From 3131977de1476185209d4d56a0494f5b30ee5557 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Thu, 24 Sep 2015 17:05:57 -0400 Subject: [PATCH] progress: store throughput display in a strbuf 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 Signed-off-by: Junio C Hamano --- progress.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/progress.c b/progress.c index 2e31bec60..a3efcfd34 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); }