blob: 0e0b2d6ac85f601d8492d5792922edc0bae05211 [file] [log] [blame]
#include "Python.h"
/* collections module implementation of a deque() datatype
Written and maintained by Raymond D. Hettinger <python@rcn.com>
Copyright (c) 2004 Python Software Foundation.
All rights reserved.
*/
#define BLOCKLEN 46
typedef struct BLOCK {
struct BLOCK *leftlink;
struct BLOCK *rightlink;
PyObject *data[BLOCKLEN];
} block;
static block *newblock(block *leftlink, block *rightlink) {
block *b = PyMem_Malloc(sizeof(block));
if (b == NULL) {
PyErr_NoMemory();
return NULL;
}
b->leftlink = leftlink;
b->rightlink = rightlink;
return b;
}
typedef struct {
PyObject_HEAD
block *leftblock;
block *rightblock;
int leftindex;
int rightindex;
int len;
} dequeobject;
static PyObject *
deque_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
dequeobject *deque;
block *b;
/* create dequeobject structure */
deque = (dequeobject *)type->tp_alloc(type, 0);
if (deque == NULL)
return NULL;
b = newblock(NULL, NULL);
if (b == NULL) {
Py_DECREF(deque);
return NULL;
}
deque->leftblock = b;
deque->rightblock = b;
deque->leftindex = BLOCKLEN / 2 + 1;
deque->rightindex = BLOCKLEN / 2;
deque->len = 0;
return (PyObject *)deque;
}
static PyObject *
deque_append(dequeobject *deque, PyObject *item)
{
deque->rightindex++;
deque->len++;
if (deque->rightindex == BLOCKLEN) {
block *b = newblock(deque->rightblock, NULL);
if (b == NULL)
return NULL;
assert(deque->rightblock->rightlink == NULL);
deque->rightblock->rightlink = b;
deque->rightblock = b;
deque->rightindex = 0;
}
Py_INCREF(item);
deque->rightblock->data[deque->rightindex] = item;
Py_RETURN_NONE;
}
PyDoc_STRVAR(append_doc, "Add an element to the right side of the deque.");
static PyObject *
deque_appendleft(dequeobject *deque, PyObject *item)
{
deque->leftindex--;
deque->len++;
if (deque->leftindex == -1) {
block *b = newblock(NULL, deque->leftblock);
if (b == NULL)
return NULL;
assert(deque->leftblock->leftlink == NULL);
deque->leftblock->leftlink = b;
deque->leftblock = b;
deque->leftindex = BLOCKLEN - 1;
}
Py_INCREF(item);
deque->leftblock->data[deque->leftindex] = item;
Py_RETURN_NONE;
}
PyDoc_STRVAR(appendleft_doc, "Add an element to the left side of the deque.");
static PyObject *
deque_pop(dequeobject *deque, PyObject *unused)
{
PyObject *item;
block *prevblock;
if (deque->len == 0) {
PyErr_SetString(PyExc_LookupError, "pop from an empty deque");
return NULL;
}
item = deque->rightblock->data[deque->rightindex];
deque->rightindex--;
deque->len--;
if (deque->rightindex == -1) {
if (deque->len == 0) {
assert(deque->leftblock == deque->rightblock);
assert(deque->leftindex == deque->rightindex+1);
/* re-center instead of freeing a block */
deque->leftindex = BLOCKLEN / 2 + 1;
deque->rightindex = BLOCKLEN / 2;
} else {
prevblock = deque->rightblock->leftlink;
assert(deque->leftblock != deque->rightblock);
PyMem_Free(deque->rightblock);
prevblock->rightlink = NULL;
deque->rightblock = prevblock;
deque->rightindex = BLOCKLEN - 1;
}
}
return item;
}
PyDoc_STRVAR(pop_doc, "Remove and return the rightmost element.");
static PyObject *
deque_popleft(dequeobject *deque, PyObject *unused)
{
PyObject *item;
block *prevblock;
if (deque->len == 0) {
PyErr_SetString(PyExc_LookupError, "pop from an empty deque");
return NULL;
}
item = deque->leftblock->data[deque->leftindex];
deque->leftindex++;
deque->len--;
if (deque->leftindex == BLOCKLEN) {
if (deque->len == 0) {
assert(deque->leftblock == deque->rightblock);
assert(deque->leftindex == deque->rightindex+1);
/* re-center instead of freeing a block */
deque->leftindex = BLOCKLEN / 2 + 1;
deque->rightindex = BLOCKLEN / 2;
} else {
assert(deque->leftblock != deque->rightblock);
prevblock = deque->leftblock->rightlink;
assert(deque->leftblock != NULL);
PyMem_Free(deque->leftblock);
assert(prevblock != NULL);
prevblock->leftlink = NULL;
