Name view index files by their function hashes for no downtime deploys. Closes COUCHDB-218

Adds ability to switch view indexes on the fly by building the index from a "staging" design doc, and then COPYing the staging doc to the production doc's id. Since indexes are referenced by view definition, the new version of the production design doc will point immediately to the index files already built in staging.

Please use and give feedback.


git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@791140 13f79535-47bb-0310-9956-ffa450edef68

11 files changed, 253 insertions, 156 deletions

diff --git a/etc/couchdb/default.ini.tpl.in b/etc/couchdb/default.ini.tpl.in
index cfe27422..25509615 100644
--- a/etc/couchdb/default.ini.tpl.in
+++ b/etc/couchdb/default.ini.tpl.in
@@ -65,6 +65,7 @@ _sleep = {couch_httpd_misc_handlers, handle_sleep_req}
 _whoami = {couch_httpd_misc_handlers, handle_whoami_req}
 
 [httpd_db_handlers]
+_view_cleanup = {couch_httpd_db, handle_view_cleanup_req}
 _compact = {couch_httpd_db, handle_compact_req}
 _design = {couch_httpd_db, handle_design_req}
 _temp_view = {couch_httpd_view, handle_temp_view_req}
@@ -80,3 +81,4 @@ _changes = {couch_httpd_db, handle_changes_req}
 _view = {couch_httpd_view, handle_view_req}
 _show = {couch_httpd_show, handle_doc_show_req}
 _list = {couch_httpd_show, handle_view_list_req}
+_info = {couch_httpd_db,   handle_design_info_req}
diff --git a/share/www/script/couch.js b/share/www/script/couch.js
index 8f3d96ad..c4c1ae9f 100644
--- a/share/www/script/couch.js
+++ b/share/www/script/couch.js
@@ -177,6 +177,19 @@ function CouchDB(name, httpHeaders) {
     return JSON.parse(this.last_req.responseText);
   }
 
+  // gets information about a design doc
+  this.designInfo = function(docid) {
+    this.last_req = this.request("GET", this.uri + docid + "/_info");
+    CouchDB.maybeThrowError(this.last_req);
+    return JSON.parse(this.last_req.responseText);
+  }
+  
+  this.viewCleanup = function() {
+    this.last_req = this.request("POST", this.uri + "_view_cleanup");
+    CouchDB.maybeThrowError(this.last_req);
+    return JSON.parse(this.last_req.responseText);
+  }
+
   this.allDocs = function(options,keys) {
     if(!keys) {
       this.last_req = this.request("GET", this.uri + "_all_docs" + encodeOptions(options));      
diff --git a/share/www/script/test/design_docs.js b/share/www/script/test/design_docs.js
index 8f003efa..b1ff8432 100644
--- a/share/www/script/test/design_docs.js
+++ b/share/www/script/test/design_docs.js
@@ -49,6 +49,14 @@ function() {
   }
   T(db.save(designDoc).ok);
 
+  // test that we get design doc info back
+  var dinfo = db.designInfo("_design/test");
+  TEquals("test", dinfo.name);
+  var vinfo = dinfo.view_index;
+  TEquals(51, vinfo.disk_size);
+  TEquals(false, vinfo.compact_running);
+  TEquals("64625dce94960fd5ca116e42aa9d011a", vinfo.signature);
+
   db.bulkSave(makeDocs(1, numDocs + 1));
 
   // test that the _all_docs view returns correctly with keys
@@ -66,7 +74,7 @@ function() {
     T(db.ensureFullCommit().ok);
     restartServer();
   };
-  
+    
   // test when language not specified, Javascript is implied
   var designDoc2 = {
     _id:"_design/test2",
@@ -110,5 +118,9 @@ function() {
   restartServer();
   T(db.open(designDoc._id) == null);
   T(db.view("test/no_docs") == null);
+  
+  // trigger ddoc cleanup
+  T(db.viewCleanup().ok);
+  
 });
 };
diff --git a/src/couchdb/couch_db.erl b/src/couchdb/couch_db.erl
index 979bd39d..2f0fa847 100644
--- a/src/couchdb/couch_db.erl
+++ b/src/couchdb/couch_db.erl
@@ -13,7 +13,7 @@
 -module(couch_db).
 -behaviour(gen_server).
 
--export([open/2,close/1,create/2,start_compact/1,get_db_info/1]).
+-export([open/2,close/1,create/2,start_compact/1,get_db_info/1,get_design_docs/1]).
 -export([open_ref_counted/2,is_idle/1,monitor/1,count_changes_since/2]).
 -export([update_doc/3,update_docs/4,update_docs/2,update_docs/3,delete_doc/3]).
 -export([get_doc_info/2,open_doc/2,open_doc/3,open_doc_revs/4]).
@@ -192,6 +192,16 @@ get_db_info(Db) ->
         ],
     {ok, InfoList}.
 
