TT#184400 No autocommit+rollback if no active watchers kamailio patch

Backport from upstream presence module
c80cccd996

Change-Id: Ic1a4efb6f780dd1119a5f199a3e38e5c50018694

debian/patches/series

@@ -41,6 +41,7 @@ upstream/dialog-fix-ki_dlg_get_var-introduced-previously.patch
 upstream/dialog-dlg_get_var-assure-return-null-on-error.patch
 upstream/dialog-w_dlg_get_var-fix-incompatible-pointer.patch
 upstream/topos-skip-adding-contact-header-for-BYE-CANCEL-PRAC.patch
+upstream/presence-No-autocommit-rollback-if-no-active-watcher.patch
 ### relevant for upstream
 sipwise/core-fix-freeaddrinfo-coredump.patch
 sipwise/pua_dialoginfo-refresh_pubruri_avps_flag.patch

debian/patches/upstream/presence-No-autocommit-rollback-if-no-active-watcher.patch

@@ -0,0 +1,72 @@
+From c80cccd996dcc3b91d4f0f68a2de51104a16d1a5 Mon Sep 17 00:00:00 2001
+From: Alessio Garzi <agarzi@sipwise.com>
+Date: Thu, 7 Jul 2022 15:22:12 +0200
+Subject: [PATCH] presence: No autocommit+rollback if no active watchers
+
+-  In case the active_watcher query returns no elements there
+   is a weird situation where kamailio first runs the select for
+   active_watcher then rollbacks.
+   This can happen a lot of times for each second since function
+   process_dialogs() runs repeatedly.
+   For this reason trying to avoid the rollback can result
+   in a quite good performance boost.
+---
+ src/modules/presence/notify.c | 20 ++++++++++++--------
+ 1 file changed, 12 insertions(+), 8 deletions(-)
+
+diff --git a/src/modules/presence/notify.c b/src/modules/presence/notify.c
+index cf52c21c22..4980dc4b0a 100644
+--- a/src/modules/presence/notify.c
++++ b/src/modules/presence/notify.c
+@@ -2867,6 +2867,7 @@ int process_dialogs(int round, int presence_winfo)
+ 	str ev_sname, winfo = str_init("presence.winfo");
+ 	int now = (int)time(NULL);
+ 	int updated = 0;
++	int no_active_watchers = 0;
+ 	db_query_f query_fn = pa_dbf.query_lock ? pa_dbf.query_lock : pa_dbf.query;
+ 
+ 	query_cols[n_query_cols] = &str_updated_col;
+@@ -2900,13 +2901,6 @@ int process_dialogs(int round, int presence_winfo)
+ 		goto error;
+ 	}
+ 
+-	if(pa_dbf.start_transaction) {
+-		if(pa_dbf.start_transaction(pa_db, pres_db_table_lock) < 0) {
+-			LM_ERR("in start_transaction\n");
+-			goto error;
+-		}
+-	}
+-
+ 	/* Step 1: Find active_watchers that require notification */
+ 	if(query_fn(pa_db, query_cols, query_ops, query_vals, result_cols,
+ 			   n_query_cols, n_result_cols, 0, &dialog_list)
+@@ -2920,7 +2914,17 @@ int process_dialogs(int round, int presence_winfo)
+ 	}
+ 
+ 	if(dialog_list->n <= 0)
++	{
++		no_active_watchers = 1;
+ 		goto done;
++	}
++
++	if(pa_dbf.start_transaction) {
++		if(pa_dbf.start_transaction(pa_db, pres_db_table_lock) < 0) {
++			LM_ERR("in start_transaction\n");
++			goto error;
++		}
++	}
+ 
+ 	/* Step 2: Update the records so they are not notified again */
+ 	if(pa_dbf.update(pa_db, query_cols, query_ops, query_vals, update_cols,
+@@ -3164,7 +3168,7 @@ error:
+ 	if(dialog)
+ 		pa_dbf.free_result(pa_db, dialog);
+ 
+-	if(pa_dbf.abort_transaction) {
++	if(no_active_watchers == 0 && pa_dbf.abort_transaction) {
+ 		if(pa_dbf.abort_transaction(pa_db) < 0)
+ 			LM_ERR("in abort_transaction\n");
+ 	}
+-- 
+2.25.1
+