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Kaydet (Commit) afb6ae84 authored tarafından Tim Peters's avatar Tim Peters
Dosyalara gözat
Seçenekler

Store the mask instead of the size in dictobjects. The mask is more 

frequently used, and in particular this allows to drop the last
remaining obvious time-waster in the crucial lookdict() and
lookdict_string() functions.  Other changes consist mostly of changing
"i < ma_size" to "i <= ma_mask" everywhere.
üst b9d973da
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Showing with 29 additions and 23 deletions
Objects/dictobject.c
Dosyayı görüntüle @ afb6ae84
......@@ -162,7 +162,13 @@ struct dictobject {
PyObject_HEAD
int ma_fill; /* # Active + # Dummy */
int ma_used; /* # Active */
int ma_size; /* total # slots in ma_table */
/* The table contains ma_mask + 1 slots, and that's a power of 2.
* We store the mask instead of the size because the mask is more
* frequently needed.
*/
int ma_mask;
/* ma_table points to ma_smalltable for small tables, else to
* additional malloc'ed memory. ma_table is never NULL! This rule
* saves repeated runtime null-tests in the workhorse getitem and
......@@ -194,7 +200,7 @@ show_counts(void)
#define empty_to_minsize(mp) do { \
memset((mp)->ma_smalltable, 0, sizeof((mp)->ma_smalltable)); \
(mp)->ma_table = (mp)->ma_smalltable; \
(mp)->ma_size = MINSIZE; \
(mp)->ma_mask = MINSIZE - 1; \
(mp)->ma_used = (mp)->ma_fill = 0; \
} while(0)
......@@ -248,7 +254,7 @@ lookdict(dictobject *mp, PyObject *key, register long hash)
register int i;
register unsigned int perturb;
register dictentry *freeslot;
register unsigned int mask = mp->ma_size-1;
register unsigned int mask = mp->ma_mask;
dictentry *ep0 = mp->ma_table;
register dictentry *ep;
register int restore_error;
......@@ -359,7 +365,7 @@ lookdict_string(dictobject *mp, PyObject *key, register long hash)
register int i;
register unsigned int perturb;
register dictentry *freeslot;
register unsigned int mask = mp->ma_size-1;
register unsigned int mask = mp->ma_mask;
dictentry *ep0 = mp->ma_table;
register dictentry *ep;
......@@ -492,7 +498,7 @@ dictresize(dictobject *mp, int minused)
/* Make the dict empty, using the new table. */
assert(newtable != oldtable);
mp->ma_table = newtable;
mp->ma_size = newsize;
mp->ma_mask = newsize - 1;
memset(newtable, 0, sizeof(dictentry) * newsize);
mp->ma_used = 0;
i = mp->ma_fill;
......@@ -580,7 +586,7 @@ PyDict_SetItem(register PyObject *op, PyObject *key, PyObject *value)
if (hash == -1)
return -1;
}
assert(mp->ma_fill < mp->ma_size);
assert(mp->ma_fill <= mp->ma_mask); /* at least one empty slot */
n_used = mp->ma_used;
Py_INCREF(value);
Py_INCREF(key);
......@@ -591,7 +597,7 @@ PyDict_SetItem(register PyObject *op, PyObject *key, PyObject *value)
* much larger than ma_used, meaning a lot of dict keys have been
* deleted).
