cpython/Modules/_functoolsmodule.c

1263 lines
36 KiB
C

#include "Python.h"
#include "structmember.h"
/* _functools module written and maintained
by Hye-Shik Chang <perky@FreeBSD.org>
with adaptations by Raymond Hettinger <python@rcn.com>
Copyright (c) 2004, 2005, 2006 Python Software Foundation.
All rights reserved.
*/
/* partial object **********************************************************/
typedef struct {
PyObject_HEAD
PyObject *fn;
PyObject *args;
PyObject *kw;
PyObject *dict;
PyObject *weakreflist; /* List of weak references */
} partialobject;
static PyTypeObject partial_type;
static PyObject *
partial_new(PyTypeObject *type, PyObject *args, PyObject *kw)
{
PyObject *func, *pargs, *nargs, *pkw;
partialobject *pto;
if (PyTuple_GET_SIZE(args) < 1) {
PyErr_SetString(PyExc_TypeError,
"type 'partial' takes at least one argument");
return NULL;
}
pargs = pkw = NULL;
func = PyTuple_GET_ITEM(args, 0);
if (Py_TYPE(func) == &partial_type && type == &partial_type) {
partialobject *part = (partialobject *)func;
if (part->dict == NULL) {
pargs = part->args;
pkw = part->kw;
func = part->fn;
assert(PyTuple_Check(pargs));
assert(PyDict_Check(pkw));
}
}
if (!PyCallable_Check(func)) {
PyErr_SetString(PyExc_TypeError,
"the first argument must be callable");
return NULL;
}
/* create partialobject structure */
pto = (partialobject *)type->tp_alloc(type, 0);
if (pto == NULL)
return NULL;
pto->fn = func;
Py_INCREF(func);
nargs = PyTuple_GetSlice(args, 1, PY_SSIZE_T_MAX);
if (nargs == NULL) {
Py_DECREF(pto);
return NULL;
}
if (pargs == NULL || PyTuple_GET_SIZE(pargs) == 0) {
pto->args = nargs;
Py_INCREF(nargs);
}
else if (PyTuple_GET_SIZE(nargs) == 0) {
pto->args = pargs;
Py_INCREF(pargs);
}
else {
pto->args = PySequence_Concat(pargs, nargs);
if (pto->args == NULL) {
Py_DECREF(nargs);
Py_DECREF(pto);
return NULL;
}
assert(PyTuple_Check(pto->args));
}
Py_DECREF(nargs);
if (pkw == NULL || PyDict_Size(pkw) == 0) {
if (kw == NULL) {
pto->kw = PyDict_New();
}
else {
Py_INCREF(kw);
pto->kw = kw;
}
}
else {
pto->kw = PyDict_Copy(pkw);
if (kw != NULL && pto->kw != NULL) {
if (PyDict_Merge(pto->kw, kw, 1) != 0) {
Py_DECREF(pto);
return NULL;
}
}
}
if (pto->kw == NULL) {
Py_DECREF(pto);
return NULL;
}
return (PyObject *)pto;
}
static void
partial_dealloc(partialobject *pto)
{
PyObject_GC_UnTrack(pto);
if (pto->weakreflist != NULL)
PyObject_ClearWeakRefs((PyObject *) pto);
Py_XDECREF(pto->fn);
Py_XDECREF(pto->args);
Py_XDECREF(pto->kw);
Py_XDECREF(pto->dict);
Py_TYPE(pto)->tp_free(pto);
}
static PyObject *
partial_call(partialobject *pto, PyObject *args, PyObject *kw)
{
PyObject *ret;
PyObject *argappl, *kwappl;
PyObject **stack;
Py_ssize_t nargs;
assert (PyCallable_Check(pto->fn));
assert (PyTuple_Check(pto->args));
assert (PyDict_Check(pto->kw));
if (PyTuple_GET_SIZE(pto->args) == 0) {
stack = &PyTuple_GET_ITEM(args, 0);
nargs = PyTuple_GET_SIZE(args);
