move query server to a design-doc based protocol, closes COUCHDB-589

git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@893249 13f79535-47bb-0310-9956-ffa450edef68

9 files changed, 590 insertions, 573 deletions

diff --git a/src/couchdb/couch_doc.erl b/src/couchdb/couch_doc.erl
index bdefb95c..ba5c7450 100644
--- a/src/couchdb/couch_doc.erl
+++ b/src/couchdb/couch_doc.erl
@@ -292,15 +292,13 @@ att_to_iolist(#att{data=DataFun, len=Len}) when is_function(DataFun)->
     lists:reverse(fold_streamed_data(DataFun, Len,
             fun(Data, Acc) -> [Data | Acc] end, [])).
 
-get_validate_doc_fun(#doc{body={Props}}) ->
-    Lang = proplists:get_value(<<"language">>, Props, <<"javascript">>),
+get_validate_doc_fun(#doc{body={Props}}=DDoc) ->
     case proplists:get_value(<<"validate_doc_update">>, Props) of
     undefined ->
         nil;
-    FunSrc ->
+    _Else ->
         fun(EditDoc, DiskDoc, Ctx) ->
-            couch_query_servers:validate_doc_update(
-                    Lang, FunSrc, EditDoc, DiskDoc, Ctx)
+            couch_query_servers:validate_doc_update(DDoc, EditDoc, DiskDoc, Ctx)
         end
     end.
 
diff --git a/src/couchdb/couch_httpd.erl b/src/couchdb/couch_httpd.erl
index a61b29fb..baa22d8f 100644
--- a/src/couchdb/couch_httpd.erl
+++ b/src/couchdb/couch_httpd.erl
@@ -51,7 +51,7 @@ start_link() ->
 
     DesignUrlHandlersList = lists:map(
         fun({UrlKey, SpecStr}) ->
-            {?l2b(UrlKey), make_arity_2_fun(SpecStr)}
+            {?l2b(UrlKey), make_arity_3_fun(SpecStr)}
         end, couch_config:get("httpd_design_handlers")),
 
     UrlHandlers = dict:from_list(UrlHandlersList),
@@ -110,6 +110,14 @@ make_arity_2_fun(SpecStr) ->
         fun(Arg1, Arg2) -> Mod:Fun(Arg1, Arg2) end
     end.
 
+make_arity_3_fun(SpecStr) ->
+    case couch_util:parse_term(SpecStr) of
+    {ok, {Mod, Fun, SpecArg}} ->
+        fun(Arg1, Arg2, Arg3) -> Mod:Fun(Arg1, Arg2, Arg3, SpecArg) end;
+    {ok, {Mod, Fun}} ->
+        fun(Arg1, Arg2, Arg3) -> Mod:Fun(Arg1, Arg2, Arg3) end
+    end.
+
 % SpecStr is "{my_module, my_fun}, {my_module2, my_fun2}"
 make_arity_1_fun_list(SpecStr) ->
     [make_arity_1_fun(FunSpecStr) || FunSpecStr <- re:split(SpecStr, "(?<=})\\s*,\\s*(?={)", [{return, list}])].
diff --git a/src/couchdb/couch_httpd_db.erl b/src/couchdb/couch_httpd_db.erl
index 8b955c88..bf24b712 100644
--- a/src/couchdb/couch_httpd_db.erl
+++ b/src/couchdb/couch_httpd_db.erl
@@ -16,7 +16,7 @@
 -export([handle_request/1, handle_compact_req/2, handle_design_req/2,
     db_req/2, couch_doc_open/4,handle_changes_req/2,
     update_doc_result_to_json/1, update_doc_result_to_json/2,
-    handle_design_info_req/2, handle_view_cleanup_req/2]).
+    handle_design_info_req/3, handle_view_cleanup_req/2]).
 
 -import(couch_httpd,
     [send_json/2,send_json/3,send_json/4,send_method_not_allowed/2,
@@ -232,26 +232,18 @@ make_filter_fun(Req, Db) ->
         end;
     [DName, FName] ->
         DesignId = <<"_design/", DName/binary>>,
-        case couch_db:open_doc(Db, DesignId) of
-        {ok, #doc{body={Props}}} ->
-            FilterSrc = try couch_util:get_nested_json_value({Props},
-                [<<"filters">>, FName])
-            catch
-            throw:{not_found, _} ->
-                throw({bad_request, "invalid filter function"})
-            end,
-            Lang = proplists:get_value(<<"language">>, Props, <<"javascript">>),
-            fun(DocInfos) ->
-                Docs = [Doc || {ok, Doc} <- [
-                    {ok, Doc} = couch_db:open_doc(Db, DInfo, [deleted])
-                    || DInfo <- DocInfos]],
-                {ok, Passes} = couch_query_servers:filter_docs(Lang, FilterSrc, Docs, Req, Db),
-                [{[{rev, couch_doc:rev_to_str(Rev)}]}
-                    || #doc_info{revs=[#rev_info{rev=Rev}|_]} <- DocInfos, 
-                    Pass <- Passes, Pass == true]
-            end;
-        _Error ->
-            throw({bad_request, "invalid design doc"})
+        DDoc = couch_httpd_db:couch_doc_open(Db, DesignId, nil, []),
+        % validate that the ddoc has the filter fun
+        #doc{body={Props}} = DDoc,
+        couch_util:get_nested_json_value({Props}, [<<"filters">>, FName]),
+        fun(DocInfos) ->
+            Docs = [Doc || {ok, Doc} <- [
+                {ok, Doc} = couch_db:open_doc(Db, DInfo, [deleted])
+                || DInfo <- DocInfos]],
+            {ok, Passes} = couch_query_servers:filter_docs(Req, Db, DDoc, FName, Docs),
+            [{[{rev, couch_doc:rev_to_str(Rev)}]}
+                || #doc_info{revs=[#rev_info{rev=Rev}|_]} <- DocInfos, 
+                Pass <- Passes, Pass == true]
         end;
     _Else ->
         throw({bad_request, 
@@ -279,11 +271,14 @@ handle_view_cleanup_req(Req, _Db) ->
 
 
 handle_design_req(#httpd{
-        path_parts=[_DbName,_Design,_DesName, <<"_",_/binary>> = Action | _Rest],
+        path_parts=[_DbName, _Design, DesignName, <<"_",_/binary>> = Action | _Rest],
         design_url_handlers = DesignUrlHandlers
     }=Req, Db) ->
+    % load ddoc
+    DesignId = <<"_design/", DesignName/binary>>,
+    DDoc = couch_httpd_db:couch_doc_open(Db, DesignId, nil, []),
     Handler = couch_util:dict_find(Action, DesignUrlHandlers, fun db_req/2),
-    Handler(Req, Db);
+    Handler(Req, Db, DDoc);
 
 handle_design_req(Req, Db) ->
     db_req(Req, Db).
@@ -291,7 +286,7 @@ handle_design_req(Req, Db) ->
 handle_design_info_req(#httpd{
             method='GET',
             path_parts=[_DbName, _Design, DesignName, _]
-        }=Req, Db) ->
+        }=Req, Db, _DDoc) ->
     DesignId = <<"_design/", DesignName/binary>>,
     {ok, GroupInfoList} = couch_view:get_group_info(Db, DesignId),
     send_json(Req, 200, {[
@@ -299,7 +294,7 @@ handle_design_info_req(#httpd{
         {view_index, {GroupInfoList}}
     ]});
 
-handle_design_info_req(Req, _Db) ->
+handle_design_info_req(Req, _Db, _DDoc) ->
     send_method_not_allowed(Req, "GET").
 
 create_db_req(#httpd{user_ctx=UserCtx}=Req, DbName) ->
@@ -725,7 +720,12 @@ db_doc_req(#httpd{method='GET'}=Req, Db, DocId) ->
         end;
     _ ->
         {DesignName, ShowName} = Format,
-        couch_httpd_show:handle_doc_show(Req, DesignName, ShowName, DocId, Db)
+        % load ddoc
+        DesignId = <<"_design/", DesignName/binary>>,
+        DDoc = couch_httpd_db:couch_doc_open(Db, DesignId, nil, []),
+        % open doc
+        Doc = couch_doc_open(Db, DocId, Rev, Options),
+        couch_httpd_show:handle_doc_show(Req, Db, DDoc, ShowName, Doc)
     end;
 
 db_doc_req(#httpd{method='POST'}=Req, Db, DocId) ->
diff --git a/src/couchdb/couch_httpd_external.erl b/src/couchdb/couch_httpd_external.erl
index 86b2bfc6..13aff847 100644
--- a/src/couchdb/couch_httpd_external.erl
+++ b/src/couchdb/couch_httpd_external.erl
@@ -13,7 +13,7 @@
 -module(couch_httpd_external).
 
 -export([handle_external_req/2, handle_external_req/3]).
--export([send_external_response/2, json_req_obj/2]).
+-export([send_external_response/2, json_req_obj/2, json_req_obj/3]).
 -export([default_or_content_type/2, parse_external_response/1]).
 
 -import(couch_httpd,[send_error/4]).
@@ -53,12 +53,12 @@ process_external_req(HttpReq, Db, Name) ->
     _ ->
         send_external_response(HttpReq, Response)
     end.
-
+json_req_obj(Req, Db) -> json_req_obj(Req, Db, null).
 json_req_obj(#httpd{mochi_req=Req,
                method=Verb,
                path_parts=Path,
                req_body=ReqBody
-            }, Db) ->
+            }, Db, DocId) ->
     Body = case ReqBody of
         undefined -> Req:recv_body();
         Else -> Else
@@ -74,6 +74,7 @@ json_req_obj(#httpd{mochi_req=Req,
     {ok, Info} = couch_db:get_db_info(Db),
     % add headers...
     {[{<<"info">>, {Info}},
+        {<<"id">>, DocId},
         {<<"verb">>, Verb},
         {<<"path">>, Path},
         {<<"query">>, to_json_terms(Req:parse_qs())},
diff --git a/src/couchdb/couch_httpd_show.erl b/src/couchdb/couch_httpd_show.erl
index 5c95070a..467c0a42 100644
--- a/src/couchdb/couch_httpd_show.erl
+++ b/src/couchdb/couch_httpd_show.erl
@@ -12,8 +12,8 @@
 
 -module(couch_httpd_show).
 
--export([handle_doc_show_req/2, handle_doc_update_req/2, handle_view_list_req/2,
-        handle_doc_show/5, handle_view_list/7]).
+-export([handle_doc_show_req/3, handle_doc_update_req/3, handle_view_list_req/3,
+        handle_doc_show/5, handle_view_list/6, get_fun_key/3]).
 
 -include("couch_db.hrl").
 
