Minor cleanups.
diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index 14f7912..371631c 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -413,8 +413,7 @@
static int
_deque_rotate(dequeobject *deque, Py_ssize_t n)
{
- Py_ssize_t i, m, len=deque->len, halflen=(len+1)>>1;
- block *prevblock;
+ Py_ssize_t m, len=deque->len, halflen=len>>1;
if (len <= 1)
return 0;
@@ -425,12 +424,13 @@
else if (n < -halflen)
n += len;
}
+ assert(len > 1);
+ assert(-halflen <= n && n <= halflen);
- assert(deque->len > 1);
deque->state++;
- for (i=0 ; i<n ; ) {
+ while (n > 0) {
if (deque->leftindex == 0) {
- block *b = newblock(NULL, deque->leftblock, deque->len);
+ block *b = newblock(NULL, deque->leftblock, len);
if (b == NULL)
return -1;
assert(deque->leftblock->leftlink == NULL);
@@ -440,22 +440,22 @@
}
assert(deque->leftindex > 0);
- m = n - i;
+ m = n;
if (m > deque->rightindex + 1)
m = deque->rightindex + 1;
if (m > deque->leftindex)
m = deque->leftindex;
- assert (m > 0);
+ assert (m > 0 && m <= len);
memcpy(&deque->leftblock->data[deque->leftindex - m],
- &deque->rightblock->data[deque->rightindex - m + 1],
+ &deque->rightblock->data[deque->rightindex + 1 - m],
m * sizeof(PyObject *));
deque->rightindex -= m;
deque->leftindex -= m;
- i += m;
+ n -= m;
if (deque->rightindex == -1) {
+ block *prevblock = deque->rightblock->leftlink;
assert(deque->rightblock != NULL);
- prevblock = deque->rightblock->leftlink;
assert(deque->leftblock != deque->rightblock);
freeblock(deque->rightblock);
prevblock->rightlink = NULL;
@@ -463,9 +463,9 @@
deque->rightindex = BLOCKLEN - 1;
}
}
- for (i=0 ; i>n ; ) {
+ while (n < 0) {
if (deque->rightindex == BLOCKLEN - 1) {
- block *b = newblock(deque->rightblock, NULL, deque->len);
+ block *b = newblock(deque->rightblock, NULL, len);
if (b == NULL)
return -1;
assert(deque->rightblock->rightlink == NULL);
@@ -475,26 +475,26 @@
}
assert (deque->rightindex < BLOCKLEN - 1);
- m = i - n;
+ m = -n;
if (m > BLOCKLEN - deque->leftindex)
m = BLOCKLEN - deque->leftindex;
if (m > BLOCKLEN - 1 - deque->rightindex)
m = BLOCKLEN - 1 - deque->rightindex;
- assert (m > 0);
+ assert (m > 0 && m <= len);
memcpy(&deque->rightblock->data[deque->rightindex + 1],
&deque->leftblock->data[deque->leftindex],
m * sizeof(PyObject *));
deque->leftindex += m;
deque->rightindex += m;
- i -= m;
+ n += m;
if (deque->leftindex == BLOCKLEN) {
+ block *nextblock = deque->leftblock->rightlink;
assert(deque->leftblock != deque->rightblock);
- prevblock = deque->leftblock->rightlink;
freeblock(deque->leftblock);
- assert(prevblock != NULL);
- prevblock->leftlink = NULL;
- deque->leftblock = prevblock;
+ assert(nextblock != NULL);
+ nextblock->leftlink = NULL;
+ deque->leftblock = nextblock;
deque->leftindex = 0;
}
}