cloudant
diff --git a/‎src/couch/src/couch_lru.erl‎
Lines changed: 27 additions & 35 deletions b/‎src/couch/src/couch_lru.erl‎
Lines changed: 27 additions & 35 deletions
diff --git a/‎src/couch/test/couch_lru_tests.erl‎
Lines changed: 0 additions & 109 deletions b/‎src/couch/test/couch_lru_tests.erl‎
Lines changed: 0 additions & 109 deletions
@@ -16,56 +16,48 @@
 -include_lib("couch/include/couch_db.hrl").
 
 new() ->
-    Updates = ets:new(couch_lru_updates, [ordered_set]),
-    Dbs = ets:new(couch_lru_dbs, [set]),
-    {0, Updates, Dbs}.
-
-insert(DbName, {Count, Updates, Dbs}) ->
-    update(DbName, {Count, Updates, Dbs}).
-
-update(DbName, {Count, Updates, Dbs}) ->
-    case ets:lookup(Dbs, DbName) of
-        [] ->
-            true = ets:insert(Dbs, {DbName, Count});
-        [{DbName, OldCount}] ->
-            true = ets:update_element(Dbs, DbName, {2, Count}),
-            true = ets:delete(Updates, {OldCount, DbName})
-    end,
-    true = ets:insert(Updates, {{Count, DbName}}),
-    {Count + 1, Updates, Dbs}.
-
-
-close({Count, Updates, Dbs}) ->
-    case close_int(ets:next(Updates, {-1, <<>>}), Updates, Dbs) of
-        true ->
-            {true, {Count, Updates, Dbs}};
-        false ->
-            false
+    {gb_trees:empty(), dict:new()}.
+
+insert(DbName, {Tree0, Dict0}) ->
+    Lru = erlang:now(),
+    {gb_trees:insert(Lru, DbName, Tree0), dict:store(DbName, Lru, Dict0)}.
+
+update(DbName, {Tree0, Dict0}) ->
+    case dict:find(DbName, Dict0) of
+    {ok, Old} ->
+        New = erlang:now(),
+        Tree = gb_trees:insert(New, DbName, gb_trees:delete(Old, Tree0)),
+        Dict = dict:store(DbName, New, Dict0),
+        {Tree, Dict};
+    error ->
+        % We closed this database before processing the update.  Ignore
+        {Tree0, Dict0}
     end.
 
+%% Attempt to close the oldest idle database.
+close({Tree, _} = Cache) ->
+    close_int(gb_trees:next(gb_trees:iterator(Tree)), Cache).
 
 %% internals
 
-close_int('$end_of_table', _Updates, _Dbs) ->
+close_int(none, _) ->
     false;
-close_int({_Count, DbName} = Key, Updates, Dbs) ->
+close_int({Lru, DbName, Iter}, {Tree, Dict} = Cache) ->
     case ets:update_element(couch_dbs, DbName, {#db.fd_monitor, locked}) of
     true ->
         [#db{main_pid = Pid} = Db] = ets:lookup(couch_dbs, DbName),
         case couch_db:is_idle(Db) of true ->
             true = ets:delete(couch_dbs, DbName),
             true = ets:delete(couch_dbs_pid_to_name, Pid),
             exit(Pid, kill),
-            true = ets:delete(Updates, Key),
-            true = ets:delete(Dbs, DbName),
-            true;
+            {true, {gb_trees:delete(Lru, Tree), dict:erase(DbName, Dict)}};
         false ->
             true = ets:update_element(couch_dbs, DbName, {#db.fd_monitor, nil}),
             couch_stats:increment_counter([couchdb, couch_server, lru_skip]),
-            close_int(ets:next(Updates, Key), Updates, Dbs)
+            close_int(gb_trees:next(Iter), update(DbName, Cache))
         end;
     false ->
-        true = ets:delete(Updates, Key),
-        true = ets:delete(Dbs, DbName),
-        close_int(ets:next(Updates, Key), Updates, Dbs)
-    end.
+        NewTree = gb_trees:delete(Lru, Tree),
+        NewIter = gb_trees:iterator(NewTree),
+        close_int(gb_trees:next(NewIter), {NewTree, dict:erase(DbName, Dict)})
+end.