cdr.c: Set stringfields only if they are different.

The CDR performance gets worse the further it gets behind in processing
stasis messages.  One of the reasons is we were repeatedly setting string
fields to potentially the same string in base_process_party_a().  Setting
a string field involves allocating room for the new string out of a memory
pool which may have to allocate even more memory.

* Check to see if the string field is already set to the desired string.

ASTERISK-27335

Change-Id: I3ccb7e23f1488417e08cafe477755033eed65a7c

1 files changed, 18 insertions, 8 deletions

diff --git a/main/cdr.c b/main/cdr.c
index fc125f254..6a3365ea0 100644
--- a/main/cdr.c
+++ b/main/cdr.c
@@ -1378,8 +1378,12 @@ static int base_process_party_a(struct cdr_object *cdr, struct ast_channel_snaps
 	 */
 	if (!ast_test_flag(&snapshot->flags, AST_FLAG_SUBROUTINE_EXEC)
 		|| ast_test_flag(&snapshot->softhangup_flags, AST_SOFTHANGUP_HANGUP_EXEC)) {
-		ast_string_field_set(cdr, context, snapshot->context);
-		ast_string_field_set(cdr, exten, snapshot->exten);
+		if (strcmp(cdr->context, snapshot->context)) {
+			ast_string_field_set(cdr, context, snapshot->context);
+		}
+		if (strcmp(cdr->exten, snapshot->exten)) {
+			ast_string_field_set(cdr, exten, snapshot->exten);
+		}
 	}
 
 	cdr_object_swap_snapshot(&cdr->party_a, snapshot);
@@ -1389,11 +1393,15 @@ static int base_process_party_a(struct cdr_object *cdr, struct ast_channel_snaps
 	 * of "AppDialX". Prevent that, and any other application changes we might not want
 	 * here.
 	 */
-	if (!ast_strlen_zero(snapshot->appl)
-			&& (strncasecmp(snapshot->appl, "appdial", 7) || ast_strlen_zero(cdr->appl))
-			&& !ast_test_flag(&cdr->flags, AST_CDR_LOCK_APP)) {
-		ast_string_field_set(cdr, appl, snapshot->appl);
-		ast_string_field_set(cdr, data, snapshot->data);
+	if (!ast_test_flag(&cdr->flags, AST_CDR_LOCK_APP)
+		&& !ast_strlen_zero(snapshot->appl)
+		&& (strncasecmp(snapshot->appl, "appdial", 7) || ast_strlen_zero(cdr->appl))) {
+		if (strcmp(cdr->appl, snapshot->appl)) {
+			ast_string_field_set(cdr, appl, snapshot->appl);
+		}
+		if (strcmp(cdr->data, snapshot->data)) {
+			ast_string_field_set(cdr, data, snapshot->data);
+		}
 
 		/* Dial (app_dial) is a special case. Because pre-dial handlers, which
 		 * execute before the dial begins, will alter the application/data to
@@ -1405,7 +1413,9 @@ static int base_process_party_a(struct cdr_object *cdr, struct ast_channel_snaps
 		}
 	}
 
-	ast_string_field_set(cdr, linkedid, snapshot->linkedid);
+	if (strcmp(cdr->linkedid, snapshot->linkedid)) {
+		ast_string_field_set(cdr, linkedid, snapshot->linkedid);
+	}
 	cdr_object_check_party_a_answer(cdr);
 	cdr_object_check_party_a_hangup(cdr);