#include "Python.h"

#include "pycore_object.h" // _PyObject_GC_TRACK

#include "pycore_pystate.h" // _PyThreadState_GET()

#include "pycore_tupleobject.h"

#include "structmember.h" // PyMemberDef

/* _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; /* __dict__ */

PyObject *weakreflist; /* List of weak references */

vectorcallfunc vectorcall;

} partialobject;

static PyTypeObject partial_type;

static void partial_setvectorcall(partialobject *pto);

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_IS_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) {

pto->args = nargs;

}

else {

pto->args = PySequence_Concat(pargs, nargs);

Py_DECREF(nargs);

if (pto->args == NULL) {

Py_DECREF(pto);

return NULL;

}

assert(PyTuple_Check(pto->args));

}

if (pkw == NULL || PyDict_GET_SIZE(pkw) == 0) {

if (kw == NULL) {

pto->kw = PyDict_New();

}

else if (Py_REFCNT(kw) == 1) {

Py_INCREF(kw);

pto->kw = kw;

}

else {

pto->kw = PyDict_Copy(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;

}

partial_setvectorcall(pto);

return (PyObject *)pto;

}

static void

partial_dealloc(partialobject *pto)

{

/* bpo-31095: UnTrack is needed before calling any callbacks */

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);

}

/* Merging keyword arguments using the vectorcall convention is messy, so

* if we would need to do that, we stop using vectorcall and fall back

* to using partial_call() instead. */

_Py_NO_INLINE static PyObject *

partial_vectorcall_fallback(PyThreadState *tstate, partialobject *pto,

PyObject *const *args, size_t nargsf,

PyObject *kwnames)

{

pto->vectorcall = NULL;

Py_ssize_t nargs = PyVectorcall_NARGS(nargsf);

return _PyObject_MakeTpCall(tstate, (PyObject *)pto,

args, nargs, kwnames);

}

static PyObject *

partial_vectorcall(partialobject *pto, PyObject *const *args,

size_t nargsf, PyObject *kwnames)

{

PyThreadState *tstate = _PyThreadState_GET();

/* pto->kw is mutable, so need to check every time */

if (PyDict_GET_SIZE(pto->kw)) {

return partial_vectorcall_fallback(tstate, pto, args, nargsf, kwnames);

}

Py_ssize_t nargs = PyVectorcall_NARGS(nargsf);

Py_ssize_t nargs_total = nargs;

if (kwnames != NULL) {

nargs_total += PyTuple_GET_SIZE(kwnames);

}

PyObject **pto_args = _PyTuple_ITEMS(pto->args);

Py_ssize_t pto_nargs = PyTuple_GET_SIZE(pto->args);

/* Fast path if we're called without arguments */

if (nargs_total == 0) {

return _PyObject_VectorcallTstate(tstate, pto->fn,

pto_args, pto_nargs, NULL);

}

/* Fast path using PY_VECTORCALL_ARGUMENTS_OFFSET to prepend a single

* positional argument */

if (pto_nargs == 1 && (nargsf & PY_VECTORCALL_ARGUMENTS_OFFSET)) {

PyObject **newargs = (PyObject **)args - 1;

PyObject *tmp = newargs[0];

newargs[0] = pto_args[0];

PyObject *ret = _PyObject_VectorcallTstate(tstate, pto->fn,

newargs, nargs + 1, kwnames);

newargs[0] = tmp;

return ret;

}

Py_ssize_t newnargs_total = pto_nargs + nargs_total;

PyObject *small_stack[_PY_FASTCALL_SMALL_STACK];

PyObject *ret;

PyObject **stack;

if (newnargs_total <= (Py_ssize_t)Py_ARRAY_LENGTH(small_stack)) {

stack = small_stack;

}

else {

stack = PyMem_Malloc(newnargs_total * sizeof(PyObject *));

if (stack == NULL) {

PyErr_NoMemory();

return NULL;

}

}

/* Copy to new stack, using borrowed references */

memcpy(stack, pto_args, pto_nargs * sizeof(PyObject*));

memcpy(stack + pto_nargs, args, nargs_total * sizeof(PyObject*));

ret = _PyObject_VectorcallTstate(tstate, pto->fn,

stack, pto_nargs + nargs, kwnames);

if (stack != small_stack) {

PyMem_Free(stack);

}

return ret;

}

/* Set pto->vectorcall depending on the parameters of the partial object */

static void

partial_setvectorcall(partialobject *pto)

{

if (PyVectorcall_Function(pto->fn) == NULL) {

/* Don't use vectorcall if the underlying function doesn't support it */

pto->vectorcall = NULL;

}

/* We could have a special case if there are no arguments,

* but that is unlikely (why use partial without arguments?),

* so we don't optimize that */

else {

pto->vectorcall = (vectorcallfunc)partial_vectorcall;

