Add SslStream.pending()

openssl-sys/src/lib.rs

@@ -496,6 +496,7 @@ extern "C" {
     pub fn SSLv23_method() -> *const SSL_METHOD;
 
     pub fn SSL_new(ctx: *mut SSL_CTX) -> *mut SSL;
+    pub fn SSL_pending(ssl: *const SSL) -> c_int;
     pub fn SSL_free(ssl: *mut SSL);
     pub fn SSL_set_bio(ssl: *mut SSL, rbio: *mut BIO, wbio: *mut BIO);
     pub fn SSL_get_rbio(ssl: *mut SSL) -> *mut BIO;

openssl/src/ssl/mod.rs

@@ -707,6 +707,13 @@ impl Ssl {
             }
         }
     }
+
+    /// pending() takes into account only bytes from the TLS/SSL record that is currently being processed (if any).
+    pub fn pending(&self) -> usize {
+        unsafe {
+            ffi::SSL_pending(self.ssl) as usize
+        }
+    }
 }
 
 macro_rules! make_LibSslError {
@@ -882,6 +889,11 @@ impl<S: Read+Write> SslStream<S> {
     pub fn get_selected_npn_protocol(&self) -> Option<&[u8]> {
         self.ssl.get_selected_npn_protocol()
     }
+
+    /// pending() takes into account only bytes from the TLS/SSL record that is currently being processed (if any).
+    pub fn pending(&self) -> usize {
+        self.ssl.pending()
+    }
 }
 
 impl<S: Read+Write> Read for SslStream<S> {

openssl/src/ssl/tests.rs

@@ -337,6 +337,30 @@ fn test_read() {
     io::copy(&mut stream, &mut io::sink()).ok().expect("read error");
 }
 
+
+#[test]
+fn test_pending() {
+    let tcp = TcpStream::connect("127.0.0.1:15418").unwrap();
+    let mut stream = SslStream::new(&SslContext::new(Sslv23).unwrap(), tcp).unwrap();
+    stream.write_all("GET /\r\n\r\n".as_bytes()).unwrap();
+    stream.flush().unwrap();
+
+    // wait for the response and read first byte...
+    let mut buf = [0u8; 16*1024];
+    stream.read(&mut buf[..1]).unwrap();
+
+    let pending = stream.pending();
+    let len = stream.read(&mut buf[1..]).unwrap();
+
+    assert_eq!(pending, len);
+
+    stream.read(&mut buf[..1]).unwrap();
+
+    let pending = stream.pending();
+    let len = stream.read(&mut buf[1..]).unwrap();
+    assert_eq!(pending, len);
+} 
+
 /// Tests that connecting with the client using NPN, but the server not does not
 /// break the existing connection behavior.
 #[test]