+void display_throughput(struct progress *progress, unsigned long n)
+{
+ struct throughput *tp;
+ struct timeval tv;
+ unsigned int misecs;
+
+ if (!progress)
+ return;
+ tp = progress->throughput;
+
+ gettimeofday(&tv, NULL);
+
+ if (!tp) {
+ progress->throughput = tp = calloc(1, sizeof(*tp));
+ if (tp)
+ tp->prev_tv = tv;
+ return;
+ }
+
+ tp->count += n;
+
+ /*
+ * We have x = bytes and y = microsecs. We want z = KiB/s:
+ *
+ * z = (x / 1024) / (y / 1000000)
+ * z = x / y * 1000000 / 1024
+ * z = x / (y * 1024 / 1000000)
+ * z = x / y'
+ *
+ * To simplify things we'll keep track of misecs, or 1024th of a sec
+ * obtained with:
+ *
+ * y' = y * 1024 / 1000000
+ * y' = y / (1000000 / 1024)
+ * y' = y / 977
+ */
+ misecs = (tv.tv_sec - tp->prev_tv.tv_sec) * 1024;
+ misecs += (int)(tv.tv_usec - tp->prev_tv.tv_usec) / 977;
+
+ if (misecs > 512) {
+ tp->prev_tv = tv;
+ tp->avg_bytes += tp->count;
+ tp->avg_misecs += misecs;
+ snprintf(tp->display, sizeof(tp->display),
+ ", %lu KiB/s", tp->avg_bytes / tp->avg_misecs);
+ tp->avg_bytes -= tp->last_bytes[tp->idx];
+ tp->avg_misecs -= tp->last_misecs[tp->idx];
+ tp->last_bytes[tp->idx] = tp->count;
+ tp->last_misecs[tp->idx] = misecs;
+ tp->idx = (tp->idx + 1) % TP_IDX_MAX;
+ tp->count = 0;
+ }
+}
+