[PATCH 1/2] progress: create public humanize() to show sizes

[Antoine Pelisse <apelisse@gmail.com>]

Currently, humanization of downloaded size is done in the same function
as text formatting. This is an issue if anyone else wants to use this.

Separate text formatting from size simplification and make the function
public so that it can easily be used by other clients.

We now can use humanize() for both downloaded size and download speed
calculation. One of the drawbacks is that speed will no look like this
when download is stalled: "0 bytes/s" instead of "0 KiB/s".

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
---
 progress.c |   60 ++++++++++++++++++++++++++++++++++--------------------------
 progress.h |    2 ++
 2 files changed, 36 insertions(+), 26 deletions(-)

diff --git a/progress.c b/progress.c
index 3971f49..76c1e42 100644
--- a/progress.c
+++ b/progress.c
@@ -8,8 +8,11 @@
  * published by the Free Software Foundation.
  */
 
+#include <string.h>
+
 #include "git-compat-util.h"
 #include "progress.h"
+#include "strbuf.h"
 
 #define TP_IDX_MAX      8
 
@@ -112,34 +115,33 @@ static int display(struct progress *progress, unsigned n, const char *done)
 	return 0;
 }
 
-static void throughput_string(struct throughput *tp, off_t total,
-			      unsigned int rate)
+void humanize(struct strbuf *buf, off_t bytes)
 {
-	int l = sizeof(tp->display);
-	if (total > 1 << 30) {
-		l -= snprintf(tp->display, l, ", %u.%2.2u GiB",
-			      (int)(total >> 30),
-			      (int)(total & ((1 << 30) - 1)) / 10737419);
-	} else if (total > 1 << 20) {
-		int x = total + 5243;  /* for rounding */
-		l -= snprintf(tp->display, l, ", %u.%2.2u MiB",
-			      x >> 20, ((x & ((1 << 20) - 1)) * 100) >> 20);
-	} else if (total > 1 << 10) {
-		int x = total + 5;  /* for rounding */
-		l -= snprintf(tp->display, l, ", %u.%2.2u KiB",
-			      x >> 10, ((x & ((1 << 10) - 1)) * 100) >> 10);
+	if (bytes > 1 << 30) {
+		strbuf_addf(buf, "%u.%2.2u GiB",
+			    (int)(bytes >> 30),
+			    (int)(bytes & ((1 << 30) - 1)) / 10737419);
+	} else if (bytes > 1 << 20) {
+		int x = bytes + 5243;  /* for rounding */
+		strbuf_addf(buf, "%u.%2.2u MiB",
+			    x >> 20, ((x & ((1 << 20) - 1)) * 100) >> 20);
+	} else if (bytes > 1 << 10) {
+		int x = bytes + 5;  /* for rounding */
+		strbuf_addf(buf, "%u.%2.2u KiB",
+			    x >> 10, ((x & ((1 << 10) - 1)) * 100) >> 10);
 	} else {
-		l -= snprintf(tp->display, l, ", %u bytes", (int)total);
+		strbuf_addf(buf, "%u bytes", (int)bytes);
 	}
+}
 
-	if (rate > 1 << 10) {
-		int x = rate + 5;  /* for rounding */
-		snprintf(tp->display + sizeof(tp->display) - l, l,
-			 " | %u.%2.2u MiB/s",
-			 x >> 10, ((x & ((1 << 10) - 1)) * 100) >> 10);
-	} else if (rate)
-		snprintf(tp->display + sizeof(tp->display) - l, l,
-			 " | %u KiB/s", rate);
+static void throughput_string(struct strbuf *buf, off_t total,
+			      unsigned int rate)
+{
+	strbuf_addstr(buf, ", ");
+	humanize(buf, total);
+	strbuf_addstr(buf, " | ");
+	humanize(buf, rate * 1024);
+	strbuf_addstr(buf, "/s");
 }
 
 void display_throughput(struct progress *progress, off_t total)
@@ -183,6 +185,7 @@ void display_throughput(struct progress *progress, off_t total)
 	misecs += (int)(tv.tv_usec - tp->prev_tv.tv_usec) / 977;
 
 	if (misecs > 512) {
+		struct strbuf buf = STRBUF_INIT;
 		unsigned int count, rate;
 
 		count = total - tp->prev_total;
@@ -197,7 +200,9 @@ void display_throughput(struct progress *progress, off_t total)
 		tp->last_misecs[tp->idx] = misecs;
 		tp->idx = (tp->idx + 1) % TP_IDX_MAX;
 
-		throughput_string(tp, total, rate);
+		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);
 	}
@@ -253,9 +258,12 @@ void stop_progress_msg(struct progress **p_progress, const char *msg)
 
 		bufp = (len < sizeof(buf)) ? buf : xmalloc(len + 1);
 		if (tp) {
+			struct strbuf strbuf = STRBUF_INIT;
 			unsigned int rate = !tp->avg_misecs ? 0 :
 					tp->avg_bytes / tp->avg_misecs;
-			throughput_string(tp, tp->curr_total, rate);
+			throughput_string(&strbuf, tp->curr_total, rate);
+			strncpy(tp->display, strbuf.buf, sizeof(tp->display));
+			strbuf_release(&strbuf);
 		}
 		progress_update = 1;
 		sprintf(bufp, ", %s.\n", msg);
diff --git a/progress.h b/progress.h
index 611e4c4..0e70f55 100644
--- a/progress.h
+++ b/progress.h
@@ -2,7 +2,9 @@
 #define PROGRESS_H
 
 struct progress;
+struct strbuf;
 
+void humanize(struct strbuf *buf, off_t bytes);
 void display_throughput(struct progress *progress, off_t total);
 int display_progress(struct progress *progress, unsigned n);
 struct progress *start_progress(const char *title, unsigned total);
-- 
1.7.9.5