Calculating duration from a single uint64_t is simpler than from a struct
timeval. Change throughput measurement from gettimeofday() to
getnanotime().
Also calculate misec only if needed, and change integer division to integer
multiplication + shift, which should be slightly faster.
Signed-off-by: Karsten Blees <bl...@dcon.de>
---
progress.c | 71 +++++++++++++++++++++++++++++++-------------------------------
1 file changed, 36 insertions(+), 35 deletions(-)
diff --git a/progress.c b/progress.c
index 261314e..412e6b1 100644
--- a/progress.c
+++ b/progress.c
@@ -12,13 +12,14 @@
#include "gettext.h"
#include "progress.h"
#include "strbuf.h"
+#include "trace.h"
#define TP_IDX_MAX 8
struct throughput {
off_t curr_total;
off_t prev_total;
- struct timeval prev_tv;
+ uint64_t prev_ns;
unsigned int avg_bytes;
unsigned int avg_misecs;
unsigned int last_bytes[TP_IDX_MAX];
@@ -127,65 +128,65 @@ static void throughput_string(struct strbuf *buf, off_t
total,
void display_throughput(struct progress *progress, off_t total)
{
struct throughput *tp;
- struct timeval tv;
- unsigned int misecs;
+ uint64_t now_ns;
+ unsigned int misecs, count, rate;
+ struct strbuf buf = STRBUF_INIT;
if (!progress)
return;
tp = progress->throughput;
- gettimeofday(&tv, NULL);
+ now_ns = getnanotime();
if (!tp) {
progress->throughput = tp = calloc(1, sizeof(*tp));
if (tp) {
tp->prev_total = tp->curr_total = total;
- tp->prev_tv = tv;
+ tp->prev_ns = now_ns;
}
return;
}
tp->curr_total = total;
+ /* only update throughput every 0.5 s */
+ if (now_ns - tp->prev_ns <= 500000000)
+ return;
+
/*
- * We have x = bytes and y = microsecs. We want z = KiB/s:
+ * We have x = bytes and y = nanosecs. We want z = KiB/s:
*
- * z = (x / 1024) / (y / 1000000)
- * z = x / y * 1000000 / 1024
- * z = x / (y * 1024 / 1000000)
+ * z = (x / 1024) / (y / 1000000000)
+ * z = x / y * 1000000000 / 1024
+ * z = x / (y * 1024 / 1000000000)
* 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
+ * y' = y * 1024 / 1000000000
+ * y' = y * (2^10 / 2^42) * (2^42 / 1000000000)
+ * y' = y / 2^32 * 4398
+ * y' = (y * 4398) >> 32
*/
- misecs = (tv.tv_sec - tp->prev_tv.tv_sec) * 1024;
- misecs += (int)(tv.tv_usec - tp->prev_tv.tv_usec) / 977;
+ misecs = ((now_ns - tp->prev_ns) * 4398) >> 32;
- if (misecs > 512) {
- struct strbuf buf = STRBUF_INIT;
- unsigned int count, rate;
+ count = total - tp->prev_total;
+ tp->prev_total = total;
+ tp->prev_ns = now_ns;
+ tp->avg_bytes += count;
+ tp->avg_misecs += misecs;
+ rate = 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] = count;
+ tp->last_misecs[tp->idx] = misecs;
+ tp->idx = (tp->idx + 1) % TP_IDX_MAX;
- count = total - tp->prev_total;
- tp->prev_total = total;
- tp->prev_tv = tv;
- tp->avg_bytes += count;
- tp->avg_misecs += misecs;
- rate = 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] = count;
- tp->last_misecs[tp->idx] = misecs;
- tp->idx = (tp->idx + 1) % TP_IDX_MAX;
-
- throughput_string(&buf, total, rate);
- strncpy(tp->display, buf.buf, sizeof(tp->display));
- strbuf_release(&buf);
- if (progress->last_value != -1 && progress_update)
- display(progress, progress->last_value, NULL);
- }
+ throughput_string(&buf, total, rate);
+ strncpy(tp->display, buf.buf, sizeof(tp->display));
+ strbuf_release(&buf);
+ if (progress->last_value != -1 && progress_update)
+ display(progress, progress->last_value, NULL);
}
int display_progress(struct progress *progress, unsigned n)
--
2.0.0.406.ge74f8ff
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