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, 38 insertions, 0 deletions

diff --git a/apps/couch/src/couch_drv.erl b/apps/couch/src/couch_drv.erl
new file mode 100644
index 00000000..70028659
--- /dev/null
+++ b/apps/couch/src/couch_drv.erl
@@ -0,0 +1,38 @@
+-module(couch_drv).
+-behaviour(gen_server).
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, 
+    code_change/3]).
+
+-export([start_link/0]).
+
+-include("couch_db.hrl").
+
+start_link() ->
+    gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
+
+init([]) ->
+    case erl_ddll:load(code:priv_dir(couch), "couch_erl_driver") of
+    ok ->
+        {ok, nil};
+    {error, already_loaded} ->
+        ?LOG_INFO("~p reloading couch_erl_driver", [?MODULE]),
+        ok = erl_ddll:reload(code:priv_dir(couch), "couch_erl_driver"),
+        {ok, nil};
+    {error, Error} ->
+        {stop, erl_ddll:format_error(Error)}
+    end.
+
+handle_call(_Request, _From, State) ->
+    {reply, ok, State}.
+
+handle_cast(_Request, State) ->
+    {noreply, State}.
+
+handle_info(_Info, State) ->
+    {noreply, State}.
+
+terminate(_Reason, _State) ->
+    ok.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.