;
- else
+ else {
+#ifdef INTERN_STRINGS
+ if (fast) {
+ if (ekey == key)
+ return ep;
+ }
+ else
+#endif
+ {
+ if (ep->me_hash == hash && cmpobject(ekey, key) == 0)
+ return ep;
+ }
freeslot = NULL;
+ }
size = mp->ma_size;
sum = hash;
@@ -184,6 +213,36 @@
end = mp->ma_table + size;
+#ifdef INTERN_STRINGS
+ if (fast) {
+ if (freeslot == NULL) {
+ for (;;) {
+ ep += incr;
+ if (ep >= end)
+ ep -= size;
+ ekey = ep->me_key;
+ if (ekey == NULL || ekey == key)
+ return ep;
+ if (ekey == dummy) {
+ freeslot = ep;
+ break;
+ }
+ }
+ }
+
+ for (;;) {
+ ep += incr;
+ if (ep >= end)
+ ep -= size;
+ ekey = ep->me_key;
+ if (ekey == NULL)
+ return freeslot;
+ if (ekey == key)
+ return ep;
+ }
+ }
+#endif
+
if (freeslot == NULL) {
for (;;) {
ep += incr;
@@ -339,13 +398,35 @@
err_badcall();
return -1;
}
-#ifdef CACHE_HASH
- if (!is_stringobject(key) || (hash = ((stringobject *) key)->ob_shash) == -1)
-#endif
- hash = hashobject(key);
- if (hash == -1)
- return -1;
mp = (mappingobject *)op;
+#ifdef CACHE_HASH
+ if (is_stringobject(key)) {
+#ifdef INTERN_STRINGS
+ if (((stringobject *)key)->ob_sinterned != NULL) {
+ key = ((stringobject *)key)->ob_sinterned;
+ hash = ((stringobject *)key)->ob_shash;
+ }
+ else
+#endif
+ {
+ hash = ((stringobject *)key)->ob_shash;
+ if (hash == -1)
+ hash = hashobject(key);
+#ifdef INTERN_STRINGS
+ mp->ma_fast = 0;
+#endif
+ }
+ }
+ else
+#endif
+ {
+ hash = hashobject(key);
+ if (hash == -1)
+ return -1;
+#ifdef INTERN_STRINGS
+ mp->ma_fast = 0;
+#endif
+ }
/* if fill >= 2/3 size, resize */
if (mp->ma_fill*3 >= mp->ma_size*2) {
if (mappingresize(mp) != 0) {
@@ -907,16 +988,22 @@
object *name;
object *value;
{
+ int err;
+ INCREF(name);
+ PyString_InternInPlace(&name);
if (v->ob_type->tp_setattro != NULL)
- return (*v->ob_type->tp_setattro)(v, name, value);
-
- if (name != last_name_object) {
- XDECREF(last_name_object);
- INCREF(name);
- last_name_object = name;
- last_name_char = getstringvalue(name);
+ err = (*v->ob_type->tp_setattro)(v, name, value);
+ else {
+ if (name != last_name_object) {
+ XDECREF(last_name_object);
+ INCREF(name);
+ last_name_object = name;
+ last_name_char = getstringvalue(name);
+ }
+ err = setattr(v, last_name_char, value);
}
- return setattr(v, last_name_char, value);
+ DECREF(name);
+ return err;
}
object *
@@ -931,6 +1018,7 @@
last_name_char = NULL;
return NULL;
}
+ PyString_InternInPlace(&last_name_object);
last_name_char = getstringvalue(last_name_object);
}
return mappinglookup(v, last_name_object);
@@ -949,6 +1037,7 @@
last_name_char = NULL;
return -1;
}
+ PyString_InternInPlace(&last_name_object);
last_name_char = getstringvalue(last_name_object);
}
return mappinginsert(v, last_name_object, item);
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 048b83c..d656fa1 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -98,6 +98,9 @@
#ifdef CACHE_HASH
op->ob_shash = -1;
#endif
+#ifdef INTERN_STRINGS
+ op->ob_sinterned = NULL;
+#endif
NEWREF(op);
if (str != NULL)
memcpy(op->ob_sval, str, size);
@@ -145,6 +148,9 @@
#ifdef CACHE_HASH
op->ob_shash = -1;
#endif
+#ifdef INTERN_STRINGS
+ op->ob_sinterned = NULL;
+#endif
NEWREF(op);
strcpy(op->ob_sval, str);
#ifndef DONT_SHARE_SHORT_STRINGS
@@ -304,6 +310,9 @@
#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);
memcpy(op->ob_sval + a->ob_size, b->ob_sval, (int) b->ob_size);
@@ -336,6 +345,9 @@
#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)
memcpy(op->ob_sval+i, a->ob_sval, (int) a->ob_size);
@@ -462,6 +474,13 @@
&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 @@
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