/*
* same as hist_check() in ratelimit.c but this one
* only counts, no updates on the window ==> faster
*/
static inline int ALLOW_UNUSED hist_count(rl_pipe_t *pipe)
{
/* Window ELement*/
#define U2MILI(__usec__) (__usec__/1000)
#define S2MILI(__sec__) (__sec__ *1000)
int i;
int first_good_index;
int rl_win_ms = rl_window_size * 1000;
int count=0;
unsigned long long now_total, start_total;
struct timeval tv;
gettimeofday(&tv, NULL);
if (pipe->rwin.start_time.tv_sec == 0) {
return 0;
} else {
start_total = S2MILI(pipe->rwin.start_time.tv_sec)
+ U2MILI(pipe->rwin.start_time.tv_usec);
now_total = S2MILI(tv.tv_sec) + U2MILI(tv.tv_usec);
if (now_total - start_total >= 2*rl_win_ms) {
/* nothing here; window is expired */
} else if (now_total - start_total >= rl_win_ms) {
first_good_index = ((((now_total - rl_win_ms) - start_total)
/rl_slot_period + 1) + pipe->rwin.start_index) %
pipe->rwin.window_size;
count = 0;
for (i=first_good_index; i != pipe->rwin.start_index;
i=(i+1)%pipe->rwin.window_size)
count += pipe->rwin.window[i];
} else {
/* count all of them; valid window */
for (i=0; i < pipe->rwin.window_size; i++)
count += pipe->rwin.window[i];
}
}
return count;
#undef U2MILI
#undef S2MILI
}
/**
* the algorithm keeps a circular window of requests in a fixed size buffer
*
* @param pipe containing the window
* @param update whether or not to inc call number
* @return number of calls in the window
*/
static inline int hist_check(rl_pipe_t *pipe, int update)
{
#define U2MILI(__usec__) (__usec__/1000)
#define S2MILI(__sec__) (__sec__ *1000)
int i;
int first_good_index;
int rl_win_ms = rl_window_size * 1000;
unsigned long long now_total, start_total;
struct timeval tv;
/* first get values from our beloved replicated friends
* current pipe counter will be calculated after this
* iteration; no need for the old one */
pipe->counter = 0;
pipe->counter = rl_get_all_counters(pipe);
gettimeofday(&tv, NULL);
if (pipe->rwin.start_time.tv_sec == 0) {
/* the lucky one to come first here */
pipe->rwin.start_time = tv;
pipe->rwin.start_index = 0;
/* we know it starts from 0 because we did memset when created*/
pipe->rwin.window[pipe->rwin.start_index] += update;
} else {
start_total = S2MILI(pipe->rwin.start_time.tv_sec)
+ U2MILI(pipe->rwin.start_time.tv_usec);
now_total = S2MILI(tv.tv_sec) + U2MILI(tv.tv_usec);
/* didn't do any update to the window for "2*window_size" secs
* we can't use any elements from the vector
* the window is invalidated; very unlikely to happen*/
if (now_total - start_total >= 2*rl_win_ms) {
memset(pipe->rwin.window, 0,
pipe->rwin.window_size * sizeof(long int));
pipe->rwin.start_index = 0;
pipe->rwin.start_time = tv;
pipe->rwin.window[pipe->rwin.start_index] += update;
} else if (now_total - start_total >= rl_win_ms) {
/* current time in interval [window_size; 2*window_size)
* all the elements in [start_time; (ctime-window_size+1) are
* invalidated(set to 0)
* */
/* the first window index not to be set to 0
* number of slots from the start_index*/
first_good_index = ((((now_total - rl_win_ms) - start_total)
/rl_slot_period + 1) + pipe->rwin.start_index) %
pipe->rwin.window_size;
/* the new start time will be the start time of the first slot */
start_total = (now_total - rl_win_ms) -
(now_total - rl_win_ms)%rl_slot_period+ rl_slot_period;
pipe->rwin.start_time.tv_sec = start_total/1000;
pipe->rwin.start_time.tv_usec = (start_total%1000)*1000;
for (i=pipe->rwin.start_index; i != first_good_index;
i=(i+1)%pipe->rwin.window_size)
pipe->rwin.window[i] = 0;
pipe->rwin.start_index = first_good_index;
/* count current call; it will be the last element in the window */
pipe->rwin.window[((pipe->rwin.start_index)
+ (pipe->rwin.window_size-1)) % pipe->rwin.window_size] += update;
} else { /* now_total - start_total < rl_win_ms */
/* no need to modify the window, the value is inside it;
* we just need to increment the number of calls for
* the current slot*/
pipe->rwin.window[(now_total-start_total)/rl_slot_period] += update;
}
}
/* count the total number of calls in the window */
for (i=0; i < pipe->rwin.window_size; i++)
pipe->counter += pipe->rwin.window[i];
return pipe->counter > pipe->limit ? -1 : 1;
#undef U2MILI
#undef S2MILI
}
