Optimize read_application_data with Okasaki queue

To avoid degenerate case with quadratic complexity that
shows up when sending large messages since the the fragment
concatenation was done by binary append.  An Okasaki queue
is much more efficient.

1 files changed, 5 insertions, 5 deletions

diff --git a/lib/ssl/src/tls_connection.erl b/lib/ssl/src/tls_connection.erl
index 35bd23a894..8d125b8a70 100644
--- a/lib/ssl/src/tls_connection.erl
+++ b/lib/ssl/src/tls_connection.erl
@@ -815,7 +815,7 @@ initial_state(Role, Sender, Host, Port, Socket, {SSLOptions, SocketOptions, Trac
        session = #session{is_resumable = new},
        connection_states = ConnectionStates,
        protocol_buffers = #protocol_buffers{},
-       user_data_buffer = <<>>,
+       user_data_buffer = {[],0,[]},
        start_or_recv_from = undefined,
        flight_buffer = [],
        protocol_specific = #{sender => Sender,
@@ -898,7 +898,7 @@ handle_info({CloseTag, Socket}, StateName,
                    connection_env = #connection_env{negotiated_version = Version},
                    socket_options = #socket_options{active = Active},
                    protocol_buffers = #protocol_buffers{tls_cipher_texts = CTs},
-                   user_data_buffer = Buffer,
+                   user_data_buffer = {_,BufferSize,_},
                    protocol_specific = PS} = State) ->
 
     %% Note that as of TLS 1.1,
@@ -906,7 +906,7 @@ handle_info({CloseTag, Socket}, StateName,
     %% session not be resumed.  This is a change from TLS 1.0 to conform
     %% with widespread implementation practice.
 
-    case (Active == false) andalso ((CTs =/= []) or (Buffer =/= <<>>)) of
+    case (Active == false) andalso ((CTs =/= []) or (BufferSize =/= 0)) of
         false ->
             case Version of
                 {1, N} when N >= 1 ->
@@ -941,9 +941,9 @@ handle_alerts(_, {stop, _, _} = Stop) ->
 handle_alerts([#alert{level = ?WARNING, description = ?CLOSE_NOTIFY} | _Alerts], 
               {next_state, connection = StateName, #state{connection_env = CEnv, 
                                                           socket_options = #socket_options{active = false},
-                                                          user_data_buffer = Buffer,
+                                                          user_data_buffer = {_,BufferSize,_},
                                                           protocol_buffers = #protocol_buffers{tls_cipher_texts = CTs}} = 
-                   State}) when (Buffer =/= <<>>) orelse
+                   State}) when (BufferSize =/= 0) orelse
                                 (CTs =/= []) -> 
     {next_state, StateName, State#state{connection_env = CEnv#connection_env{terminated = true}}};
 handle_alerts([Alert | Alerts], {next_state, StateName, State}) ->