Add thrift_file_transport, useful for reading from files dumped by thrift_disk_log_tr...

Test plan: using this in a local tool in reader mode, and works fine. Haven't tested write mode, sorry

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@666471 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/lib/alterl/src/thrift_file_transport.erl b/lib/alterl/src/thrift_file_transport.erl
new file mode 100644 (file)
index 0000000..99255ee
--- /dev/null
+++ b/lib/alterl/src/thrift_file_transport.erl
@@ -0,0 +1,69 @@
+-module(thrift_file_transport).
+-author(todd@amiestreet.com).
+
+-behaviour(thrift_transport).
+
+-export([new_reader/1,
+         new/1,
+         new/2,
+         write/2, read/2, flush/1, close/1]).
+
+-record(t_file_transport, {device,
+                           should_close = true,
+                           mode = write}).
+
+%%%% CONSTRUCTION   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+new_reader(Filename) ->
+    case file:open(Filename, [read, binary, {read_ahead, 1024*1024}]) of
+        {ok, IODevice} ->
+            new(IODevice, [{should_close, true}, {mode, read}]);
+        Error -> Error
+    end.
+
+new(Device) ->
+    new(Device, []).
+
+%% Device :: io_device()
+%%
+%% Device should be opened in raw and binary mode.
+new(Device, Opts) when is_list(Opts) ->
+    State = parse_opts(Opts, #t_file_transport{device = Device}),
+    thrift_transport:new(?MODULE, State).
+
+
+%% Parse options
+parse_opts([{should_close, Bool} | Rest], State) when is_boolean(Bool) ->
+    parse_opts(Rest, State#t_file_transport{should_close = Bool});
+parse_opts([{mode, Mode} | Rest], State)
+  when Mode =:= write;
+       Mode =:= read ->
+    parse_opts(Rest, State#t_file_transport{mode = Mode});
+parse_opts([], State) ->
+     State.
+
+
+%%%% TRANSPORT IMPL %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+write(#t_file_transport{device = Device, mode = write}, Data) ->
+    file:write(Device, Data);
+write(_T, _D) ->
+    {error, read_mode}.
+
+
+read(#t_file_transport{device = Device, mode = read}, Len)
+  when is_integer(Len), Len >= 0 ->
+    file:read(Device, Len);
+read(_T, _D) ->
+    {error, read_mode}.
+
+flush(#t_file_transport{device = Device, mode = write}) ->
+    file:sync(Device).
+
+close(#t_file_transport{device = Device, should_close = SC}) ->
+    case SC of
+        true ->
+            file:close(Device);
+        false ->
+            ok
+    end.