tweak msg_store_index initialisation API

4 files changed, 27 insertions, 25 deletions

diff --git a/include/rabbit_msg_store_index.hrl b/include/rabbit_msg_store_index.hrl
index eb0ad5cb68..88a474aebc 100644
--- a/include/rabbit_msg_store_index.hrl
+++ b/include/rabbit_msg_store_index.hrl
@@ -41,8 +41,8 @@
 -type(fieldpos() :: non_neg_integer()).
 -type(fieldvalue() :: any()).
 
--spec(init/2 :: (('fresh'|'recover'), dir()) ->
-                     {'fresh'|'recovered', index_state()}).
+-spec(new/1 :: (dir()) -> index_state()).
+-spec(recover/1 :: (dir()) -> {'ok', index_state()} | {'error', any()}).
 -spec(lookup/2 :: (guid(), index_state()) -> ('not_found' | keyvalue())).
 -spec(insert/2 :: (keyvalue(), index_state()) -> 'ok').
 -spec(update/2 :: (keyvalue(), index_state()) -> 'ok').
diff --git a/src/rabbit_msg_store.erl b/src/rabbit_msg_store.erl
index 701ca29df6..508bc60d4b 100644
--- a/src/rabbit_msg_store.erl
+++ b/src/rabbit_msg_store.erl
@@ -496,11 +496,11 @@ init([Server, BaseDir, ClientRefs, {MsgRefDeltaGen, MsgRefDeltaGenInit}]) ->
     rabbit_log:info("Using ~p to provide index for message store~n",
                     [IndexModule]),
 
+    Fresh = fun () -> {false, IndexModule:new(Dir), sets:new()} end,
     {AllCleanShutdown, IndexState, ClientRefs1} =
         case detect_clean_shutdown(Dir) of
             {false, _Error} ->
-                {fresh, IndexState1} = IndexModule:init(fresh, Dir),
-                {false, IndexState1, sets:new()};
+                Fresh();
             {true, Terms} ->
                 RecClientRefs  = proplists:get_value(client_refs, Terms, []),
                 RecIndexModule = proplists:get_value(index_module, Terms),
@@ -508,15 +508,14 @@ init([Server, BaseDir, ClientRefs, {MsgRefDeltaGen, MsgRefDeltaGenInit}]) ->
                       lists:sort(ClientRefs) == lists:sort(RecClientRefs)
                       andalso IndexModule == RecIndexModule) of
                     true ->
-                        case IndexModule:init(recover, Dir) of
-                            {fresh, IndexState1} ->
-                                {false, IndexState1, sets:new()};
-                            {recovered, IndexState1} ->
-                                {true, IndexState1, sets:from_list(ClientRefs)}
+                        case IndexModule:recover(Dir) of
+                            {ok, IndexState1} ->
+                                {true, IndexState1, sets:from_list(ClientRefs)};
+                            _Error ->
+                                Fresh()
                         end;
                     false ->
-                        {fresh, IndexState1} = IndexModule:init(fresh, Dir),
-                        {false, IndexState1, sets:new()}
+                        Fresh()
                 end
         end,
 
diff --git a/src/rabbit_msg_store_ets_index.erl b/src/rabbit_msg_store_ets_index.erl
index b4fb5ef174..1eb3c11fb5 100644
--- a/src/rabbit_msg_store_ets_index.erl
+++ b/src/rabbit_msg_store_ets_index.erl
@@ -33,7 +33,8 @@
 
 -behaviour(rabbit_msg_store_index).
 
--export([init/2, lookup/2, insert/2, update/2, update_fields/3, delete/2,
+-export([new/1, recover/1,
+         lookup/2, insert/2, update/2, update_fields/3, delete/2,
          delete_by_file/2, terminate/1]).
 
 -define(MSG_LOC_NAME, rabbit_msg_store_ets_index).
@@ -43,16 +44,17 @@
 
 -record(state, { table, dir }).
 
-init(fresh, Dir) ->
+new(Dir) ->
     file:delete(filename:join(Dir, ?FILENAME)),
     Tid = ets:new(?MSG_LOC_NAME, [set, public, {keypos, #msg_location.guid}]),
-    {fresh, #state { table = Tid, dir = Dir }};
-init(recover, Dir) ->
+    #state { table = Tid, dir = Dir }.
+
+recover(Dir) ->
     Path = filename:join(Dir, ?FILENAME),
     case ets:file2tab(Path) of
         {ok, Tid}  -> file:delete(Path),
-                      {recovered, #state { table = Tid, dir = Dir }};
-        {error, _} -> init(fresh, Dir)
+                      {ok, #state { table = Tid, dir = Dir }};
+        Error      -> Error
     end.
 
 lookup(Key, State) ->
diff --git a/src/rabbit_msg_store_index.erl b/src/rabbit_msg_store_index.erl
index 2c9de3fda8..0ed64a9d81 100644
--- a/src/rabbit_msg_store_index.erl
+++ b/src/rabbit_msg_store_index.erl
@@ -34,13 +34,14 @@
 -export([behaviour_info/1]).
 
 behaviour_info(callbacks) ->
-    [{init,            2},
-     {lookup,          2},
-     {insert,          2},
-     {update,          2},
-     {update_fields,   3},
-     {delete,          2},
-     {delete_by_file,  2},
-     {terminate,       1}];
+    [{new,            1},
+     {recover,        1},
+     {lookup,         2},
+     {insert,         2},
+     {update,         2},
+     {update_fields,  3},
+     {delete,         2},
+     {delete_by_file, 2},
+     {terminate,      1}];
 behaviour_info(_Other) ->
     undefined.