1 files changed, 110 insertions, 0 deletions
diff --git a/progress.c b/progress.c
new file mode 100644
index 0000000..4344f4e
--- /dev/null
+++ b/progress.c
@@ -0,0 +1,110 @@
+#include "git-compat-util.h"
+#include "progress.h"
+
+static volatile sig_atomic_t progress_update;
+
+static void progress_interval(int signum)
+{
+	progress_update = 1;
+}
+
+static void set_progress_signal(void)
+{
+	struct sigaction sa;
+	struct itimerval v;
+
+	progress_update = 0;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_handler = progress_interval;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_RESTART;
+	sigaction(SIGALRM, &sa, NULL);
+
+	v.it_interval.tv_sec = 1;
+	v.it_interval.tv_usec = 0;
+	v.it_value = v.it_interval;
+	setitimer(ITIMER_REAL, &v, NULL);
+}
+
+static void clear_progress_signal(void)
+{
+	struct itimerval v = {{0,},};
+	setitimer(ITIMER_REAL, &v, NULL);
+	signal(SIGALRM, SIG_IGN);
+	progress_update = 0;
+}
+
+int display_progress(struct progress *progress, unsigned n)
+{
+	if (progress->delay) {
+		char buf[80];
+		if (!progress_update || --progress->delay)
+			return 0;
+		if (progress->total) {
+			unsigned percent = n * 100 / progress->total;
+			if (percent > progress->delayed_percent_treshold) {
+				/* inhibit this progress report entirely */
+				clear_progress_signal();
+				progress->delay = -1;
+				progress->total = 0;
+				return 0;
+			}
+		}
+		if (snprintf(buf, sizeof(buf),
+			     progress->delayed_title, progress->total))
+			fprintf(stderr, "%s\n", buf);
+	}
+	if (progress->total) {
+		unsigned percent = n * 100 / progress->total;
+		if (percent != progress->last_percent || progress_update) {
+			progress->last_percent = percent;
+			fprintf(stderr, "%s%4u%% (%u/%u) done\r",
+				progress->prefix, percent, n, progress->total);
+			progress_update = 0;
+			progress->need_lf = 1;
+			return 1;
+		}
+	} else if (progress_update) {
+		fprintf(stderr, "%s%u\r", progress->prefix, n);
+		progress_update = 0;
+		progress->need_lf = 1;
+		return 1;
+	}
+	return 0;
+}
+
+void start_progress(struct progress *progress, const char *title,
+		    const char *prefix, unsigned total)
+{
+	char buf[80];
+	progress->prefix = prefix;
+	progress->total = total;
+	progress->last_percent = -1;
+	progress->delay = 0;
+	progress->need_lf = 0;
+	if (snprintf(buf, sizeof(buf), title, total))
+		fprintf(stderr, "%s\n", buf);
+	set_progress_signal();
+}
+
+void start_progress_delay(struct progress *progress, const char *title,
+			  const char *prefix, unsigned total,
+			  unsigned percent_treshold, unsigned delay)
+{
+	progress->prefix = prefix;
+	progress->total = total;
+	progress->last_percent = -1;
+	progress->delayed_percent_treshold = percent_treshold;
+	progress->delayed_title = title;
+	progress->delay = delay;
+	progress->need_lf = 0;
+	set_progress_signal();
+}
+
+void stop_progress(struct progress *progress)
+{
+	clear_progress_signal();
+	if (progress->need_lf)
+		fputc('\n', stderr);
+}