mirrors/cpython
0
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2024-12-13 20:05:53 +08:00
Code Issues Packages Projects Releases Wiki Activity
ec8f0df229
cpython/Modules/_collectionsmodule.c
Raymond Hettinger 512d2cc643 Issue #11004: Repair edge case in deque.count(). 
(Reviewed by Georg Brandl.)

Also made similar changes to deque.reverse() though this wasn't
strictly necessary (the edge case cannot occur with two pointers
moving to meet in the middle).  Making the change in reverse()
was more a matter of future-proofing.
2011-01-25 21:32:39 +00:00

1666 lines
50 KiB
C
Raw Blame History

#include "Python.h"
#include "structmember.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.
*/
/* The block length may be set to any number over 1. Larger numbers
* reduce the number of calls to the memory allocator but take more
* memory. Ideally, BLOCKLEN should be set with an eye to the
* length of a cache line.
*/
#define BLOCKLEN 62
#define CENTER ((BLOCKLEN - 1) / 2)
/* A `dequeobject` is composed of a doubly-linked list of `block` nodes.
* This list is not circular (the leftmost block has leftlink==NULL,
* and the rightmost block has rightlink==NULL). A deque d's first
* element is at d.leftblock[leftindex] and its last element is at
* d.rightblock[rightindex]; note that, unlike as for Python slice
* indices, these indices are inclusive on both ends. By being inclusive
* on both ends, algorithms for left and right operations become
* symmetrical which simplifies the design.
*
* The list of blocks is never empty, so d.leftblock and d.rightblock
* are never equal to NULL.
*
* The indices, d.leftindex and d.rightindex are always in the range
* 0 <= index < BLOCKLEN.
* Their exact relationship is:
* (d.leftindex + d.len - 1) % BLOCKLEN == d.rightindex.
*
* Empty deques have d.len == 0; d.leftblock==d.rightblock;
* d.leftindex == CENTER+1; and d.rightindex == CENTER.
* Checking for d.len == 0 is the intended way to see whether d is empty.
*
* Whenever d.leftblock == d.rightblock,
* d.leftindex + d.len - 1 == d.rightindex.
*
* However, when d.leftblock != d.rightblock, d.leftindex and d.rightindex
* become indices into distinct blocks and either may be larger than the
* other.
*/
typedef struct BLOCK {
struct BLOCK *leftlink;
struct BLOCK *rightlink;
PyObject *data[BLOCKLEN];
} block;
#define MAXFREEBLOCKS 10
static Py_ssize_t numfreeblocks = 0;
static block *freeblocks[MAXFREEBLOCKS];
static block *
newblock(block *leftlink, block *rightlink, Py_ssize_t len) {
block *b;
/* To prevent len from overflowing PY_SSIZE_T_MAX on 64-bit machines, we
* refuse to allocate new blocks if the current len is dangerously
* close. There is some extra margin to prevent spurious arithmetic
* overflows at various places. The following check ensures that
* the blocks allocated to the deque, in the worst case, can only
* have PY_SSIZE_T_MAX-2 entries in total.
*/
if (len >= PY_SSIZE_T_MAX - 2*BLOCKLEN) {
PyErr_SetString(PyExc_OverflowError,
"cannot add more blocks to the deque");
return NULL;
}
if (numfreeblocks) {
numfreeblocks -= 1;
b = freeblocks[numfreeblocks];
} else {
b = PyMem_Malloc(sizeof(block));
if (b == NULL) {
PyErr_NoMemory();
return NULL;
}
}
b->leftlink = leftlink;
b->rightlink = rightlink;
return b;
}
static void
freeblock(block *b)
{
if (numfreeblocks < MAXFREEBLOCKS) {
freeblocks[numfreeblocks] = b;
numfreeblocks++;
} else {
PyMem_Free(b);
}
}
typedef struct {
PyObject_HEAD
block *leftblock;
block *rightblock;
Py_ssize_t leftindex; /* in range(BLOCKLEN) */
Py_ssize_t rightindex; /* in range(BLOCKLEN) */
Py_ssize_t len;
Py_ssize_t maxlen;
long state; /* incremented whenever the indices move */
PyObject *weakreflist; /* List of weak references */
} dequeobject;
/* The deque's size limit is d.maxlen. The limit can be zero or positive.
* If there is no limit, then d.maxlen == -1.
*
* After an item is added to a deque, we check to see if the size has grown past
* the limit. If it has, we get the size back down to the limit by popping an
* item off of the opposite end. The methods that can trigger this are append(),
* appendleft(), extend(), and extendleft().