argappl = NULL;
}
else if (PyTuple_GET_SIZE(args) == 0) {
stack = &PyTuple_GET_ITEM(pto->args, 0);
nargs = PyTuple_GET_SIZE(pto->args);
argappl = NULL;
}
else {
stack = NULL;
argappl = PySequence_Concat(pto->args, args);
if (argappl == NULL) {
return NULL;
}
assert(PyTuple_Check(argappl));
}
if (PyDict_Size(pto->kw) == 0) {
kwappl = kw;
Py_XINCREF(kwappl);
}
else {
kwappl = PyDict_Copy(pto->kw);
if (kwappl == NULL) {
Py_XDECREF(argappl);
return NULL;
}
if (kw != NULL) {
if (PyDict_Merge(kwappl, kw, 1) != 0) {
Py_XDECREF(argappl);
Py_DECREF(kwappl);
return NULL;
}
}
}
if (stack) {
ret = _PyObject_FastCallDict(pto->fn, stack, nargs, kwappl);
}
else {
ret = PyObject_Call(pto->fn, argappl, kwappl);
Py_DECREF(argappl);
}
Py_XDECREF(kwappl);
return ret;
}
static int
partial_traverse(partialobject *pto, visitproc visit, void *arg)
{
Py_VISIT(pto->fn);
Py_VISIT(pto->args);
Py_VISIT(pto->kw);
Py_VISIT(pto->dict);
return 0;
}
PyDoc_STRVAR(partial_doc,
"partial(func, *args, **keywords) - new function with partial application\n\
of the given arguments and keywords.\n");
#define OFF(x) offsetof(partialobject, x)
static PyMemberDef partial_memberlist[] = {
{"func", T_OBJECT, OFF(fn), READONLY,
"function object to use in future partial calls"},
{"args", T_OBJECT, OFF(args), READONLY,
"tuple of arguments to future partial calls"},
{"keywords", T_OBJECT, OFF(kw), READONLY,
"dictionary of keyword arguments to future partial calls"},
{NULL} /* Sentinel */
};
static PyGetSetDef partial_getsetlist[] = {
{"__dict__", PyObject_GenericGetDict, PyObject_GenericSetDict},
{NULL} /* Sentinel */
};
static PyObject *
partial_repr(partialobject *pto)
{
PyObject *result = NULL;
PyObject *arglist;
Py_ssize_t i, n;
PyObject *key, *value;
int status;
status = Py_ReprEnter((PyObject *)pto);
if (status != 0) {
if (status < 0)
return NULL;
return PyUnicode_FromFormat("%s(...)", Py_TYPE(pto)->tp_name);
}
arglist = PyUnicode_FromString("");
if (arglist == NULL)
goto done;
/* Pack positional arguments */
assert (PyTuple_Check(pto->args));
n = PyTuple_GET_SIZE(pto->args);
for (i = 0; i < n; i++) {
Py_SETREF(arglist, PyUnicode_FromFormat("%U, %R", arglist,
PyTuple_GET_ITEM(pto->args, i)));
if (arglist == NULL)
goto done;
}
/* Pack keyword arguments */
assert (PyDict_Check(pto->kw));
for (i = 0; PyDict_Next(pto->kw, &i, &key, &value);) {
Py_SETREF(arglist, PyUnicode_FromFormat("%U, %U=%R", arglist,
key, value));
if (arglist == NULL)
goto done;
}
result = PyUnicode_FromFormat("%s(%R%U)", Py_TYPE(pto)->tp_name,
pto->fn, arglist);
Py_DECREF(arglist);
done:
Py_ReprLeave((PyObject *)pto);
return result;
}
/* Pickle strategy:
__reduce__ by itself doesn't support getting kwargs in the unpickle
operation so we define a __setstate__ that replaces all the information
about the partial. If we only replaced part of it someone would use
it as a hook to do strange things.