}

}

static PyObject *

partial_call(partialobject *pto, PyObject *args, PyObject *kwargs)

{

assert(PyCallable_Check(pto->fn));

assert(PyTuple_Check(pto->args));

assert(PyDict_Check(pto->kw));

/* Merge keywords */

PyObject *kwargs2;

if (PyDict_GET_SIZE(pto->kw) == 0) {

/* kwargs can be NULL */

kwargs2 = kwargs;

Py_XINCREF(kwargs2);

}

else {

/* bpo-27840, bpo-29318: dictionary of keyword parameters must be

copied, because a function using "**kwargs" can modify the

dictionary. */

kwargs2 = PyDict_Copy(pto->kw);

if (kwargs2 == NULL) {

return NULL;

}

if (kwargs != NULL) {

if (PyDict_Merge(kwargs2, kwargs, 1) != 0) {

Py_DECREF(kwargs2);

return NULL;

}

}

}

/* Merge positional arguments */

/* Note: tupleconcat() is optimized for empty tuples */

PyObject *args2 = PySequence_Concat(pto->args, args);

if (args2 == NULL) {

Py_XDECREF(kwargs2);

return NULL;

}

PyObject *res = PyObject_Call(pto->fn, args2, kwargs2);

Py_DECREF(args2);

Py_XDECREF(kwargs2);

return res;

}

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_FromString("...");

}

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);) {

/* Prevent key.__str__ from deleting the value. */

Py_INCREF(value);

Py_SETREF(arglist, PyUnicode_FromFormat("%U, %S=%R", arglist,

key, value));

Py_DECREF(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;

}

if (dict == Py_None)

dict = NULL;

else

Py_INCREF(dict);

Py_INCREF(fn);

Py_SETREF(pto->fn, fn);

Py_SETREF(pto->args, fnargs);

Py_SETREF(pto->kw, kw);

Py_XSETREF(pto->dict, dict);

partial_setvectorcall(pto);

Py_RETURN_NONE;

}

static PyMethodDef partial_methods[] = {

{"__reduce__", (PyCFunction)partial_reduce, METH_NOARGS},

{"__setstate__", (PyCFunction)partial_setstate, METH_O},

{"__class_getitem__", (PyCFunction)Py_GenericAlias,

METH_O|METH_CLASS, PyDoc_STR("See PEP 585")},

{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 */

offsetof(partialobject, vectorcall),/* tp_vectorcall_offset */

0, /* tp_getattr */

0, /* tp_setattr */

0, /* tp_as_async */

(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 |

Py_TPFLAGS_HAVE_VECTORCALL, /* 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_vectorcall_offset */

0, /* tp_getattr */

0, /* tp_setattr */

0, /* tp_as_async */

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;

PyObject* stack[2];

if (!Py_IS_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, _PyLong_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 (Py_REFCNT(args) > 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 {

/* Update the args tuple in-place */

assert(Py_REFCNT(args) == 1);

Py_XSETREF(_PyTuple_ITEMS(args)[0], result);

Py_XSETREF(_PyTuple_ITEMS(args)[1], op2);

if ((result = PyObject_Call(func, args, NULL)) == NULL) {

goto Fail;

}

// bpo-42536: The GC may have untracked this args tuple. Since we're

// recycling it, make sure it's tracked again:

if (!_PyObject_GC_IS_TRACKED(args)) {

_PyObject_GC_TRACK(args);

}

}

}

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 **********************************************************/

/* There are four principal algorithmic differences from the pure python version:

1). The C version relies on the GIL instead of having its own reentrant lock.

2). The prev/next link fields use borrowed references.

3). For a full cache, the pure python version rotates the location of the

root entry so that it never has to move individual links and it can

limit updates to just the key and result fields. However, in the C

version, links are temporarily removed while the cache dict updates are

occurring. Afterwards, they are appended or prepended back into the

doubly-linked lists.

4) In the Python version, the _HashSeq class is used to prevent __hash__

from being called more than once. In the C version, the "known hash"

variants of dictionary calls as used to the same effect.

