void
ngx_queue_sort(ngx_queue_t *queue,
ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *))
{
ngx_queue_t *q, *prev, *next;
q = ngx_queue_head(queue);
if (q == ngx_queue_last(queue)) {
return;
}
for (q = ngx_queue_next(q); q != ngx_queue_sentinel(queue); q = next) {
prev = ngx_queue_prev(q);
next = ngx_queue_next(q);
ngx_queue_remove(q);
do {
if (cmp(prev, q) <= 0) {/* 比较 */
break;
}
prev = ngx_queue_prev(prev); /* prev指针前移 */
} while (prev != ngx_queue_sentinel(queue));
ngx_queue_insert_after(prev, q);/* 将q插入prev节点之后(此处即为简单插入) */
}
}
// cmp 指向函数的指针
// 队列排序采用的是稳定的简单插入排序方法，即从第一个节点开始遍历，依次将节点(q)插入前面已经排序好的队列(链表)中
// prev 为已经排序好的queue
void
ngx_queue_sort(ngx_queue_t *queue,
ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *))
{
ngx_queue_t *q, *prev, *next;
q = ngx_queue_head(queue);
// 若只有一个元素，则无须排序
if (q == ngx_queue_last(queue)) {
return;
}
for (q = ngx_queue_next(q); q != ngx_queue_sentinel(queue); q = next) {
prev = ngx_queue_prev(q);
// 也充当了循环条件
next = ngx_queue_next(q);
ngx_queue_remove(q);
do {
// 指针函数调用
if (cmp(prev, q) <= 0) {
break;
}
prev = ngx_queue_prev(prev);
} while (prev != ngx_queue_sentinel(queue));
ngx_queue_insert_after(prev, q);
}
}
static void
ngx_http_v2_waiting_queue(ngx_http_v2_connection_t *h2c,
ngx_http_v2_stream_t *stream)
{
ngx_queue_t *q;
ngx_http_v2_stream_t *s;
if (stream->handled) {
return;
}
stream->handled = 1;
for (q = ngx_queue_last(&h2c->waiting);
q != ngx_queue_sentinel(&h2c->waiting);
q = ngx_queue_prev(q))
{
s = ngx_queue_data(q, ngx_http_v2_stream_t, queue);
if (s->node->rank < stream->node->rank
|| (s->node->rank == stream->node->rank
&& s->node->rel_weight >= stream->node->rel_weight))
{
break;
}
}
ngx_queue_insert_after(q, &stream->queue);
}
static void
ngx_http_spdy_waiting_queue(ngx_http_spdy_connection_t *sc,
ngx_http_spdy_stream_t *stream)
{
ngx_queue_t *q;
ngx_http_spdy_stream_t *s;
if (stream->handled)
{
return;
}
stream->handled = 1;
for (q = ngx_queue_last(&sc->waiting);
q != ngx_queue_sentinel(&sc->waiting);
q = ngx_queue_prev(q))
{
s = ngx_queue_data(q, ngx_http_spdy_stream_t, queue);
/*
* NB: higher values represent lower priorities.
*/
if (stream->priority >= s->priority)
{
break;
}
}
ngx_queue_insert_after(q, &stream->queue);
}
void
ngx_queue_sort(ngx_queue_t *queue,
intptr_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *))
{
ngx_queue_t *q, *prev, *next;
q = ngx_queue_head(queue);
if (q == ngx_queue_last(queue)) {
return;
}
for (q = ngx_queue_next(q); q != ngx_queue_sentinel(queue); q = next) {
prev = ngx_queue_prev(q);
next = ngx_queue_next(q);
ngx_queue_remove(q);
do {
if (cmp(prev, q) <= 0) {
break;
}
prev = ngx_queue_prev(prev);
} while (prev != ngx_queue_sentinel(queue));
ngx_queue_insert_after(prev, q);
}
}
int main(int argc, char const *argv[])
{
ngx_queue_t queueContainer;
ngx_queue_init(&queueContainer);
int i = 0;
my_queue node[5];
for(;i < 5;++i){
node[i].num = i;
}
ngx_queue_insert_tail(&queueContainer,&node[0].que);
ngx_queue_insert_head(&queueContainer,&node[1].que);
ngx_queue_insert_tail(&queueContainer,&node[2].que);
ngx_queue_insert_after(&queueContainer,&node[3].que);
ngx_queue_insert_tail(&queueContainer,&node[4].que);
ngx_queue_sort(&queueContainer,compTestNode);
ngx_queue_t *q;
for(q = ngx_queue_head(&queueContainer);q != ngx_queue_sentinel(&queueContainer)
;q = ngx_queue_next(q)){
my_queue* eleNode = ngx_queue_data(q,my_queue,que);
printf("%d\n",eleNode -> num );
}
return 0;
}
/*
* [analy] 队列排序采用的是稳定的简单插入排序方法，即从第一个节点开始遍历，依次将当前节点(q)插入前面已经排好序的队列(链表)中
* 由于排序仅简单的修改了指针指向的操作，所以效率较高的。
*/
void
ngx_queue_sort(ngx_queue_t *queue,
ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *))
{
ngx_queue_t *q, *prev, *next;
q = ngx_queue_head(queue);
if (q == ngx_queue_last(queue)) { // 第一个节点和最后一个节点相等，不需要排序（有0或1个节点）
return;
}
for (q = ngx_queue_next(q); q != ngx_queue_sentinel(queue); q = next) {
prev = ngx_queue_prev(q); // 取当前节点的前一个节点
next = ngx_queue_next(q); // 取当前节点的后一个节点
ngx_queue_remove(q); // 删除当前节点
do {
if (cmp(prev, q) <= 0) {
break;
}
prev = ngx_queue_prev(prev); // 这里取前一个节点的目的是为了检查循环条件是否成立，如果成立说明头节点之后还有节点，需要继续比较
// 不成立，说明头结点之后已经无接点，直接插入到头结点后
} while (prev != ngx_queue_sentinel(queue));
ngx_queue_insert_after(prev, q);
}
}
int main(int argc, char *argv[])
{
ngx_int_t n;
ngx_log_t * log;
ngx_queue_t queue_container;
ngx_queue_t *q;
test_node node[5];
test_node *ele_node;
ngx_pagesize = getpagesize();
n = ngx_strerror_init();
if (n == NGX_ERROR){
return NGX_ERROR;
}
ngx_time_init();
log = ngx_log_init((u_char *)"./");
ngx_use_stderr = 0;
if (log == NULL){
ngx_log_stderr(NGX_ERROR,(const char*)"can not init log ");
return NGX_ERROR;
}
ngx_queue_init(&queue_container);
for (n = 0;n < 5;n++){
node[n].num = n;
}
ngx_queue_insert_tail(&queue_container,&node[0].queue);
ngx_queue_insert_head(&queue_container,&node[1].queue);
ngx_queue_insert_after(&queue_container,&node[2].queue);
ngx_queue_insert_head(&queue_container,&node[3].queue);
ngx_queue_insert_tail(&queue_container,&node[4].queue);
for (q = ngx_queue_head(&queue_container);
q != ngx_queue_sentinel(&queue_container);
q = ngx_queue_next(q)){
ele_node = ngx_queue_data(q,test_node,queue);
printf("%d\n",ele_node->num);
}
ngx_queue_sort(&queue_container,cmp_test_node);
for (q = ngx_queue_head(&queue_container);
q != ngx_queue_sentinel(&queue_container);
q = ngx_queue_next(q)){
ele_node = ngx_queue_data(q,test_node,queue);
printf("%d\n",ele_node->num);
}
return NGX_OK;
}