*/
static PyObject *
partial_reduce(partialobject *pto, PyObject *unused)
{
return Py_BuildValue("O(O)(OOOO)", Py_TYPE(pto), pto->fn, pto->fn,
pto->args, pto->kw,
pto->dict ? pto->dict : Py_None);
}
static PyObject *
partial_setstate(partialobject *pto, PyObject *state)
{
PyObject *fn, *fnargs, *kw, *dict;
if (!PyTuple_Check(state) ||
!PyArg_ParseTuple(state, "OOOO", &fn, &fnargs, &kw, &dict) ||
!PyCallable_Check(fn) ||
!PyTuple_Check(fnargs) ||
(kw != Py_None && !PyDict_Check(kw)))
{
PyErr_SetString(PyExc_TypeError, "invalid partial state");
return NULL;
}
if(!PyTuple_CheckExact(fnargs))
fnargs = PySequence_Tuple(fnargs);
else
Py_INCREF(fnargs);
if (fnargs == NULL)
return NULL;
if (kw == Py_None)
kw = PyDict_New();
else if(!PyDict_CheckExact(kw))
kw = PyDict_Copy(kw);
else
Py_INCREF(kw);
if (kw == NULL) {
Py_DECREF(fnargs);
return NULL;
}
Py_INCREF(fn);
if (dict == Py_None)
dict = NULL;
else
Py_INCREF(dict);
Py_SETREF(pto->fn, fn);
Py_SETREF(pto->args, fnargs);
Py_SETREF(pto->kw, kw);
Py_XSETREF(pto->dict, dict);
Py_RETURN_NONE;
}
static PyMethodDef partial_methods[] = {
{"__reduce__", (PyCFunction)partial_reduce, METH_NOARGS},
{"__setstate__", (PyCFunction)partial_setstate, METH_O},
{NULL, NULL} /* sentinel */
};
static PyTypeObject partial_type = {
PyVarObject_HEAD_INIT(NULL, 0)
"functools.partial", /* tp_name */
sizeof(partialobject), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
(destructor)partial_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
(reprfunc)partial_repr, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
(ternaryfunc)partial_call, /* tp_call */
0, /* tp_str */
PyObject_GenericGetAttr, /* tp_getattro */
PyObject_GenericSetAttr, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
Py_TPFLAGS_BASETYPE, /* tp_flags */
partial_doc, /* tp_doc */
(traverseproc)partial_traverse, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
offsetof(partialobject, weakreflist), /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
partial_methods, /* tp_methods */
partial_memberlist, /* tp_members */
partial_getsetlist, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
offsetof(partialobject, dict), /* tp_dictoffset */
0, /* tp_init */
0, /* tp_alloc */
partial_new, /* tp_new */
PyObject_GC_Del, /* tp_free */
};
/* cmp_to_key ***************************************************************/
typedef struct {
PyObject_HEAD
PyObject *cmp;
PyObject *object;
} keyobject;
static void
keyobject_dealloc(keyobject *ko)
{
Py_DECREF(ko->cmp);
Py_XDECREF(ko->object);
PyObject_FREE(ko);
}
static int
keyobject_traverse(keyobject *ko, visitproc visit, void *arg)
{
Py_VISIT(ko->cmp);
if (ko->object)
Py_VISIT(ko->object);
return 0;
}
static int
keyobject_clear(keyobject *ko)
{
Py_CLEAR(ko->cmp);
if (ko->object)
Py_CLEAR(ko->object);
return 0;
}
static PyMemberDef keyobject_members[] = {
{"obj", T_OBJECT,
offsetof(keyobject, object), 0,
PyDoc_STR("Value wrapped by a key function.")},
{NULL}
};
static PyObject *
keyobject_call(keyobject *ko, PyObject *args, PyObject *kwds);
static PyObject *
keyobject_richcompare(PyObject *ko, PyObject *other, int op);
static PyTypeObject keyobject_type = {
PyVarObject_HEAD_INIT(&PyType_Type, 0)
"functools.KeyWrapper", /* tp_name */
sizeof(keyobject), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
(destructor)keyobject_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
0, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
(ternaryfunc)keyobject_call, /* tp_call */
0, /* tp_str */
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT, /* tp_flags */
0, /* tp_doc */
(traverseproc)keyobject_traverse, /* tp_traverse */
(inquiry)keyobject_clear, /* tp_clear */
keyobject_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
0, /* tp_methods */
keyobject_members, /* tp_members */
0, /* tp_getset */
};
static PyObject *
keyobject_call(keyobject *ko, PyObject *args, PyObject *kwds)
{
PyObject *object;
keyobject *result;
static char *kwargs[] = {"obj", NULL};
if (!PyArg_ParseTupleAndKeywords(args, kwds, "O:K", kwargs, &object))
return NULL;
result = PyObject_New(keyobject, &keyobject_type);
if (!result)
return NULL;
Py_INCREF(ko->cmp);
result->cmp = ko->cmp;
Py_INCREF(object);
result->object = object;
return (PyObject *)result;
}
static PyObject *
keyobject_richcompare(PyObject *ko, PyObject *other, int op)
{
PyObject *res;
PyObject *x;
PyObject *y;
PyObject *compare;
PyObject *answer;
static PyObject *zero;
PyObject* stack[2];
if (zero == NULL) {
zero = PyLong_FromLong(0);
if (!zero)
return NULL;
}
if (Py_TYPE(other) != &keyobject_type){
PyErr_Format(PyExc_TypeError, "other argument must be K instance");
return NULL;
}
compare = ((keyobject *) ko)->cmp;
assert(compare != NULL);
x = ((keyobject *) ko)->object;
y = ((keyobject *) other)->object;
if (!x || !y){
PyErr_Format(PyExc_AttributeError, "object");
return NULL;
}
/* Call the user's comparison function and translate the 3-way
* result into true or false (or error).
