split cluster status file and running nodes file

1 files changed, 89 insertions, 111 deletions

diff --git a/src/rabbit_node_monitor.erl b/src/rabbit_node_monitor.erl
index d29408de..b98fa5fd 100644
--- a/src/rabbit_node_monitor.erl
+++ b/src/rabbit_node_monitor.erl
@@ -19,11 +19,12 @@
 -behaviour(gen_server).
 
 -export([cluster_status_file_name/0,
-         prepare_cluster_status_file/0,
-         write_cluster_status_file/1,
-         read_cluster_status_file/0,
-         update_cluster_status_file/0,
-         reset_cluster_status_file/0,
+         running_nodes_file_name/0,
+         prepare_cluster_status_files/0,
+         write_cluster_status/1,
+         read_cluster_status/0,
+         update_cluster_status/0,
+         reset_cluster_status/0,
 
          joined_cluster/2,
          notify_joined_cluster/0,
@@ -49,12 +50,12 @@
 -ifdef(use_specs).
 
 -spec(cluster_status_file_name/0 :: () -> string()).
--spec(prepare_cluster_status_file/0 :: () -> 'ok').
--spec(write_cluster_status_file/1 :: (rabbit_mnesia:cluster_status())
-                                  -> 'ok').
--spec(read_cluster_status_file/0 :: () -> rabbit_mnesia:cluster_status()).
--spec(update_cluster_status_file/0 :: () -> 'ok').
--spec(reset_cluster_status_file/0 :: () -> 'ok').
+-spec(prepare_cluster_status_files/0 :: () -> 'ok').
+-spec(write_cluster_status/1 :: (rabbit_mnesia:cluster_status())
+                                -> 'ok').
+-spec(read_cluster_status/0 :: () -> rabbit_mnesia:cluster_status()).
+-spec(update_cluster_status/0 :: () -> 'ok').
+-spec(reset_cluster_status/0 :: () -> 'ok').
 
 -spec(joined_cluster/2 :: (node(), boolean()) -> 'ok').
 -spec(notify_joined_cluster/0 :: () -> 'ok').
@@ -85,70 +86,72 @@
 cluster_status_file_name() ->
     rabbit_mnesia:dir() ++ "/cluster_nodes.config".
 
-prepare_cluster_status_file() ->
-    NotPresent =
-        fun (AllNodes0, WantDiscNode) ->
-                ThisNode = [node()],
-
-                RunningNodes0 = legacy_read_previously_running_nodes(),
-                legacy_delete_previously_running_nodes(),
-
-                RunningNodes = lists:usort(RunningNodes0 ++ ThisNode),
-                AllNodes =
-                    lists:usort(AllNodes0 ++ RunningNodes),
-                DiscNodes = case WantDiscNode of
-                                true  -> ThisNode;
-                                false -> []
-                            end,
+running_nodes_file_name() ->
+    filename:join(rabbit_mnesia:dir(), "nodes_running_at_shutdown").
 
-                ok = write_cluster_status_file({AllNodes, DiscNodes,
-                                                RunningNodes})
+prepare_cluster_status_files() ->
+    RunningNodes1 = case try_read_file(running_nodes_file_name()) of
+                        {ok, [Nodes]} when is_list(Nodes) -> Nodes;
+                        non_existant                      -> []
+                    end,
+    {AllNodes1, WantDiscNode} =
+        case try_read_file(cluster_status_file_name()) of
+            {ok, [{_, _}]} ->
+                ok;
+            {ok, [AllNodes0]} when is_list(AllNodes0) ->
+                {AllNodes0, legacy_should_be_disc_node(AllNodes0)};
+            non_existant ->
+                {[], true}
         end,
-    case try_read_cluster_status_file() of
-        {ok, _} ->
-            ok;
-        {error, {invalid_term, _, [AllNodes]}} ->
-            %% Legacy file
-            NotPresent(AllNodes, legacy_should_be_disc_node(AllNodes));
-        {error, {cannot_read_file, _, enoent}} ->
-            NotPresent([], true)
-    end.
 