@@ -22,217 +22,245 @@
     start_json_response/2,send_chunk/2,last_chunk/1,send_chunked_error/2,
     start_chunked_response/3, send_error/4]).
 
+% /db/_design/foo/show/bar/docid
+% show converts a json doc to a response of any content-type. 
+% it looks up the doc an then passes it to the query server.
+% then it sends the response from the query server to the http client.
 handle_doc_show_req(#httpd{
-        method='GET',
-        path_parts=[_DbName, _Design, DesignName, _Show, ShowName, DocId]
-    }=Req, Db) ->
-    handle_doc_show(Req, DesignName, ShowName, DocId, Db);
+        path_parts=[_, _, _, _, ShowName, DocId]
+    }=Req, Db, DDoc) ->
+    % open the doc
+    Doc = couch_httpd_db:couch_doc_open(Db, DocId, nil, [conflicts]),
+    % we don't handle revs here b/c they are an internal api
+    % returns 404 if there is no doc with DocId
+    handle_doc_show(Req, Db, DDoc, ShowName, Doc);
 
 handle_doc_show_req(#httpd{
-        path_parts=[_DbName, _Design, DesignName, _Show, ShowName]
-    }=Req, Db) ->
-    handle_doc_show(Req, DesignName, ShowName, nil, Db);
+        path_parts=[_, _, _, _, ShowName]
+    }=Req, Db, DDoc) ->
+    % with no docid the doc is nil
+    handle_doc_show(Req, Db, DDoc, ShowName, nil);
 
-handle_doc_show_req(#httpd{method='GET'}=Req, _Db) ->
-    send_error(Req, 404, <<"show_error">>, <<"Invalid path.">>);
+handle_doc_show_req(Req, _Db, _DDoc) ->
+    send_error(Req, 404, <<"show_error">>, <<"Invalid path.">>).
+
+handle_doc_show(Req, Db, DDoc, ShowName, Doc) ->
+    % get responder for ddoc/showname
+    CurrentEtag = show_etag(Req, Doc, DDoc, []),
+    couch_httpd:etag_respond(Req, CurrentEtag, fun() ->
+        JsonReq = couch_httpd_external:json_req_obj(Req, Db),
+        JsonDoc = couch_query_servers:json_doc(Doc),
+        [<<"resp">>, ExternalResp] = 
+            couch_query_servers:ddoc_prompt(DDoc, [<<"shows">>, ShowName], [JsonDoc, JsonReq]),
+        JsonResp = apply_etag(ExternalResp, CurrentEtag),
+        couch_httpd_external:send_external_response(Req, JsonResp)
+    end).
 
-handle_doc_show_req(Req, _Db) ->
-    send_method_not_allowed(Req, "GET,POST,HEAD").
 
 
-handle_doc_update_req(#httpd{method = 'GET'}=Req, _Db) ->
-    send_method_not_allowed(Req, "POST,PUT,DELETE,ETC");
+show_etag(#httpd{user_ctx=UserCtx}=Req, Doc, DDoc, More) ->
+    Accept = couch_httpd:header_value(Req, "Accept"),
+    DocPart = case Doc of
+        nil -> nil;
+        Doc -> couch_httpd:doc_etag(Doc)
+    end,
+    couch_httpd:make_etag({couch_httpd:doc_etag(DDoc), DocPart, Accept, UserCtx#user_ctx.roles, More}).
+
+get_fun_key(DDoc, Type, Name) ->
+    #doc{body={Props}} = DDoc,
+    Lang = proplists:get_value(<<"language">>, Props, <<"javascript">>),
+    Src = couch_util:get_nested_json_value({Props}, [Type, Name]),
+    {Lang, Src}.
+
+% /db/_design/foo/update/bar/docid
+% updates a doc based on a request
+% handle_doc_update_req(#httpd{method = 'GET'}=Req, _Db, _DDoc) ->
+%     % anything but GET
+%     send_method_not_allowed(Req, "POST,PUT,DELETE,ETC");
     
 handle_doc_update_req(#httpd{
-        path_parts=[_DbName, _Design, DesignName, _Update, UpdateName, DocId]
-    }=Req, Db) ->
-    DesignId = <<"_design/", DesignName/binary>>,
-    #doc{body={Props}} = couch_httpd_db:couch_doc_open(Db, DesignId, nil, []),
-    Lang = proplists:get_value(<<"language">>, Props, <<"javascript">>),
-    UpdateSrc = couch_util:get_nested_json_value({Props}, [<<"updates">>, UpdateName]),
+        path_parts=[_, _, _, _, UpdateName, DocId]
+    }=Req, Db, DDoc) ->
     Doc = try couch_httpd_db:couch_doc_open(Db, DocId, nil, [conflicts])
-	  catch
-	      _ -> nil
-	  end,
-    send_doc_update_response(Lang, UpdateSrc, DocId, Doc, Req, Db);
+    catch
+      _ -> nil
+    end,
+    send_doc_update_response(Req, Db, DDoc, UpdateName, Doc, DocId);
 
 handle_doc_update_req(#httpd{
-        path_parts=[_DbName, _Design, DesignName, _Update, UpdateName]
-    }=Req, Db) ->
-    DesignId = <<"_design/", DesignName/binary>>,
-    #doc{body={Props}} = couch_httpd_db:couch_doc_open(Db, DesignId, nil, []),
-    Lang = proplists:get_value(<<"language">>, Props, <<"javascript">>),
-    UpdateSrc = couch_util:get_nested_json_value({Props}, [<<"updates">>, UpdateName]),
-    send_doc_update_response(Lang, UpdateSrc, nil, nil, Req, Db);
+        path_parts=[_, _, _, _, UpdateName]
+    }=Req, Db, DDoc) ->
+    send_doc_update_response(Req, Db, DDoc, UpdateName, nil, null);
 
-handle_doc_update_req(Req, _Db) ->
+handle_doc_update_req(Req, _Db, _DDoc) ->
     send_error(Req, 404, <<"update_error">>, <<"Invalid path.">>).
 
-
-
-handle_doc_show(Req, DesignName, ShowName, DocId, Db) ->
-    DesignId = <<"_design/", DesignName/binary>>,
-    #doc{body={Props}} = couch_httpd_db:couch_doc_open(Db, DesignId, nil, []),
-    Lang = proplists:get_value(<<"language">>, Props, <<"javascript">>),
-    ShowSrc = couch_util:get_nested_json_value({Props}, [<<"shows">>, ShowName]),
-    Doc = case DocId of
-        nil -> nil;
-        _ ->
-        try couch_httpd_db:couch_doc_open(Db, DocId, nil, [conflicts])
-        catch
-            _ -> nil
-        end
+send_doc_update_response(Req, Db, DDoc, UpdateName, Doc, DocId) ->
+    JsonReq = couch_httpd_external:json_req_obj(Req, Db, DocId),
+    JsonDoc = couch_query_servers:json_doc(Doc),
+    case couch_query_servers:ddoc_prompt(DDoc, [<<"updates">>, UpdateName], [JsonDoc, JsonReq]) of
+        [<<"up">>, {NewJsonDoc}, JsonResp] ->
+            Options = case couch_httpd:header_value(Req, "X-Couch-Full-Commit", "false") of
+            "true" ->
+                [full_commit];
+            _ ->
+                []
+            end,
+            NewDoc = couch_doc:from_json_obj({NewJsonDoc}),
+            Code = 201,
+            {ok, _NewRev} = couch_db:update_doc(Db, NewDoc, Options);
+        [<<"up">>, _Other, JsonResp] ->
+            Code = 200,
+            ok
     end,
-    send_doc_show_response(Lang, ShowSrc, DocId, Doc, Req, Db).
+    JsonResp2 = json_apply_field({<<"code">>, Code}, JsonResp),
+    % todo set location field
+    couch_httpd_external:send_external_response(Req, JsonResp2).
+
 
 % view-list request with view and list from same design doc.
 handle_view_list_req(#httpd{method='GET',
-        path_parts=[_DbName, _Design, DesignName, _List, ListName, ViewName]}=Req, Db) ->
-    handle_view_list(Req, DesignName, ListName, DesignName, ViewName, Db, nil);
+        path_parts=[_, _, DesignName, _, ListName, ViewName]}=Req, Db, DDoc) ->
+    handle_view_list(Req, Db, DDoc, ListName, {DesignName, ViewName}, nil);
 
 % view-list request with view and list from different design docs.
 handle_view_list_req(#httpd{method='GET',
-        path_parts=[_DbName, _Design, DesignName, _List, ListName, ViewDesignName, ViewName]}=Req, Db) ->
-    handle_view_list(Req, DesignName, ListName, ViewDesignName, ViewName, Db, nil);
+        path_parts=[_, _, _, _, ListName, ViewDesignName, ViewName]}=Req, Db, DDoc) ->
+    handle_view_list(Req, Db, DDoc, ListName, {ViewDesignName, ViewName}, nil);
 
-handle_view_list_req(#httpd{method='GET'}=Req, _Db) ->
+handle_view_list_req(#httpd{method='GET'}=Req, _Db, _DDoc) ->
     send_error(Req, 404, <<"list_error">>, <<"Invalid path.">>);
 
 handle_view_list_req(#httpd{method='POST',
-        path_parts=[_DbName, _Design, DesignName, _List, ListName, ViewName]}=Req, Db) ->
+        path_parts=[_, _, DesignName, _, ListName, ViewName]}=Req, Db, DDoc) ->
+    % {Props2} = couch_httpd:json_body(Req),
     ReqBody = couch_httpd:body(Req),
     {Props2} = ?JSON_DECODE(ReqBody),
     Keys = proplists:get_value(<<"keys">>, Props2, nil),
-    handle_view_list(Req#httpd{req_body=ReqBody}, DesignName, ListName, DesignName, ViewName, Db, Keys);
-
-handle_view_list_req(Req, _Db) ->
-    send_method_not_allowed(Req, "GET,POST,HEAD").
+    handle_view_list(Req#httpd{req_body=ReqBody}, Db, DDoc, ListName, {DesignName, ViewName}, Keys);
 
-handle_view_list(Req, ListDesignName, ListName, ViewDesignName, ViewName, Db, Keys) ->
-    ListDesignId = <<"_design/", ListDesignName/binary>>,
-    #doc{body={ListProps}} = couch_httpd_db:couch_doc_open(Db, ListDesignId, nil, []),
-    if
-    ViewDesignName == ListDesignName ->
-        ViewDesignId = ListDesignId;
-    true ->
-        ViewDesignId = <<"_design/", ViewDesignName/binary>>
-    end,
+handle_view_list_req(#httpd{method='POST',
+        path_parts=[_, _, _, _, ListName, ViewDesignName, ViewName]}=Req, Db, DDoc) ->
+    % {Props2} = couch_httpd:json_body(Req),
+    ReqBody = couch_httpd:body(Req),
+    {Props2} = ?JSON_DECODE(ReqBody),
+    Keys = proplists:get_value(<<"keys">>, Props2, nil),
+    handle_view_list(Req#httpd{req_body=ReqBody}, Db, DDoc, ListName, {ViewDesignName, ViewName}, Keys);
 