*/
stack[0] = x;
stack[1] = y;
res = _PyObject_FastCall(compare, stack, 2);
if (res == NULL) {
return NULL;
}
answer = PyObject_RichCompare(res, zero, op);
Py_DECREF(res);
return answer;
}
static PyObject *
functools_cmp_to_key(PyObject *self, PyObject *args, PyObject *kwds)
{
PyObject *cmp;
static char *kwargs[] = {"mycmp", NULL};
keyobject *object;
if (!PyArg_ParseTupleAndKeywords(args, kwds, "O:cmp_to_key", kwargs, &cmp))
return NULL;
object = PyObject_New(keyobject, &keyobject_type);
if (!object)
return NULL;
Py_INCREF(cmp);
object->cmp = cmp;
object->object = NULL;
return (PyObject *)object;
}
PyDoc_STRVAR(functools_cmp_to_key_doc,
"Convert a cmp= function into a key= function.");
/* reduce (used to be a builtin) ********************************************/
static PyObject *
functools_reduce(PyObject *self, PyObject *args)
{
PyObject *seq, *func, *result = NULL, *it;
if (!PyArg_UnpackTuple(args, "reduce", 2, 3, &func, &seq, &result))
return NULL;
if (result != NULL)
Py_INCREF(result);
it = PyObject_GetIter(seq);
if (it == NULL) {
if (PyErr_ExceptionMatches(PyExc_TypeError))
PyErr_SetString(PyExc_TypeError,
"reduce() arg 2 must support iteration");
Py_XDECREF(result);
return NULL;
}
if ((args = PyTuple_New(2)) == NULL)
goto Fail;
for (;;) {
PyObject *op2;
if (args->ob_refcnt > 1) {
Py_DECREF(args);
if ((args = PyTuple_New(2)) == NULL)
goto Fail;
}
op2 = PyIter_Next(it);
if (op2 == NULL) {
if (PyErr_Occurred())
goto Fail;
break;
}
if (result == NULL)
result = op2;
else {
PyTuple_SetItem(args, 0, result);
PyTuple_SetItem(args, 1, op2);
if ((result = PyEval_CallObject(func, args)) == NULL)
goto Fail;
}
}
Py_DECREF(args);
if (result == NULL)
PyErr_SetString(PyExc_TypeError,
"reduce() of empty sequence with no initial value");
Py_DECREF(it);
return result;
Fail:
Py_XDECREF(args);
Py_XDECREF(result);
Py_DECREF(it);
return NULL;
}
PyDoc_STRVAR(functools_reduce_doc,
"reduce(function, sequence[, initial]) -> value\n\
\n\
Apply a function of two arguments cumulatively to the items of a sequence,\n\
from left to right, so as to reduce the sequence to a single value.\n\
For example, reduce(lambda x, y: x+y, [1, 2, 3, 4, 5]) calculates\n\
((((1+2)+3)+4)+5). If initial is present, it is placed before the items\n\
of the sequence in the calculation, and serves as a default when the\n\
sequence is empty.");
/* lru_cache object **********************************************************/
/* this object is used delimit args and keywords in the cache keys */
static PyObject *kwd_mark = NULL;
struct lru_list_elem;
struct lru_cache_object;
typedef struct lru_list_elem {
PyObject_HEAD
struct lru_list_elem *prev, *next; /* borrowed links */
Py_hash_t hash;
PyObject *key, *result;
} lru_list_elem;
static void
lru_list_elem_dealloc(lru_list_elem *link)
{
_PyObject_GC_UNTRACK(link);
Py_XDECREF(link->key);
Py_XDECREF(link->result);
PyObject_GC_Del(link);
}
static int
lru_list_elem_traverse(lru_list_elem *link, visitproc visit, void *arg)
{
Py_VISIT(link->key);
Py_VISIT(link->result);
return 0;
}
static int
lru_list_elem_clear(lru_list_elem *link)
{
Py_CLEAR(link->key);
Py_CLEAR(link->result);
return 0;
}
static PyTypeObject lru_list_elem_type = {
PyVarObject_HEAD_INIT(&PyType_Type, 0)
"functools._lru_list_elem", /* tp_name */
sizeof(lru_list_elem), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