+get_design_docs(#db{fulldocinfo_by_id_btree=Btree}=Db) ->
+    couch_btree:foldl(Btree, <<"_design/">>,
+        fun(#full_doc_info{id= <<"_design/",_/binary>>}=FullDocInfo, _Reds, AccDocs) ->
+            {ok, Doc} = couch_db:open_doc_int(Db, FullDocInfo, []),
+            {ok, [Doc | AccDocs]};
+        (_, _Reds, AccDocs) ->
+            {stop, AccDocs}
+        end,
+        []).
+
 check_is_admin(#db{admins=Admins, user_ctx=#user_ctx{name=Name,roles=Roles}}) ->
     DbAdmins = [<<"_admin">> | Admins],
     case DbAdmins -- [Name | Roles] of
diff --git a/src/couchdb/couch_db.hrl b/src/couchdb/couch_db.hrl
index 580b91cb..905b489b 100644
--- a/src/couchdb/couch_db.hrl
+++ b/src/couchdb/couch_db.hrl
@@ -190,8 +190,7 @@
     headers = []
 }).
 
--record(group,
-    {type=view, % can also be temp_view
+-record(group, {
     sig=nil,
     db=nil,
     fd=nil,
diff --git a/src/couchdb/couch_db_updater.erl b/src/couchdb/couch_db_updater.erl
index 31ddbf8c..6fef29eb 100644
--- a/src/couchdb/couch_db_updater.erl
+++ b/src/couchdb/couch_db_updater.erl
@@ -350,7 +350,7 @@ close_db(#db{fd_ref_counter = RefCntr}) ->
     
 
 refresh_validate_doc_funs(Db) ->
-    {ok, DesignDocs} = get_design_docs(Db),
+    {ok, DesignDocs} = couch_db:get_design_docs(Db),
     ProcessDocFuns = lists:flatmap(
         fun(DesignDoc) ->
             case couch_doc:get_validate_doc_fun(DesignDoc) of
@@ -360,16 +360,6 @@ refresh_validate_doc_funs(Db) ->
         end, DesignDocs),
     Db#db{validate_doc_funs=ProcessDocFuns}.
 
-get_design_docs(#db{fulldocinfo_by_id_btree=Btree}=Db) ->
-    couch_btree:foldl(Btree, <<"_design/">>,
-        fun(#full_doc_info{id= <<"_design/",_/binary>>}=FullDocInfo, _Reds, AccDocs) ->
-            {ok, Doc} = couch_db:open_doc_int(Db, FullDocInfo, []),
-            {ok, [Doc | AccDocs]};
-        (_, _Reds, AccDocs) ->
-            {stop, AccDocs}
-        end,
-        []).
-
 % rev tree functions
 
 flush_trees(_Db, [], AccFlushedTrees) ->
diff --git a/src/couchdb/couch_httpd_db.erl b/src/couchdb/couch_httpd_db.erl
index 8c692f8d..edb2f310 100644
--- a/src/couchdb/couch_httpd_db.erl
+++ b/src/couchdb/couch_httpd_db.erl
@@ -15,7 +15,8 @@
 
 -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]).
+    update_doc_result_to_json/1, update_doc_result_to_json/2,
+    handle_design_info_req/2, handle_view_cleanup_req/2]).
 
 -import(couch_httpd,
     [send_json/2,send_json/3,send_json/4,send_method_not_allowed/2,
@@ -156,6 +157,15 @@ handle_compact_req(#httpd{method='POST'}=Req, Db) ->
 handle_compact_req(Req, _Db) ->
     send_method_not_allowed(Req, "POST").
 
+handle_view_cleanup_req(#httpd{method='POST'}=Req, Db) ->
+    % delete unreferenced index files
+    ok = couch_view:cleanup_index_files(Db),
+    send_json(Req, 202, {[{ok, true}]});
+
+handle_view_cleanup_req(Req, _Db) ->
+    send_method_not_allowed(Req, "POST").
+
+
 handle_design_req(#httpd{
         path_parts=[_DbName,_Design,_DesName, <<"_",_/binary>> = Action | _Rest],
         design_url_handlers = DesignUrlHandlers
@@ -166,6 +176,23 @@ handle_design_req(#httpd{
 handle_design_req(Req, Db) ->
     db_req(Req, Db).
 