deque->leftblock = prevblock;
deque->leftindex = 0;
}
}
return item;
}
PyDoc_STRVAR(popleft_doc, "Remove and return the leftmost element.");
static PyObject *
deque_extend(dequeobject *deque, PyObject *iterable)
{
PyObject *it, *item;
it = PyObject_GetIter(iterable);
if (it == NULL)
return NULL;
while ((item = PyIter_Next(it)) != NULL) {
deque->rightindex++;
deque->len++;
if (deque->rightindex == BLOCKLEN) {
block *b = newblock(deque->rightblock, NULL);
if (b == NULL) {
Py_DECREF(item);
Py_DECREF(it);
return NULL;
}
assert(deque->rightblock->rightlink == NULL);
deque->rightblock->rightlink = b;
deque->rightblock = b;
deque->rightindex = 0;
}
deque->rightblock->data[deque->rightindex] = item;
}
Py_DECREF(it);
if (PyErr_Occurred())
return NULL;
Py_RETURN_NONE;
}
PyDoc_STRVAR(extend_doc,
"Extend the right side of the deque with elements from the iterable");
static PyObject *
deque_extendleft(dequeobject *deque, PyObject *iterable)
{
PyObject *it, *item;
it = PyObject_GetIter(iterable);
if (it == NULL)
return NULL;
while ((item = PyIter_Next(it)) != NULL) {
deque->leftindex--;
deque->len++;
if (deque->leftindex == -1) {
block *b = newblock(NULL, deque->leftblock);
if (b == NULL) {
Py_DECREF(item);
Py_DECREF(it);
return NULL;
}
assert(deque->leftblock->leftlink == NULL);
deque->leftblock->leftlink = b;
deque->leftblock = b;
deque->leftindex = BLOCKLEN - 1;
}
deque->leftblock->data[deque->leftindex] = item;
}
Py_DECREF(it);
if (PyErr_Occurred())
return NULL;
Py_RETURN_NONE;
}
PyDoc_STRVAR(extendleft_doc,
"Extend the left side of the deque with elements from the iterable");
static PyObject *
deque_rotate(dequeobject *deque, PyObject *args)
{
int i, n=1, len=deque->len, halflen=(len+1)>>1;
PyObject *item, *rv;
if (!PyArg_ParseTuple(args, "|i:rotate", &n))
return NULL;
if (len == 0)
Py_RETURN_NONE;
if (n > halflen || n < -halflen) {
n %= len;
if (n > halflen)
n -= len;
else if (n < -halflen)
n += len;
}
for (i=0 ; i<n ; i++) {
item = deque_pop(deque, NULL);
if (item == NULL)
return NULL;
rv = deque_appendleft(deque, item);
Py_DECREF(item);
if (rv == NULL)
return NULL;
Py_DECREF(rv);
}
for (i=0 ; i>n ; i--) {
item = deque_popleft(deque, NULL);
if (item == NULL)
return NULL;
rv = deque_append(deque, item);
Py_DECREF(item);
if (rv == NULL)
return NULL;
Py_DECREF(rv);
}
Py_RETURN_NONE;
}
PyDoc_STRVAR(rotate_doc,
"Rotate the deque n steps to the right (default n=1). If n is negative, rotates left.");
static int
deque_len(dequeobject *deque)
{
return deque->len;
}
static int
deque_clear(dequeobject *deque)
{
PyObject *item;
while (deque_len(deque)) {
item = deque_pop(deque, NULL);
if (item == NULL)
return -1;
Py_DECREF(item);
}
assert(deque->leftblock == deque->rightblock &&
deque->leftindex > deque->rightindex);
return 0;
}
static PyObject *
deque_clearmethod(dequeobject *deque)
{
if (deque_clear(deque) == -1)
return NULL;
Py_RETURN_NONE;
}
PyDoc_STRVAR(clear_doc, "Remove all elements from the deque.");
static void
deque_dealloc(dequeobject *deque)
{
PyObject_GC_UnTrack(deque);
if (deque->leftblock != NULL) {
int err = deque_clear(deque);
assert(err == 0);
assert(deque->leftblock != NULL);
PyMem_Free(deque->leftblock);
}
deque->leftblock = NULL;
deque->rightblock = NULL;
deque->ob_type->tp_free(deque);
}
static int
set_traverse(dequeobject *deque, visitproc visit, void *arg)
{
block * b = deque->leftblock;
int index = deque->leftindex;
int err;
PyObject *item;
while (b != deque->rightblock || index <= deque->rightindex) {
item = b->data[index];
index++;
if (index == BLOCKLEN && b->rightlink != NULL) {
b = b->rightlink;
index = 0;
}
err = visit(item, arg);
if (err)
return err;
}
return 0;
}
static long
deque_nohash(PyObject *self)
{
PyErr_SetString(PyExc_TypeError, "deque objects are unhashable");
return -1;
}
static PyObject *
deque_copy(PyObject *deque)
{
