FS-8130 more cleanup on jb mods

This commit is contained in:
Anthony Minessale 2015-09-15 17:23:34 -05:00
parent 9cff1eb71f
commit 3ae5c7ce57
1 changed files with 67 additions and 85 deletions

View File

@ -97,113 +97,97 @@ struct switch_jb_s {
};
/*
* https://gist.github.com/ideasman42/5921b0edfc6aa41a9ce0
*
* Originally from: http://stackoverflow.com/a/27663998/432509
*
* With following modifications:
* - Use a pointer to the tail (remove 2x conditional checks, reduces code-size).
* - Avoid re-assigning empty values the size doesn't change.
* - Corrected comments.
*/
static int node_cmp(const void *l, const void *r)
{
switch_jb_node_t *a = (switch_jb_node_t *) l;
switch_jb_node_t *b = (switch_jb_node_t *) r;
if (!a->visible) return 0;
if (!b->visible) return 1;
if (!a->visible && !b->visible) {
return 0;
}
if (a->visible != b->visible) {
if (a->visible) {
return 1;
} else {
return -1;
}
}
return a->packet.header.seq - b->packet.header.seq;
return ntohs(a->packet.header.seq) - ntohs(b->packet.header.seq);
}
static switch_jb_node_t *sort_nodes(switch_jb_node_t *head, int (*cmp)(const void *, const void *))
{
int block_size = 1, block_count;
//http://www.chiark.greenend.org.uk/~sgtatham/algorithms/listsort.c
switch_jb_node_t *sort_nodes(switch_jb_node_t *list, int (*cmp)(const void *, const void *)) {
switch_jb_node_t *p, *q, *e, *tail;
int insize, nmerges, psize, qsize, i;
do {
/* Maintain two lists pointing to two blocks, 'l' and 'r' */
switch_jb_node_t *l = head, *r = head, **tail_p;
head = NULL; /* Start a new list */
tail_p = &head;
if (!list) {
return NULL;
}
block_count = 0;
insize = 1;
/* Walk through entire list in blocks of 'block_size'*/
while (l != NULL) {
/* Move 'r' to start of next block, measure size of 'l' list while doing so */
int l_size, r_size = block_size;
int l_empty, r_empty;
while (1) {
p = list;
list = NULL;
tail = NULL;
block_count++;
for (l_size = 0; (l_size < block_size) && (r != NULL); l_size++) {
r = r->next;
nmerges = 0; /* count number of merges we do in this pass */
while (p) {
nmerges++; /* there exists a merge to be done */
/* step `insize' places along from p */
q = p;
psize = 0;
for (i = 0; i < insize; i++) {
psize++;
q = q->next;
if (!q) break;
}
/* Merge two list until their individual ends */
l_empty = (l_size == 0);
r_empty = (r_size == 0 || r == NULL);
while (!l_empty || !r_empty) {
switch_jb_node_t *s;
/* Using <= instead of < gives us sort stability */
if (r_empty || (!l_empty && cmp(l, r) <= 0)) {
s = l;
l = l->next;
l_size--;
l_empty = (l_size == 0);
/* if q hasn't fallen off end, we have two lists to merge */
qsize = insize;
/* now we have two lists; merge them */
while (psize > 0 || (qsize > 0 && q)) {
/* decide whether next switch_jb_node_t of merge comes from p or q */
if (psize == 0) {
/* p is empty; e must come from q. */
e = q; q = q->next; qsize--;
} else if (qsize == 0 || !q) {
/* q is empty; e must come from p. */
e = p; p = p->next; psize--;
} else if (cmp(p,q) <= 0) {
/* First switch_jb_node_t of p is lower (or same);
* e must come from p. */
e = p; p = p->next; psize--;
} else {
s = r;
r = r->next;
r_size--;
r_empty = (r_size == 0) || (r == NULL);
/* First switch_jb_node_t of q is lower; e must come from q. */
e = q; q = q->next; qsize--;
}
/* Update new list */
(*tail_p) = s;
tail_p = &(s->next);
/* add the next switch_jb_node_t to the merged list */
if (tail) {
tail->next = e;
} else {
list = e;
}
/* Maintain reverse pointers in a doubly linked list. */
e->prev = tail;
tail = e;
}
/* 'r' now points to next block for 'l' */
l = r;
/* now p has stepped `insize' places along, and q has too */
p = q;
}
/* terminate new list, take care of case when input list is NULL */
*tail_p = NULL;
tail->next = NULL;
/* Lg n iterations */
block_size <<= 1;
/* If we have done only one merge, we're finished. */
if (nmerges <= 1) /* allow for nmerges==0, the empty list case */
return list;
} while (block_count > 1);
if (head) {
switch_jb_node_t *np, *last = NULL;
head->prev = NULL;
for (np = head; np ; np = np->next) {
if (last) {
np->prev = last;
}
last = np;
}
/* Otherwise repeat, merging lists twice the size */
insize *= 2;
}
return head;
}
static inline switch_jb_node_t *new_node(switch_jb_t *jb)
{
switch_jb_node_t *np;
@ -489,9 +473,7 @@ static inline int verify_oldest_frame(switch_jb_t *jb)
}
if (np->packet.header.ts != lowest->packet.header.ts || !np->next) {
if (np->prev->packet.header.m) {
r = 1;
}
r = 1;
}
}