*/

/* 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)

{

Py_XDECREF(link->key);

Py_XDECREF(link->result);

PyObject_Del(link);

}

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_vectorcall_offset */

0, /* tp_getattr */

0, /* tp_setattr */

0, /* tp_as_async */

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, /* tp_flags */

};

typedef PyObject *(*lru_cache_ternaryfunc)(struct lru_cache_object *, PyObject *, PyObject *);

typedef struct lru_cache_object {

lru_list_elem root; /* includes PyObject_HEAD */

lru_cache_ternaryfunc wrapper;

int typed;

PyObject *cache;

Py_ssize_t hits;

PyObject *func;

Py_ssize_t maxsize;

Py_ssize_t misses;

PyObject *cache_info_type;

PyObject *dict;

PyObject *weakreflist;

} lru_cache_object;

static PyTypeObject lru_cache_type;

static PyObject *

lru_cache_make_key(PyObject *args, PyObject *kwds, int typed)

{

PyObject *key, *keyword, *value;

Py_ssize_t key_size, pos, key_pos, kwds_size;

kwds_size = kwds ? PyDict_GET_SIZE(kwds) : 0;

/* short path, key will match args anyway, which is a tuple */

if (!typed && !kwds_size) {

if (PyTuple_GET_SIZE(args) == 1) {

key = PyTuple_GET_ITEM(args, 0);

if (PyUnicode_CheckExact(key) || PyLong_CheckExact(key)) {

/* For common scalar keys, save space by

dropping the enclosing args tuple */

Py_INCREF(key);

return key;

}

}

Py_INCREF(args);

return args;

}

key_size = PyTuple_GET_SIZE(args);

if (kwds_size)

key_size += kwds_size * 2 + 1;

if (typed)

key_size += PyTuple_GET_SIZE(args) + kwds_size;

key = PyTuple_New(key_size);

if (key == NULL)

return NULL;

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 (kwds_size) {

Py_INCREF(kwd_mark);

PyTuple_SET_ITEM(key, key_pos++, kwd_mark);

for (pos = 0; PyDict_Next(kwds, &pos, &keyword, &value);) {

Py_INCREF(keyword);

PyTuple_SET_ITEM(key, key_pos++, keyword);

Py_INCREF(value);

PyTuple_SET_ITEM(key, key_pos++, value);

}

assert(key_pos == PyTuple_GET_SIZE(args) + kwds_size * 2 + 1);

}

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 (kwds_size) {

for (pos = 0; PyDict_Next(kwds, &pos, &keyword, &value);) {

PyObject *item = (PyObject *)Py_TYPE(value);

Py_INCREF(item);

PyTuple_SET_ITEM(key, key_pos++, item);

}

}

}

assert(key_pos == key_size);

return key;

}

static PyObject *

uncached_lru_cache_wrapper(lru_cache_object *self, PyObject *args, PyObject *kwds)

{

PyObject *result;

self->misses++;

result = PyObject_Call(self->func, args, kwds);

if (!result)

return NULL;

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) {

Py_DECREF(key);

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;

}

self->misses++;

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);

return result;

}

static void

lru_cache_extract_link(lru_list_elem *link)

{

lru_list_elem *link_prev = link->prev;

lru_list_elem *link_next = link->next;

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 void

lru_cache_prepend_link(lru_cache_object *self, lru_list_elem *link)

{

lru_list_elem *root = &self->root;

lru_list_elem *first = root->next;

first->prev = root->next = link;

link->prev = root;

link->next = first;

}

/* General note on reentrancy:

There are four dictionary calls in the bounded_lru_cache_wrapper():

1) The initial check for a cache match. 2) The post user-function

check for a cache match. 3) The deletion of the oldest entry.

4) The addition of the newest entry.

In all four calls, we have a known hash which lets use avoid a call

to __hash__(). That leaves only __eq__ as a possible source of a

reentrant call.

The __eq__ method call is always made for a cache hit (dict access #1).

Accordingly, we have make sure not modify the cache state prior to

this call.

The __eq__ method call is never made for the deletion (dict access #3)

because it is an identity match.

For the other two accesses (#2 and #4), calls to __eq__ only occur

when some other entry happens to have an exactly matching hash (all

64-bits). Though rare, this can happen, so we have to make sure to

either call it at the top of its code path before any cache

state modifications (dict access #2) or be prepared to restore

invariants at the end of the code path (dict access #4).

Another possible source of reentrancy is a decref which can trigger

arbitrary code execution. To make the code easier to reason about,

the decrefs are deferred to the end of the each possible code path

so that we know the cache is a consistent state.

*/

static PyObject *

bounded_lru_cache_wrapper(lru_cache_object *self, PyObject *args, PyObject *kwds)

{

lru_list_elem *link;

PyObject *key, *result, *testresult;

Py_hash_t hash;

key = lru_cache_make_key(args, kwds, self->typed);

if (!key)

return NULL;

hash = PyObject_Hash(key);

if (hash == -1) {

Py_DECREF(key);

return NULL;

}

link = (lru_list_elem *)_PyDict_GetItem_KnownHash(self->cache, key, hash);

if (link != NULL) {

lru_cache_extract_link(link);

lru_cache_append_link(self, link);

result = link->result;

self->hits++;

Py_INCREF(result);

Py_DECREF(key);

return result;

}