Change supervision heirarchy to allow ports to support:

       1) Owner process dies - shut down connection cleanly.
       2) Port driver dies - restart port driver

1 files changed, 54 insertions, 0 deletions

diff --git a/src/mysqlerl_port.erl b/src/mysqlerl_port.erl
new file mode 100644
index 0000000..afcdbf8
--- /dev/null
+++ b/src/mysqlerl_port.erl
@@ -0,0 +1,54 @@
+-module(mysqlerl_port).
+-author('bjc@kublai.com').
+
+-include("mysqlerl_port.hrl").
+
+-behavior(gen_server).
+
+-export([start_link/1]).
+-export([init/1, terminate/2, code_change/3,
+         handle_call/3, handle_cast/2, handle_info/2]).
+
+-record(state, {ref}).
+-record(port_closed, {reason}).
+
+start_link(Cmd) ->
+    gen_server:start_link(?MODULE, [Cmd], []).
+
+init([Cmd]) ->
+    process_flag(trap_exit, true),
+    Ref = open_port({spawn, Cmd}, [{packet, 4}, binary]),
+    {ok, #state{ref = Ref}}.
+
+terminate(#port_closed{reason = Reason}, #state{ref = Ref}) ->
+    io:format("DEBUG: mysqlerl connection ~p shutting down (~p).~n",
+              [Ref, Reason]),
+    ok;
+terminate(Reason, State) ->
+    catch port_close(State#state.ref),
+    io:format("DEBUG: mysqlerl_port got terminate: ~p~n", [Reason]),
+    ok.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+handle_call(#req{request = Request}, _From, State) ->
+    {reply, make_request(State#state.ref, Request), State}.
+
+handle_cast(_Request, State) ->
+    {noreply, State}.
+
+handle_info({'EXIT', Ref, Reason}, #state{ref = Ref} = State) ->
+    io:format("DEBUG: Port ~p closed on ~p.~n", [Ref, State]),
+    {stop, #port_closed{reason = Reason}, State}.
+
+make_request(Ref, Req) ->
+    io:format("DEBUG: Sending request: ~p~n", [Req]),
+    port_command(Ref, term_to_binary(Req)),
+    receive
+        {Ref, {data, Res}} -> binary_to_term(Res);
+        Other ->
+            error_logger:warning_msg("Got unknown query response: ~p~n",
+                                     [Other]),
+            exit({badreply, Other})
+    end.