return PyObject_CallFunctionObjArgs((PyObject *)(deque->ob_type),
deque, NULL);
}
PyDoc_STRVAR(copy_doc, "Return a shallow copy of a deque.");
static PyObject *
deque_reduce(dequeobject *deque)
{
PyObject *seq, *args, *result;
seq = PySequence_Tuple((PyObject *)deque);
if (seq == NULL)
return NULL;
args = PyTuple_Pack(1, seq);
if (args == NULL) {
Py_DECREF(seq);
return NULL;
}
result = PyTuple_Pack(2, deque->ob_type, args);
Py_DECREF(seq);
Py_DECREF(args);
return result;
}
PyDoc_STRVAR(reduce_doc, "Return state information for pickling.");
static PyObject *
deque_repr(PyObject *deque)
{
PyObject *aslist, *result, *fmt;
int i;
i = Py_ReprEnter(deque);
if (i != 0) {
if (i < 0)
return NULL;
return PyString_FromString("[...]");
}
aslist = PySequence_List(deque);
if (aslist == NULL) {
Py_ReprLeave(deque);
return NULL;
}
fmt = PyString_FromString("deque(%r)");
if (fmt == NULL) {
Py_DECREF(aslist);
Py_ReprLeave(deque);
return NULL;
}
result = PyString_Format(fmt, aslist);
Py_DECREF(fmt);
Py_DECREF(aslist);
Py_ReprLeave(deque);
return result;
}
static int
deque_tp_print(PyObject *deque, FILE *fp, int flags)
{
PyObject *it, *item;
int pos=0;
char *emit = ""; /* No separator emitted on first pass */
char *separator = ", ";
int i;
i = Py_ReprEnter(deque);
if (i != 0) {
if (i < 0)
return i;
fputs("[...]", fp);
return 0;
}
it = PyObject_GetIter(deque);
if (it == NULL)
return -1;
fputs("deque([", fp);
while ((item = PyIter_Next(it)) != NULL) {
fputs(emit, fp);
emit = separator;
if (PyObject_Print(item, fp, 0) != 0) {
Py_DECREF(item);
Py_DECREF(it);
Py_ReprLeave(deque);
return -1;
}
Py_DECREF(item);
}
Py_ReprLeave(deque);
Py_DECREF(it);
if (PyErr_Occurred())
return -1;
fputs("])", fp);
return 0;
}
static int
deque_init(dequeobject *deque, PyObject *args, PyObject *kwds)
{
PyObject *iterable = NULL;
if (!PyArg_UnpackTuple(args, "deque", 0, 1, &iterable))
return -1;
if (iterable != NULL) {
PyObject *rv = deque_extend(deque, iterable);
if (rv == NULL)
return -1;
Py_DECREF(rv);
}
return 0;
}
static PySequenceMethods deque_as_sequence = {
(inquiry)deque_len, /* sq_length */
0, /* sq_concat */
};
/* deque object ********************************************************/
static PyObject *deque_iter(dequeobject *deque);
static PyObject *deque_reviter(dequeobject *deque);
PyDoc_STRVAR(reversed_doc,
"D.__reversed__() -- return a reverse iterator over the deque");
static PyMethodDef deque_methods[] = {
{"append", (PyCFunction)deque_append,
METH_O, append_doc},
{"appendleft", (PyCFunction)deque_appendleft,
METH_O, appendleft_doc},
{"clear", (PyCFunction)deque_clearmethod,
METH_NOARGS, clear_doc},
{"__copy__", (PyCFunction)deque_copy,
METH_NOARGS, copy_doc},
{"extend", (PyCFunction)deque_extend,
METH_O, extend_doc},
{"extendleft", (PyCFunction)deque_extendleft,
METH_O, extendleft_doc},
{"pop", (PyCFunction)deque_pop,
METH_NOARGS, pop_doc},
{"popleft", (PyCFunction)deque_popleft,
METH_NOARGS, popleft_doc},
{"__reduce__", (PyCFunction)deque_reduce,
METH_NOARGS, reduce_doc},
{"__reversed__", (PyCFunction)deque_reviter,
METH_NOARGS, reversed_doc},
{"rotate", (PyCFunction)deque_rotate,
METH_VARARGS, rotate_doc},
{NULL, NULL} /* sentinel */
};
PyDoc_STRVAR(deque_doc,
"deque(iterable) --> deque object\n\
\n\
Build an ordered collection accessible from endpoints only.");
PyTypeObject deque_type = {
PyObject_HEAD_INIT(NULL)
0, /* ob_size */
"collections.deque", /* tp_name */
sizeof(dequeobject), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
(destructor)deque_dealloc, /* tp_dealloc */
(printfunc)deque_tp_print, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
(reprfunc)deque_repr, /* tp_repr */
0, /* tp_as_number */
&deque_as_sequence, /* tp_as_sequence */
0, /* tp_as_mapping */
deque_nohash, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC, /* tp_flags */
deque_doc, /* tp_doc */
(traverseproc)set_traverse, /* tp_traverse */
