ffi: add quiche_conn_dgram_recv_front_len()

Motivation:

It is useful to know the len of the datagram in the recv queue so we can allocate a buffer with the correct size. This is already possible in rust but wasn't exposed in the c layer.

Modifications:

Add quiche_conn_dgram_recv_front_len which expose this functionality in the c layer.

Result:

Be able to obtain the len of the first datagram in the recv queue.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/ffi.rs b/src/ffi.rs
index b2ae81de..f2e88574 100644
--- a/src/ffi.rs
+++ b/src/ffi.rs
@@ -790,6 +790,15 @@ pub extern fn quiche_conn_dgram_max_writable_len(conn: &Connection) -> ssize_t {
 }
 
 #[no_mangle]
+pub extern fn quiche_conn_dgram_recv_front_len(conn: &Connection) -> ssize_t {
+    match conn.dgram_recv_front_len() {
+        None => Error::Done.to_c(),
+
+        Some(v) => v as ssize_t,
+    }
+}
+
+#[no_mangle]
 pub extern fn quiche_conn_dgram_send(
     conn: &mut Connection, buf: *const u8, buf_len: size_t,
 ) -> ssize_t {