(destructor)lru_list_elem_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
0, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */
0, /* tp_doc */
(traverseproc)lru_list_elem_traverse, /* tp_traverse */
(inquiry)lru_list_elem_clear, /* tp_clear */
};
typedef PyObject *(*lru_cache_ternaryfunc)(struct lru_cache_object *, PyObject *, PyObject *);
typedef struct lru_cache_object {
lru_list_elem root; /* includes PyObject_HEAD */
Py_ssize_t maxsize;
PyObject *maxsize_O;
PyObject *func;
lru_cache_ternaryfunc wrapper;
PyObject *cache;
PyObject *cache_info_type;
Py_ssize_t misses, hits;
int typed;
PyObject *dict;
int full;
} lru_cache_object;
static PyTypeObject lru_cache_type;
static PyObject *
lru_cache_make_key(PyObject *args, PyObject *kwds, int typed)
{
PyObject *key, *sorted_items;
Py_ssize_t key_size, pos, key_pos;
/* short path, key will match args anyway, which is a tuple */
if (!typed && !kwds) {
Py_INCREF(args);
return args;
}
if (kwds && PyDict_Size(kwds) > 0) {
sorted_items = PyDict_Items(kwds);
if (!sorted_items)
return NULL;
if (PyList_Sort(sorted_items) < 0) {
Py_DECREF(sorted_items);
return NULL;
}
} else
sorted_items = NULL;
key_size = PyTuple_GET_SIZE(args);
if (sorted_items)
key_size += PyList_GET_SIZE(sorted_items);
if (typed)
key_size *= 2;
if (sorted_items)
key_size++;
key = PyTuple_New(key_size);
if (key == NULL)
goto done;
key_pos = 0;
for (pos = 0; pos < PyTuple_GET_SIZE(args); ++pos) {
PyObject *item = PyTuple_GET_ITEM(args, pos);
Py_INCREF(item);
PyTuple_SET_ITEM(key, key_pos++, item);
}
if (sorted_items) {
Py_INCREF(kwd_mark);
PyTuple_SET_ITEM(key, key_pos++, kwd_mark);
for (pos = 0; pos < PyList_GET_SIZE(sorted_items); ++pos) {
PyObject *item = PyList_GET_ITEM(sorted_items, pos);
Py_INCREF(item);
PyTuple_SET_ITEM(key, key_pos++, item);
}
}
if (typed) {
for (pos = 0; pos < PyTuple_GET_SIZE(args); ++pos) {
PyObject *item = (PyObject *)Py_TYPE(PyTuple_GET_ITEM(args, pos));
Py_INCREF(item);
PyTuple_SET_ITEM(key, key_pos++, item);
}
if (sorted_items) {
for (pos = 0; pos < PyList_GET_SIZE(sorted_items); ++pos) {
PyObject *tp_items = PyList_GET_ITEM(sorted_items, pos);
PyObject *item = (PyObject *)Py_TYPE(PyTuple_GET_ITEM(tp_items, 1));
Py_INCREF(item);
PyTuple_SET_ITEM(key, key_pos++, item);
}
}
}
assert(key_pos == key_size);
done:
if (sorted_items)
Py_DECREF(sorted_items);
return key;
}
static PyObject *
uncached_lru_cache_wrapper(lru_cache_object *self, PyObject *args, PyObject *kwds)
{
PyObject *result = PyObject_Call(self->func, args, kwds);
if (!result)
return NULL;
self->misses++;
return result;
}
static PyObject *
infinite_lru_cache_wrapper(lru_cache_object *self, PyObject *args, PyObject *kwds)
{
PyObject *result;
Py_hash_t hash;
PyObject *key = lru_cache_make_key(args, kwds, self->typed);
if (!key)
return NULL;
hash = PyObject_Hash(key);
if (hash == -1)
return NULL;
result = _PyDict_GetItem_KnownHash(self->cache, key, hash);
if (result) {
Py_INCREF(result);
self->hits++;
Py_DECREF(key);
return result;
}
if (PyErr_Occurred()) {
Py_DECREF(key);
return NULL;
}
result = PyObject_Call(self->func, args, kwds);
if (!result) {
Py_DECREF(key);
return NULL;
}
if (_PyDict_SetItem_KnownHash(self->cache, key, result, hash) < 0) {
Py_DECREF(result);
Py_DECREF(key);
return NULL;
}
Py_DECREF(key);
