Grab bag of Cloudant patches to couch OTP application

- Removal of couch_db and couch_ref_counter processes. Active DBs are
  accessible through a protected ets table owned by couch_server.
- #full_doc_info{} in by_id and by_seq trees for faster compaction at the
  expense of more disk usage afterwards. Proposed as COUCHDB-738 but not
  accepted upstream.
- Replication via distributed Erlang.
- Better hot upgrade support (uses exported functions much more often).
- Configurable btree chunk sizes allow for larger (but still bounded)
  reductions.
- Shorter names for btree fields in #db{} and #db_header{}.
- couch_view_group does not keep a reference to the #db{}.
- Terms are stored compressed (again).

1 files changed, 21 insertions, 85 deletions

diff --git a/apps/couch/src/couch_server_sup.erl b/apps/couch/src/couch_server_sup.erl
index 4f0445da..1f31209b 100644
--- a/apps/couch/src/couch_server_sup.erl
+++ b/apps/couch/src/couch_server_sup.erl
@@ -14,9 +14,8 @@
 -behaviour(supervisor).
 
 
--export([start_link/1,stop/0, couch_config_start_link_wrapper/2,
-        start_primary_services/0,start_secondary_services/0,
-        restart_core_server/0]).
+-export([start_link/1, couch_config_start_link_wrapper/2,
+    restart_core_server/0, config_change/2]).
 
 -include("couch_db.hrl").
 
@@ -68,59 +67,46 @@ start_server(IniFiles) ->
     _ -> ok
     end,
 
-    LibDir =
-    case couch_config:get("couchdb", "util_driver_dir", null) of
-    null ->
-        filename:join(couch_util:priv_dir(), "lib");
-    LibDir0 -> LibDir0
-    end,
-
-    ok = couch_util:start_driver(LibDir),
-
     BaseChildSpecs =
-    {{one_for_all, 10, 3600},
+    {{one_for_all, 10, 60},
         [{couch_config,
             {couch_server_sup, couch_config_start_link_wrapper, [IniFiles, ConfigPid]},
             permanent,
             brutal_kill,
             worker,
             [couch_config]},
+        {couch_config_event,
+            {couch_config_event, start_link, []},
+            permanent,
+            1000,
+            worker,
+            dynamic},
         {couch_primary_services,
-            {couch_server_sup, start_primary_services, []},
+            {couch_primary_sup, start_link, []},
             permanent,
             infinity,
             supervisor,
-            [couch_server_sup]},
+            [couch_primary_sup]},
         {couch_secondary_services,
-            {couch_server_sup, start_secondary_services, []},
+            {couch_secondary_sup, start_link, []},
             permanent,
             infinity,
             supervisor,
-            [couch_server_sup]}
+            [couch_secondary_sup]}
         ]},
 
-    % ensure these applications are running
-    application:start(ibrowse),
-    application:start(crypto),
-
     {ok, Pid} = supervisor:start_link(
         {local, couch_server_sup}, couch_server_sup, BaseChildSpecs),
 
-    % launch the icu bridge
     % just restart if one of the config settings change.
-
-    couch_config:register(
-        fun("couchdb", "util_driver_dir") ->
-            ?MODULE:stop();
-        ("daemons", _) ->
-            ?MODULE:stop()
-        end, Pid),
+    couch_config:register(fun ?MODULE:config_change/2, Pid),
 
     unlink(ConfigPid),
 
     Ip = couch_config:get("httpd", "bind_address"),
     Port = mochiweb_socket_server:get(couch_httpd, port),
     io:format("Apache CouchDB has started. Time to relax.~n"),
+
     ?LOG_INFO("Apache CouchDB has started on http://~s:~w/", [Ip, Port]),
     
     case couch_config:get("couchdb", "uri_file", null) of 
@@ -132,62 +118,12 @@ start_server(IniFiles) ->
 
     {ok, Pid}.
 
-start_primary_services() ->
-    supervisor:start_link({local, couch_primary_services}, couch_server_sup,
-        {{one_for_one, 10, 3600},
-            [{couch_log,
-                {couch_log, start_link, []},
-                permanent,
-                brutal_kill,
-                worker,
-                [couch_log]},
-            {couch_replication_supervisor,
-                {couch_rep_sup, start_link, []},
-                permanent,
-                infinity,
-                supervisor,
-                [couch_rep_sup]},
-            {couch_task_status,
-                {couch_task_status, start_link, []},
-                permanent,
-                brutal_kill,
-                worker,
-                [couch_task_status]},
-            {couch_server,
-                {couch_server, sup_start_link, []},
-                permanent,
-                1000,
-                worker,
-                [couch_server]},
-            {couch_db_update_event,
-                {gen_event, start_link, [{local, couch_db_update}]},
-                permanent,
-                brutal_kill,
-                worker,
-                dynamic}
-            ]
-        }).
-
-start_secondary_services() ->
-    DaemonChildSpecs = [
-        begin
-            {ok, {Module, Fun, Args}} = couch_util:parse_term(SpecStr),
-
-            {list_to_atom(Name),
-                {Module, Fun, Args},
-                permanent,
-                1000,
-                worker,
-                [Module]}
-        end
-        || {Name, SpecStr}
-        <- couch_config:get("daemons"), SpecStr /= ""],
-
-    supervisor:start_link({local, couch_secondary_services}, couch_server_sup,
-        {{one_for_one, 10, 3600}, DaemonChildSpecs}).
-
-stop() ->
-    catch exit(whereis(couch_server_sup), normal).
+config_change("daemons", _) ->
+    exit(whereis(couch_server_sup), shutdown);
+config_change("couchdb", "util_driver_dir") ->
+    [Pid] = [P || {collation_driver,P,_,_}
+        <- supervisor:which_children(couch_primary_services)],
+    Pid ! reload_driver.
 
 init(ChildSpecs) ->
     {ok, ChildSpecs}.