-    ListLang = proplists:get_value(<<"language">>, ListProps, <<"javascript">>),
-    ListSrc = couch_util:get_nested_json_value({ListProps}, [<<"lists">>, ListName]),
-    send_view_list_response(ListLang, ListSrc, ViewName, ViewDesignId, Req, Db, Keys).
-
-
-send_view_list_response(Lang, ListSrc, ViewName, DesignId, Req, Db, Keys) ->
-    Stale = couch_httpd_view:get_stale_type(Req),
-    Reduce = couch_httpd_view:get_reduce_type(Req),
-    case couch_view:get_map_view(Db, DesignId, ViewName, Stale) of
-    {ok, View, Group} ->
-        QueryArgs = couch_httpd_view:parse_view_params(Req, Keys, map),
-        output_map_list(Req, Lang, ListSrc, View, Group, Db, QueryArgs, Keys);
-    {not_found, _Reason} ->
-        case couch_view:get_reduce_view(Db, DesignId, ViewName, Stale) of
-        {ok, ReduceView, Group} ->
-            case Reduce of
-            false ->
-                QueryArgs = couch_httpd_view:parse_view_params(
-                    Req, Keys, map_red
-                ),
-                MapView = couch_view:extract_map_view(ReduceView),
-                output_map_list(Req, Lang, ListSrc, MapView, Group, Db, QueryArgs, Keys);
-            _ ->
-                QueryArgs = couch_httpd_view:parse_view_params(
-                    Req, Keys, reduce
-                ),
-                output_reduce_list(Req, Lang, ListSrc, ReduceView, Group, Db, QueryArgs, Keys)
-            end;
-        {not_found, Reason} ->
-            throw({not_found, Reason})
-        end
-    end.
+handle_view_list_req(#httpd{method='POST'}=Req, _Db, _DDoc) ->
+    send_error(Req, 404, <<"list_error">>, <<"Invalid path.">>);
 
+handle_view_list_req(Req, _Db, _DDoc) ->
+    send_method_not_allowed(Req, "GET,POST,HEAD").
 
-output_map_list(#httpd{mochi_req=MReq, user_ctx=UserCtx}=Req, Lang, ListSrc, View, Group, Db, QueryArgs, nil) ->
+handle_view_list(Req, Db, DDoc, LName, {ViewDesignName, ViewName}, Keys) ->
+    ViewDesignId = <<"_design/", ViewDesignName/binary>>,
+    {ViewType, View, Group, QueryArgs} = couch_httpd_view:load_view(Req, Db, {ViewDesignId, ViewName}, Keys),
+    Etag = list_etag(Req, Db, Group, {couch_httpd:doc_etag(DDoc), Keys}),    
+    couch_httpd:etag_respond(Req, Etag, fun() ->
+            output_list(ViewType, Req, Db, DDoc, LName, View, QueryArgs, Etag, Keys)
+        end).    
+
+list_etag(#httpd{user_ctx=UserCtx}=Req, Db, Group, More) ->
+    Accept = couch_httpd:header_value(Req, "Accept"),
+    couch_httpd_view:view_group_etag(Group, Db, {More, Accept, UserCtx#user_ctx.roles}).
+
+output_list(map, Req, Db, DDoc, LName, View, QueryArgs, Etag, Keys) ->
+    output_map_list(Req, Db, DDoc, LName, View, QueryArgs, Etag, Keys);
+output_list(reduce, Req, Db, DDoc, LName, View, QueryArgs, Etag, Keys) ->
+    output_reduce_list(Req, Db, DDoc, LName, View, QueryArgs, Etag, Keys).
+    
+% next step:
+% use with_ddoc_proc/2 to make this simpler
+output_map_list(Req, Db, DDoc, LName, View, QueryArgs, Etag, Keys) ->
     #view_query_args{
         limit = Limit,
         skip = SkipCount
     } = QueryArgs,
+
+    FoldAccInit = {Limit, SkipCount, undefined, []},
     {ok, RowCount} = couch_view:get_row_count(View),
-    Headers = MReq:get(headers),
-    Hlist = mochiweb_headers:to_list(Headers),
-    Accept = proplists:get_value('Accept', Hlist),
-    CurrentEtag = couch_httpd_view:view_group_etag(Group, Db, {Lang, ListSrc, Accept, UserCtx}),
-    couch_httpd:etag_respond(Req, CurrentEtag, fun() ->
-        % get the os process here
-        % pass it into the view fold with closures
-        {ok, QueryServer} = couch_query_servers:start_view_list(Lang, ListSrc),
+    
 
-        StartListRespFun = make_map_start_resp_fun(QueryServer, Db),
-        SendListRowFun = make_map_send_row_fun(QueryServer),
+    couch_query_servers:with_ddoc_proc(DDoc, fun(QServer) ->
+
+        ListFoldHelpers = #view_fold_helper_funs{
+            reduce_count = fun couch_view:reduce_to_count/1,
+            start_response = StartListRespFun = make_map_start_resp_fun(QServer, Db, LName),
+            send_row = make_map_send_row_fun(QServer)
+        },        
+
+        {ok, _, FoldResult} = case Keys of
+            nil ->
+                FoldlFun = couch_httpd_view:make_view_fold_fun(Req, QueryArgs, Etag, Db, RowCount, ListFoldHelpers),        
+                    couch_view:fold(View, FoldlFun, FoldAccInit, 
+                    couch_httpd_view:make_key_options(QueryArgs));
+            Keys ->
+                lists:foldl(
+                    fun(Key, {ok, _, FoldAcc}) ->
+                        QueryArgs2 = QueryArgs#view_query_args{
+                                start_key = Key,
+                                end_key = Key
+                            },
+                        FoldlFun = couch_httpd_view:make_view_fold_fun(Req, QueryArgs2, Etag, Db, RowCount, ListFoldHelpers),
+                        couch_view:fold(View, FoldlFun, FoldAcc,
+                            couch_httpd_view:make_key_options(QueryArgs2))
+                    end, {ok, nil, FoldAccInit}, Keys)
+            end,
+        finish_list(Req, QServer, Etag, FoldResult, StartListRespFun, RowCount)
+    end).
 
-        FoldlFun = couch_httpd_view:make_view_fold_fun(Req, QueryArgs, CurrentEtag, Db, RowCount,
-            #view_fold_helper_funs{
-                reduce_count = fun couch_view:reduce_to_count/1,
-                start_response = StartListRespFun,
-                send_row = SendListRowFun
-            }),
-        FoldAccInit = {Limit, SkipCount, undefined, []},
-        {ok, _, FoldResult} = couch_view:fold(View, FoldlFun, FoldAccInit,
-                couch_httpd_view:make_key_options(QueryArgs)),
-        finish_list(Req, QueryServer, CurrentEtag, FoldResult, StartListRespFun, RowCount)
-    end);
 
-output_map_list(#httpd{mochi_req=MReq, user_ctx=UserCtx}=Req, Lang, ListSrc, View, Group, Db, QueryArgs, Keys) ->
+output_reduce_list(Req, Db, DDoc, LName, View, QueryArgs, Etag, Keys) ->
     #view_query_args{
         limit = Limit,
-        skip = SkipCount
+        skip = SkipCount,
+        group_level = GroupLevel
     } = QueryArgs,
-    {ok, RowCount} = couch_view:get_row_count(View),
-    Headers = MReq:get(headers),
-    Hlist = mochiweb_headers:to_list(Headers),
-    Accept = proplists:get_value('Accept', Hlist),
-    CurrentEtag = couch_httpd_view:view_group_etag(Group, Db, {Lang, ListSrc, Accept, UserCtx, Keys}),
-    couch_httpd:etag_respond(Req, CurrentEtag, fun() ->
-        % get the os process here
-        % pass it into the view fold with closures
-        {ok, QueryServer} = couch_query_servers:start_view_list(Lang, ListSrc),
-
-        StartListRespFun = make_map_start_resp_fun(QueryServer, Db),
-        SendListRowFun = make_map_send_row_fun(QueryServer),
 
+    couch_query_servers:with_ddoc_proc(DDoc, fun(QServer) ->
+        StartListRespFun = make_reduce_start_resp_fun(QServer, Db, LName),
+        SendListRowFun = make_reduce_send_row_fun(QServer, Db),
+        {ok, GroupRowsFun, RespFun} = couch_httpd_view:make_reduce_fold_funs(Req,
+            GroupLevel, QueryArgs, Etag,
+            #reduce_fold_helper_funs{
+                start_response = StartListRespFun,
+                send_row = SendListRowFun
+            }),
         FoldAccInit = {Limit, SkipCount, undefined, []},
-        {ok, _, FoldResult} = lists:foldl(
-            fun(Key, {ok, _, FoldAcc}) ->
-                QueryArgs2 = QueryArgs#view_query_args{
-                        start_key = Key,
-                        end_key = Key
-                    },
-                FoldlFun = couch_httpd_view:make_view_fold_fun(Req, QueryArgs2, CurrentEtag, Db, RowCount,
-                    #view_fold_helper_funs{
-                        reduce_count = fun couch_view:reduce_to_count/1,
-                        start_response = StartListRespFun,
-                        send_row = SendListRowFun
-                    }),
-                couch_view:fold(View, FoldlFun, FoldAcc,
-                    couch_httpd_view:make_key_options(QueryArgs2))
-            end, {ok, nil, FoldAccInit}, Keys),
-        finish_list(Req, QueryServer, CurrentEtag, FoldResult, StartListRespFun, RowCount)
+        {ok, FoldResult} = case Keys of
+            nil ->
+                couch_view:fold_reduce(View, RespFun, FoldAccInit, [{key_group_fun, GroupRowsFun} | 
+                    couch_httpd_view:make_key_options(QueryArgs)]);
+            Keys ->
+                lists:foldl(
+                    fun(Key, {ok, FoldAcc}) ->
+                        couch_view:fold_reduce(View, RespFun, FoldAcc,
+                            [{key_group_fun, GroupRowsFun} | 
+                                couch_httpd_view:make_key_options(
+                                QueryArgs#view_query_args{start_key=Key, end_key=Key})]
+                            )    
+                    end, {ok, FoldAccInit}, Keys)
+            end,
+        finish_list(Req, QServer, Etag, FoldResult, StartListRespFun, null)
     end).
 
