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Issue #23359: Specialize set_lookkey intoa lookup function and an insert function.

This commit is contained in:
Raymond Hettinger 2015-05-27 10:37:20 -07:00
parent 8544e2584d
commit 8651a50475
2 changed files with 107 additions and 41 deletions
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3
Misc/NEWS
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@ -42,6 +42,9 @@ Core and Builtins
- Issue #24268: PEP 489: Multi-phase extension module initialization.
Patch by Petr Viktorin.
- Issue #23359: Optimize set object internals by specializing the
hash table search into a lookup function and an insert function.
- Issue #23955: Add pyvenv.cfg option to suppress registry/environment
lookup for generating sys.path on Windows.

145
Objects/setobject.c
View File

@ -52,7 +52,6 @@ static setentry *
set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
{
setentry *table = so->table;
setentry *freeslot = NULL;
setentry *entry;
size_t perturb = hash;
size_t mask = so->mask;
@ -86,14 +85,12 @@ set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
return entry;
mask = so->mask; /* help avoid a register spill */
}
if (entry->hash == -1 && freeslot == NULL)
freeslot = entry;
if (i + LINEAR_PROBES <= mask) {
for (j = 0 ; j < LINEAR_PROBES ; j++) {
entry++;
if (entry->key == NULL)
goto found_null;
if (entry->hash == 0 && entry->key == NULL)
return entry;
if (entry->hash == hash) {
PyObject *startkey = entry->key;
assert(startkey != dummy);
@ -114,6 +111,89 @@ set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
return entry;
mask = so->mask;
}
}
}
perturb >>= PERTURB_SHIFT;
i = (i * 5 + 1 + perturb) & mask;
entry = &table[i];
if (entry->hash == 0 && entry->key == NULL)
return entry;
}
}
/*
Internal routine to insert a new key into the table.
Used by the public insert routine.
Eats a reference to key.
*/
static int
set_insert_key(PySetObject *so, PyObject *key, Py_hash_t hash)
{
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;
int cmp;
entry = &table[i];
if (entry->key == NULL)
goto found_null;
while (1) {
if (entry->hash == hash) {
PyObject *startkey = entry->key;
/* startkey cannot be a dummy because the dummy hash field is -1 */
assert(startkey != dummy);
if (startkey == key)
goto found_active;
if (PyUnicode_CheckExact(startkey)
&& PyUnicode_CheckExact(key)
&& unicode_eq(startkey, key))
goto found_active;
Py_INCREF(startkey);
cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
Py_DECREF(startkey);
if (cmp < 0) /* unlikely */
return -1;
if (table != so->table || entry->key != startkey) /* unlikely */
return set_insert_key(so, key, hash);
if (cmp > 0) /* likely */
goto found_active;
mask = so->mask; /* help avoid a register spill */
}
if (entry->hash == -1 && freeslot == NULL)
freeslot = entry;
if (i + LINEAR_PROBES <= mask) {
for (j = 0 ; j < LINEAR_PROBES ; j++) {
entry++;
if (entry->hash == 0 && entry->key == NULL)
goto found_null;
if (entry->hash == hash) {
PyObject *startkey = entry->key;
assert(startkey != dummy);
if (startkey == key)
goto found_active;
if (PyUnicode_CheckExact(startkey)
&& PyUnicode_CheckExact(key)
&& unicode_eq(startkey, key))
goto found_active;
Py_INCREF(startkey);
cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
Py_DECREF(startkey);
if (cmp < 0)
return -1;
if (table != so->table || entry->key != startkey)
return set_insert_key(so, key, hash);
if (cmp > 0)
goto found_active;
mask = so->mask;
}
if (entry->hash == -1 && freeslot == NULL)
freeslot = entry;
}
@ -123,11 +203,26 @@ set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
i = (i * 5 + 1 + perturb) & mask;
entry = &table[i];
if (entry->key == NULL)
if (entry->hash == 0 && entry->key == NULL)
goto found_null;
}
found_null:
return freeslot == NULL ? entry : freeslot;
if (freeslot == NULL) {
/* UNUSED */
so->fill++;
} else {
/* DUMMY */
entry = freeslot;
}
so->used++;
entry->key = key;
entry->hash = hash;
return 0;
found_active:
Py_DECREF(key);
return 0;
}
/*
@ -172,38 +267,6 @@ set_insert_clean(PySetObject *so, PyObject *key, Py_hash_t hash)
/* ======== End logic for probing the hash table ========================== */
/* ======================================================================== */
/*
Internal routine to insert a new key into the table.
Used by the public insert routine.
Eats a reference to key.
*/
static int
set_insert_key(PySetObject *so, PyObject *key, Py_hash_t hash)
{
setentry *entry;
entry = set_lookkey(so, key, hash);
if (entry == NULL)
return -1;
if (entry->key == NULL) {
/* UNUSED */
entry->key = key;
entry->hash = hash;
so->fill++;
so->used++;
} else if (entry->key == dummy) {
/* DUMMY */
entry->key = key;
entry->hash = hash;
so->used++;
} else {
/* ACTIVE */
Py_DECREF(key);
}
return 0;
}
/*
Restructure the table by allocating a new table and reinserting all
keys again. When entries have been deleted, the new table may
@ -345,7 +408,7 @@ set_discard_entry(PySetObject *so, setentry *oldentry)
entry = set_lookkey(so, oldentry->key, oldentry->hash);
if (entry == NULL)
return -1;
if (entry->key == NULL || entry->key == dummy)
if (entry->key == NULL)
return DISCARD_NOTFOUND;
old_key = entry->key;
entry->key = dummy;
@ -623,7 +686,7 @@ set_contains_entry(PySetObject *so, setentry *entry)
if (lu_entry == NULL)
return -1;
key = lu_entry->key;
return key != NULL && key != dummy;
return key != NULL;
}
static int