self->misses++;
return result;
}
static void
lru_cache_extricate_link(lru_list_elem *link)
{
link->prev->next = link->next;
link->next->prev = link->prev;
}
static void
lru_cache_append_link(lru_cache_object *self, lru_list_elem *link)
{
lru_list_elem *root = &self->root;
lru_list_elem *last = root->prev;
last->next = root->prev = link;
link->prev = last;
link->next = root;
}
static PyObject *
bounded_lru_cache_wrapper(lru_cache_object *self, PyObject *args, PyObject *kwds)
{
lru_list_elem *link;
PyObject *key, *result;
Py_hash_t hash;
key = lru_cache_make_key(args, kwds, self->typed);
if (!key)
return NULL;
hash = PyObject_Hash(key);
if (hash == -1)
return NULL;
link = (lru_list_elem *)_PyDict_GetItem_KnownHash(self->cache, key, hash);
if (link) {
lru_cache_extricate_link(link);
lru_cache_append_link(self, link);
self->hits++;
result = link->result;
Py_INCREF(result);
Py_DECREF(key);
return result;
}
if (PyErr_Occurred()) {
Py_DECREF(key);
return NULL;
}
result = PyObject_Call(self->func, args, kwds);
if (!result) {
Py_DECREF(key);
return NULL;
}
if (self->full && self->root.next != &self->root) {
/* Use the oldest item to store the new key and result. */
PyObject *oldkey, *oldresult;
/* Extricate the oldest item. */
link = self->root.next;
lru_cache_extricate_link(link);
/* Remove it from the cache.
The cache dict holds one reference to the link,
and the linked list holds yet one reference to it. */
if (_PyDict_DelItem_KnownHash(self->cache, link->key,
link->hash) < 0) {
lru_cache_append_link(self, link);
Py_DECREF(key);
Py_DECREF(result);
return NULL;
}
/* Keep a reference to the old key and old result to
prevent their ref counts from going to zero during the
update. That will prevent potentially arbitrary object
clean-up code (i.e. __del__) from running while we're
still adjusting the links. */
oldkey = link->key;
oldresult = link->result;
link->hash = hash;
link->key = key;
link->result = result;
if (_PyDict_SetItem_KnownHash(self->cache, key, (PyObject *)link,
hash) < 0) {
Py_DECREF(link);
Py_DECREF(oldkey);
Py_DECREF(oldresult);
return NULL;
}
lru_cache_append_link(self, link);
Py_INCREF(result); /* for return */
Py_DECREF(oldkey);
Py_DECREF(oldresult);
} else {
/* Put result in a new link at the front of the queue. */
link = (lru_list_elem *)PyObject_GC_New(lru_list_elem,
&lru_list_elem_type);
if (link == NULL) {
Py_DECREF(key);
Py_DECREF(result);
return NULL;
}
link->hash = hash;
link->key = key;
link->result = result;
_PyObject_GC_TRACK(link);
if (_PyDict_SetItem_KnownHash(self->cache, key, (PyObject *)link,
hash) < 0) {
Py_DECREF(link);
return NULL;
}
lru_cache_append_link(self, link);
Py_INCREF(result); /* for return */
self->full = (PyDict_Size(self->cache) >= self->maxsize);
}
self->misses++;
return result;
}
static PyObject *
lru_cache_new(PyTypeObject *type, PyObject *args, PyObject *kw)
{
PyObject *func, *maxsize_O, *cache_info_type, *cachedict;
int typed;
lru_cache_object *obj;
Py_ssize_t maxsize;
PyObject *(*wrapper)(lru_cache_object *, PyObject *, PyObject *);
static char *keywords[] = {"user_function", "maxsize", "typed",
"cache_info_type", NULL};
if (!PyArg_ParseTupleAndKeywords(args, kw, "OOpO:lru_cache", keywords,
&func, &maxsize_O, &typed,
&cache_info_type)) {
return NULL;
}
if (!PyCallable_Check(func)) {
PyErr_SetString(PyExc_TypeError,
