Merge branch 'jh/builtin-fsmonitor-part3'

More fsmonitor--daemon.

* jh/builtin-fsmonitor-part3: (30 commits)
  t7527: improve implicit shutdown testing in fsmonitor--daemon
  fsmonitor--daemon: allow --super-prefix argument
  t7527: test Unicode NFC/NFD handling on MacOS
  t/lib-unicode-nfc-nfd: helper prereqs for testing unicode nfc/nfd
  t/helper/hexdump: add helper to print hexdump of stdin
  fsmonitor: on macOS also emit NFC spelling for NFD pathname
  t7527: test FSMonitor on case insensitive+preserving file system
  fsmonitor: never set CE_FSMONITOR_VALID on submodules
  t/perf/p7527: add perf test for builtin FSMonitor
  t7527: FSMonitor tests for directory moves
  fsmonitor: optimize processing of directory events
  fsm-listen-darwin: shutdown daemon if worktree root is moved/renamed
  fsm-health-win32: force shutdown daemon if worktree root moves
  fsm-health-win32: add polling framework to monitor daemon health
  fsmonitor--daemon: stub in health thread
  fsmonitor--daemon: rename listener thread related variables
  fsmonitor--daemon: prepare for adding health thread
  fsmonitor--daemon: cd out of worktree root
  fsm-listen-darwin: ignore FSEvents caused by xattr changes on macOS
  unpack-trees: initialize fsmonitor_has_run_once in o->result
  ...

1 files changed, 147 insertions, 20 deletions

diff --git a/fsmonitor-settings.c b/fsmonitor-settings.c
index 757d230d53..658cb79da0 100644
--- a/fsmonitor-settings.c
+++ b/fsmonitor-settings.c
@@ -9,23 +9,52 @@
  */
 struct fsmonitor_settings {
 	enum fsmonitor_mode mode;
+	enum fsmonitor_reason reason;
 	char *hook_path;
 };
 
-static void lookup_fsmonitor_settings(struct repository *r)
+static enum fsmonitor_reason check_for_incompatible(struct repository *r)
+{
+	if (!r->worktree) {
+		/*
+		 * Bare repositories don't have a working directory and
+		 * therefore have nothing to watch.
+		 */
+		return FSMONITOR_REASON_BARE;
+	}
+
+#ifdef HAVE_FSMONITOR_OS_SETTINGS
+	{
+		enum fsmonitor_reason reason;
+
+		reason = fsm_os__incompatible(r);
+		if (reason != FSMONITOR_REASON_OK)
+			return reason;
+	}
+#endif
+
+	return FSMONITOR_REASON_OK;
+}
+
+static struct fsmonitor_settings *alloc_settings(void)
 {
 	struct fsmonitor_settings *s;
+
+	CALLOC_ARRAY(s, 1);
+	s->mode = FSMONITOR_MODE_DISABLED;
+	s->reason = FSMONITOR_REASON_UNTESTED;
+
+	return s;
+}
+
+static void lookup_fsmonitor_settings(struct repository *r)
+{
 	const char *const_str;
 	int bool_value;
 
 	if (r->settings.fsmonitor)
 		return;
 
-	CALLOC_ARRAY(s, 1);
-	s->mode = FSMONITOR_MODE_DISABLED;
-
-	r->settings.fsmonitor = s;
-
 	/*
 	 * Overload the existing "core.fsmonitor" config setting (which
 	 * has historically been either unset or a hook pathname) to
@@ -38,6 +67,8 @@ static void lookup_fsmonitor_settings(struct repository *r)
 	case 0: /* config value was set to <bool> */
 		if (bool_value)
 			fsm_settings__set_ipc(r);
+		else
+			fsm_settings__set_disabled(r);
 		return;
 
 	case 1: /* config value was unset */
@@ -53,18 +84,18 @@ static void lookup_fsmonitor_settings(struct repository *r)
 		return;
 	}
 
-	if (!const_str || !*const_str)
-		return;
-
-	fsm_settings__set_hook(r, const_str);
+	if (const_str && *const_str)
+		fsm_settings__set_hook(r, const_str);
+	else
+		fsm_settings__set_disabled(r);
 }
 
 enum fsmonitor_mode fsm_settings__get_mode(struct repository *r)
 {
 	if (!r)
 		r = the_repository;
-
-	lookup_fsmonitor_settings(r);
+	if (!r->settings.fsmonitor)
+		lookup_fsmonitor_settings(r);
 
 	return r->settings.fsmonitor->mode;
 }
@@ -73,31 +104,55 @@ const char *fsm_settings__get_hook_path(struct repository *r)
 {
 	if (!r)
 		r = the_repository;
-
-	lookup_fsmonitor_settings(r);
+	if (!r->settings.fsmonitor)
+		lookup_fsmonitor_settings(r);
 