*/
#define TRIM(d, popfunction) \
if (d->maxlen != -1 && d->len > d->maxlen) { \
PyObject *rv = popfunction(d, NULL); \
assert(rv != NULL && d->len <= d->maxlen); \
Py_DECREF(rv); \
}
static PyTypeObject deque_type;
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, 0);
if (b == NULL) {
Py_DECREF(deque);
return NULL;
}
assert(BLOCKLEN >= 2);
deque->leftblock = b;
deque->rightblock = b;
deque->leftindex = CENTER + 1;
deque->rightindex = CENTER;
deque->len = 0;
deque->state = 0;
deque->weakreflist = NULL;
deque->maxlen = -1;
return (PyObject *)deque;
}
static PyObject *
deque_pop(dequeobject *deque, PyObject *unused)
{
PyObject *item;
block *prevblock;
if (deque->len == 0) {
PyErr_SetString(PyExc_IndexError, "pop from an empty deque");
return NULL;
}
item = deque->rightblock->data[deque->rightindex];
deque->rightindex--;
deque->len--;
deque->state++;
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 = CENTER + 1;
deque->rightindex = CENTER;
} else {
prevblock = deque->rightblock->leftlink;
assert(deque->leftblock != deque->rightblock);
freeblock(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_IndexError, "pop from an empty deque");
return NULL;
}
assert(deque->leftblock != NULL);
item = deque->leftblock->data[deque->leftindex];
deque->leftindex++;
deque->len--;
deque->state++;
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 = CENTER + 1;
deque->rightindex = CENTER;
} else {
assert(deque->leftblock != deque->rightblock);
prevblock = deque->leftblock->rightlink;
freeblock(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_append(dequeobject *deque, PyObject *item)
{
deque->state++;
if (deque->rightindex == BLOCKLEN-1) {
block *b = newblock(deque->rightblock, NULL, deque->len);
if (b == NULL)
return NULL;
assert(deque->rightblock->rightlink == NULL);
deque->rightblock->rightlink = b;
deque->rightblock = b;
deque->rightindex = -1;
}
Py_INCREF(item);
deque->len++;
deque->rightindex++;
deque->rightblock->data[deque->rightindex] = item;
TRIM(deque, deque_popleft);
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->state++;
if (deque->leftindex == 0) {
block *b = newblock(NULL, deque->leftblock, deque->len);
if (b == NULL)
return NULL;
assert(deque->leftblock->leftlink == NULL);
deque->leftblock->leftlink = b;
deque->leftblock = b;
deque->leftindex = BLOCKLEN;
}
Py_INCREF(item);
deque->len++;
deque->leftindex--;
deque->leftblock->data[deque->leftindex] = item;
TRIM(deque, deque_pop);
Py_RETURN_NONE;
}
PyDoc_STRVAR(appendleft_doc, "Add an element to the left side of the deque.");
/* Run an iterator to exhaustion. Shortcut for
the extend/extendleft methods when maxlen == 0. */
static PyObject*
consume_iterator(PyObject *it)
{
PyObject *item;
while ((item = PyIter_Next(it)) != NULL) {
Py_DECREF(item);
}
Py_DECREF(it);
if (PyErr_Occurred())
return NULL;
Py_RETURN_NONE;
}
static PyObject *
deque_extend(dequeobject *deque, PyObject *iterable)
{
PyObject *it, *item;
/* Handle case where id(deque) == id(iterable) */
if ((PyObject *)deque == iterable) {
PyObject *result;
PyObject *s = PySequence_List(iterable);
if (s == NULL)
return NULL;
result = deque_extend(deque, s);
Py_DECREF(s);
return result;
}
it = PyObject_GetIter(iterable);
if (it == NULL)
return NULL;
if (deque->maxlen == 0)
return consume_iterator(it);
while ((item = PyIter_Next(it)) != NULL) {
deque->state++;
if (deque->rightindex == BLOCKLEN-1) {
block *b = newblock(deque->rightblock, NULL,
deque->len);
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 = -1;
}
deque->len++;
deque->rightindex++;
deque->rightblock->data[deque->rightindex] = item;
TRIM(deque, deque_popleft);
}
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;
/* Handle case where id(deque) == id(iterable) */
if ((PyObject *)deque == iterable) {
PyObject *result;
PyObject *s = PySequence_List(iterable);
if (s == NULL)
return NULL;
result = deque_extendleft(deque, s);
Py_DECREF(s);
return result;
}
it = PyObject_GetIter(iterable);
if (it == NULL)
return NULL;
if (deque->maxlen == 0)
return consume_iterator(it);
while ((item = PyIter_Next(it)) != NULL) {
deque->state++;
if (deque->leftindex == 0) {
block *b = newblock(NULL, deque->leftblock,
deque->len);
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;
}
deque->len++;
deque->leftindex--;
deque->leftblock->data[deque->leftindex] = item;
TRIM(deque, deque_pop);
}
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_inplace_concat(dequeobject *deque, PyObject *other)
{
PyObject *result;
result = deque_extend(deque, other);
if (result == NULL)
return result;
Py_DECREF(result);
Py_INCREF(deque);
return (PyObject *)deque;
}
static int
_deque_rotate(dequeobject *deque, Py_ssize_t n)
{
Py_ssize_t i, len=deque->len, halflen=(len+1)>>1;