"the first argument must be callable");
return NULL;
}
/* select the caching function, and make/inc maxsize_O */
if (maxsize_O == Py_None) {
wrapper = infinite_lru_cache_wrapper;
/* use this only to initialize lru_cache_object attribute maxsize */
maxsize = -1;
} else if (PyIndex_Check(maxsize_O)) {
maxsize = PyNumber_AsSsize_t(maxsize_O, PyExc_OverflowError);
if (maxsize == -1 && PyErr_Occurred())
return NULL;
if (maxsize == 0)
wrapper = uncached_lru_cache_wrapper;
else
wrapper = bounded_lru_cache_wrapper;
} else {
PyErr_SetString(PyExc_TypeError, "maxsize should be integer or None");
return NULL;
}
if (!(cachedict = PyDict_New()))
return NULL;
obj = (lru_cache_object *)type->tp_alloc(type, 0);
if (obj == NULL) {
Py_DECREF(cachedict);
return NULL;
}
obj->cache = cachedict;
obj->root.prev = &obj->root;
obj->root.next = &obj->root;
obj->maxsize = maxsize;
Py_INCREF(maxsize_O);
obj->maxsize_O = maxsize_O;
Py_INCREF(func);
obj->func = func;
obj->wrapper = wrapper;
obj->misses = obj->hits = 0;
obj->typed = typed;
Py_INCREF(cache_info_type);
obj->cache_info_type = cache_info_type;
return (PyObject *)obj;
}
static lru_list_elem *
lru_cache_unlink_list(lru_cache_object *self)
{
lru_list_elem *root = &self->root;
lru_list_elem *link = root->next;
if (link == root)
return NULL;
root->prev->next = NULL;
root->next = root->prev = root;
return link;
}
static void
lru_cache_clear_list(lru_list_elem *link)
{
while (link != NULL) {
lru_list_elem *next = link->next;
Py_DECREF(link);
link = next;
}
}
static void
lru_cache_dealloc(lru_cache_object *obj)
{
lru_list_elem *list = lru_cache_unlink_list(obj);
Py_XDECREF(obj->maxsize_O);
Py_XDECREF(obj->func);
Py_XDECREF(obj->cache);
Py_XDECREF(obj->dict);
Py_XDECREF(obj->cache_info_type);
lru_cache_clear_list(list);
Py_TYPE(obj)->tp_free(obj);
}
static PyObject *
lru_cache_call(lru_cache_object *self, PyObject *args, PyObject *kwds)
{
return self->wrapper(self, args, kwds);
}
static PyObject *
lru_cache_descr_get(PyObject *self, PyObject *obj, PyObject *type)
{
if (obj == Py_None || obj == NULL) {
Py_INCREF(self);
return self;
}
return PyMethod_New(self, obj);
}
static PyObject *
lru_cache_cache_info(lru_cache_object *self, PyObject *unused)
{
return PyObject_CallFunction(self->cache_info_type, "nnOn",
self->hits, self->misses, self->maxsize_O,
PyDict_Size(self->cache));
}
static PyObject *
lru_cache_cache_clear(lru_cache_object *self, PyObject *unused)
{
lru_list_elem *list = lru_cache_unlink_list(self);
self->hits = self->misses = 0;
self->full = 0;
PyDict_Clear(self->cache);
lru_cache_clear_list(list);
Py_RETURN_NONE;
}
static PyObject *
lru_cache_reduce(PyObject *self, PyObject *unused)
{
return PyObject_GetAttrString(self, "__qualname__");
}
static PyObject *
lru_cache_copy(PyObject *self, PyObject *unused)
{
Py_INCREF(self);
return self;
}
static PyObject *
lru_cache_deepcopy(PyObject *self, PyObject *unused)
{
Py_INCREF(self);
return self;
}
static int
lru_cache_tp_traverse(lru_cache_object *self, visitproc visit, void *arg)
{
lru_list_elem *link = self->root.next;
while (link != &self->root) {
lru_list_elem *next = link->next;
Py_VISIT(link);
link = next;
}
Py_VISIT(self->maxsize_O);
Py_VISIT(self->func);
Py_VISIT(self->cache);
Py_VISIT(self->cache_info_type);
Py_VISIT(self->dict);
return 0;
}
static int
