drivers/main.{c,h}: introduce may_log_reconnect_trying() for drivers that retain custom logging of reconnection details for now [#3541]

Signed-off-by: Jim Klimov <jimklimov+nut@gmail.com>

Author: jimklimov

drivers/main.c

@@ -2214,6 +2214,25 @@ void setup_signals(void)
 }
 #endif /* !WIN32*/
 
+/* Return 1 if driver can now report custom reconnection start/progress details */
+int may_log_reconnect_trying(int throttle_hit) {
+	if (reconnect_count > 0) {
+		/* Accounting reconnections already, no care about throttling - be quiet */
+		if (!throttle_hit || reconnect_report_freq < 1)
+			return 0;
+
+		/* At that point in throttling where we may talk */
+		if ((reconnect_count % reconnect_report_freq) == 0)
+			return 1;
+
+		/* Throttling - be quiet */
+		return 0;
+	}
+
+	/* Not counting yet, would be a first report */
+	return 1;
+}
+
 /* Called by a driver to either enter/continue a reconnection loop
  * (trying=1), almost done (trying=2), or to end it (trying=0).
  * Return how many attempts remain before driver exits (-1 if it won't).

drivers/main.h

@@ -134,6 +134,17 @@ typedef enum reconnect_state {
  */
 int reconnect_trying(reconnect_state_t trying);
 
+/** Return 1 if driver can now report custom reconnection start/progress
+ *  details, with common information to be logged by reconnect_trying(),
+ *  otherwise 0. If `throttle_hit!=0`, check if `reconnect_report_freq>0`
+ *  and `reconnect_count%reconnect_report_freq == 0` to allow a progress
+ *  report to be logged.
+ *
+ *  This method should be called before reconnect_trying(RECONNECT_TRYING)
+ *  bumps the counters involved.
+ */
+int may_log_reconnect_trying(int throttle_hit);
+
 /* Several helpers for driver configuration reloading follow:
  * * testval_reloadable() checks if we are currently reloading (or initially
  *   loading) the configuration, and if strings oldval==newval or not,