+handle_design_info_req(#httpd{
+            method='GET',
+            path_parts=[_DbName, _Design, DesignName, _]
+        }=Req, Db) ->
+    DesignId = <<"_design/", DesignName/binary>>,
+    ?LOG_ERROR("DesignId ~p",[DesignId]),
+    {ok, GroupInfoList} = couch_view:get_group_info(Db, DesignId),
+    ?LOG_ERROR("GroupInfoList ~p",[GroupInfoList]),
+    send_json(Req, 200, {[
+        {name, DesignName},
+        {view_index, {GroupInfoList}}
+    ]});
+    
+handle_design_info_req(Req, _Db) ->
+    send_method_not_allowed(Req, "GET").
+
+
 create_db_req(#httpd{user_ctx=UserCtx}=Req, DbName) ->
     ok = couch_httpd:verify_is_server_admin(Req),
     case couch_server:create(DbName, [{user_ctx, UserCtx}]) of
diff --git a/src/couchdb/couch_task_status.erl b/src/couchdb/couch_task_status.erl
index ff2c7bee..ee7bdff5 100644
--- a/src/couchdb/couch_task_status.erl
+++ b/src/couchdb/couch_task_status.erl
@@ -107,12 +107,12 @@ handle_call(all, _, Server) ->
 
 handle_cast({update_status, Pid, StatusText}, Server) ->
     [{Pid, {Type, TaskName, _StatusText}}] = ets:lookup(?MODULE, Pid),
+    ?LOG_DEBUG("New task status for ~s: ~s",[TaskName, StatusText]),
     true = ets:insert(?MODULE, {Pid, {Type, TaskName, StatusText}}),
     {noreply, Server};
 handle_cast(stop, State) ->
     {stop, normal, State}.
 
-
 handle_info({'DOWN', _MonitorRef, _Type, Pid, _Info}, Server) ->
     %% should we also erlang:demonitor(_MonitorRef), ?
     ets:delete(?MODULE, Pid),
diff --git a/src/couchdb/couch_view.erl b/src/couchdb/couch_view.erl
index 301ea8b7..87feea12 100644
--- a/src/couchdb/couch_view.erl
+++ b/src/couchdb/couch_view.erl
@@ -17,7 +17,7 @@
     detuple_kvs/2,init/1,terminate/2,handle_call/3,handle_cast/2,handle_info/2,
     code_change/3,get_reduce_view/4,get_temp_reduce_view/5,get_temp_map_view/4,
     get_map_view/4,get_row_count/1,reduce_to_count/1,fold_reduce/7,
-    extract_map_view/1,get_group_server/2]).
+    extract_map_view/1,get_group_server/2,get_group_info/2,cleanup_index_files/1]).
 
 -include("couch_db.hrl").
 
@@ -28,18 +28,32 @@
 start_link() ->
     gen_server:start_link({local, couch_view}, couch_view, [], []).
 
-get_temp_updater(DbName, Type, DesignOptions, MapSrc, RedSrc) ->
-    {ok, Pid} = gen_server:call(couch_view,
-            {start_temp_updater, DbName, Type, DesignOptions, MapSrc, RedSrc}),
-    Pid.
-
-get_group_server(DbName, GroupId) ->
-    case gen_server:call(couch_view, {start_group_server, DbName, GroupId}) of
+get_temp_updater(DbName, Language, DesignOptions, MapSrc, RedSrc) ->
+    % make temp group
+    % do we need to close this db?
+    {ok, _Db, Group} = 
+        couch_view_group:open_temp_group(DbName, Language, DesignOptions, MapSrc, RedSrc),
+    case gen_server:call(couch_view, {get_group_server, DbName, Group}) of
     {ok, Pid} ->
         Pid;
     Error ->
         throw(Error)
     end.
+
+get_group_server(DbName, GroupId) ->
+    % get signature for group
+    case couch_view_group:open_db_group(DbName, GroupId) of
+    % do we need to close this db?
+    {ok, _Db, Group} ->        
+        case gen_server:call(couch_view, {get_group_server, DbName, Group}) of
+        {ok, Pid} ->
+            Pid;
+        Error ->
+            throw(Error)
+        end;
+    Error ->
+        throw(Error)
+    end.
     
 get_group(Db, GroupId, Stale) ->
     MinUpdateSeq = case Stale of
@@ -50,18 +64,52 @@ get_group(Db, GroupId, Stale) ->
             get_group_server(couch_db:name(Db), GroupId),
             MinUpdateSeq).
 