PyObject *item, *rv;
if (len == 0)
return 0;
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);
assert (item != NULL);
rv = deque_appendleft(deque, item);
Py_DECREF(item);
if (rv == NULL)
return -1;
Py_DECREF(rv);
}
for (i=0 ; i>n ; i--) {
item = deque_popleft(deque, NULL);
assert (item != NULL);
rv = deque_append(deque, item);
Py_DECREF(item);
if (rv == NULL)
return -1;
Py_DECREF(rv);
}
return 0;
}
static PyObject *
deque_rotate(dequeobject *deque, PyObject *args)
{
Py_ssize_t n=1;
if (!PyArg_ParseTuple(args, "|n:rotate", &n))
return NULL;
if (_deque_rotate(deque, n) == 0)
Py_RETURN_NONE;
return NULL;
}
PyDoc_STRVAR(rotate_doc,
"Rotate the deque n steps to the right (default n=1). If n is negative, rotates left.");
static PyObject *
deque_reverse(dequeobject *deque, PyObject *unused)
{
block *leftblock = deque->leftblock;
block *rightblock = deque->rightblock;
Py_ssize_t leftindex = deque->leftindex;
Py_ssize_t rightindex = deque->rightindex;
Py_ssize_t n = (deque->len)/2;
Py_ssize_t i;
PyObject *tmp;
for (i=0 ; i<n ; i++) {
/* Validate that pointers haven't met in the middle */
assert(leftblock != rightblock || leftindex < rightindex);
/* Swap */
tmp = leftblock->data[leftindex];
leftblock->data[leftindex] = rightblock->data[rightindex];
rightblock->data[rightindex] = tmp;
/* Advance left block/index pair */
leftindex++;
if (leftindex == BLOCKLEN) {
if (leftblock->rightlink == NULL)
break;
leftblock = leftblock->rightlink;
leftindex = 0;
}
/* Step backwards with the right block/index pair */
rightindex--;
if (rightindex == -1) {
if (rightblock->leftlink == NULL)
break;
rightblock = rightblock->leftlink;
rightindex = BLOCKLEN - 1;
}
}
Py_RETURN_NONE;
}
PyDoc_STRVAR(reverse_doc,
"D.reverse() -- reverse *IN PLACE*");
static PyObject *
deque_count(dequeobject *deque, PyObject *v)
{
block *leftblock = deque->leftblock;
Py_ssize_t leftindex = deque->leftindex;
Py_ssize_t n = deque->len;
Py_ssize_t i;
Py_ssize_t count = 0;
PyObject *item;
long start_state = deque->state;
int cmp;
for (i=0 ; i<n ; i++) {
item = leftblock->data[leftindex];
cmp = PyObject_RichCompareBool(item, v, Py_EQ);
if (cmp > 0)
count++;
else if (cmp < 0)
return NULL;
if (start_state != deque->state) {
PyErr_SetString(PyExc_RuntimeError,
"deque mutated during iteration");
return NULL;
}
/* Advance left block/index pair */
leftindex++;
if (leftindex == BLOCKLEN) {
if (leftblock->rightlink == NULL) /* can occur when i==n-1 */
break;
leftblock = leftblock->rightlink;
leftindex = 0;
}
}
return PyLong_FromSsize_t(count);
}
PyDoc_STRVAR(count_doc,
"D.count(value) -> integer -- return number of occurrences of value");
static Py_ssize_t
deque_len(dequeobject *deque)
{
return deque->len;
}
static PyObject *
deque_remove(dequeobject *deque, PyObject *value)
{
Py_ssize_t i, n=deque->len;
for (i=0 ; i<n ; i++) {
PyObject *item = deque->leftblock->data[deque->leftindex];
int cmp = PyObject_RichCompareBool(item, value, Py_EQ);
if (deque->len != n) {
PyErr_SetString(PyExc_IndexError,
"deque mutated during remove().");
return NULL;
}
if (cmp > 0) {
PyObject *tgt = deque_popleft(deque, NULL);
assert (tgt != NULL);
Py_DECREF(tgt);
if (_deque_rotate(deque, i) == -1)
return NULL;
Py_RETURN_NONE;
}
else if (cmp < 0) {
_deque_rotate(deque, i);
return NULL;
}
_deque_rotate(deque, -1);
}
PyErr_SetString(PyExc_ValueError, "deque.remove(x): x not in deque");
return NULL;
}
PyDoc_STRVAR(remove_doc,
"D.remove(value) -- remove first occurrence of value.");
static int
deque_clear(dequeobject *deque)
{
PyObject *item;
while (deque->len) {
item = deque_pop(deque, NULL);
assert (item != NULL);
Py_DECREF(item);
}
assert(deque->leftblock == deque->rightblock &&
deque->leftindex - 1 == deque->rightindex &&
deque->len == 0);
return 0;
}
static PyObject *
deque_item(dequeobject *deque, Py_ssize_t i)
{
block *b;
PyObject *item;
Py_ssize_t n, index=i;
if (i < 0 || i >= deque->len) {
PyErr_SetString(PyExc_IndexError,
"deque index out of range");
return NULL;
}
if (i == 0) {
i = deque->leftindex;
b = deque->leftblock;
} else if (i == deque->len - 1) {
i = deque->rightindex;
b = deque->rightblock;
} else {
i += deque->leftindex;
n = i / BLOCKLEN;
i %= BLOCKLEN;
if (index < (deque->len >> 1)) {
b = deque->leftblock;
while (n--)
b = b->rightlink;
} else {
n = (deque->leftindex + deque->len - 1) / BLOCKLEN - n;
b = deque->rightblock;
while (n--)
b = b->leftlink;
}
}
item = b->data[i];
Py_INCREF(item);
return item;
}
/* delitem() implemented in terms of rotate for simplicity and reasonable
performance near the end points. If for some reason this method becomes
popular, it is not hard to re-implement this using direct data movement
(similar to code in list slice assignment) and achieve a two or threefold
performance boost.