-
-write_cluster_status_file(Status) ->
-    FileName = cluster_status_file_name(),
-    case rabbit_file:write_term_file(FileName, [Status]) of
-        ok -> ok;
-        {error, Reason} ->
-            throw({error, {cannot_write_cluster_status_file,
-                           FileName, Reason}})
+    ThisNode = [node()],
+
+    RunningNodes2 = lists:usort(RunningNodes1 ++ ThisNode),
+    AllNodes2 = lists:usort(AllNodes1 ++ RunningNodes2),
+    DiscNodes = case WantDiscNode of
+                    true  -> ThisNode;
+                    false -> []
+                end,
+
+    ok = write_cluster_status({AllNodes2, DiscNodes, RunningNodes2}).
+
+write_cluster_status({All, Disc, Running}) ->
+    ClusterStatusFN = cluster_status_file_name(),
+    Res = case rabbit_file:write_term_file(ClusterStatusFN, [{All, Disc}]) of
+              ok ->
+                  RunningNodesFN = running_nodes_file_name(),
+                  {RunningNodesFN,
+                   rabbit_file:write_term_file(RunningNodesFN, [Running])};
+              E1 = {error, _} ->
+                  {ClusterStatusFN, E1}
+          end,
+    case Res of
+        {_, ok}           -> ok;
+        {FN, {error, E2}} -> throw({error, {could_not_write_file, FN, E2}})
     end.
 
-try_read_cluster_status_file() ->
-    FileName = cluster_status_file_name(),
+try_read_file(FileName) ->
     case rabbit_file:read_term_file(FileName) of
-        {ok, [{_, _, _} = Status]} ->
-            {ok, Status};
-        {ok, Term} ->
-            {error, {invalid_term, FileName, Term}};
-        {error, Reason} ->
-            {error, {cannot_read_file, FileName, Reason}}
+        {ok, Term}      -> {ok, Term};
+        {error, enoent} -> non_existant;
+        {error, E}      -> throw({error, {cannot_read_file, FileName, E}})
     end.
 
-read_cluster_status_file() ->
-    case try_read_cluster_status_file() of
-        {ok, Status} ->
-            Status;
-        {error, Reason} ->
-            throw({error, {cannot_read_cluster_status_file, Reason}})
+read_cluster_status() ->
+    case {try_read_file(cluster_status_file_name()),
+          try_read_file(running_nodes_file_name())} of
+        {{ok, [{All, Disc}]}, {ok, [Running]}} when is_list(Running) ->
+            {All, Disc, Running};
+        {_, _} ->
+            throw({error, corrupt_or_missing_cluster_files})
     end.
 
-update_cluster_status_file() ->
+update_cluster_status() ->
     {ok, Status} = rabbit_mnesia:cluster_status_from_mnesia(),
-    write_cluster_status_file(Status).
+    write_cluster_status(Status).
 
-reset_cluster_status_file() ->
-    write_cluster_status_file({[node()], [node()], [node()]}).
+reset_cluster_status() ->
+    write_cluster_status({[node()], [node()], [node()]}).
 