-
-get_temp_group(Db, Type, DesignOptions, MapSrc, RedSrc) ->
+get_temp_group(Db, Language, DesignOptions, MapSrc, RedSrc) ->
     couch_view_group:request_group(
-            get_temp_updater(couch_db:name(Db), Type, DesignOptions, MapSrc, RedSrc),
-            couch_db:get_update_seq(Db)).
+        get_temp_updater(couch_db:name(Db), Language, DesignOptions, MapSrc, RedSrc),
+        couch_db:get_update_seq(Db)).
+
+get_group_info(Db, GroupId) ->
+    couch_view_group:request_group_info(
+        get_group_server(couch_db:name(Db), GroupId)).
+
+cleanup_index_files(Db) -> 
+    % load all ddocs
+    {ok, DesignDocs} = couch_db:get_design_docs(Db),
+    
+    % make unique list of group sigs
+    Sigs = lists:map(fun(#doc{id = GroupId} = DDoc) ->
+        {ok, Info} = get_group_info(Db, GroupId),
+        ?b2l(proplists:get_value(signature, Info))
+    end, [DD||DD <- DesignDocs, DD#doc.deleted == false]),
+    
+    FileList = list_index_files(Db),
+    
+    % regex that matches all ddocs
+    RegExp = "("++ string:join(Sigs, "|") ++")",
+
+    % filter out the ones in use
+    DeleteFiles = lists:filter(fun(FilePath) -> 
+            regexp:first_match(FilePath, RegExp)==nomatch
+        end, FileList),
+    % delete unused files
+    ?LOG_DEBUG("deleting unused view index files: ~p",[DeleteFiles]),
+    [file:delete(File)||File <- DeleteFiles],
+    ok.
+
+list_index_files(Db) ->
+    % call server to fetch the index files
+    RootDir = couch_config:get("couchdb", "view_index_dir"),
+    Files = filelib:wildcard(RootDir ++ "/." ++ ?b2l(couch_db:name(Db)) ++ "_design"++"/*").
+
 
 get_row_count(#view{btree=Bt}) ->
     {ok, {Count, _Reds}} = couch_btree:full_reduce(Bt),
     {ok, Count}.
 
-get_temp_reduce_view(Db, Type, DesignOptions, MapSrc, RedSrc) ->
-    {ok, #group{views=[View]}=Group} = get_temp_group(Db, Type, DesignOptions, MapSrc, RedSrc),
+get_temp_reduce_view(Db, Language, DesignOptions, MapSrc, RedSrc) ->
+    {ok, #group{views=[View]}=Group} = 
+        get_temp_group(Db, Language, DesignOptions, MapSrc, RedSrc),
     {ok, {temp_reduce, View}, Group}.
 
 
@@ -141,8 +189,8 @@ get_key_pos(Key, [_|Rest], N) ->
     get_key_pos(Key, Rest, N+1).
 
 
-get_temp_map_view(Db, Type, DesignOptions, Src) ->
-    {ok, #group{views=[View]}=Group} = get_temp_group(Db, Type, DesignOptions, Src, []),
+get_temp_map_view(Db, Language, DesignOptions, Src) ->
+    {ok, #group{views=[View]}=Group} = get_temp_group(Db, Language, DesignOptions, Src, []),
     {ok, View, Group}.
 
 get_map_view(Db, GroupId, Name, Stale) ->
@@ -220,9 +268,8 @@ init([]) ->
             ok
         end),
     ets:new(couch_groups_by_db, [bag, private, named_table]),
-    ets:new(group_servers_by_name, [set, protected, named_table]),
+    ets:new(group_servers_by_sig, [set, protected, named_table]),
     ets:new(couch_groups_by_updater, [set, private, named_table]),
-    ets:new(couch_temp_group_fd_by_db, [set, protected, named_table]),
     process_flag(trap_exit, true),
     {ok, #server{root_dir=RootDir}}.
 
@@ -232,37 +279,15 @@ terminate(Reason, _Srv) ->
     ok.
 
 
-handle_call({start_temp_updater, DbName, Lang, DesignOptions, MapSrc, RedSrc},
-                                                _From, #server{root_dir=Root}=Server) ->
-    <<SigInt:128/integer>> = erlang:md5(term_to_binary({Lang, DesignOptions, MapSrc, RedSrc})),
-    Name = lists:flatten(io_lib:format("_temp_~.36B",[SigInt])),
-    Pid = 
-    case ets:lookup(group_servers_by_name, {DbName, Name}) of
+handle_call({get_group_server, DbName, 
+    #group{name=GroupId,sig=Sig}=Group}, _From, #server{root_dir=Root}=Server) ->
+    case ets:lookup(group_servers_by_sig, {DbName, Sig}) of
     [] ->
-        case ets:lookup(couch_temp_group_fd_by_db, DbName) of
-        [] ->
-            FileName = Root ++ "/." ++ binary_to_list(DbName) ++ "_temp",
-            {ok, Fd} = couch_file:open(FileName, [create, overwrite]),
-            Count = 0;
-        [{_, Fd, Count}] ->
-            ok
-        end,
-        ?LOG_DEBUG("Spawning new temp update process for db ~s.", [DbName]),
-        {ok, NewPid} = couch_view_group:start_link({slow_view, DbName, Fd, Lang, DesignOptions, MapSrc, RedSrc}),
-        true = ets:insert(couch_temp_group_fd_by_db, {DbName, Fd, Count + 1}),
-        add_to_ets(NewPid, DbName, Name),
-        NewPid;
-    [{_, ExistingPid0}] ->
-        ExistingPid0
-    end,
-    {reply, {ok, Pid}, Server};
-handle_call({start_group_server, DbName, GroupId}, _From, #server{root_dir=Root}=Server) ->
-    case ets:lookup(group_servers_by_name, {DbName, GroupId}) of
-    [] ->
-        ?LOG_DEBUG("Spawning new group server for view group ~s in database ~s.", [GroupId, DbName]),
-        case (catch couch_view_group:start_link({view, Root, DbName, GroupId})) of
+        ?LOG_DEBUG("Spawning new group server for view group ~s in database ~s.", 
+            [GroupId, DbName]),
+        case (catch couch_view_group:start_link({Root, DbName, Group})) of
         {ok, NewPid} ->
-            add_to_ets(NewPid, DbName, GroupId),
+            add_to_ets(NewPid, DbName, Sig),
             {reply, {ok, NewPid}, Server};
         Error ->
             {reply, Error, Server}
@@ -272,22 +297,22 @@ handle_call({start_group_server, DbName, GroupId}, _From, #server{root_dir=Root}
     end.
 