*/
static int
deque_del_item(dequeobject *deque, Py_ssize_t i)
{
PyObject *item;
assert (i >= 0 && i < deque->len);
if (_deque_rotate(deque, -i) == -1)
return -1;
item = deque_popleft(deque, NULL);
assert (item != NULL);
Py_DECREF(item);
return _deque_rotate(deque, i);
}
static int
deque_ass_item(dequeobject *deque, Py_ssize_t i, PyObject *v)
{
PyObject *old_value;
block *b;
Py_ssize_t n, len=deque->len, halflen=(len+1)>>1, index=i;
if (i < 0 || i >= len) {
PyErr_SetString(PyExc_IndexError,
"deque index out of range");
return -1;
}
if (v == NULL)
return deque_del_item(deque, i);
i += deque->leftindex;
n = i / BLOCKLEN;
i %= BLOCKLEN;
if (index <= halflen) {
b = deque->leftblock;
while (n--)
b = b->rightlink;
} else {
n = (deque->leftindex + len - 1) / BLOCKLEN - n;
b = deque->rightblock;
while (n--)
b = b->leftlink;
}
Py_INCREF(v);
old_value = b->data[i];
b->data[i] = v;
Py_DECREF(old_value);
return 0;
}
static PyObject *
deque_clearmethod(dequeobject *deque)
{
int rv;
rv = deque_clear(deque);
assert (rv != -1);
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->weakreflist != NULL)
PyObject_ClearWeakRefs((PyObject *) deque);
if (deque->leftblock != NULL) {
deque_clear(deque);
assert(deque->leftblock != NULL);
freeblock(deque->leftblock);
}
deque->leftblock = NULL;
deque->rightblock = NULL;
Py_TYPE(deque)->tp_free(deque);
}
static int
deque_traverse(dequeobject *deque, visitproc visit, void *arg)
{
block *b;
PyObject *item;
Py_ssize_t index;
Py_ssize_t indexlo = deque->leftindex;
for (b = deque->leftblock; b != NULL; b = b->rightlink) {
const Py_ssize_t indexhi = b == deque->rightblock ?
deque->rightindex :
BLOCKLEN - 1;
for (index = indexlo; index <= indexhi; ++index) {
item = b->data[index];
Py_VISIT(item);
}
indexlo = 0;
}
return 0;
}
static PyObject *
deque_copy(PyObject *deque)
{
if (((dequeobject *)deque)->maxlen == -1)
return PyObject_CallFunction((PyObject *)(Py_TYPE(deque)), "O", deque, NULL);
else
return PyObject_CallFunction((PyObject *)(Py_TYPE(deque)), "Oi",
deque, ((dequeobject *)deque)->maxlen, NULL);
}
PyDoc_STRVAR(copy_doc, "Return a shallow copy of a deque.");
static PyObject *
deque_reduce(dequeobject *deque)
{
PyObject *dict, *result, *aslist;
dict = PyObject_GetAttrString((PyObject *)deque, "__dict__");
if (dict == NULL)
PyErr_Clear();
aslist = PySequence_List((PyObject *)deque);
if (aslist == NULL) {
Py_XDECREF(dict);
return NULL;
}
if (dict == NULL) {
if (deque->maxlen == -1)
result = Py_BuildValue("O(O)", Py_TYPE(deque), aslist);
else
result = Py_BuildValue("O(On)", Py_TYPE(deque), aslist, deque->maxlen);
} else {
if (deque->maxlen == -1)
result = Py_BuildValue("O(OO)O", Py_TYPE(deque), aslist, Py_None, dict);
else
result = Py_BuildValue("O(On)O", Py_TYPE(deque), aslist, deque->maxlen, dict);
}
Py_XDECREF(dict);
Py_DECREF(aslist);
return result;
}
PyDoc_STRVAR(reduce_doc, "Return state information for pickling.");
static PyObject *
deque_repr(PyObject *deque)
{
PyObject *aslist, *result;
int i;
i = Py_ReprEnter(deque);
if (i != 0) {
if (i < 0)
return NULL;
return PyUnicode_FromString("[...]");
}
aslist = PySequence_List(deque);
if (aslist == NULL) {
Py_ReprLeave(deque);
return NULL;
}
if (((dequeobject *)deque)->maxlen != -1)
result = PyUnicode_FromFormat("deque(%R, maxlen=%zd)",
aslist, ((dequeobject *)deque)->maxlen);
else
result = PyUnicode_FromFormat("deque(%R)", aslist);
Py_DECREF(aslist);
Py_ReprLeave(deque);
return result;
}
static PyObject *
deque_richcompare(PyObject *v, PyObject *w, int op)
{
PyObject *it1=NULL, *it2=NULL, *x, *y;
Py_ssize_t vs, ws;
int b, cmp=-1;
if (!PyObject_TypeCheck(v, &deque_type) ||
!PyObject_TypeCheck(w, &deque_type)) {
Py_INCREF(Py_NotImplemented);
return Py_NotImplemented;
}
/* Shortcuts */
vs = ((dequeobject *)v)->len;
ws = ((dequeobject *)w)->len;
if (op == Py_EQ) {
if (v == w)
Py_RETURN_TRUE;
if (vs != ws)
Py_RETURN_FALSE;
}
if (op == Py_NE) {
if (v == w)
Py_RETURN_FALSE;
if (vs != ws)
Py_RETURN_TRUE;
}
/* Search for the first index where items are different */
it1 = PyObject_GetIter(v);
if (it1 == NULL)
goto done;
it2 = PyObject_GetIter(w);
if (it2 == NULL)
goto done;
for (;;) {
x = PyIter_Next(it1);
if (x == NULL && PyErr_Occurred())
goto done;
y = PyIter_Next(it2);
if (x == NULL || y == NULL)
