# define LLONG_MAX 9223372036854775807LL
#endif
-#ifndef HISTOGRAM_NUM_BINS
-# define HISTOGRAM_NUM_BINS 1000
-#endif
-
#ifndef HISTOGRAM_DEFAULT_BIN_WIDTH
/* 1048576 = 2^20 ^= 1/1024 s */
# define HISTOGRAM_DEFAULT_BIN_WIDTH 1048576
if (lc->max < latency)
lc->max = latency;
- /* A latency of _exactly_ 1.0 ms should be stored in the buffer 0, so
+ /* A latency of _exactly_ 1.0 ms is stored in the buffer 0, so
* subtract one from the cdtime_t value so that exactly 1.0 ms get sorted
* accordingly. */
bin = (latency - 1) / lc->bin_width;
return (latency_interpolated);
} /* }}} cdtime_t latency_counter_get_percentile */
+cdtime_t latency_counter_get_start_time (const latency_counter_t *lc) /* {{{ */
+{
+ if (lc == NULL)
+ return (0);
+
+ return lc->start_time;
+} /* }}} cdtime_t latency_counter_get_start_time */
+
+
+double latency_counter_get_rate (const latency_counter_t *lc, /* {{{ */
+ cdtime_t lower, cdtime_t upper, const cdtime_t now)
+{
+ cdtime_t lower_bin;
+ cdtime_t upper_bin;
+ double sum = 0;
+
+ if ((lc == NULL) || (lc->num == 0))
+ return (0);
+
+ if (upper && (upper < lower))
+ return (0);
+
+ /* Buckets have an exclusive lower bound and an inclusive upper bound. That
+ * means that the first bucket, index 0, represents (0-bin_width]. That means
+ * that lower==bin_width needs to result in lower_bin=0, hence the -1. */
+ if (lower)
+ lower_bin = (lower - 1) / lc->bin_width;
+ else
+ lower_bin = 0;
+
+ if (upper)
+ upper_bin = (upper - 1) / lc->bin_width;
+ else
+ upper_bin = HISTOGRAM_NUM_BINS - 1;
+
+ if (lower_bin >= HISTOGRAM_NUM_BINS)
+ lower_bin = HISTOGRAM_NUM_BINS - 1;
+
+ if (upper_bin >= HISTOGRAM_NUM_BINS) {
+ upper_bin = HISTOGRAM_NUM_BINS - 1;
+ upper = 0;
+ }
+
+ sum = 0;
+ for (size_t i = lower_bin; i <= upper_bin; i++)
+ {
+ sum += lc->histogram[i];
+ }
+
+ if (lower) {
+ /* Approximate ratio of requests in lower_bin, that fall between
+ * lower_bin_boundary and lower. This ratio is then subtracted from sum to
+ * increase accuracy. */
+ cdtime_t lower_bin_boundary = lower_bin * lc->bin_width;
+ assert (lower > lower_bin_boundary);
+ double lower_ratio = (double)(lower - lower_bin_boundary - 1) / ((double) lc->bin_width);
+ sum -= lower_ratio * lc->histogram[lower_bin];
+ }
+
+ if (upper)
+ {
+ /* As above: approximate ratio of requests in upper_bin, that fall between
+ * upper and upper_bin_boundary. */
+ cdtime_t upper_bin_boundary = (upper_bin + 1) * lc->bin_width;
+ assert (upper <= upper_bin_boundary);
+ double ratio = (double)(upper_bin_boundary - upper) / (double)lc->bin_width;
+ sum -= ratio * lc->histogram[upper_bin];
+ }
+
+ return sum / (CDTIME_T_TO_DOUBLE (now - lc->start_time));
+} /* }}} double latency_counter_get_rate */
+
/* vim: set sw=2 sts=2 et fdm=marker : */