 handle_cast({reset_indexes, DbName}, #server{root_dir=Root}=Server) ->
-    % shutdown all the updaters
+    % shutdown all the updaters and clear the files, the db got changed
     Names = ets:lookup(couch_groups_by_db, DbName),
     lists:foreach(
-        fun({_DbName, GroupId}) ->
-            ?LOG_DEBUG("Killing update process for view group ~s. in database ~s.", [GroupId, DbName]),
-            [{_, Pid}] = ets:lookup(group_servers_by_name, {DbName, GroupId}),
+        fun({_DbName, Sig}) ->
+            ?LOG_DEBUG("Killing update process for view group ~s. in database ~s.", [Sig, DbName]),
+            [{_, Pid}] = ets:lookup(group_servers_by_sig, {DbName, Sig}),
             exit(Pid, kill),
             receive {'EXIT', Pid, _} ->
-                delete_from_ets(Pid, DbName, GroupId)
+                delete_from_ets(Pid, DbName, Sig)
             end
         end, Names),
     delete_index_dir(Root, DbName),
     file:delete(Root ++ "/." ++ binary_to_list(DbName) ++ "_temp"),
     {noreply, Server}.
 
-handle_info({'EXIT', FromPid, Reason}, #server{root_dir=RootDir}=Server) ->
+handle_info({'EXIT', FromPid, Reason}, Server) ->
     case ets:lookup(couch_groups_by_updater, FromPid) of
     [] ->
         if Reason /= normal ->
@@ -296,40 +321,27 @@ handle_info({'EXIT', FromPid, Reason}, #server{root_dir=RootDir}=Server) ->
             exit(Reason);
         true -> ok
         end;
-    [{_, {DbName, "_temp_" ++ _ = GroupId}}] ->
-        delete_from_ets(FromPid, DbName, GroupId),
-        [{_, Fd, Count}] = ets:lookup(couch_temp_group_fd_by_db, DbName),
-        case Count of
-        1 -> % Last ref
-            couch_file:close(Fd),
-            file:delete(RootDir ++ "/." ++ binary_to_list(DbName) ++ "_temp"),
-            true = ets:delete(couch_temp_group_fd_by_db, DbName);
-        _ ->
-            true = ets:insert(couch_temp_group_fd_by_db, {DbName, Fd, Count - 1})
-        end;
     [{_, {DbName, GroupId}}] ->
         delete_from_ets(FromPid, DbName, GroupId)
     end,
     {noreply, Server}.
     
-add_to_ets(Pid, DbName, GroupId) ->
-    true = ets:insert(couch_groups_by_updater, {Pid, {DbName, GroupId}}),
-    true = ets:insert(group_servers_by_name, {{DbName, GroupId}, Pid}),
-    true = ets:insert(couch_groups_by_db, {DbName, GroupId}).
+add_to_ets(Pid, DbName, Sig) ->
+    true = ets:insert(couch_groups_by_updater, {Pid, {DbName, Sig}}),
+    true = ets:insert(group_servers_by_sig, {{DbName, Sig}, Pid}),
+    true = ets:insert(couch_groups_by_db, {DbName, Sig}).
     
-delete_from_ets(Pid, DbName, GroupId) ->
+delete_from_ets(Pid, DbName, Sig) ->
     true = ets:delete(couch_groups_by_updater, Pid),
-    true = ets:delete(group_servers_by_name, {DbName, GroupId}),
-    true = ets:delete_object(couch_groups_by_db, {DbName, GroupId}).
+    true = ets:delete(group_servers_by_sig, {DbName, Sig}),
+    true = ets:delete_object(couch_groups_by_db, {DbName, Sig}).
 
 code_change(_OldVsn, State, _Extra) ->
     {ok, State}.
 
