From bcfa241b278eedd5a5fcba7054f4ff07b7adc534 Mon Sep 17 00:00:00 2001
From: Roland Walker <walker@pobox.com>
Date: Wed, 16 Aug 2017 13:36:24 -0400
Subject: [PATCH] POC refresh display on filesystem change via entr

---
 src/display.c              | 17 +++++++++++++++++
 src/tig.c                  | 19 +++++++++++++++++++
 test/main/filter-args-test |  2 +-
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/src/display.c b/src/display.c
index 7179895e3..95aad05b6 100644
--- a/src/display.c
+++ b/src/display.c
@@ -701,6 +701,8 @@ get_input(int prompt_position, struct key *key)
 {
 	struct view *view;
 	int i, key_value, cursor_y, cursor_x;
+	static time_t last_winch = 0;
+	int winch_refresh_throttle = 1;
 
 	if (prompt_position > 0)
 		input_mode = true;
@@ -766,6 +768,21 @@ get_input(int prompt_position, struct key *key)
 
 		} else if (key_value == KEY_RESIZE) {
 			int height, width;
+			bool refs_refreshed = false;
+			time_t now = time(NULL);
+
+			if ((now - last_winch) >= winch_refresh_throttle) {
+				foreach_displayed_view (view, i) {
+					if (view_can_refresh(view)) {
+						if (!refs_refreshed) {
+							load_refs(true);
+							refs_refreshed = true;
+						}
+						refresh_view(view);
+					}
+				}
+			}
+			last_winch = now;
 
 			getmaxyx(stdscr, height, width);
 
diff --git a/src/tig.c b/src/tig.c
index 4ae62e207..fcaf5e9f7 100644
--- a/src/tig.c
+++ b/src/tig.c
@@ -714,6 +714,14 @@ die_if_failed(enum status_code code, const char *msg)
 		die("%s: %s", msg, get_status_message(code));
 }
 
+void
+hangup_children(void)
+{
+	if (signal(SIGHUP, SIG_IGN) == SIG_ERR)
+		return;
+	killpg(getpid(), SIGHUP);
+}
+
 int
 main(int argc, const char *argv[])
 {
@@ -722,6 +730,8 @@ main(int argc, const char *argv[])
 	enum request request = parse_options(argc, argv, pager_mode);
 	struct view *view;
 
+	atexit(hangup_children);
+
 	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
 		die("Failed to setup signal handler");
 
@@ -768,6 +778,15 @@ main(int argc, const char *argv[])
 		run_prompt_command(NULL, script_command);
 	}
 
+	if (repo.git_dir[0]) {
+		const char *watcher_argv[] = { "sh", "-c", NULL, NULL };
+		char cmd[SIZEOF_STR] = "";
+		int restart_interval = 30;  /* better would be 300 */
+		string_format(cmd, "(export TIG_PID=\"%d\"; export ENTR_RESTART_SEC=\"%d\"; test \"$TIG_PID\" -gt 0 || exit; which entr || exit; sleep 1; while true; do git ls-files \"$(git rev-parse --show-toplevel)\" | entr -d kill -WINCH \"$TIG_PID\" & export ENTR_PID=\"$!\"; (sleep \"$ENTR_RESTART_SEC\" && kill -INT \"$ENTR_PID\") & export RESTARTER_PID=\"$!\"; wait \"$ENTR_PID\"; kill -WINCH \"$TIG_PID\"; kill -HUP \"$RESTARTER_PID\"; sleep 1; kill -0 \"$TIG_PID\" || break; done) &", getpid(), restart_interval);
+		watcher_argv[2] = cmd;
+		io_run_bg(watcher_argv, repo.cdup);
+	}
+
 	while (view_driver(display[current_view], request)) {
 		view = display[current_view];
 		request = read_key_combo(view->keymap);
diff --git a/test/main/filter-args-test b/test/main/filter-args-test
index 784b754ad..f2031167c 100755
--- a/test/main/filter-args-test
+++ b/test/main/filter-args-test
@@ -27,7 +27,7 @@ steps '
 
 test_tig --exclude=refs/remotes/origin/* --exclude=refs/heads/master --all -- common tracer
 
-grep 'git rev-parse' < "$TIG_TRACE" > rev-parse.trace
+grep 'git rev-parse' < "$TIG_TRACE" | grep -v 'TIG_PID' > rev-parse.trace
 grep 'git log' < "$TIG_TRACE" > log.trace
 
 assert_equals 'rev-parse.trace' <<EOF