 	return r->settings.fsmonitor->hook_path;
 }
 
 void fsm_settings__set_ipc(struct repository *r)
 {
+	enum fsmonitor_reason reason = check_for_incompatible(r);
+
+	if (reason != FSMONITOR_REASON_OK) {
+		fsm_settings__set_incompatible(r, reason);
+		return;
+	}
+
+	/*
+	 * Caller requested IPC explicitly, so avoid (possibly
+	 * recursive) config lookup.
+	 */
 	if (!r)
 		r = the_repository;
-
-	lookup_fsmonitor_settings(r);
+	if (!r->settings.fsmonitor)
+		r->settings.fsmonitor = alloc_settings();
 
 	r->settings.fsmonitor->mode = FSMONITOR_MODE_IPC;
+	r->settings.fsmonitor->reason = reason;
 	FREE_AND_NULL(r->settings.fsmonitor->hook_path);
 }
 
 void fsm_settings__set_hook(struct repository *r, const char *path)
 {
+	enum fsmonitor_reason reason = check_for_incompatible(r);
+
+	if (reason != FSMONITOR_REASON_OK) {
+		fsm_settings__set_incompatible(r, reason);
+		return;
+	}
+
+	/*
+	 * Caller requested hook explicitly, so avoid (possibly
+	 * recursive) config lookup.
+	 */
 	if (!r)
 		r = the_repository;
-
-	lookup_fsmonitor_settings(r);
+	if (!r->settings.fsmonitor)
+		r->settings.fsmonitor = alloc_settings();
 
 	r->settings.fsmonitor->mode = FSMONITOR_MODE_HOOK;
+	r->settings.fsmonitor->reason = reason;
 	FREE_AND_NULL(r->settings.fsmonitor->hook_path);
 	r->settings.fsmonitor->hook_path = strdup(path);
 }
@@ -106,9 +161,81 @@ void fsm_settings__set_disabled(struct repository *r)
 {
 	if (!r)
 		r = the_repository;
-
-	lookup_fsmonitor_settings(r);
+	if (!r->settings.fsmonitor)
+		r->settings.fsmonitor = alloc_settings();
 
 	r->settings.fsmonitor->mode = FSMONITOR_MODE_DISABLED;
+	r->settings.fsmonitor->reason = FSMONITOR_REASON_OK;
 	FREE_AND_NULL(r->settings.fsmonitor->hook_path);
 }
+
+void fsm_settings__set_incompatible(struct repository *r,
+				    enum fsmonitor_reason reason)
+{
+	if (!r)
+		r = the_repository;
+	if (!r->settings.fsmonitor)
+		r->settings.fsmonitor = alloc_settings();
+
+	r->settings.fsmonitor->mode = FSMONITOR_MODE_INCOMPATIBLE;
+	r->settings.fsmonitor->reason = reason;
+	FREE_AND_NULL(r->settings.fsmonitor->hook_path);
+}
+
+enum fsmonitor_reason fsm_settings__get_reason(struct repository *r)
+{
+	if (!r)
+		r = the_repository;
+	if (!r->settings.fsmonitor)
+		lookup_fsmonitor_settings(r);
+
+	return r->settings.fsmonitor->reason;
+}
+
+char *fsm_settings__get_incompatible_msg(const struct repository *r,
+					 enum fsmonitor_reason reason)
+{
+	struct strbuf msg = STRBUF_INIT;
+
+	switch (reason) {
+	case FSMONITOR_REASON_UNTESTED:
+	case FSMONITOR_REASON_OK:
+		goto done;
+
+	case FSMONITOR_REASON_BARE:
+		strbuf_addf(&msg,
+			    _("bare repository '%s' is incompatible with fsmonitor"),
+			    xgetcwd());
+		goto done;
+
+	case FSMONITOR_REASON_ERROR:
+		strbuf_addf(&msg,
+			    _("repository '%s' is incompatible with fsmonitor due to errors"),
+			    r->worktree);
+		goto done;
+
+	case FSMONITOR_REASON_REMOTE:
+		strbuf_addf(&msg,
+			    _("remote repository '%s' is incompatible with fsmonitor"),
+			    r->worktree);
+		goto done;
+
+	case FSMONITOR_REASON_VFS4GIT:
+		strbuf_addf(&msg,
+			    _("virtual repository '%s' is incompatible with fsmonitor"),
+			    r->worktree);
+		goto done;
+
+	case FSMONITOR_REASON_NOSOCKETS:
+		strbuf_addf(&msg,
+			    _("repository '%s' is incompatible with fsmonitor due to lack of Unix sockets"),
+			    r->worktree);
+		goto done;
+	}
+
+	BUG("Unhandled case in fsm_settings__get_incompatible_msg: '%d'",
+	    reason);
+
+done:
+	return strbuf_detach(&msg, NULL);
+}