*/
if (mp->ma_used > n_used && mp->ma_fill*3 >= mp->ma_size*2) {
if (mp->ma_used > n_used && mp->ma_fill*3 >= (mp->ma_mask+1)*2) {
if (dictresize(mp, mp->ma_used*2) != 0)
return -1;
}
......@@ -652,7 +658,7 @@ PyDict_Clear(PyObject *op)
return;
mp = (dictobject *)op;
#ifdef Py_DEBUG
n = mp->ma_size;
n = mp->ma_mask + 1;
i = 0;
#endif
......@@ -721,10 +727,10 @@ PyDict_Next(PyObject *op, int *ppos, PyObject **pkey, PyObject **pvalue)
i = *ppos;
if (i < 0)
return 0;
while (i < mp->ma_size && mp->ma_table[i].me_value == NULL)
while (i <= mp->ma_mask && mp->ma_table[i].me_value == NULL)
i++;
*ppos = i+1;
if (i >= mp->ma_size)
if (i > mp->ma_mask)
return 0;
if (pkey)
*pkey = mp->ma_table[i].me_key;
......@@ -772,7 +778,7 @@ dict_print(register dictobject *mp, register FILE *fp, register int flags)
fprintf(fp, "{");
any = 0;
for (i = 0; i < mp->ma_size; i++) {
for (i = 0; i <= mp->ma_mask; i++) {
dictentry *ep = mp->ma_table + i;
PyObject *pvalue = ep->me_value;
if (pvalue != NULL) {
......@@ -819,7 +825,7 @@ dict_repr(dictobject *mp)
sepa = PyString_FromString(", ");
colon = PyString_FromString(": ");
any = 0;
for (i = 0; i < mp->ma_size && v; i++) {
for (i = 0; i <= mp->ma_mask && v; i++) {
dictentry *ep = mp->ma_table + i;
PyObject *pvalue = ep->me_value;
if (pvalue != NULL) {
......@@ -905,7 +911,7 @@ dict_keys(register dictobject *mp, PyObject *args)
Py_DECREF(v);
goto again;
}
for (i = 0, j = 0; i < mp->ma_size; i++) {
for (i = 0, j = 0; i <= mp->ma_mask; i++) {
if (mp->ma_table[i].me_value != NULL) {
PyObject *key = mp->ma_table[i].me_key;
Py_INCREF(key);
......@@ -936,7 +942,7 @@ dict_values(register dictobject *mp, PyObject *args)
Py_DECREF(v);
goto again;
}
for (i = 0, j = 0; i < mp->ma_size; i++) {
for (i = 0, j = 0; i <= mp->ma_mask; i++) {
if (mp->ma_table[i].me_value != NULL) {
PyObject *value = mp->ma_table[i].me_value;
Py_INCREF(value);
......@@ -981,7 +987,7 @@ dict_items(register dictobject *mp, PyObject *args)
goto again;
}
/* Nothing we do below makes any function calls. */
for (i = 0, j = 0; i < mp->ma_size; i++) {
for (i = 0, j = 0; i <= mp->ma_mask; i++) {
if (mp->ma_table[i].me_value != NULL) {
key = mp->ma_table[i].me_key;
value = mp->ma_table[i].me_value;
......@@ -1010,11 +1016,11 @@ dict_update(register dictobject *mp, PyObject *args)
/* Do one big resize at the start, rather than incrementally
resizing as we insert new items. Expect that there will be
no (or few) overlapping keys. */
if ((mp->ma_fill + other->ma_used)*3 >= mp->ma_size*2) {
if ((mp->ma_fill + other->ma_used)*3 >= (mp->ma_mask+1)*2) {
if (dictresize(mp, (mp->ma_used + other->ma_used)*3/2) != 0)
return NULL;
}
for (i = 0; i < other->ma_size; i++) {
for (i = 0; i <= other->ma_mask; i++) {
entry = &other->ma_table[i];
if (entry->me_value != NULL) {
Py_INCREF(entry->me_key);
......@@ -1055,7 +1061,7 @@ PyDict_Copy(PyObject *o)
if (mp->ma_used > 0) {
if (dictresize(copy, mp->ma_used*3/2) != 0)
return NULL;
for (i = 0; i < mp->ma_size; i++) {
for (i = 0; i <= mp->ma_mask; i++) {
entry = &mp->ma_table[i];
if (entry->me_value != NULL) {
Py_INCREF(entry->me_key);
......@@ -1123,7 +1129,7 @@ characterize(dictobject *a, dictobject *b, PyObject **pval)
PyObject *aval = NULL; /* a[akey] */
int i, cmp;
for (i = 0; i < a->ma_size; i++) {
for (i = 0; i <= a->ma_mask; i++) {
PyObject *thiskey, *thisaval, *thisbval;
if (a->ma_table[i].me_value == NULL)
continue;
......@@ -1136,7 +1142,7 @@ characterize(dictobject *a, dictobject *b, PyObject **pval)
goto Fail;
}
if (cmp > 0 ||
i >= a->ma_size ||
i > a->ma_mask ||
a->ma_table[i].me_value == NULL)
{
/* Not the *smallest* a key; or maybe it is
......@@ -1251,7 +1257,7 @@ dict_equal(dictobject *a, dictobject *b)
return 0;
/* Same # of entries -- check all of 'em. Exit early on any diff. */
for (i = 0; i < a->ma_size; i++) {
for (i = 0; i <= a->ma_mask; i++) {
PyObject *aval = a->ma_table[i].me_value;
if (aval != NULL) {
int cmp;
......@@ -1427,11 +1433,11 @@ dict_popitem(dictobject *mp, PyObject *args)
* finger that's out of bounds now because it wrapped around
* or the table shrunk -- simply make sure it's in bounds now.
*/
if (i >= mp->ma_size || i < 1)
if (i > mp->ma_mask || i < 1)
i = 1; /* skip slot 0 */
while ((ep = &mp->ma_table[i])->me_value == NULL) {
i++;
if (i >= mp->ma_size)
if (i > mp->ma_mask)
i = 1;
}
}
......
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