res_pjsip/pjsip_options: Add StatsD statistics for PJSIP contacts

This patch adds the ability to send StatsD statistics related to the
state of PJSIP contacts. This includes:
 * A GUAGE statistic measuring the count of contacts in a particular state.
   This measures how many contacts are reachable, unreachable, etc.
 * The RTT time for each contact, if those contacts are qualified. This
   provides StatsD engines useful time-based data about each contact.

ASTERISK-25571

Change-Id: Ib8378d73afedfc622be0643b87c542557e0b332c

CHANGES

@@ -233,6 +233,14 @@ res_pjsip
  * The ability to use "like" has been added to the pjsip list and show
    CLI commands.  For instance: CLI> pjsip list endpoints like abc
 
+ * If res_statsd is loaded and a StatsD server is configured, basic statistics
+   regarding the state of PJSIP contacts will not be emitted. This includes:
+   - A GUAGE statistic for the overall number of contacts in a particular
+     state, e.g.:
+       PJSIP.contacts.states.Reachable
+   - A TIMER statistic for the RTT time for each qualified contact, e.g.:
+       PJSIP.contacts.alice@@127.0.0.1:5061.rtt
+
 func_callerid
 -------------------
  * CALLERID(pres) is now documented as a valid alternative to setting both

res/res_pjsip/location.c

@@ -26,6 +26,7 @@
 #include "asterisk/sorcery.h"
 #include "include/res_pjsip_private.h"
 #include "asterisk/res_pjsip_cli.h"
+#include "asterisk/statsd.h"
 
 /*! \brief Destructor for AOR */
 static void aor_destroy(void *obj)
@@ -940,6 +941,8 @@ static int contact_apply_handler(const struct ast_sorcery *sorcery, void *object
 int ast_sip_initialize_sorcery_location(void)
 {
 	struct ast_sorcery *sorcery = ast_sip_get_sorcery();
+	int i;
+
 	ast_sorcery_apply_default(sorcery, "contact", "astdb", "registrar");
 	ast_sorcery_apply_default(sorcery, "aor", "config", "pjsip.conf,criteria=type=aor");
 
@@ -1006,6 +1009,15 @@ int ast_sip_initialize_sorcery_location(void)
 	ast_sip_register_cli_formatter(aor_formatter);
 	ast_cli_register_multiple(cli_commands, ARRAY_LEN(cli_commands));
 
+	/*
+	 * Reset StatsD gauges in case we didn't shut down cleanly.
+	 * Note that this must done here, as contacts will create the contact_status
+	 * object before PJSIP options handling is initialized.
+	 */
+	for (i = 0; i < REMOVED; i++) {
+		ast_statsd_log_full_va("PJSIP.contacts.states.%s", AST_STATSD_GUAGE, 0, 1.0, ast_sip_get_contact_status_label(i));
+	}
+
 	return 0;
 }
 

res/res_pjsip/pjsip_options.c

@@ -29,6 +29,7 @@
 #include "asterisk/cli.h"
 #include "asterisk/time.h"
 #include "asterisk/test.h"
+#include "asterisk/statsd.h"
 #include "include/res_pjsip_private.h"
 
 #define DEFAULT_LANGUAGE "en"
@@ -113,6 +114,9 @@ struct ast_sip_contact_status *ast_res_pjsip_find_or_create_contact_status(const
 		return NULL;
 	}
 
+	ast_statsd_log_string_va("PJSIP.contacts.states.%s", AST_STATSD_GUAGE,
+		"+1", 1.0, ast_sip_get_contact_status_label(status->status));
+
 	return status;
 }
 
@@ -143,6 +147,12 @@ static void update_contact_status(const struct ast_sip_contact *contact,
 
 	update->last_status = status->status;
 	update->status = value;
+	if (update->last_status != update->status) {
+		ast_statsd_log_string_va("PJSIP.contacts.states.%s", AST_STATSD_GUAGE,
+			"-1", 1.0, ast_sip_get_contact_status_label(update->last_status));
+		ast_statsd_log_string_va("PJSIP.contacts.states.%s", AST_STATSD_GUAGE,
+			"+1", 1.0, ast_sip_get_contact_status_label(update->status));
+	}
 
 	/* if the contact is available calculate the rtt as
 	   the diff between the last start time and "now" */
@@ -151,10 +161,12 @@ static void update_contact_status(const struct ast_sip_contact *contact,
 
 	update->rtt_start = ast_tv(0, 0);
 
+	ast_statsd_log_full_va("PJSIP.contacts.%s.rtt", AST_STATSD_TIMER,
+		update->rtt / 1000, 1.0, ast_sorcery_object_get_id(update));
 	ast_test_suite_event_notify("AOR_CONTACT_QUALIFY_RESULT",
 		"Contact: %s\r\n"
-			"Status: %s\r\n"
-			"RTT: %" PRId64,
+		"Status: %s\r\n"
+		"RTT: %" PRId64,
 		ast_sorcery_object_get_id(update),
 		ast_sip_get_contact_status_label(update->status),
 		update->rtt);