(inquiry)deque_clear, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset*/
(getiterfunc)deque_iter, /* tp_iter */
0, /* tp_iternext */
deque_methods, /* tp_methods */
0, /* tp_members */
0, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
(initproc)deque_init, /* tp_init */
PyType_GenericAlloc, /* tp_alloc */
deque_new, /* tp_new */
PyObject_GC_Del, /* tp_free */
};
/*********************** Deque Iterator **************************/
typedef struct {
PyObject_HEAD
int index;
block *b;
dequeobject *deque;
int len;
} dequeiterobject;
PyTypeObject dequeiter_type;
static PyObject *
deque_iter(dequeobject *deque)
{
dequeiterobject *it;
it = PyObject_New(dequeiterobject, &dequeiter_type);
if (it == NULL)
return NULL;
it->b = deque->leftblock;
it->index = deque->leftindex;
Py_INCREF(deque);
it->deque = deque;
it->len = deque->len;
return (PyObject *)it;
}
static void
dequeiter_dealloc(dequeiterobject *dio)
{
Py_XDECREF(dio->deque);
dio->ob_type->tp_free(dio);
}
static PyObject *
dequeiter_next(dequeiterobject *it)
{
PyObject *item;
if (it->b == it->deque->rightblock && it->index > it->deque->rightindex)
return NULL;
if (it->len != it->deque->len) {
it->len = -1; /* Make this state sticky */
PyErr_SetString(PyExc_RuntimeError,
"deque changed size during iteration");
return NULL;
}
item = it->b->data[it->index];
it->index++;
if (it->index == BLOCKLEN && it->b->rightlink != NULL) {
it->b = it->b->rightlink;
it->index = 0;
}
Py_INCREF(item);
return item;
}
PyTypeObject dequeiter_type = {
PyObject_HEAD_INIT(NULL)
0, /* ob_size */
"deque_iterator", /* tp_name */
sizeof(dequeiterobject), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
(destructor)dequeiter_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
0, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT, /* tp_flags */
0, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
PyObject_SelfIter, /* tp_iter */
(iternextfunc)dequeiter_next, /* tp_iternext */
0,
};
/*********************** Deque Reverse Iterator **************************/
PyTypeObject dequereviter_type;
static PyObject *
deque_reviter(dequeobject *deque)
{
dequeiterobject *it;
it = PyObject_New(dequeiterobject, &dequereviter_type);
if (it == NULL)
return NULL;
it->b = deque->rightblock;
it->index = deque->rightindex;
Py_INCREF(deque);
it->deque = deque;
it->len = deque->len;
return (PyObject *)it;
}
static PyObject *
dequereviter_next(dequeiterobject *it)
{
PyObject *item;
if (it->b == it->deque->leftblock && it->index < it->deque->leftindex)
return NULL;
if (it->len != it->deque->len) {
it->len = -1; /* Make this state sticky */
PyErr_SetString(PyExc_RuntimeError,
"deque changed size during iteration");
return NULL;
}
item = it->b->data[it->index];
it->index--;
if (it->index == -1 && it->b->leftlink != NULL) {
it->b = it->b->leftlink;
it->index = BLOCKLEN - 1;
}
Py_INCREF(item);
return item;
}
PyTypeObject dequereviter_type = {
PyObject_HEAD_INIT(NULL)
0, /* ob_size */
"deque_reverse_iterator", /* tp_name */
sizeof(dequeiterobject), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
(destructor)dequeiter_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
0, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT, /* tp_flags */
0, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
PyObject_SelfIter, /* tp_iter */
(iternextfunc)dequereviter_next, /* tp_iternext */
0,
};
/* module level code ********************************************************/
PyDoc_STRVAR(module_doc,
"High performance data structures\n\
");
PyMODINIT_FUNC
initcollections(void)
{
PyObject *m;
m = Py_InitModule3("collections", NULL, module_doc);
if (PyType_Ready(&deque_type) < 0)
return;
Py_INCREF(&deque_type);
PyModule_AddObject(m, "deque", (PyObject *)&deque_type);
if (PyType_Ready(&dequeiter_type) < 0)
return;
if (PyType_Ready(&dequereviter_type) < 0)
return;
return;
}