break;
b = PyObject_RichCompareBool(x, y, Py_EQ);
if (b == 0) {
cmp = PyObject_RichCompareBool(x, y, op);
Py_DECREF(x);
Py_DECREF(y);
goto done;
}
Py_DECREF(x);
Py_DECREF(y);
if (b == -1)
goto done;
}
/* We reached the end of one deque or both */
Py_XDECREF(x);
Py_XDECREF(y);
if (PyErr_Occurred())
goto done;
switch (op) {
case Py_LT: cmp = y != NULL; break; /* if w was longer */
case Py_LE: cmp = x == NULL; break; /* if v was not longer */
case Py_EQ: cmp = x == y; break; /* if we reached the end of both */
case Py_NE: cmp = x != y; break; /* if one deque continues */
case Py_GT: cmp = x != NULL; break; /* if v was longer */
case Py_GE: cmp = y == NULL; break; /* if w was not longer */
}
done:
Py_XDECREF(it1);
Py_XDECREF(it2);
if (cmp == 1)
Py_RETURN_TRUE;
if (cmp == 0)
Py_RETURN_FALSE;
return NULL;
}
static int
deque_init(dequeobject *deque, PyObject *args, PyObject *kwdargs)
{
PyObject *iterable = NULL;
PyObject *maxlenobj = NULL;
Py_ssize_t maxlen = -1;
char *kwlist[] = {"iterable", "maxlen", 0};
if (!PyArg_ParseTupleAndKeywords(args, kwdargs, "|OO:deque", kwlist, &iterable, &maxlenobj))
return -1;
if (maxlenobj != NULL && maxlenobj != Py_None) {
maxlen = PyLong_AsSsize_t(maxlenobj);
if (maxlen == -1 && PyErr_Occurred())
return -1;
if (maxlen < 0) {
PyErr_SetString(PyExc_ValueError, "maxlen must be non-negative");
return -1;
}
}
deque->maxlen = maxlen;
deque_clear(deque);
if (iterable != NULL) {
PyObject *rv = deque_extend(deque, iterable);
if (rv == NULL)
return -1;
Py_DECREF(rv);
}
return 0;
}
static PyObject *
deque_get_maxlen(dequeobject *deque)
{
if (deque->maxlen == -1)
Py_RETURN_NONE;
return PyLong_FromSsize_t(deque->maxlen);
}
static PyGetSetDef deque_getset[] = {
{"maxlen", (getter)deque_get_maxlen, (setter)NULL,
"maximum size of a deque or None if unbounded"},
{0}
};
static PySequenceMethods deque_as_sequence = {
(lenfunc)deque_len, /* sq_length */
0, /* sq_concat */
0, /* sq_repeat */
(ssizeargfunc)deque_item, /* sq_item */
0, /* sq_slice */
(ssizeobjargproc)deque_ass_item, /* sq_ass_item */
0, /* sq_ass_slice */
0, /* sq_contains */
(binaryfunc)deque_inplace_concat, /* sq_inplace_concat */
0, /* sq_inplace_repeat */
};
/* 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},
{"count", (PyCFunction)deque_count,
METH_O, count_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},
{"remove", (PyCFunction)deque_remove,
METH_O, remove_doc},
{"__reversed__", (PyCFunction)deque_reviter,
METH_NOARGS, reversed_doc},
{"reverse", (PyCFunction)deque_reverse,
METH_NOARGS, reverse_doc},
{"rotate", (PyCFunction)deque_rotate,
METH_VARARGS, rotate_doc},
{NULL, NULL} /* sentinel */
};
PyDoc_STRVAR(deque_doc,
"deque(iterable[, maxlen]) --> deque object\n\
\n\
Build an ordered collection accessible from endpoints only.");
static PyTypeObject deque_type = {
PyVarObject_HEAD_INIT(NULL, 0)
"collections.deque", /* tp_name */
sizeof(dequeobject), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
(destructor)deque_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
deque_repr, /* tp_repr */
0, /* tp_as_number */
&deque_as_sequence, /* tp_as_sequence */
0, /* tp_as_mapping */
PyObject_HashNotImplemented, /* 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)deque_traverse, /* tp_traverse */
(inquiry)deque_clear, /* tp_clear */
(richcmpfunc)deque_richcompare, /* tp_richcompare */
offsetof(dequeobject, weakreflist), /* tp_weaklistoffset*/
(getiterfunc)deque_iter, /* tp_iter */
0, /* tp_iternext */
deque_methods, /* tp_methods */
0, /* tp_members */
deque_getset, /* 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
Py_ssize_t index;
block *b;
dequeobject *deque;
long state; /* state when the iterator is created */
Py_ssize_t counter; /* number of items remaining for iteration */
} dequeiterobject;
static PyTypeObject dequeiter_type;
static PyObject *
deque_iter(dequeobject *deque)
{
dequeiterobject *it;
it = PyObject_GC_New(dequeiterobject, &dequeiter_type);
if (it == NULL)
return NULL;
it->b = deque->leftblock;
it->index = deque->leftindex;
Py_INCREF(deque);
it->deque = deque;
it->state = deque->state;
it->counter = deque->len;
PyObject_GC_Track(it);
return (PyObject *)it;
}
static int
dequeiter_traverse(dequeiterobject *dio, visitproc visit, void *arg)
