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Kaydet (Commit) afe89092 authored tarafından Raymond Hettinger's avatar Raymond Hettinger
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Tighten-up the lookkey() logic and beautify the code a bit. 

Use less code by moving many of the steps from the initial
lookup into the main search loop.

Beautify the code but keep the overall logic unchanged.
üst 7c1017bf
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Showing with 43 additions and 88 deletions
Objects/setobject.c
Dosyayı görüntüle @ afe89092
......@@ -79,101 +79,66 @@ NULL if the rich comparison returns an error.
static setentry *
set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
{
size_t i, j; /* Unsigned for defined overflow behavior. */
size_t perturb;
setentry *freeslot;
size_t mask = so->mask;
setentry *table = so->table;
setentry *freeslot = NULL;
setentry *entry;
size_t perturb = hash;
size_t mask = so->mask;
size_t i = (size_t)hash & mask; /* Unsigned for defined overflow behavior. */
size_t j = i;
int cmp;
PyObject *startkey;
i = (size_t)hash & mask;
entry = &table[i];
if (entry->key == NULL || entry->key == key)
if (entry->key == NULL)
return entry;
if (entry->hash == hash && entry->key != dummy) {
startkey = entry->key;
Py_INCREF(startkey);
cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
Py_DECREF(startkey);
if (cmp < 0)
return NULL;
if (table == so->table && entry->key == startkey) {
if (cmp > 0)
return entry;
}
else {
/* Start over if the compare altered the set */
return set_lookkey(so, key, hash);
}
}
freeslot = (entry->key == dummy) ? entry : NULL;
/* In the loop, key == dummy is by far (factor of 100s)
the least likely outcome, so test for that last. */
j = i;
perturb = hash;
while (1) {
j ^= 1;
entry = &table[j];
if (entry->key == NULL) {
if (freeslot != NULL)
entry = freeslot;
break;
}
if (entry->key == key)
break;
return entry;
if (entry->hash == hash && entry->key != dummy) {
startkey = entry->key;
PyObject *startkey = entry->key;
Py_INCREF(startkey);
cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
Py_DECREF(startkey);
if (cmp < 0)
return NULL;
if (table == so->table && entry->key == startkey) {
if (cmp > 0)
break;
}
else {
if (table != so->table || entry->key != startkey)
return set_lookkey(so, key, hash);
}
if (cmp > 0)
return entry;
}
if (entry->key == dummy && freeslot == NULL)
freeslot = entry;
i = i * 5 + perturb + 1;
j = i & mask;
perturb >>= PERTURB_SHIFT;
entry = &table[j];
if (entry->key == NULL) {
if (freeslot != NULL)
entry = freeslot;
entry = &table[j ^ 1];
if (entry->key == NULL)
break;
}
if (entry->key == key)
break;
return entry;
if (entry->hash == hash && entry->key != dummy) {
startkey = entry->key;
PyObject *startkey = entry->key;
Py_INCREF(startkey);
cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
Py_DECREF(startkey);
if (cmp < 0)
return NULL;
if (table == so->table && entry->key == startkey) {
if (cmp > 0)
break;
}
else {
if (table != so->table || entry->key != startkey)
return set_lookkey(so, key, hash);
}
if (cmp > 0)
return entry;
}
if (entry->key == dummy && freeslot == NULL)
freeslot = entry;
i = i * 5 + perturb + 1;
j = i & mask;
perturb >>= PERTURB_SHIFT;
entry = &table[j];
if (entry->key == NULL)
break;
}
return entry;
return freeslot == NULL ? entry : freeslot;
}
/*
......@@ -184,12 +149,13 @@ set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
static setentry *
set_lookkey_unicode(PySetObject *so, PyObject *key, Py_hash_t hash)
{
size_t i, j; /* Unsigned for defined overflow behavior. */
size_t perturb;
setentry *freeslot;
size_t mask = so->mask;
setentry *table = so->table;
setentry *freeslot = NULL;
setentry *entry;
size_t perturb = hash;
size_t mask = so->mask;
size_t i = (size_t)hash & mask;
size_t j = i;
/* Make sure this function doesn't have to handle non-unicode keys,
including subclasses of str; e.g., one reason to subclass
......@@ -200,25 +166,11 @@ set_lookkey_unicode(PySetObject *so, PyObject *key, Py_hash_t hash)
return set_lookkey(so, key, hash);
}
i = (size_t)hash & mask;
entry = &table[i];
if (entry->key == NULL || entry->key == key)
if (entry->key == NULL)
return entry;
if (entry->key == dummy)
freeslot = entry;
else {
if (entry->hash == hash && unicode_eq(entry->key, key))
return entry;
freeslot = NULL;
}
j = i;
perturb = hash;
while (1) {
j ^= 1;
entry = &table[j];
if (entry->key == NULL)
return freeslot == NULL ? entry : freeslot;
if (entry->key == key
|| (entry->hash == hash
&& entry->key != dummy
......@@ -227,13 +179,9 @@ set_lookkey_unicode(PySetObject *so, PyObject *key, Py_hash_t hash)
if (entry->key == dummy && freeslot == NULL)
freeslot = entry;
i = i * 5 + perturb + 1;
j = i & mask;
perturb >>= PERTURB_SHIFT;
entry = &table[j];
entry = &table[j ^ 1];
if (entry->key == NULL)
return freeslot == NULL ? entry : freeslot;
break;
if (entry->key == key
|| (entry->hash == hash
&& entry->key != dummy
......@@ -241,9 +189,16 @@ set_lookkey_unicode(PySetObject *so, PyObject *key, Py_hash_t hash)
return entry;
if (entry->key == dummy && freeslot == NULL)
freeslot = entry;
i = i * 5 + perturb + 1;
j = i & mask;
perturb >>= PERTURB_SHIFT;
entry = &table[j];
if (entry->key == NULL)
break;
}
assert(0); /* NOT REACHED */
return 0;
return freeslot == NULL ? entry : freeslot;
}
/*
......
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