Coverity noticed that we strncpy() into a fixed-size buffer
without making sure that it actually ended up
NUL-terminated. This is unlikely to be a bug in practice,
since throughput strings rarely hit 32 characters, but it
would be nice to clean it up.
The most obvious way to do so is to add a NUL-terminator.
But instead, this patch switches the fixed-size buffer out
for a strbuf. At first glance this seems much less
efficient, until we realize that filling in the fixed-size
buffer is done by writing into a strbuf and copying the
result!
By writing straight to the buffer, we actually end up more
efficient:
1. We avoid an extra copy of the bytes.
2. Rather than malloc/free each time progress is shown, we
can strbuf_reset and use the same buffer each time.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
I actually sent this one to the list in June:
http://thread.gmane.org/gmane.comp.version-control.git/271880
but it got overlooked. Good luck overlooking this 67-patch
monstrosity. :)
progress.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)
diff --git a/progress.c b/progress.c
index 2e31bec..a3efcfd 100644
--- a/progress.c
+++ b/progress.c
@@ -25,7 +25,7 @@ struct throughput {
unsigned int last_bytes[TP_IDX_MAX];
unsigned int last_misecs[TP_IDX_MAX];
unsigned int idx;
- char display[32];
+ struct strbuf display;
};
struct progress {
@@ -98,7 +98,7 @@ static int display(struct progress *progress, unsigned n, const char *done)
}
progress->last_value = n;
- tp = (progress->throughput) ? progress->throughput->display : "";
+ tp = (progress->throughput) ? progress->throughput->display.buf : "";
eol = done ? done : " \r";
if (progress->total) {
unsigned percent = n * 100 / progress->total;
@@ -129,6 +129,7 @@ static int display(struct progress *progress, unsigned n, const char *done)
static void throughput_string(struct strbuf *buf, off_t total,
unsigned int rate)
{
+ strbuf_reset(buf);
strbuf_addstr(buf, ", ");
strbuf_humanise_bytes(buf, total);
strbuf_addstr(buf, " | ");
@@ -141,7 +142,6 @@ void display_throughput(struct progress *progress, off_t total)
struct throughput *tp;
uint64_t now_ns;
unsigned int misecs, count, rate;
- struct strbuf buf = STRBUF_INIT;
if (!progress)
return;
@@ -154,6 +154,7 @@ void display_throughput(struct progress *progress, off_t total)
if (tp) {
tp->prev_total = tp->curr_total = total;
tp->prev_ns = now_ns;
+ strbuf_init(&tp->display, 0);
}
return;
}
@@ -193,9 +194,7 @@ 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(&buf, total, rate);
- strncpy(tp->display, buf.buf, sizeof(tp->display));
- strbuf_release(&buf);
+ throughput_string(&tp->display, total, rate);
if (progress->last_value != -1 && progress_update)
display(progress, progress->last_value, NULL);
}
@@ -250,12 +249,9 @@ 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(&strbuf, tp->curr_total, rate);
- strncpy(tp->display, strbuf.buf, sizeof(tp->display));
- strbuf_release(&strbuf);
+ throughput_string(&tp->display, tp->curr_total, rate);
}
progress_update = 1;
sprintf(bufp, ", %s.\n", msg);
@@ -264,6 +260,8 @@ void stop_progress_msg(struct progress **p_progress, const char *msg)
free(bufp);
}
clear_progress_signal();
+ if (progress->throughput)
+ strbuf_release(&progress->throughput->display);
free(progress->throughput);
free(progress);
}
--
2.6.0.rc2.408.ga2926b9
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