-make_map_start_resp_fun(QueryServer, Db) ->
+
+make_map_start_resp_fun(QueryServer, Db, LName) ->
     fun(Req, Etag, TotalRows, Offset, _Acc) ->
         Head = {[{<<"total_rows">>, TotalRows}, {<<"offset">>, Offset}]},
-        start_list_resp(QueryServer, Req, Db, Head, Etag)
+        start_list_resp(QueryServer, LName, Req, Db, Head, Etag)
     end.
 
-make_reduce_start_resp_fun(QueryServer, _Req, Db, _CurrentEtag) ->
+make_reduce_start_resp_fun(QueryServer, Db, LName) ->
     fun(Req2, Etag, _Acc) ->
-        start_list_resp(QueryServer, Req2, Db, {[]}, Etag)
+        start_list_resp(QueryServer, LName, Req2, Db, {[]}, Etag)
     end.
 
-start_list_resp(QueryServer, Req, Db, Head, Etag) ->
-    [<<"start">>,Chunks,JsonResp] = couch_query_servers:render_list_head(QueryServer,
-        Req, Db, Head),
+start_list_resp(QServer, LName, Req, Db, Head, Etag) ->
+    JsonReq = couch_httpd_external:json_req_obj(Req, Db),
+    [<<"start">>,Chunks,JsonResp] = couch_query_servers:ddoc_proc_prompt(QServer, 
+        [<<"lists">>, LName], [Head, JsonReq]),
     JsonResp2 = apply_etag(JsonResp, Etag),
     #extern_resp_args{
         code = Code,
@@ -255,7 +283,7 @@ make_reduce_send_row_fun(QueryServer, Db) ->
 
 send_list_row(Resp, QueryServer, Db, Row, RowFront, IncludeDoc) ->
     try
-        [Go,Chunks] = couch_query_servers:render_list_row(QueryServer, Db, Row, IncludeDoc),
+        [Go,Chunks] = prompt_list_row(QueryServer, Db, Row, IncludeDoc),
         Chunk = RowFront ++ ?b2l(?l2b(Chunks)),
         send_non_empty_chunk(Resp, Chunk),
         case Go of
@@ -270,78 +298,22 @@ send_list_row(Resp, QueryServer, Db, Row, RowFront, IncludeDoc) ->
             throw({already_sent, Resp, Error})
     end.
 
+
+prompt_list_row({Proc, _DDocId}, Db, {{Key, DocId}, Value}, IncludeDoc) ->
+    JsonRow = couch_httpd_view:view_row_obj(Db, {{Key, DocId}, Value}, IncludeDoc),
+    couch_query_servers:proc_prompt(Proc, [<<"list_row">>, JsonRow]);
+
+prompt_list_row({Proc, _DDocId}, _, {Key, Value}, _IncludeDoc) ->
+    JsonRow = {[{key, Key}, {value, Value}]},
+    couch_query_servers:proc_prompt(Proc, [<<"list_row">>, JsonRow]).
+
 send_non_empty_chunk(Resp, Chunk) ->
     case Chunk of
         [] -> ok;
         _ -> send_chunk(Resp, Chunk)
     end.
 
-output_reduce_list(#httpd{mochi_req=MReq, user_ctx=UserCtx}=Req, Lang, ListSrc, View, Group, Db, QueryArgs, nil) ->
-    #view_query_args{
-        limit = Limit,
-        skip = SkipCount,
-        group_level = GroupLevel
-    } = QueryArgs,
-    Headers = MReq:get(headers),
-    Hlist = mochiweb_headers:to_list(Headers),
-    Accept = proplists:get_value('Accept', Hlist),
-    CurrentEtag = couch_httpd_view:view_group_etag(Group, Db, {Lang, ListSrc, Accept, UserCtx}),
-    couch_httpd:etag_respond(Req, CurrentEtag, fun() ->
-        % get the os process here
-        % pass it into the view fold with closures
-        {ok, QueryServer} = couch_query_servers:start_view_list(Lang, ListSrc),
-        StartListRespFun = make_reduce_start_resp_fun(QueryServer, Req, Db, CurrentEtag),
-        SendListRowFun = make_reduce_send_row_fun(QueryServer, Db),
-
-        {ok, GroupRowsFun, RespFun} = couch_httpd_view:make_reduce_fold_funs(Req,
-            GroupLevel, QueryArgs, CurrentEtag,
-            #reduce_fold_helper_funs{
-                start_response = StartListRespFun,
-                send_row = SendListRowFun
-            }),
-        FoldAccInit = {Limit, SkipCount, undefined, []},
-        {ok, FoldResult} = couch_view:fold_reduce(View, RespFun, FoldAccInit, 
-            [{key_group_fun, GroupRowsFun} | 
-                couch_httpd_view:make_key_options(QueryArgs)]),
-        finish_list(Req, QueryServer, CurrentEtag, FoldResult, StartListRespFun, null)
-    end);
-
-output_reduce_list(#httpd{mochi_req=MReq, user_ctx=UserCtx}=Req, Lang, ListSrc, View, Group, Db, QueryArgs, Keys) ->
-    #view_query_args{
-        limit = Limit,
-        skip = SkipCount,
-        group_level = GroupLevel
-    } = QueryArgs,
-    Headers = MReq:get(headers),
-    Hlist = mochiweb_headers:to_list(Headers),
-    Accept = proplists:get_value('Accept', Hlist),
-    CurrentEtag = couch_httpd_view:view_group_etag(Group, Db, {Lang, ListSrc, Accept, UserCtx, Keys}),
-    couch_httpd:etag_respond(Req, CurrentEtag, fun() ->
-        % get the os process here
-        % pass it into the view fold with closures
-        {ok, QueryServer} = couch_query_servers:start_view_list(Lang, ListSrc),
-        StartListRespFun = make_reduce_start_resp_fun(QueryServer, Req, Db, CurrentEtag),
-        SendListRowFun = make_reduce_send_row_fun(QueryServer, Db),
-
-        {ok, GroupRowsFun, RespFun} = couch_httpd_view:make_reduce_fold_funs(Req,
-            GroupLevel, QueryArgs, CurrentEtag,
-            #reduce_fold_helper_funs{
-                start_response = StartListRespFun,
-                send_row = SendListRowFun
-            }),
-        FoldAccInit = {Limit, SkipCount, undefined, []},
-        {ok, FoldResult} = lists:foldl(
-            fun(Key, {ok, FoldAcc}) ->
-                couch_view:fold_reduce(View, RespFun, FoldAcc,
-                    [{key_group_fun, GroupRowsFun} | 
-                        couch_httpd_view:make_key_options(
-                        QueryArgs#view_query_args{start_key=Key, end_key=Key})]
-                    )    
-            end, {ok, FoldAccInit}, Keys),
-        finish_list(Req, QueryServer, CurrentEtag, FoldResult, StartListRespFun, null)
-    end).
-
-finish_list(Req, QueryServer, Etag, FoldResult, StartFun, TotalRows) ->
+finish_list(Req, {Proc, _DDocId}, Etag, FoldResult, StartFun, TotalRows) ->
     FoldResult2 = case FoldResult of
         {Limit, SkipCount, Response, RowAcc} ->
             {Limit, SkipCount, Response, RowAcc, nil};
@@ -352,16 +324,15 @@ finish_list(Req, QueryServer, Etag, FoldResult, StartFun, TotalRows) ->
         {_, _, undefined, _, _} ->
             {ok, Resp, BeginBody} =
                 render_head_for_empty_list(StartFun, Req, Etag, TotalRows),
-            [<<"end">>, Chunks] = couch_query_servers:render_list_tail(QueryServer),
+            [<<"end">>, Chunks] = couch_query_servers:proc_prompt(Proc, [<<"list_end">>]),            
             Chunk = BeginBody ++ ?b2l(?l2b(Chunks)),
             send_non_empty_chunk(Resp, Chunk);
         {_, _, Resp, stop, _} ->
             ok;
         {_, _, Resp, _, _} ->
-            [<<"end">>, Chunks] = couch_query_servers:render_list_tail(QueryServer),
+            [<<"end">>, Chunks] = couch_query_servers:proc_prompt(Proc, [<<"list_end">>]),
             send_non_empty_chunk(Resp, ?b2l(?l2b(Chunks)))
     end,
-    couch_query_servers:stop_doc_map(QueryServer),
     last_chunk(Resp).
 
 
@@ -370,53 +341,6 @@ render_head_for_empty_list(StartListRespFun, Req, Etag, null) ->
 render_head_for_empty_list(StartListRespFun, Req, Etag, TotalRows) ->
     StartListRespFun(Req, Etag, TotalRows, null, []).
 
-send_doc_show_response(Lang, ShowSrc, DocId, nil, #httpd{mochi_req=MReq, user_ctx=UserCtx}=Req, Db) ->
-    % compute etag with no doc
-    Headers = MReq:get(headers),
-    Hlist = mochiweb_headers:to_list(Headers),
-    Accept = proplists:get_value('Accept', Hlist),
-    CurrentEtag = couch_httpd:make_etag({Lang, ShowSrc, nil, Accept, UserCtx}),
-    couch_httpd:etag_respond(Req, CurrentEtag, fun() ->
-        [<<"resp">>, ExternalResp] = couch_query_servers:render_doc_show(Lang, ShowSrc,
-            DocId, nil, Req, Db),
-        JsonResp = apply_etag(ExternalResp, CurrentEtag),
-        couch_httpd_external:send_external_response(Req, JsonResp)
-    end);
-
-send_doc_show_response(Lang, ShowSrc, DocId, #doc{revs=Revs}=Doc, #httpd{mochi_req=MReq, user_ctx=UserCtx}=Req, Db) ->
-    % calculate the etag
-    Headers = MReq:get(headers),
-    Hlist = mochiweb_headers:to_list(Headers),
-    Accept = proplists:get_value('Accept', Hlist),
-    CurrentEtag = couch_httpd:make_etag({Lang, ShowSrc, Revs, Accept, UserCtx}),
-    % We know our etag now
-    couch_httpd:etag_respond(Req, CurrentEtag, fun() ->
-        [<<"resp">>, ExternalResp] = couch_query_servers:render_doc_show(Lang, ShowSrc,
-            DocId, Doc, Req, Db),
-        JsonResp = apply_etag(ExternalResp, CurrentEtag),
-        couch_httpd_external:send_external_response(Req, JsonResp)
-    end).
-
-send_doc_update_response(Lang, UpdateSrc, DocId, Doc, Req, Db) ->
-    case couch_query_servers:render_doc_update(Lang, UpdateSrc, 
-        DocId, Doc, Req, Db) of
-    [<<"up">>, {NewJsonDoc}, JsonResp] ->
-        Options = case couch_httpd:header_value(Req, "X-Couch-Full-Commit", "false") of
-        "true" ->
-            [full_commit];
-        _ ->
-            []
-        end,
-        NewDoc = couch_doc:from_json_obj({NewJsonDoc}),
-        Code = 201,
-        % todo set location field
-        {ok, _NewRev} = couch_db:update_doc(Db, NewDoc, Options);
-    [<<"up">>, _Other, JsonResp] ->
-        Code = 200,
-        ok
-    end,
-    JsonResp2 = json_apply_field({<<"code">>, Code}, JsonResp),
-    couch_httpd_external:send_external_response(Req, JsonResp2).
 
