Improve ast_agi_fdprintf() by using the ast_str() API.

* Use a thread local ast_str for building the string that will be written out
   to the console for debug, and to the FD for the AGI itself, instead of allocating
   a buffer on the heap every time the function is called.
 * Use the information contained within the ast_str to determine how many bytes
   need to be written instead of calling strlen().


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@77791 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_agi.c

@@ -115,14 +115,20 @@ enum agi_result {
 
 static agi_command *find_command(char *cmds[], int exact);
 
+AST_THREADSTORAGE(agi_buf);
+#define AGI_BUF_INITSIZE 256
+
 int ast_agi_fdprintf(int fd, char *fmt, ...)
 {
-	char *stuff;
 	int res = 0;
-
 	va_list ap;
+	struct ast_str *buf;
+
+	if (!(buf = ast_str_thread_get(&agi_buf, AGI_BUF_INITSIZE)))
+		return -1;
+
 	va_start(ap, fmt);
-	res = vasprintf(&stuff, fmt, ap);
+	res = ast_str_set_va(&buf, 0, fmt, ap);
 	va_end(ap);
 
 	if (res == -1) {
@@ -131,9 +137,9 @@ int ast_agi_fdprintf(int fd, char *fmt, ...)
 	}
 
 	if (agidebug)
-		ast_verbose("AGI Tx >> %s", stuff);
-	ast_carefulwrite(fd, stuff, strlen(stuff), 100);
-	ast_free(stuff);
+		ast_verbose("AGI Tx >> %s", buf->str);
+
+	ast_carefulwrite(fd, buf->str, buf->used, 100);
 
 	return res;
 }