 
-
-
 delete_index_dir(RootDir, DbName) ->
-    nuke_dir(RootDir ++ "/." ++ binary_to_list(DbName) ++ "_design").
+    nuke_dir(RootDir ++ "/." ++ ?b2l(DbName) ++ "_design").
 
 nuke_dir(Dir) ->
     case file:list_dir(Dir) of
diff --git a/src/couchdb/couch_view_group.erl b/src/couchdb/couch_view_group.erl
index 0ab1077e..0b390b22 100644
--- a/src/couchdb/couch_view_group.erl
+++ b/src/couchdb/couch_view_group.erl
@@ -14,8 +14,8 @@
 -behaviour(gen_server).
 
 %% API
--export([start_link/1, request_group/2]).
--export([design_doc_to_view_group/1]).
+-export([start_link/1, request_group/2, request_group_info/1]).
+-export([open_db_group/2, open_temp_group/5, design_doc_to_view_group/1,design_root/2]).
 
 %% gen_server callbacks
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
@@ -47,6 +47,22 @@ request_group(Pid, Seq) ->
         throw(Error)
     end.
 
+request_group_info(Pid) ->
+    case gen_server:call(Pid, request_group_info) of
+    {ok, GroupInfoList} ->
+        {ok, GroupInfoList};
+    Error ->
+        throw(Error)
+    end.
+
+request_index_files(Pid) ->
+    case gen_server:call(Pid, request_index_files) of
+    {ok, Filelist} ->
+        {ok, Filelist};
+    Error ->
+        throw(Error)
+    end.
+
 
 % from template
 start_link(InitArgs) ->
@@ -67,9 +83,7 @@ start_link(InitArgs) ->
         Error
     end.
 
-% init differentiates between temp and design_doc views. It creates a closure
-% which spawns the appropriate view_updater. (It might also spawn the first
-% view_updater run.)
+% init creates a closure which spawns the appropriate view_updater. 
 init({InitArgs, ReturnPid, Ref}) ->
     process_flag(trap_exit, true),
     case prepare_group(InitArgs, false) of
@@ -95,8 +109,7 @@ init({InitArgs, ReturnPid, Ref}) ->
 % view group, and the couch_view_updater, which when spawned, updates the
 % group and sends it back here. We employ a caching mechanism, so that between
 % database writes, we don't have to spawn a couch_view_updater with every view
-% request. This should give us more control, and the ability to request view
-% statuses eventually.
+% request.
 
 % The caching mechanism: each request is submitted with a seq_id for the
 % database at the time it was read. We guarantee to return a view from that
@@ -137,8 +150,14 @@ handle_call({request_group, RequestSeq}, From,
         #group_state{waiting_list=WaitList}=State) ->
     {noreply, State#group_state{
         waiting_list=[{From, RequestSeq}|WaitList]
-        }, infinity}.
+        }, infinity};
 
+handle_call(request_group_info, _From, #group_state{
+            group = Group,
+            compactor_pid = CompactorPid
+        } = State) ->
+    GroupInfo = get_group_info(Group, CompactorPid),
+    {reply, {ok, GroupInfo}, State}.
 
 handle_cast({start_compact, CompactFun}, #group_state{ compactor_pid=nil, 
         group=Group, init_args={view, RootDir, DbName, GroupId} } = State) ->
@@ -154,15 +173,14 @@ handle_cast({start_compact, _}, State) ->
 
 handle_cast({compact_done, #group{fd=NewFd, current_seq=NewSeq} = NewGroup}, 
         #group_state{ 
-            group = #group{current_seq=OldSeq} = Group,
-            init_args = {view, RootDir, DbName, GroupId}, 
+            group = #group{current_seq=OldSeq, sig=GroupSig} = Group,
+            init_args = {view, RootDir, DbName, _GroupId}, 
             updater_pid = nil,
             ref_counter = RefCounter
         } = State) when NewSeq >= OldSeq ->
     ?LOG_INFO("View Group compaction complete", []),
-    BaseName = RootDir ++ "/." ++ ?b2l(DbName) ++ ?b2l(GroupId),
-    FileName = BaseName ++ ".view",
-    CompactName = BaseName ++".compact.view",
+    FileName = index_file_name(RootDir, DbName, GroupSig),
+    CompactName = index_file_name(compact, RootDir, DbName, GroupSig),
     file:delete(FileName),
     ok = file:rename(CompactName, FileName),
     
@@ -224,8 +242,7 @@ handle_info({'EXIT', FromPid, {new_group, #group{db=Db}=Group}},
             waiting_list=WaitList,
             waiting_commit=WaitingCommit}=State) when UpPid == FromPid ->
     ok = couch_db:close(Db),
-
-    if Group#group.type == view andalso not WaitingCommit ->
+    if not WaitingCommit ->
         erlang:send_after(1000, self(), delayed_commit);
     true -> ok
     end,
@@ -306,12 +323,13 @@ reply_all(#group_state{waiting_list=WaitList}=State, Reply) ->
     [catch gen_server:reply(Pid, Reply) || {Pid, _} <- WaitList],
     State#group_state{waiting_list=[]}.
 