 % Maybe this is in the proplists API
 % todo move to couch_util
diff --git a/src/couchdb/couch_httpd_view.erl b/src/couchdb/couch_httpd_view.erl
index af31ac9c..6419ca55 100644
--- a/src/couchdb/couch_httpd_view.erl
+++ b/src/couchdb/couch_httpd_view.erl
@@ -13,21 +13,21 @@
 -module(couch_httpd_view).
 -include("couch_db.hrl").
 
--export([handle_view_req/2,handle_temp_view_req/2,handle_db_view_req/2]).
+-export([handle_view_req/3,handle_temp_view_req/2]).
 
 -export([get_stale_type/1, get_reduce_type/1, parse_view_params/3]).
 -export([make_view_fold_fun/6, finish_view_fold/4, view_row_obj/3]).
 -export([view_group_etag/2, view_group_etag/3, make_reduce_fold_funs/5]).
 -export([design_doc_view/5, parse_bool_param/1, doc_member/2]).
--export([make_key_options/1]).
+-export([make_key_options/1, load_view/4]).
 
 -import(couch_httpd,
     [send_json/2,send_json/3,send_json/4,send_method_not_allowed/2,send_chunk/2,
     start_json_response/2, start_json_response/3, end_json_response/1,
     send_chunked_error/2]).
 
-design_doc_view(Req, Db, Id, ViewName, Keys) ->
-    DesignId = <<"_design/", Id/binary>>,
+design_doc_view(Req, Db, DName, ViewName, Keys) ->
+    DesignId = <<"_design/", DName/binary>>,
     Stale = get_stale_type(Req),
     Reduce = get_reduce_type(Req),
     Result = case couch_view:get_map_view(Db, DesignId, ViewName, Stale) of
@@ -54,11 +54,11 @@ design_doc_view(Req, Db, Id, ViewName, Keys) ->
     Result.
 
 handle_view_req(#httpd{method='GET',
-        path_parts=[_Db, _Design, DName, _View, ViewName]}=Req, Db) ->
+        path_parts=[_, _, DName, _, ViewName]}=Req, Db, _DDoc) ->
     design_doc_view(Req, Db, DName, ViewName, nil);
 
 handle_view_req(#httpd{method='POST',
-        path_parts=[_Db, _Design, DName, _View, ViewName]}=Req, Db) ->
+        path_parts=[_, _, DName, _, ViewName]}=Req, Db, _DDoc) ->
     {Fields} = couch_httpd:json_body_obj(Req),
     case proplists:get_value(<<"keys">>, Fields, nil) of
     nil ->
@@ -71,50 +71,7 @@ handle_view_req(#httpd{method='POST',
         throw({bad_request, "`keys` member must be a array."})
     end;
 
-handle_view_req(Req, _Db) ->
-    send_method_not_allowed(Req, "GET,POST,HEAD").
-
-handle_db_view_req(#httpd{method='GET',
-        path_parts=[_Db, _View, DName, ViewName]}=Req, Db) ->
-    QueryArgs = couch_httpd_view:parse_view_params(Req, nil, nil),
-    #view_query_args{
-        list = ListName
-    } = QueryArgs,
-    ?LOG_DEBUG("ici ~p", [ListName]),
-    case ListName of
-        nil -> couch_httpd_view:design_doc_view(Req, Db, DName, ViewName, nil);
-        _ ->
-            couch_httpd_show:handle_view_list(Req, DName, ListName, DName, ViewName, Db, nil)
-    end;
-
-handle_db_view_req(#httpd{method='POST',
-        path_parts=[_Db, _View, DName, ViewName]}=Req, Db) ->
-    QueryArgs = couch_httpd_view:parse_view_params(Req, nil, nil),
-    #view_query_args{
-        list = ListName
-    } = QueryArgs,
-    case ListName of
-    nil ->
-        {Fields} = couch_httpd:json_body_obj(Req),
-        case proplists:get_value(<<"keys">>, Fields, nil) of
-        nil ->
-            Fmt = "POST to view ~p/~p in database ~p with no keys member.",
-            ?LOG_DEBUG(Fmt, [DName, ViewName, Db]),
-            couch_httpd_view:design_doc_view(Req, Db, DName, ViewName, nil);
-        Keys when is_list(Keys) ->
-            couch_httpd_view:design_doc_view(Req, Db, DName, ViewName, Keys);
-        _ ->
-            throw({bad_request, "`keys` member must be a array."})
-        end;
-    _ ->
-        ReqBody = couch_httpd:body(Req),
-        {Props2} = ?JSON_DECODE(ReqBody),
-        Keys = proplists:get_value(<<"keys">>, Props2, nil),
-        couch_httpd_show:handle_view_list(Req#httpd{req_body=ReqBody},
-            DName, ListName, DName, ViewName, Db, Keys)
-    end;
-
-handle_db_view_req(Req, _Db) ->
+handle_view_req(Req, _Db, _DDoc) ->
     send_method_not_allowed(Req, "GET,POST,HEAD").
 
 handle_temp_view_req(#httpd{method='POST'}=Req, Db) ->
@@ -236,6 +193,35 @@ get_stale_type(Req) ->
 get_reduce_type(Req) ->
     list_to_atom(couch_httpd:qs_value(Req, "reduce", "true")).
 
+load_view(Req, Db, {ViewDesignId, ViewName}, Keys) ->
+    Stale = couch_httpd_view:get_stale_type(Req),
+    Reduce = couch_httpd_view:get_reduce_type(Req),
+    case couch_view:get_map_view(Db, ViewDesignId, ViewName, Stale) of
+    {ok, View, Group} ->
+        QueryArgs = couch_httpd_view:parse_view_params(Req, Keys, map),
+        {map, View, Group, QueryArgs};
+    {not_found, _Reason} ->
+        case couch_view:get_reduce_view(Db, ViewDesignId, ViewName, Stale) of
+        {ok, ReduceView, Group} ->
+            case Reduce of
+            false ->
+                QueryArgs = couch_httpd_view:parse_view_params(Req, Keys, map_red),
+                MapView = couch_view:extract_map_view(ReduceView),
+                {map, MapView, Group, QueryArgs};
+            _ ->
+                QueryArgs = couch_httpd_view:parse_view_params(Req, Keys, reduce),                
+                {reduce, ReduceView, Group, QueryArgs}
+            end;
+        {not_found, Reason} ->
+            throw({not_found, Reason})
+        end
+    end.
+
+% query_parse_error could be removed
+% we wouldn't need to pass the view type, it'd just parse params.
+% I'm not sure what to do about the error handling, but
+% it might simplify things to have a parse_view_params function
+% that doesn't throw().
 parse_view_params(Req, Keys, ViewType) ->
     QueryList = couch_httpd:qs(Req),
     QueryParams =
@@ -258,6 +244,7 @@ parse_view_params(Req, Keys, ViewType) ->
         {reduce, _, false} ->
             QueryArgs;
         {reduce, _, _} ->
+            % we can simplify code if we just drop this error message.
             Msg = <<"Multi-key fetchs for reduce "
                     "view must include `group=true`">>,
             throw({query_parse_error, Msg});
diff --git a/src/couchdb/couch_native_process.erl b/src/couchdb/couch_native_process.erl
index 2b74073c..65e4e131 100644
--- a/src/couchdb/couch_native_process.erl
+++ b/src/couchdb/couch_native_process.erl
@@ -38,63 +38,102 @@
 % extensions will evolve which offer useful layers on top of this view server
 % to help simplify your view code.
 -module(couch_native_process).
+-behaviour(gen_server).
 
--export([start_link/0]).
--export([set_timeout/2, prompt/2, stop/1]).
+-export([start_link/0,init/1,terminate/2,handle_call/3,handle_cast/2]).
+-export([set_timeout/2, prompt/2]).
 
 -define(STATE, native_proc_state).
--record(evstate, {funs=[], query_config=[], list_pid=nil, timeout=5000}).
+-record(evstate, {ddocs, funs=[], query_config=[], list_pid=nil, timeout=5000}).
 
 -include("couch_db.hrl").
 
 start_link() ->
-    {ok, self()}.
+    gen_server:start_link(?MODULE, [], []).
 
-stop(_Pid) ->
-    ok.
+% this is a bit messy, see also couch_query_servers handle_info
+% stop(_Pid) ->
+%     ok.
 
-set_timeout(_Pid, TimeOut) ->
-    NewState = case get(?STATE) of
-    undefined ->
-        #evstate{timeout=TimeOut};
-    State ->
-        State#evstate{timeout=TimeOut}
-    end,
-    put(?STATE, NewState),
-    ok.
+set_timeout(Pid, TimeOut) ->
+    gen_server:call(Pid, {set_timeout, TimeOut}).
 
-prompt(Pid, Data) when is_pid(Pid), is_list(Data) ->
-    case get(?STATE) of
-    undefined ->
-        State = #evstate{},
-        put(?STATE, State);
-    State ->
-        State
-    end,
-    case is_pid(State#evstate.list_pid) of
-        true ->
-            case hd(Data) of
-                <<"list_row">> -> ok;
-                <<"list_end">> -> ok;
-                _ -> throw({error, query_server_error})
-            end;
-        _ ->
-            ok % Not listing
-    end,
-    {NewState, Resp} = run(State, to_binary(Data)),
-    put(?STATE, NewState),
+prompt(Pid, Data) when is_list(Data) ->
+    gen_server:call(Pid, {prompt, Data}).
+
+% gen_server callbacks
+init([]) ->
+    {ok, #evstate{ddocs=dict:new()}}.
+
+handle_call({set_timeout, TimeOut}, _From, State) ->
+    {reply, ok, State#evstate{timeout=TimeOut}};
+
+handle_call({prompt, Data}, _From, State) ->
+    ?LOG_DEBUG("Prompt native qs: ~s",[?JSON_ENCODE(Data)]),
+    {NewState, Resp} = try run(State, to_binary(Data)) of
+        {S, R} -> {S, R}
+        catch
+            throw:{error, Why} ->
+                {State, [<<"error">>, Why, Why]}
+        end,
+    
     case Resp of
         {error, Reason} ->
             Msg = io_lib:format("couch native server error: ~p", [Reason]),
-            {[{<<"error">>, list_to_binary(Msg)}]};
-        _ ->
-            Resp
+            {reply, [<<"error">>, <<"native_query_server">>, list_to_binary(Msg)], NewState};
+        [<<"error">> | Rest] ->
+            Msg = io_lib:format("couch native server error: ~p", [Rest]),
+            {reply, [<<"error">> | Rest], NewState};
+        [<<"fatal">> | Rest] ->
+            Msg = io_lib:format("couch native server error: ~p", [Rest]),
+            {stop, fatal, [<<"error">> | Rest], NewState};
+        Resp ->
+            {reply, Resp, NewState}
     end.
 
