This commits the performance mods that give the priority processing engine in the pbx, a 25-30% speed boost. The two updates used, are, first, to merge the ast_exists_extension() and the ast_spawn_extension() where they are called sequentially in a loop in the code, into a slightly upgraded version of ast_spawn_extension(), with a few extra args; and, second, I modified the substitute_variables_helper_full, so it zeroes out the byte after the evaluated string instead of demanding you pre-zero the buffer; I also went thru the code and removed the code that zeroed this buffer before every call to the substitute_variables_helper_full. The first fix provides about a 9% speedup, and the second the rest. These figures come from the 'PIPS' benchmark I describe in blogs, conf. reports, etc.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@88166 65c4cc65-6c06-0410-ace0-fbb531ad65f3

cdr/cdr_sqlite3_custom.c

@@ -158,7 +158,7 @@ static int sqlite3_log(struct ast_cdr *cdr)
 
 	{ /* Make it obvious that only sql_cmd should be used outside of this block */
 		char *sql_tmp_cmd;
-		char sql_insert_cmd[2048] = "";
+		char sql_insert_cmd[2048];
 		sql_tmp_cmd = sqlite3_mprintf("INSERT INTO %q (%q) VALUES (%q)", table, columns, values);
 		dummy.cdr = cdr;
 		pbx_substitute_variables_helper(&dummy, sql_tmp_cmd, sql_insert_cmd, sizeof(sql_insert_cmd) - 1);