{
Py_VISIT(dio->deque);
return 0;
}
static void
dequeiter_dealloc(dequeiterobject *dio)
{
Py_XDECREF(dio->deque);
PyObject_GC_Del(dio);
}
static PyObject *
dequeiter_next(dequeiterobject *it)
{
PyObject *item;
if (it->deque->state != it->state) {
it->counter = 0;
PyErr_SetString(PyExc_RuntimeError,
"deque mutated during iteration");
return NULL;
}
if (it->counter == 0)
return NULL;
assert (!(it->b == it->deque->rightblock &&
it->index > it->deque->rightindex));
item = it->b->data[it->index];
it->index++;
it->counter--;
if (it->index == BLOCKLEN && it->counter > 0) {
assert (it->b->rightlink != NULL);
it->b = it->b->rightlink;
it->index = 0;
}
Py_INCREF(item);
return item;
}
static PyObject *
dequeiter_len(dequeiterobject *it)
{
return PyLong_FromSsize_t(it->counter);
}
PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
static PyMethodDef dequeiter_methods[] = {
{"__length_hint__", (PyCFunction)dequeiter_len, METH_NOARGS, length_hint_doc},
{NULL, NULL} /* sentinel */
};
static PyTypeObject dequeiter_type = {
PyVarObject_HEAD_INIT(NULL, 0)
"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_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 */
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
0, /* tp_doc */
(traverseproc)dequeiter_traverse, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
PyObject_SelfIter, /* tp_iter */
(iternextfunc)dequeiter_next, /* tp_iternext */
dequeiter_methods, /* tp_methods */
0,
};
/*********************** Deque Reverse Iterator **************************/
static PyTypeObject dequereviter_type;
static PyObject *
deque_reviter(dequeobject *deque)
{
dequeiterobject *it;
it = PyObject_GC_New(dequeiterobject, &dequereviter_type);
if (it == NULL)
return NULL;
it->b = deque->rightblock;
it->index = deque->rightindex;
Py_INCREF(deque);
it->deque = deque;
it->state = deque->state;
it->counter = deque->len;
PyObject_GC_Track(it);
return (PyObject *)it;
}
static PyObject *
dequereviter_next(dequeiterobject *it)
{
PyObject *item;
if (it->counter == 0)
return NULL;
if (it->deque->state != it->state) {
it->counter = 0;
PyErr_SetString(PyExc_RuntimeError,
"deque mutated during iteration");
return NULL;
}
assert (!(it->b == it->deque->leftblock &&
it->index < it->deque->leftindex));
item = it->b->data[it->index];
it->index--;
it->counter--;
if (it->index == -1 && it->counter > 0) {
assert (it->b->leftlink != NULL);
it->b = it->b->leftlink;
it->index = BLOCKLEN - 1;
}
Py_INCREF(item);
return item;
}
static PyTypeObject dequereviter_type = {
PyVarObject_HEAD_INIT(NULL, 0)
"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_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 */
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
0, /* tp_doc */
(traverseproc)dequeiter_traverse, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
PyObject_SelfIter, /* tp_iter */
(iternextfunc)dequereviter_next, /* tp_iternext */
dequeiter_methods, /* tp_methods */
0,
};
/* defaultdict type *********************************************************/
typedef struct {
PyDictObject dict;
PyObject *default_factory;
} defdictobject;
static PyTypeObject defdict_type; /* Forward */
PyDoc_STRVAR(defdict_missing_doc,
"__missing__(key) # Called by __getitem__ for missing key; pseudo-code:\n\
if self.default_factory is None: raise KeyError((key,))\n\
self[key] = value = self.default_factory()\n\
return value\n\
");
static PyObject *
defdict_missing(defdictobject *dd, PyObject *key)
{
PyObject *factory = dd->default_factory;
PyObject *value;
if (factory == NULL || factory == Py_None) {
/* XXX Call dict.__missing__(key) */
PyObject *tup;
tup = PyTuple_Pack(1, key);
if (!tup) return NULL;
PyErr_SetObject(PyExc_KeyError, tup);
Py_DECREF(tup);
return NULL;
}
value = PyEval_CallObject(factory, NULL);
if (value == NULL)
return value;
if (PyObject_SetItem((PyObject *)dd, key, value) < 0) {
Py_DECREF(value);
return NULL;
}
return value;
}
PyDoc_STRVAR(defdict_copy_doc, "D.copy() -> a shallow copy of D.");
static PyObject *
defdict_copy(defdictobject *dd)
{
/* This calls the object's class. That only works for subclasses
whose class constructor has the same signature. Subclasses that
define a different constructor signature must override copy().