-run(_, [<<"reset">>]) ->
-    {#evstate{}, true};
-run(_, [<<"reset">>, QueryConfig]) ->
-    {#evstate{query_config=QueryConfig}, true};
+handle_cast(_Msg, State) -> {noreply, State}.
+handle_info(_Msg, State) -> {noreply, State}.
+terminate(_Reason, _State) -> ok.
+code_change(_OldVersion, State, _Extra) -> {ok, State}.
+
+run(#evstate{list_pid=Pid}=State, [<<"list_row">>, Row]) when is_pid(Pid) ->
+    Pid ! {self(), list_row, Row},
+    receive
+        {Pid, chunks, Data} ->
+            {State, [<<"chunks">>, Data]};
+        {Pid, list_end, Data} ->
+            receive
+                {'EXIT', Pid, normal} -> ok
+            after State#evstate.timeout ->
+                throw({timeout, list_cleanup})
+            end,
+            process_flag(trap_exit, erlang:get(do_trap)),
+            {State#evstate{list_pid=nil}, [<<"end">>, Data]}
+    after State#evstate.timeout ->
+        throw({timeout, list_row})
+    end;
+run(#evstate{list_pid=Pid}=State, [<<"list_end">>]) when is_pid(Pid) ->
+    Pid ! {self(), list_end},
+    Resp =
+    receive
+        {Pid, list_end, Data} ->
+            receive
+                {'EXIT', Pid, normal} -> ok
+            after State#evstate.timeout ->
+                throw({timeout, list_cleanup})
+            end,
+            [<<"end">>, Data]
+    after State#evstate.timeout ->
+        throw({timeout, list_end})
+    end,
+    process_flag(trap_exit, erlang:get(do_trap)),
+    {State#evstate{list_pid=nil}, Resp};
+run(#evstate{list_pid=Pid}=State, _Command) when is_pid(Pid) ->
+    {State, [<<"error">>, list_error, list_error]};
+run(#evstate{ddocs=DDocs}, [<<"reset">>]) ->
+    {#evstate{ddocs=DDocs}, true};
+run(#evstate{ddocs=DDocs}, [<<"reset">>, QueryConfig]) ->
+    {#evstate{ddocs=DDocs, query_config=QueryConfig}, true};
 run(#evstate{funs=Funs}=State, [<<"add_fun">> , BinFunc]) ->
     FunInfo = makefun(State, BinFunc),
     {State#evstate{funs=Funs ++ [FunInfo]}, true};
@@ -115,41 +154,55 @@ run(State, [<<"reduce">>, Funs, KVs]) ->
     {State, catch reduce(State, Funs, Keys2, Vals2, false)};
 run(State, [<<"rereduce">>, Funs, Vals]) ->
     {State, catch reduce(State, Funs, null, Vals, true)};
-run(State, [<<"validate">>, BFun, NDoc, ODoc, Ctx]) ->
-    {_Sig, Fun} = makefun(State, BFun),
-    {State, catch Fun(NDoc, ODoc, Ctx)};
-run(State, [<<"filter">>, Docs, Req]) ->
-    {_Sig, Fun} = hd(State#evstate.funs),
+run(#evstate{ddocs=DDocs}=State, [<<"ddoc">>, <<"new">>, DDocId, DDoc]) ->
+    DDocs2 = store_ddoc(DDocs, DDocId, DDoc),
+    {State#evstate{ddocs=DDocs2}, true};
+run(#evstate{ddocs=DDocs}=State, [<<"ddoc">>, DDocId | Rest]) ->
+    DDoc = load_ddoc(DDocs, DDocId),
+    ddoc(State, DDoc, Rest);
+run(_, Unknown) ->
+    ?LOG_ERROR("Native Process: Unknown command: ~p~n", [Unknown]),
+    throw({error, unknown_command}).
+    
+ddoc(State, {DDoc}, [FunPath, Args]) ->
+    % load fun from the FunPath
+    BFun = lists:foldl(fun
+        (Key, {Props}) when is_list(Props) ->
+            proplists:get_value(Key, Props, nil);
+        (Key, Fun) when is_binary(Fun) ->
+            Fun;
+        (Key, nil) ->
+            throw({error, not_found});
+        (Key, Fun) -> 
+            throw({error, malformed_ddoc})
+        end, {DDoc}, FunPath),
+    ddoc(State, makefun(State, BFun, {DDoc}), FunPath, Args).
+
+ddoc(State, {_, Fun}, [<<"validate_doc_update">>], Args) ->
+    {State, (catch apply(Fun, Args))};
+ddoc(State, {_, Fun}, [<<"filters">>|_], [Docs, Req]) ->
     Resp = lists:map(fun(Doc) -> (catch Fun(Doc, Req)) =:= true end, Docs),
     {State, [true, Resp]};
-run(State, [<<"show">>, BFun, Doc, Req]) ->
-    {_Sig, Fun} = makefun(State, BFun),
-    Resp = case (catch Fun(Doc, Req)) of
+ddoc(State, {_, Fun}, [<<"shows">>|_], Args) ->
+    Resp = case (catch apply(Fun, Args)) of
         FunResp when is_list(FunResp) ->
             FunResp;
-        FunResp when tuple_size(FunResp) =:= 1 ->
-            [<<"resp">>, FunResp];
+        {FunResp} ->
+            [<<"resp">>, {FunResp}];
         FunResp ->
             FunResp
     end,
     {State, Resp};
-run(State, [<<"update">>, BFun, Doc, Req]) ->
-    {_Sig, Fun} = makefun(State, BFun),
-    Resp = case (catch Fun(Doc, Req)) of
+ddoc(State, {_, Fun}, [<<"updates">>|_], Args) ->
+    Resp = case (catch apply(Fun, Args)) of
         [JsonDoc, JsonResp]  ->
             [<<"up">>, JsonDoc, JsonResp]
     end,
     {State, Resp};
-run(State, [<<"list">>, Head, Req]) ->
-    {Sig, Fun} = hd(State#evstate.funs),
-    % This is kinda dirty
-    case is_function(Fun, 2) of
-        false -> throw({error, render_error});
-        true -> ok
-    end,
+ddoc(State, {Sig, Fun}, [<<"lists">>|_], Args) ->
     Self = self(),
     SpawnFun = fun() ->
-        LastChunk = (catch Fun(Head, Req)),
+        LastChunk = (catch apply(Fun, Args)),
         case start_list_resp(Self, Sig) of
             started ->
                 receive
@@ -177,44 +230,20 @@ run(State, [<<"list">>, Head, Req]) ->
     after State#evstate.timeout ->
         throw({timeout, list_start})
     end,
-    {State#evstate{list_pid=Pid}, Resp};
-run(#evstate{list_pid=Pid}=State, [<<"list_row">>, Row]) when is_pid(Pid) ->
-    Pid ! {self(), list_row, Row},
-    receive
-        {Pid, chunks, Data} ->
-            {State, [<<"chunks">>, Data]};
-        {Pid, list_end, Data} ->
-            receive
-                {'EXIT', Pid, normal} -> ok
-            after State#evstate.timeout ->
-                throw({timeout, list_cleanup})
-            end,
-            process_flag(trap_exit, erlang:get(do_trap)),
-            {State#evstate{list_pid=nil}, [<<"end">>, Data]}
-    after State#evstate.timeout ->
-        throw({timeout, list_row})
-    end;
-run(#evstate{list_pid=Pid}=State, [<<"list_end">>]) when is_pid(Pid) ->
-    Pid ! {self(), list_end},
-    Resp =
-    receive
-        {Pid, list_end, Data} ->
-            receive
-                {'EXIT', Pid, normal} -> ok
-            after State#evstate.timeout ->
-                throw({timeout, list_cleanup})
-            end,
-            [<<"end">>, Data]
-    after State#evstate.timeout ->
-        throw({timeout, list_end})
-    end,
-    process_flag(trap_exit, erlang:get(do_trap)),
-    {State#evstate{list_pid=nil}, Resp};
-run(_, Unknown) ->
-    ?LOG_ERROR("Native Process: Unknown command: ~p~n", [Unknown]),
-    throw({error, query_server_error}).
+    {State#evstate{list_pid=Pid}, Resp}.
+
+store_ddoc(DDocs, DDocId, DDoc) ->
+    dict:store(DDocId, DDoc, DDocs).
+load_ddoc(DDocs, DDocId) ->
+    try dict:fetch(DDocId, DDocs) of
+        {DDoc} -> {DDoc}
+    catch
+        _:Else -> throw({error, ?l2b(io_lib:format("Native Query Server missing DDoc with Id: ~s",[DDocId]))})
+    end.
 
 bindings(State, Sig) ->
+    bindings(State, Sig, nil).
+bindings(State, Sig, DDoc) ->
     Self = self(),
 
     Log = fun(Msg) ->
@@ -262,14 +291,19 @@ bindings(State, Sig) ->
    
     FoldRows = fun(Fun, Acc) -> foldrows(GetRow, Fun, Acc) end,
 
-    [
+    Bindings = [
         {'Log', Log},
         {'Emit', Emit},
         {'Start', Start},
         {'Send', Send},
         {'GetRow', GetRow},
         {'FoldRows', FoldRows}
-    ].
+    ],
+    case DDoc of
+        {Props} ->
+            Bindings ++ [{'DDoc', DDoc}];
+        _Else -> Bindings
+    end.
 