lru_cache_tp_clear(lru_cache_object *self)
{
lru_list_elem *list = lru_cache_unlink_list(self);
Py_CLEAR(self->maxsize_O);
Py_CLEAR(self->func);
Py_CLEAR(self->cache);
Py_CLEAR(self->cache_info_type);
Py_CLEAR(self->dict);
lru_cache_clear_list(list);
return 0;
}
PyDoc_STRVAR(lru_cache_doc,
"Create a cached callable that wraps another function.\n\
\n\
user_function: the function being cached\n\
\n\
maxsize: 0 for no caching\n\
None for unlimited cache size\n\
n for a bounded cache\n\
\n\
typed: False cache f(3) and f(3.0) as identical calls\n\
True cache f(3) and f(3.0) as distinct calls\n\
\n\
cache_info_type: namedtuple class with the fields:\n\
hits misses currsize maxsize\n"
);
static PyMethodDef lru_cache_methods[] = {
{"cache_info", (PyCFunction)lru_cache_cache_info, METH_NOARGS},
{"cache_clear", (PyCFunction)lru_cache_cache_clear, METH_NOARGS},
{"__reduce__", (PyCFunction)lru_cache_reduce, METH_NOARGS},
{"__copy__", (PyCFunction)lru_cache_copy, METH_VARARGS},
{"__deepcopy__", (PyCFunction)lru_cache_deepcopy, METH_VARARGS},
{NULL}
};
static PyGetSetDef lru_cache_getsetlist[] = {
{"__dict__", PyObject_GenericGetDict, PyObject_GenericSetDict},
{NULL}
};
static PyTypeObject lru_cache_type = {
PyVarObject_HEAD_INIT(NULL, 0)
"functools._lru_cache_wrapper", /* tp_name */
sizeof(lru_cache_object), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
(destructor)lru_cache_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
0, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
(ternaryfunc)lru_cache_call, /* tp_call */
0, /* tp_str */
0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE|Py_TPFLAGS_HAVE_GC,
/* tp_flags */
lru_cache_doc, /* tp_doc */
(traverseproc)lru_cache_tp_traverse,/* tp_traverse */
(inquiry)lru_cache_tp_clear, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
lru_cache_methods, /* tp_methods */
0, /* tp_members */
lru_cache_getsetlist, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
lru_cache_descr_get, /* tp_descr_get */
0, /* tp_descr_set */
offsetof(lru_cache_object, dict), /* tp_dictoffset */
0, /* tp_init */
0, /* tp_alloc */
lru_cache_new, /* tp_new */
};
/* module level code ********************************************************/
PyDoc_STRVAR(module_doc,
"Tools that operate on functions.");
static PyMethodDef module_methods[] = {
{"reduce", functools_reduce, METH_VARARGS, functools_reduce_doc},
{"cmp_to_key", (PyCFunction)functools_cmp_to_key,
METH_VARARGS | METH_KEYWORDS, functools_cmp_to_key_doc},
{NULL, NULL} /* sentinel */
};
static void
module_free(void *m)
{
Py_CLEAR(kwd_mark);
}
static struct PyModuleDef _functoolsmodule = {
PyModuleDef_HEAD_INIT,
"_functools",
module_doc,
-1,
module_methods,
NULL,
NULL,
NULL,
module_free,
};
PyMODINIT_FUNC
PyInit__functools(void)
{
int i;
PyObject *m;
char *name;
PyTypeObject *typelist[] = {
&partial_type,
&lru_cache_type,
NULL
};
m = PyModule_Create(&_functoolsmodule);
if (m == NULL)
return NULL;
kwd_mark = PyObject_CallObject((PyObject *)&PyBaseObject_Type, NULL);
if (!kwd_mark) {
Py_DECREF(m);
return NULL;
}
for (i=0 ; typelist[i] != NULL ; i++) {
if (PyType_Ready(typelist[i]) < 0) {
Py_DECREF(m);
return NULL;
}
name = strchr(typelist[i]->tp_name, '.');
assert (name != NULL);
Py_INCREF(typelist[i]);
PyModule_AddObject(m, name+1, (PyObject *)typelist[i]);
}
return m;
}