-prepare_group({view, RootDir, DbName, GroupId}, ForceReset)->
-    case open_db_group(DbName, GroupId) of
-    {ok, Db, #group{sig=Sig}=Group} ->
-        case open_index_file(RootDir, DbName, GroupId) of
+prepare_group({RootDir, DbName, #group{sig=Sig}=Group}, ForceReset)->
+    case couch_db:open(DbName, []) of
+    {ok, Db} ->
+        case open_index_file(RootDir, DbName, Sig) of
         {ok, Fd} ->
             if ForceReset ->
+                % this can happen if we missed a purge
                 {ok, reset_file(Db, Fd, DbName, Group)};
             true ->
                 % 09 UPGRADE CODE
@@ -321,32 +339,18 @@ prepare_group({view, RootDir, DbName, GroupId}, ForceReset)->
                     % sigs match!
                     {ok, init_group(Db, Fd, Group, HeaderInfo)};
                 _ ->
+                    % this happens on a new file
                     {ok, reset_file(Db, Fd, DbName, Group)}
                 end
             end;
         Error ->
-            catch delete_index_file(RootDir, DbName, GroupId),
+            catch delete_index_file(RootDir, DbName, Sig),
             Error
         end;
-    Error ->
-        catch delete_index_file(RootDir, DbName, GroupId),
-        Error
-    end;
-prepare_group({slow_view, DbName, Fd, Lang, DesignOptions, MapSrc, RedSrc}, _ForceReset) ->
-    case couch_db:open(DbName, []) of
-    {ok, Db} ->
-        View = #view{map_names=[<<"_temp">>],
-            id_num=0,
-            btree=nil,
-            def=MapSrc,
-            reduce_funs= if RedSrc==[] -> []; true -> [{<<"_temp">>, RedSrc}] end},
-        {ok, init_group(Db, Fd, #group{type=slow_view, name= <<"_temp">>, db=Db,
-            views=[View], def_lang=Lang, design_options=DesignOptions}, nil)};
-    Error ->
-        Error
+    Else ->
+        Else
     end.
 
-
 get_index_header_data(#group{current_seq=Seq, purge_seq=PurgeSeq, 
             id_btree=IdBtree,views=Views}) ->
     ViewStates = [couch_btree:get_state(Btree) || #view{btree=Btree} <- Views],
@@ -355,14 +359,47 @@ get_index_header_data(#group{current_seq=Seq, purge_seq=PurgeSeq,
             id_btree_state=couch_btree:get_state(IdBtree),
             view_states=ViewStates}.
 
+hex_sig(GroupSig) ->
+    couch_util:to_hex(?b2l(GroupSig)).
+
+design_root(RootDir, DbName) ->
+    RootDir ++ "/." ++ ?b2l(DbName) ++ "_design/".
+    
+index_file_name(RootDir, DbName, GroupSig) ->
+    design_root(RootDir, DbName) ++ hex_sig(GroupSig) ++".view".
 
-open_index_file(RootDir, DbName, GroupId) ->
-    FileName = RootDir ++ "/." ++ ?b2l(DbName) ++ ?b2l(GroupId) ++".view",
+index_file_name(compact, RootDir, DbName, GroupSig) ->
+    design_root(RootDir, DbName) ++ hex_sig(GroupSig) ++".compact.view".
+
+
+open_index_file(RootDir, DbName, GroupSig) ->
+    FileName = index_file_name(RootDir, DbName, GroupSig),
     case couch_file:open(FileName) of
     {ok, Fd}        -> {ok, Fd};
     {error, enoent} -> couch_file:open(FileName, [create]);
     Error           -> Error
     end.
+
+open_temp_group(DbName, Language, DesignOptions, MapSrc, RedSrc) ->
+    case couch_db:open(DbName, []) of
+    {ok, Db} ->
+        View = #view{map_names=[<<"_temp">>],
+            id_num=0,
+            btree=nil,
+            def=MapSrc,
+            reduce_funs= if RedSrc==[] -> []; true -> [{<<"_temp">>, RedSrc}] end},
+
+        {ok, Db, #group{
+            name = <<"_temp">>, 
+            db=Db,
+            views=[View], 
+            def_lang=Language, 
+            design_options=DesignOptions,
+            sig = erlang:md5(term_to_binary({[View], Language, DesignOptions}))
+        }};
+    Error ->
+        Error
+    end.
     
 open_db_group(DbName, GroupId) ->
     case couch_db:open(DbName, []) of
@@ -378,12 +415,28 @@ open_db_group(DbName, GroupId) ->
         Else
     end.
 