 % thanks to erlview, via:
 % http://erlang.org/pipermail/erlang-questions/2003-November/010544.html
@@ -277,8 +311,11 @@ makefun(State, Source) ->
     Sig = erlang:md5(Source),
     BindFuns = bindings(State, Sig),
     {Sig, makefun(State, Source, BindFuns)}.
-
-makefun(_State, Source, BindFuns) ->
+makefun(State, Source, {DDoc}) ->
+    Sig = erlang:md5(lists:flatten([Source, term_to_binary(DDoc)])),
+    BindFuns = bindings(State, Sig, {DDoc}),
+    {Sig, makefun(State, Source, BindFuns)};
+makefun(_State, Source, BindFuns) when is_list(BindFuns) ->
     FunStr = binary_to_list(Source),
     {ok, Tokens, _} = erl_scan:string(FunStr),
     Form = case (catch erl_parse:parse_exprs(Tokens)) of
diff --git a/src/couchdb/couch_os_process.erl b/src/couchdb/couch_os_process.erl
index 72b715c3..5ac13715 100644
--- a/src/couchdb/couch_os_process.erl
+++ b/src/couchdb/couch_os_process.erl
@@ -53,7 +53,7 @@ prompt(Pid, Data) ->
         {ok, Result} ->
             Result;
         Error ->
-            ?LOG_ERROR("OS Process Error :: ~p",[Error]),
+            ?LOG_ERROR("OS Process Error ~p :: ~p",[Pid,Error]),
             throw(Error)
     end.
 
@@ -80,22 +80,24 @@ readline(#os_proc{port = Port} = OsProc, Acc) ->
 
 % Standard JSON functions
 writejson(OsProc, Data) when is_record(OsProc, os_proc) ->
-    % ?LOG_DEBUG("OS Process Input :: ~p", [Data]),
-    true = writeline(OsProc, ?JSON_ENCODE(Data)).
+    JsonData = ?JSON_ENCODE(Data),
+    ?LOG_DEBUG("OS Process ~p Input  :: ~s", [OsProc#os_proc.port, JsonData]),
+    true = writeline(OsProc, JsonData).
 
 readjson(OsProc) when is_record(OsProc, os_proc) ->
     Line = readline(OsProc),
+    ?LOG_DEBUG("OS Process ~p Output :: ~s", [OsProc#os_proc.port, Line]),
     case ?JSON_DECODE(Line) of
     [<<"log">>, Msg] when is_binary(Msg) ->
         % we got a message to log. Log it and continue
-        ?LOG_INFO("OS Process :: ~s", [Msg]),
+        ?LOG_INFO("OS Process ~p Log :: ~s", [OsProc#os_proc.port, Msg]),
         readjson(OsProc);
-    {[{<<"error">>, Id}, {<<"reason">>, Reason}]} ->
+    [<<"error">>, Id, Reason] ->
         throw({list_to_atom(binary_to_list(Id)),Reason});
-    {[{<<"reason">>, Reason}, {<<"error">>, Id}]} ->
+    [<<"fatal">>, Id, Reason] ->
+        ?LOG_INFO("OS Process ~p Fatal Error :: ~s ~p",[OsProc#os_proc.port, Id, Reason]),
         throw({list_to_atom(binary_to_list(Id)),Reason});
     Result ->
-        % ?LOG_DEBUG("OS Process Output :: ~p", [Result]),
         Result
     end.
 
@@ -112,6 +114,7 @@ init([Command, Options, PortOptions]) ->
     },
     KillCmd = readline(BaseProc),
     Pid = self(),
+    ?LOG_DEBUG("OS Process Start :: ~p", [BaseProc#os_proc.port]),
     spawn(fun() ->
             % this ensure the real os process is killed when this process dies.
             erlang:monitor(process, Pid),
@@ -143,8 +146,12 @@ handle_call({prompt, Data}, _From, OsProc) ->
         Writer(OsProc, Data),
         {reply, {ok, Reader(OsProc)}, OsProc}
     catch
-        throw:OsError ->
-            {stop, normal, OsError, OsProc}
+        throw:{error, OsError} ->
+            {reply, OsError, OsProc};
+        throw:{fatal, OsError} ->
+            {stop, normal, OsError, OsProc};
+        throw:OtherError ->
+            {stop, normal, OtherError, OsProc}
     end.
 
 handle_cast({send, Data}, #os_proc{writer=Writer}=OsProc) ->
diff --git a/src/couchdb/couch_query_servers.erl b/src/couchdb/couch_query_servers.erl
index 4ac56727..30f4c4c7 100644
--- a/src/couchdb/couch_query_servers.erl
+++ b/src/couchdb/couch_query_servers.erl
@@ -17,10 +17,11 @@
 
 -export([init/1, terminate/2, handle_call/3, handle_cast/2, handle_info/2,code_change/3,stop/0]).
 -export([start_doc_map/2, map_docs/2, stop_doc_map/1]).
--export([reduce/3, rereduce/3,validate_doc_update/5]).
--export([render_doc_show/6, render_doc_update/6, start_view_list/2,
-        render_list_head/4, render_list_row/4, render_list_tail/1]).
+-export([reduce/3, rereduce/3,validate_doc_update/4]).
 -export([filter_docs/5]).
+
+-export([with_ddoc_proc/2, proc_prompt/2, ddoc_prompt/3, ddoc_proc_prompt/3, json_doc/1]).
+
 % -export([test/0]).
 
 -include("couch_db.hrl").
@@ -28,6 +29,7 @@
 -record(proc, {
     pid,
     lang,
+    ddoc_keys = [],
     prompt_fun,
     set_timeout_fun,
     stop_fun
@@ -37,7 +39,7 @@ start_link() ->
     gen_server:start_link({local, couch_query_servers}, couch_query_servers, [], []).
 
 stop() ->
-    exit(whereis(couch_query_servers), close).
+    exit(whereis(couch_query_servers), normal).
 
 start_doc_map(Lang, Functions) ->
     Proc = get_os_process(Lang),
@@ -91,21 +93,15 @@ group_reductions_results(List) ->
 rereduce(_Lang, [], _ReducedValues) ->
     {ok, []};
 rereduce(Lang, RedSrcs, ReducedValues) ->
-    Proc = get_os_process(Lang),
-    Grouped = group_reductions_results(ReducedValues),
-    Results = try lists:zipwith(
+    Grouped = group_reductions_results(ReducedValues),    
+    Results = lists:zipwith(
         fun
         (<<"_", _/binary>> = FunSrc, Values) ->
             {ok, [Result]} = builtin_reduce(rereduce, [FunSrc], [[[], V] || V <- Values], []),
             Result;
         (FunSrc, Values) ->
-            [true, [Result]] =
-                proc_prompt(Proc, [<<"rereduce">>, [FunSrc], Values]),
-            Result
-        end, RedSrcs, Grouped)
-    after
-        ok = ret_os_process(Proc)
-    end,
+            os_rereduce(Lang, [FunSrc], Values)
+        end, RedSrcs, Grouped),
     {ok, Results}.
 
 reduce(_Lang, [], _KVs) ->
@@ -137,6 +133,17 @@ os_reduce(Lang, OsRedSrcs, KVs) ->
     end,
     {ok, OsResults}.
 
+os_rereduce(_Lang, [], _KVs) ->
+    {ok, []};
+os_rereduce(Lang, OsRedSrcs, KVs) ->
+    Proc = get_os_process(Lang),
+    try proc_prompt(Proc, [<<"rereduce">>, OsRedSrcs, KVs]) of
+        [true, [Reduction]] -> Reduction
+    after
+        ok = ret_os_process(Proc)
+    end.
+
+
 builtin_reduce(_Re, [], _KVs, Acc) ->
     {ok, lists:reverse(Acc)};
 builtin_reduce(Re, [<<"_sum">>|BuiltinReds], KVs, Acc) ->
@@ -157,92 +164,49 @@ builtin_sum_rows(KVs) ->
             throw({invalid_value, <<"builtin _sum function requires map values to be numbers">>})
     end, 0, KVs).
 
-validate_doc_update(Lang, FunSrc, EditDoc, DiskDoc, Ctx) ->
-    Proc = get_os_process(Lang),
-    JsonEditDoc = couch_doc:to_json_obj(EditDoc, [revs]),
-    JsonDiskDoc =
-    if DiskDoc == nil ->
-        null;
-    true ->
-        couch_doc:to_json_obj(DiskDoc, [revs])
-    end,
-    try proc_prompt(Proc,
-            [<<"validate">>, FunSrc, JsonEditDoc, JsonDiskDoc, Ctx]) of
-    1 ->
-        ok;
-    {[{<<"forbidden">>, Message}]} ->
-        throw({forbidden, Message});
-    {[{<<"unauthorized">>, Message}]} ->
-        throw({unauthorized, Message})
-    after
-        ok = ret_os_process(Proc)
-    end.
-% todo use json_apply_field
-append_docid(DocId, JsonReqIn) ->
-    [{<<"docId">>, DocId} | JsonReqIn].
 
-render_doc_show(Lang, ShowSrc, DocId, Doc, Req, Db) ->
-    Proc = get_os_process(Lang),
-    {JsonReqIn} = couch_httpd_external:json_req_obj(Req, Db),
-
-    {JsonReq, JsonDoc} = case {DocId, Doc} of
-        {nil, nil} -> {{JsonReqIn}, null};
-        {DocId, nil} -> {{append_docid(DocId, JsonReqIn)}, null};
-        _ -> {{append_docid(DocId, JsonReqIn)}, couch_doc:to_json_obj(Doc, [revs])}
-    end,
-    try proc_prompt(Proc, [<<"show">>, ShowSrc, JsonDoc, JsonReq])
-    after
-        ok = ret_os_process(Proc)
-    end.
-
-render_doc_update(Lang, UpdateSrc, DocId, Doc, Req, Db) ->
-    Proc = get_os_process(Lang),
-    {JsonReqIn} = couch_httpd_external:json_req_obj(Req, Db),
-
-    {JsonReq, JsonDoc} = case {DocId, Doc} of
-        {nil, nil} -> {{JsonReqIn}, null};
-        {DocId, nil} -> {{append_docid(DocId, JsonReqIn)}, null};
-        _ -> {{append_docid(DocId, JsonReqIn)}, couch_doc:to_json_obj(Doc, [revs])}
-    end,
-    try proc_prompt(Proc, [<<"update">>, UpdateSrc, JsonDoc, JsonReq])
-    after
-        ok = ret_os_process(Proc)
+% use the function stored in ddoc.validate_doc_update to test an update.
+validate_doc_update(DDoc, EditDoc, DiskDoc, Ctx) ->
+    JsonEditDoc = couch_doc:to_json_obj(EditDoc, [revs]),
+    JsonDiskDoc = json_doc(DiskDoc),  
+    case ddoc_prompt(DDoc, [<<"validate_doc_update">>], [JsonEditDoc, JsonDiskDoc, Ctx]) of
+        1 ->
+            ok;
+        {[{<<"forbidden">>, Message}]} ->
+            throw({forbidden, Message});
+        {[{<<"unauthorized">>, Message}]} ->
+            throw({unauthorized, Message})
     end.
 