*/
if (dd->default_factory == NULL)
return PyObject_CallFunctionObjArgs((PyObject*)Py_TYPE(dd), Py_None, dd, NULL);
return PyObject_CallFunctionObjArgs((PyObject*)Py_TYPE(dd),
dd->default_factory, dd, NULL);
}
static PyObject *
defdict_reduce(defdictobject *dd)
{
/* __reduce__ must return a 5-tuple as follows:
- factory function
- tuple of args for the factory function
- additional state (here None)
- sequence iterator (here None)
- dictionary iterator (yielding successive (key, value) pairs
This API is used by pickle.py and copy.py.
For this to be useful with pickle.py, the default_factory
must be picklable; e.g., None, a built-in, or a global
function in a module or package.
Both shallow and deep copying are supported, but for deep
copying, the default_factory must be deep-copyable; e.g. None,
or a built-in (functions are not copyable at this time).
This only works for subclasses as long as their constructor
signature is compatible; the first argument must be the
optional default_factory, defaulting to None.
*/
PyObject *args;
PyObject *items;
PyObject *iter;
PyObject *result;
if (dd->default_factory == NULL || dd->default_factory == Py_None)
args = PyTuple_New(0);
else
args = PyTuple_Pack(1, dd->default_factory);
if (args == NULL)
return NULL;
items = PyObject_CallMethod((PyObject *)dd, "items", "()");
if (items == NULL) {
Py_DECREF(args);
return NULL;
}
iter = PyObject_GetIter(items);
if (iter == NULL) {
Py_DECREF(items);
Py_DECREF(args);
return NULL;
}
result = PyTuple_Pack(5, Py_TYPE(dd), args,
Py_None, Py_None, iter);
Py_DECREF(iter);
Py_DECREF(items);
Py_DECREF(args);
return result;
}
static PyMethodDef defdict_methods[] = {
{"__missing__", (PyCFunction)defdict_missing, METH_O,
defdict_missing_doc},
{"copy", (PyCFunction)defdict_copy, METH_NOARGS,
defdict_copy_doc},
{"__copy__", (PyCFunction)defdict_copy, METH_NOARGS,
defdict_copy_doc},
{"__reduce__", (PyCFunction)defdict_reduce, METH_NOARGS,
reduce_doc},
{NULL}
};
static PyMemberDef defdict_members[] = {
{"default_factory", T_OBJECT,
offsetof(defdictobject, default_factory), 0,
PyDoc_STR("Factory for default value called by __missing__().")},
{NULL}
};
static void
defdict_dealloc(defdictobject *dd)
{
Py_CLEAR(dd->default_factory);
PyDict_Type.tp_dealloc((PyObject *)dd);
}
static PyObject *
defdict_repr(defdictobject *dd)
{
PyObject *baserepr;
PyObject *defrepr;
PyObject *result;
baserepr = PyDict_Type.tp_repr((PyObject *)dd);
if (baserepr == NULL)
return NULL;
if (dd->default_factory == NULL)
defrepr = PyUnicode_FromString("None");
else
{
int status = Py_ReprEnter(dd->default_factory);
if (status != 0) {
if (status < 0)
return NULL;
defrepr = PyUnicode_FromString("...");
}
else
defrepr = PyObject_Repr(dd->default_factory);
Py_ReprLeave(dd->default_factory);
}
if (defrepr == NULL) {
Py_DECREF(baserepr);
return NULL;
}
result = PyUnicode_FromFormat("defaultdict(%U, %U)",
defrepr, baserepr);
Py_DECREF(defrepr);
Py_DECREF(baserepr);
return result;
}
static int
defdict_traverse(PyObject *self, visitproc visit, void *arg)
{
Py_VISIT(((defdictobject *)self)->default_factory);
return PyDict_Type.tp_traverse(self, visit, arg);
}
static int
defdict_tp_clear(defdictobject *dd)
{
Py_CLEAR(dd->default_factory);
return PyDict_Type.tp_clear((PyObject *)dd);
}
static int
defdict_init(PyObject *self, PyObject *args, PyObject *kwds)
{
defdictobject *dd = (defdictobject *)self;
PyObject *olddefault = dd->default_factory;
PyObject *newdefault = NULL;
PyObject *newargs;
int result;
if (args == NULL || !PyTuple_Check(args))
newargs = PyTuple_New(0);
else {
Py_ssize_t n = PyTuple_GET_SIZE(args);
if (n > 0) {
newdefault = PyTuple_GET_ITEM(args, 0);
if (!PyCallable_Check(newdefault) && newdefault != Py_None) {
PyErr_SetString(PyExc_TypeError,
"first argument must be callable");
return -1;
}
}
newargs = PySequence_GetSlice(args, 1, n);
}
if (newargs == NULL)
return -1;
Py_XINCREF(newdefault);
dd->default_factory = newdefault;
result = PyDict_Type.tp_init(self, newargs, kwds);
Py_DECREF(newargs);
Py_XDECREF(olddefault);
return result;
}
PyDoc_STRVAR(defdict_doc,
"defaultdict(default_factory) --> dict with default factory\n\