+get_group_info(#group{
+        fd = Fd,
+        sig = GroupSig,
+        def_lang = Lang
+    }, CompactorPid) ->
+    {ok, Size} = couch_file:bytes(Fd),
+    [
+        {signature, ?l2b(hex_sig(GroupSig))},
+        {language, Lang},
+        {disk_size, Size},
+        {compact_running, CompactorPid /= nil}   
+    ].
+
 % maybe move to another module
 design_doc_to_view_group(#doc{id=Id,body={Fields}}) ->
     Language = proplists:get_value(<<"language">>, Fields, <<"javascript">>),
     {DesignOptions} = proplists:get_value(<<"options">>, Fields, {[]}),
     {RawViews} = proplists:get_value(<<"views">>, Fields, {[]}),
-
+    % sort the views by name to avoid spurious signature changes
+    SortedRawViews = lists:sort(fun({Name1, _}, {Name2, _}) ->
+            Name1 >= Name2
+        end, RawViews),
     % add the views to a dictionary object, with the map source as the key
     DictBySrc =
     lists:foldl(
@@ -402,7 +455,7 @@ design_doc_to_view_group(#doc{id=Id,body={Fields}}) ->
                 View#view{reduce_funs=[{Name,RedSrc}|View#view.reduce_funs]}
             end,
             dict:store(MapSrc, View2, DictBySrcAcc)
-        end, dict:new(), RawViews),
+        end, dict:new(), SortedRawViews),
     % number the views
     {Views, _N} = lists:mapfoldl(
         fun({_Src, View}, N) ->
@@ -410,7 +463,7 @@ design_doc_to_view_group(#doc{id=Id,body={Fields}}) ->
         end, 0, dict:to_list(DictBySrc)),
 
     Group = #group{name=Id, views=Views, def_lang=Language, design_options=DesignOptions},
-    Group#group{sig=erlang:md5(term_to_binary(Group))}.
+    Group#group{sig=erlang:md5(term_to_binary({Views, Language, DesignOptions}))}.
 
 reset_group(#group{views=Views}=Group) ->
     Views2 = [View#view{btree=nil} || View <- Views],
@@ -423,9 +476,8 @@ reset_file(Db, Fd, DbName, #group{sig=Sig,name=Name} = Group) ->
     ok = couch_file:write_header(Fd, {Sig, nil}),
     init_group(Db, Fd, reset_group(Group), nil).
 
-delete_index_file(RootDir, DbName, GroupId) ->
-    file:delete(RootDir ++ "/." ++ binary_to_list(DbName)
-            ++ binary_to_list(GroupId) ++ ".view").
+delete_index_file(RootDir, DbName, GroupSig) ->
+    file:delete(index_file_name(RootDir, DbName, GroupSig)).
 
 init_group(Db, Fd, #group{views=Views}=Group, nil) ->
     init_group(Db, Fd, Group,
diff --git a/src/couchdb/couch_view_updater.erl b/src/couchdb/couch_view_updater.erl
index 3c4c9108..11dfb544 100644
--- a/src/couchdb/couch_view_updater.erl
+++ b/src/couchdb/couch_view_updater.erl
@@ -106,26 +106,6 @@ process_doc(Db, DocInfo, {Docs, #group{sig=Sig,name=GroupId,design_options=Desig
             [conflicts, deleted_conflicts]
     end,
     case {IncludeDesign, DocId} of
-    {_, GroupId} ->
-        % uh oh. this is the design doc with our definitions. See if
-        % anything in the definition changed.
-        case couch_db:open_doc_int(Db, DocInfo, DocOpts) of
-        {ok, Doc} ->
-            case couch_view_group:design_doc_to_view_group(Doc) of
-            #group{sig=Sig} ->
-                % The same md5 signature, keep on computing
-                case IncludeDesign of
-                true ->
-                    {[Doc | Docs], Group, ViewKVs, DocIdViewIdKeys};
-                _ ->
-                    {Docs, Group, ViewKVs, DocIdViewIdKeys}
-                end;
-            _ ->
-                exit(reset)
-            end;
-        {not_found, missing} ->
-            exit(reset)
-        end;
     {false, <<?DESIGN_DOC_PREFIX, _/binary>>} -> % we skip design docs
         {Docs, Group, ViewKVs, DocIdViewIdKeys};
     _ ->