-start_view_list(Lang, ListSrc) ->
-    Proc = get_os_process(Lang),
-    proc_prompt(Proc, [<<"add_fun">>, ListSrc]),
-    {ok, Proc}.
-
-render_list_head(Proc, Req, Db, Head) ->
-    JsonReq = couch_httpd_external:json_req_obj(Req, Db),
-    proc_prompt(Proc, [<<"list">>, Head, JsonReq]).
-
-render_list_row(Proc, Db, {{Key, DocId}, Value}, IncludeDoc) ->
-    JsonRow = couch_httpd_view:view_row_obj(Db, {{Key, DocId}, Value}, IncludeDoc),
-    proc_prompt(Proc, [<<"list_row">>, JsonRow]);
-
-render_list_row(Proc, _, {Key, Value}, _IncludeDoc) ->
-    JsonRow = {[{key, Key}, {value, Value}]},
-    proc_prompt(Proc, [<<"list_row">>, JsonRow]).
-
-render_list_tail(Proc) ->
-    JsonResp = proc_prompt(Proc, [<<"list_end">>]),
-    ok = ret_os_process(Proc),
-    JsonResp.
+json_doc(nil) -> null;
+json_doc(Doc) ->
+    couch_doc:to_json_obj(Doc, [revs]).
 
-filter_docs(Lang, Src, Docs, Req, Db) ->
+filter_docs(Req, Db, DDoc, FName, Docs) ->
     JsonReq = couch_httpd_external:json_req_obj(Req, Db),
     JsonDocs = [couch_doc:to_json_obj(Doc, [revs]) || Doc <- Docs],
     JsonCtx = couch_util:json_user_ctx(Db),
-    Proc = get_os_process(Lang),
-    [true, Passes] = proc_prompt(Proc,
-        [<<"filter">>, Src, JsonDocs, JsonReq, JsonCtx]),
-    ret_os_process(Proc),
-    {ok, Passes}.    
+    [true, Passes] = ddoc_prompt(DDoc, [<<"filters">>, FName], [JsonDocs, JsonReq, JsonCtx]),
+    {ok, Passes}.
+
+ddoc_proc_prompt({Proc, DDocId}, FunPath, Args) -> 
+    proc_prompt(Proc, [<<"ddoc">>, DDocId, FunPath, Args]).
+
+ddoc_prompt(DDoc, FunPath, Args) ->
+    with_ddoc_proc(DDoc, fun({Proc, DDocId}) ->
+        proc_prompt(Proc, [<<"ddoc">>, DDocId, FunPath, Args])
+    end).
+
+with_ddoc_proc(#doc{id=DDocId,revs={Start, [DiskRev|_]}}=DDoc, Fun) ->
+    Rev = couch_doc:rev_to_str({Start, DiskRev}),
+    DDocKey = {DDocId, Rev},
+    Proc = get_ddoc_process(DDoc, DDocKey),
+    try Fun({Proc, DDocId})
+    after
+        ok = ret_os_process(Proc)
+    end.
 
 init([]) ->
-
     % read config and register for configuration changes
 
     % just stop if one of the config settings change. couch_server_sup
@@ -282,7 +246,39 @@ init([]) ->
 terminate(_Reason, _Server) ->
     ok.
 
-
+handle_call({get_proc, #doc{body={Props}}=DDoc, DDocKey}, _From, {Langs, PidProcs, LangProcs, InUse}=Server) ->
+    % Note to future self. Add max process limit.
+    Lang = proplists:get_value(<<"language">>, Props, <<"javascript">>),    
+    case ets:lookup(LangProcs, Lang) of
+    [{Lang, [P|Rest]}] ->
+        % find a proc in the set that has the DDoc
+        case proc_with_ddoc(DDoc, DDocKey, [P|Rest]) of
+            {ok, Proc} ->
+                % looks like the proc isn't getting dropped from the list.
+                % we need to change this to take a fun for equality checking
+                % so we can do a comparison on portnum
+                rem_from_list(LangProcs, Lang, Proc),
+                add_to_list(InUse, Lang, Proc),
+                {reply, {ok, Proc, get_query_server_config()}, Server};
+            Error -> 
+                {reply, Error, Server}
+            end;
+    _ ->
+        case (catch new_process(Langs, Lang)) of
+        {ok, Proc} ->
+            add_value(PidProcs, Proc#proc.pid, Proc),
+            case proc_with_ddoc(DDoc, DDocKey, [Proc]) of
+                {ok, Proc2} ->
+                    rem_from_list(LangProcs, Lang, Proc),
+                    add_to_list(InUse, Lang, Proc2),
+                    {reply, {ok, Proc2, get_query_server_config()}, Server};
+                Error -> 
+                    {reply, Error, Server}
+                end;
+        Error ->
+            {reply, Error, Server}
+        end
+    end;
 handle_call({get_proc, Lang}, _From, {Langs, PidProcs, LangProcs, InUse}=Server) ->
     % Note to future self. Add max process limit.
     case ets:lookup(LangProcs, Lang) of
@@ -290,12 +286,13 @@ handle_call({get_proc, Lang}, _From, {Langs, PidProcs, LangProcs, InUse}=Server)
         add_value(PidProcs, Proc#proc.pid, Proc),
         rem_from_list(LangProcs, Lang, Proc),
         add_to_list(InUse, Lang, Proc),
-        {reply, {recycled, Proc, get_query_server_config()}, Server};
+        {reply, {ok, Proc, get_query_server_config()}, Server};
     _ ->
         case (catch new_process(Langs, Lang)) of
         {ok, Proc} ->
+            add_value(PidProcs, Proc#proc.pid, Proc),
             add_to_list(InUse, Lang, Proc),
-            {reply, {new, Proc}, Server};
+            {reply, {ok, Proc, get_query_server_config()}, Server};
         Error ->
             {reply, Error, Server}
         end
@@ -350,6 +347,23 @@ new_process(Langs, Lang) ->
         {unknown_query_language, Lang}
     end.
 
+proc_with_ddoc(DDoc, DDocKey, LangProcs) ->
+    DDocProcs = lists:filter(fun(#proc{ddoc_keys=Keys}) -> 
+            lists:any(fun(Key) ->
+                Key == DDocKey
+            end, Keys)
+        end, LangProcs),
+    case DDocProcs of
+        [DDocProc|_] ->
+            ?LOG_DEBUG("DDocProc found for DDocKey: ~p",[DDocKey]),
+            {ok, DDocProc};
+        [] ->
+            [TeachProc|_] = LangProcs,
+            ?LOG_DEBUG("Teach ddoc to new proc ~p with DDocKey: ~p",[TeachProc, DDocKey]),
+            {ok, SmartProc} = teach_ddoc(DDoc, DDocKey, TeachProc),
+            {ok, SmartProc}
+    end.
+
 proc_prompt(Proc, Args) ->
     {Mod, Func} = Proc#proc.prompt_fun,
     apply(Mod, Func, [Proc#proc.pid, Args]).
@@ -362,14 +376,44 @@ proc_set_timeout(Proc, Timeout) ->
     {Mod, Func} = Proc#proc.set_timeout_fun,
     apply(Mod, Func, [Proc#proc.pid, Timeout]).
 
+teach_ddoc(DDoc, {DDocId, _Rev}=DDocKey, #proc{ddoc_keys=Keys}=Proc) ->
+    % send ddoc over the wire
+    % we only share the rev with the client we know to update code
+    % but it only keeps the latest copy, per each ddoc, around.
+    true = proc_prompt(Proc, [<<"ddoc">>, <<"new">>, DDocId, couch_doc:to_json_obj(DDoc, [])]),
+    % we should remove any other ddocs keys for this docid
+    % because the query server overwrites without the rev
+    Keys2 = [{D,R} || {D,R} <- Keys, D /= DDocId],
+    % add ddoc to the proc
+    {ok, Proc#proc{ddoc_keys=[DDocKey|Keys2]}}.
+
+get_ddoc_process(#doc{} = DDoc, DDocKey) ->
+    % remove this case statement
+    case gen_server:call(couch_query_servers, {get_proc, DDoc, DDocKey}) of
+    {ok, Proc, QueryConfig} ->
+        % process knows the ddoc
+        case (catch proc_prompt(Proc, [<<"reset">>, QueryConfig])) of
+        true ->
+            proc_set_timeout(Proc, list_to_integer(couch_config:get(
+                                "couchdb", "os_process_timeout", "5000"))),
+            link(Proc#proc.pid),
+            Proc;
+        _ ->
+            catch proc_stop(Proc),
+            get_ddoc_process(DDoc, DDocKey)
+        end;
+    Error ->
+        throw(Error)
+    end.
+
+ret_ddoc_process(Proc) ->
+    true = gen_server:call(couch_query_servers, {ret_proc, Proc}),
+    catch unlink(Proc#proc.pid),
+    ok.
+
 get_os_process(Lang) ->
     case gen_server:call(couch_query_servers, {get_proc, Lang}) of
-    {new, Proc} ->
-        proc_set_timeout(Proc, list_to_integer(couch_config:get(
-                            "couchdb", "os_process_timeout", "5000"))),
-        link(Proc#proc.pid),
-        Proc;
-    {recycled, Proc, QueryConfig} ->
+    {ok, Proc, QueryConfig} ->
         case (catch proc_prompt(Proc, [<<"reset">>, QueryConfig])) of
         true ->
             proc_set_timeout(Proc, list_to_integer(couch_config:get(
@@ -403,9 +447,20 @@ add_to_list(Tid, Key, Value) ->
         true = ets:insert(Tid, {Key, [Value]})
     end.
 
+rem_from_list(Tid, Key, Value) when is_record(Value, proc)->
+    Pid = Value#proc.pid,
+    case ets:lookup(Tid, Key) of
+    [{Key, Vals}] ->
+        % make a new values list that doesn't include the Value arg
+        NewValues = [Val || #proc{pid=P}=Val <- Vals, P /= Pid],
+        ets:insert(Tid, {Key, NewValues});
+    [] -> ok
+    end;
 rem_from_list(Tid, Key, Value) ->
     case ets:lookup(Tid, Key) of
     [{Key, Vals}] ->
-        ets:insert(Tid, {Key, [Val || Val <- Vals, Val /= Value]});
+        % make a new values list that doesn't include the Value arg
+        NewValues = [Val || Val <- Vals, Val /= Value],
+        ets:insert(Tid, {Key, NewValues});
     [] -> ok
     end.