Introduce libseat_set_log_level

The default level is SILENT. log_init no longer takes an initial log
level (so that calls to libseat_set_log_level prior to log_init work
correctly).

common/log.c

@@ -12,7 +12,7 @@ const long NSEC_PER_SEC = 1000000000;
 
 static void log_stderr(enum libseat_log_level level, const char *fmt, va_list args);
 
-static enum libseat_log_level current_log_level;
+static enum libseat_log_level current_log_level = LIBSEAT_LOG_LEVEL_SILENT;
 static libseat_log_func current_log_handler = log_stderr;
 static struct timespec start_time = {-1, -1};
 static bool colored = false;
@@ -64,12 +64,11 @@ static void log_stderr(enum libseat_log_level level, const char *fmt, va_list ar
 	fprintf(stderr, "%s", postfix);
 }
 
-void log_init(enum libseat_log_level level) {
+void log_init(void) {
 	if (start_time.tv_sec >= 0) {
 		return;
 	}
 	clock_gettime(CLOCK_MONOTONIC, &start_time);
-	current_log_level = level;
 	colored = isatty(STDERR_FILENO);
 }
 
@@ -93,3 +92,7 @@ void libseat_set_log_handler(libseat_log_func handler) {
 	}
 	current_log_handler = handler;
 }
+
+void libseat_set_log_level(enum libseat_log_level level) {
+	current_log_level = level;
+}

include/libseat.h

@@ -160,4 +160,12 @@ typedef void (*libseat_log_func)(enum libseat_log_level level, const char *forma
  */
 void libseat_set_log_handler(libseat_log_func handler);
 
+/*
+ * Sets the libseat log level.
+ *
+ * Only log messages whose level is lower or equal than the current log level
+ * will be processed, others will be ignored.
+ */
+void libseat_set_log_level(enum libseat_log_level level);
+
 #endif

include/log.h

@@ -43,7 +43,7 @@
 #define log_debug(str)
 #endif
 
-void log_init(enum libseat_log_level level);
+void log_init(void);
 void _logf(enum libseat_log_level level, const char *fmt, ...) ATTRIB_PRINTF(2, 3);
 
 #endif

libseat/libseat.c

@@ -37,7 +37,7 @@ struct libseat *libseat_open_seat(struct libseat_seat_listener *listener, void *
 		return NULL;
 	}
 
-	log_init(LIBSEAT_LOG_LEVEL_SILENT);
+	log_init();
 
 	char *backend_type = getenv("LIBSEAT_BACKEND");
 	struct libseat *backend = NULL;

seatd/seatd.c

@@ -64,7 +64,8 @@ int main(int argc, char *argv[]) {
 			level = LIBSEAT_LOG_LEVEL_DEBUG;
 		}
 	}
-	log_init(level);
+	log_init();
+	libseat_set_log_level(level);
 
 	const char *usage = "Usage: seatd [options]\n"
 			    "\n"