\n\
The default factory is called without arguments to produce\n\
a new value when a key is not present, in __getitem__ only.\n\
A defaultdict compares equal to a dict with the same items.\n\
");
/* See comment in xxsubtype.c */
#define DEFERRED_ADDRESS(ADDR) 0
static PyTypeObject defdict_type = {
PyVarObject_HEAD_INIT(DEFERRED_ADDRESS(&PyType_Type), 0)
"collections.defaultdict", /* tp_name */
sizeof(defdictobject), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
(destructor)defdict_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
(reprfunc)defdict_repr, /* 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 | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
/* tp_flags */
defdict_doc, /* tp_doc */
defdict_traverse, /* tp_traverse */
(inquiry)defdict_tp_clear, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset*/
0, /* tp_iter */
0, /* tp_iternext */
defdict_methods, /* tp_methods */
defdict_members, /* tp_members */
0, /* tp_getset */
DEFERRED_ADDRESS(&PyDict_Type), /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
defdict_init, /* tp_init */
PyType_GenericAlloc, /* tp_alloc */
0, /* tp_new */
PyObject_GC_Del, /* tp_free */
};
/* helper function for Counter *********************************************/
PyDoc_STRVAR(_count_elements_doc,
"_count_elements(mapping, iterable) -> None\n\
\n\
Count elements in the iterable, updating the mappping");
static PyObject *
_count_elements(PyObject *self, PyObject *args)
{
PyObject *it, *iterable, *mapping, *oldval;
PyObject *newval = NULL;
PyObject *key = NULL;
PyObject *one = NULL;
if (!PyArg_UnpackTuple(args, "_count_elements", 2, 2, &mapping, &iterable))
return NULL;
it = PyObject_GetIter(iterable);
if (it == NULL)
return NULL;
one = PyLong_FromLong(1);
if (one == NULL) {
Py_DECREF(it);
return NULL;
}
if (PyDict_CheckExact(mapping)) {
while (1) {
key = PyIter_Next(it);
if (key == NULL) {
if (PyErr_Occurred() && PyErr_ExceptionMatches(PyExc_StopIteration))
PyErr_Clear();
else
break;
}
oldval = PyDict_GetItem(mapping, key);
if (oldval == NULL) {
if (PyDict_SetItem(mapping, key, one) == -1)
break;
} else {
newval = PyNumber_Add(oldval, one);
if (newval == NULL)
break;
if (PyDict_SetItem(mapping, key, newval) == -1)
break;
Py_CLEAR(newval);
}
Py_DECREF(key);
}
} else {
while (1) {
key = PyIter_Next(it);
if (key == NULL) {
if (PyErr_Occurred() && PyErr_ExceptionMatches(PyExc_StopIteration))
PyErr_Clear();
else
break;
}
oldval = PyObject_GetItem(mapping, key);
if (oldval == NULL) {
if (!PyErr_Occurred() || !PyErr_ExceptionMatches(PyExc_KeyError))
break;
PyErr_Clear();
Py_INCREF(one);
newval = one;
} else {
newval = PyNumber_Add(oldval, one);
Py_DECREF(oldval);
if (newval == NULL)
break;
}
if (PyObject_SetItem(mapping, key, newval) == -1)
break;
Py_CLEAR(newval);
Py_DECREF(key);
}
}
Py_DECREF(it);
Py_XDECREF(key);
Py_XDECREF(newval);
Py_DECREF(one);
if (PyErr_Occurred())
return NULL;
Py_RETURN_NONE;
}
/* module level code ********************************************************/
PyDoc_STRVAR(module_doc,
"High performance data structures.\n\
- deque: ordered collection accessible from endpoints only\n\
- defaultdict: dict subclass with a default value factory\n\
");
static struct PyMethodDef module_functions[] = {
{"_count_elements", _count_elements, METH_VARARGS, _count_elements_doc},
{NULL, NULL} /* sentinel */
};
static struct PyModuleDef _collectionsmodule = {
PyModuleDef_HEAD_INIT,
"_collections",
module_doc,
-1,
module_functions,
NULL,
NULL,
NULL,
NULL
};
PyMODINIT_FUNC
PyInit__collections(void)
{
PyObject *m;
m = PyModule_Create(&_collectionsmodule);
if (m == NULL)
return NULL;
if (PyType_Ready(&deque_type) < 0)
return NULL;
Py_INCREF(&deque_type);
PyModule_AddObject(m, "deque", (PyObject *)&deque_type);
defdict_type.tp_base = &PyDict_Type;
if (PyType_Ready(&defdict_type) < 0)
return NULL;
Py_INCREF(&defdict_type);
PyModule_AddObject(m, "defaultdict", (PyObject *)&defdict_type);
if (PyType_Ready(&dequeiter_type) < 0)
return NULL;
if (PyType_Ready(&dequereviter_type) < 0)
return NULL;
return m;
}
Reference in New Issue View Git Blame Copy Permalink