Switch away from passing funs between nodes when uploading attachments

src/fabric/src/fabric.erl

@@ -277,7 +277,7 @@ purge_docs(_DbName, _IdsRevs) ->
         {unknown_transfer_encoding, any()}) ->
     function() | binary().
 att_receiver(Req, Length) ->
-    fabric_doc_attachments:receiver(Req, Length).
+    fabric_doc_attachments2:receiver_tuple(Req, Length).
 
 %% @equiv all_docs(DbName, [], Callback, Acc0, QueryArgs)
 all_docs(DbName, Callback, Acc, QueryArgs) ->

src/fabric/src/fabric_doc_attachments.erl

@@ -15,23 +15,34 @@
 -include_lib("fabric/include/fabric.hrl").
 -include_lib("couch/include/couch_db.hrl").
 
-%% couch api calls
--export([receiver/2]).
+-export([
+    receiver_tuple/2,
+    receiver_callback/2
+]).
 
-receiver(_Req, undefined) ->
+
+receiver_tuple(_Req, undefined) ->
     <<"">>;
-receiver(_Req, {unknown_transfer_encoding, Unknown}) ->
+receiver_tuple(_Req, {unknown_transfer_encoding, Unknown}) ->
     exit({unknown_transfer_encoding, Unknown});
-receiver(Req, chunked) ->
+receiver_tuple(Req, chunked) ->
     MiddleMan = spawn(fun() -> middleman(Req, chunked) end),
-    fun(4096, ChunkFun, State) ->
-        write_chunks(MiddleMan, ChunkFun, State)
-    end;
-receiver(_Req, 0) ->
+    {fabric_attachment_receiver, MiddleMan, chunked};
+receiver_tuple(_Req, 0) ->
     <<"">>;
-receiver(Req, Length) when is_integer(Length) ->
+receiver_tuple(Req, Length) when is_integer(Length) ->
     maybe_send_continue(Req),
     Middleman = spawn(fun() -> middleman(Req, Length) end),
+    {fabric_attachment_receiver, Middleman, Length};
+receiver_tuple(_Req, Length) ->
+    exit({length_not_integer, Length}).
+
+
+receiver_callback(Middleman, chunked) ->
+    fun(4096, ChunkFun, State) ->
+        write_chunks(Middleman, ChunkFun, State)
+    end;
+receiver_callback(Middleman, Length) when is_integer(Length) ->
     fun() ->
         Middleman ! {self(), gimme_data},
         Timeout = fabric_util:attachments_timeout(),
@@ -42,9 +53,8 @@ receiver(Req, Length) when is_integer(Length) ->
         after Timeout ->
             exit(timeout)
         end
-    end;
-receiver(_Req, Length) ->
-    exit({length_not_integer, Length}).
+    end.
+
 
 %%
 %% internal

src/fabric/src/fabric_rpc.erl

@@ -440,6 +440,8 @@ make_att_reader({follows, Parser, Ref}) ->
                 throw({mp_parser_died, Reason})
         end
     end;
+make_att_reader({fabric_attachment_receiver, Middleman, Length}) ->
+    fabric_doc_attachments2:receiver_callback(Middleman, Length);
 make_att_reader(Else) ->
     Else.