 %%----------------------------------------------------------------------------
 %% Cluster notifications
@@ -198,42 +201,42 @@ handle_cast({node_up, Node, IsDiscNode}, State) ->
     case is_already_monitored({rabbit, Node}) of
         true  -> {noreply, State};
         false -> rabbit_log:info("rabbit on node ~p up~n", [Node]),
-                 {AllNodes, DiscNodes, RunningNodes} = read_cluster_status_file(),
-                 write_cluster_status_file(
-                   {ordsets:add_element(Node, AllNodes),
-                    case IsDiscNode of
-                        true  -> ordsets:add_element(Node, DiscNodes);
-                        false -> DiscNodes
-                    end,
-                    ordsets:add_element(Node, RunningNodes)}),
+                 {AllNodes, DiscNodes, RunningNodes} = read_cluster_status(),
+                 write_cluster_status({ordsets:add_element(Node, AllNodes),
+                                       case IsDiscNode of
+                                           true  -> ordsets:add_element(
+                                                      Node, DiscNodes);
+                                           false -> DiscNodes
+                                       end,
+                                       ordsets:add_element(Node, RunningNodes)}),
                  erlang:monitor(process, {rabbit, Node}),
                  ok = handle_live_rabbit(Node),
                  {noreply, State}
     end;
 handle_cast({joined_cluster, Node, IsDiscNode}, State) ->
-    {AllNodes, DiscNodes, RunningNodes} = read_cluster_status_file(),
-    write_cluster_status_file({ordsets:add_element(Node, AllNodes),
-                               case IsDiscNode of
-                                    true  -> ordsets:add_element(Node,
-                                                                 DiscNodes);
-                                    false -> DiscNodes
-                                end,
-                               RunningNodes}),
+    {AllNodes, DiscNodes, RunningNodes} = read_cluster_status(),
+    write_cluster_status({ordsets:add_element(Node, AllNodes),
+                          case IsDiscNode of
+                              true  -> ordsets:add_element(Node,
+                                                           DiscNodes);
+                              false -> DiscNodes
+                          end,
+                          RunningNodes}),
     {noreply, State};
 handle_cast({left_cluster, Node}, State) ->
-    {AllNodes, DiscNodes, RunningNodes} = read_cluster_status_file(),
-    write_cluster_status_file({ordsets:del_element(Node, AllNodes),
-                               ordsets:del_element(Node, DiscNodes),
-                               ordsets:del_element(Node, RunningNodes)}),
+    {AllNodes, DiscNodes, RunningNodes} = read_cluster_status(),
+    write_cluster_status({ordsets:del_element(Node, AllNodes),
+                          ordsets:del_element(Node, DiscNodes),
+                          ordsets:del_element(Node, RunningNodes)}),
     {noreply, State};
 handle_cast(_Msg, State) ->
     {noreply, State}.
 
 handle_info({'DOWN', _MRef, process, {rabbit, Node}, _Reason}, State) ->
     rabbit_log:info("rabbit on node ~p down~n", [Node]),
-    {AllNodes, DiscNodes, RunningNodes} = read_cluster_status_file(),
-    write_cluster_status_file({AllNodes, DiscNodes,
-                               ordsets:del_element(Node, RunningNodes)}),
+    {AllNodes, DiscNodes, RunningNodes} = read_cluster_status(),
+    write_cluster_status({AllNodes, DiscNodes,
+                          ordsets:del_element(Node, RunningNodes)}),
     ok = handle_dead_rabbit(Node),
     {noreply, State};
 handle_info(_Info, State) ->
@@ -285,28 +288,3 @@ is_already_monitored(Item) ->
 
 legacy_should_be_disc_node(DiscNodes) ->
     DiscNodes == [] orelse lists:member(node(), DiscNodes).
-
-%%--------------------------------------------------------------------
-%% Legacy functions related to the "running nodes" file
-%%--------------------------------------------------------------------
-
-legacy_running_nodes_filename() ->
-    filename:join(rabbit_mnesia:dir(), "nodes_running_at_shutdown").
-
-legacy_read_previously_running_nodes() ->
-    FileName = legacy_running_nodes_filename(),
-    case rabbit_file:read_term_file(FileName) of
-        {ok, [Nodes]}   -> Nodes;
-        {error, enoent} -> [];
-        {error, Reason} -> throw({error, {cannot_read_previous_nodes_file,
-                                          FileName, Reason}})
-    end.
-
-legacy_delete_previously_running_nodes() ->
-    FileName = legacy_running_nodes_filename(),
-    case file:delete(FileName) of
-        ok              -> ok;
-        {error, enoent} -> ok;
-        {error, Reason} -> throw({error, {cannot_delete_previous_nodes_file,
-                                          FileName, Reason}})
-    end.