md5sum the queue index directory. Also detect and crash if a collision occursbug23019

3 files changed, 15 insertions, 12 deletions

diff --git a/src/rabbit_queue_index.erl b/src/rabbit_queue_index.erl
index 91b19976..d6b8bb28 100644
--- a/src/rabbit_queue_index.erl
+++ b/src/rabbit_queue_index.erl
@@ -31,7 +31,7 @@
 
 -module(rabbit_queue_index).
 
--export([init/3, terminate/2, delete_and_terminate/1, publish/4,
+-export([init/4, terminate/2, delete_and_terminate/1, publish/4,
          deliver/2, ack/2, sync/2, flush/1, read/3,
          next_segment_boundary/1, bounds/1, recover/1]).
 
@@ -193,7 +193,7 @@
         {(fun ((A) -> 'finished' | {rabbit_guid:guid(), non_neg_integer(), A})),
          A}).
 
--spec(init/3 :: (rabbit_amqqueue:name(), boolean(),
+-spec(init/4 :: (rabbit_amqqueue:name(), boolean(), boolean(),
                  fun ((rabbit_guid:guid()) -> boolean())) ->
              {'undefined' | non_neg_integer(), [any()], qistate()}).
 -spec(terminate/2 :: ([any()], qistate()) -> qistate()).
@@ -220,8 +220,8 @@
 %% public API
 %%----------------------------------------------------------------------------
 
-init(Name, MsgStoreRecovered, ContainsCheckFun) ->
-    State = #qistate { dir = Dir } = blank_state(Name),
+init(Name, Recover, MsgStoreRecovered, ContainsCheckFun) ->
+    State = #qistate { dir = Dir } = blank_state(Name, not Recover),
     Terms = case read_shutdown_terms(Dir) of
                 {error, _}   -> [];
                 {ok, Terms1} -> Terms1
@@ -356,9 +356,14 @@ recover(DurableQueues) ->
 %% startup and shutdown
 %%----------------------------------------------------------------------------
 
-blank_state(QueueName) ->
+blank_state(QueueName, EnsureFresh) ->
     StrName = queue_name_to_dir_name(QueueName),
     Dir = filename:join(queues_dir(), StrName),
+    ok = case EnsureFresh of
+             true  -> false = filelib:is_file(Dir), %% is_file == is file or dir
+                      ok;
+             false -> ok
+         end,
     ok = filelib:ensure_dir(filename:join(Dir, "nothing")),
     {ok, MaxJournal} =
         application:get_env(rabbit, queue_index_max_journal_entries),
@@ -463,9 +468,7 @@ recover_message(false,     _, no_del,  RelSeq, Segment) ->
     add_to_journal(RelSeq, ack, add_to_journal(RelSeq, del, Segment)).
 
 queue_name_to_dir_name(Name = #resource { kind = queue }) ->
-    Bin = term_to_binary(Name),
-    Size = 8*size(Bin),
-    <<Num:Size>> = Bin,
+    <<Num:128>> = erlang:md5(term_to_binary(Name)),
     lists:flatten(io_lib:format("~.36B", [Num])).
 
 queues_dir() ->
@@ -497,7 +500,7 @@ queue_index_walker({next, Gatherer}) when is_pid(Gatherer) ->
 
 queue_index_walker_reader(QueueName, Gatherer) ->
     State = #qistate { segments = Segments, dir = Dir } =
-        recover_journal(blank_state(QueueName)),
+        recover_journal(blank_state(QueueName, false)),
     [ok = segment_entries_foldr(
             fun (_RelSeq, {{Guid, true}, _IsDelivered, no_ack}, ok) ->
                     gatherer:in(Gatherer, {Guid, 1});
diff --git a/src/rabbit_tests.erl b/src/rabbit_tests.erl
index 516e9134..0b92682a 100644
--- a/src/rabbit_tests.erl
+++ b/src/rabbit_tests.erl
@@ -1546,7 +1546,7 @@ test_queue() ->
 
 init_test_queue() ->
     rabbit_queue_index:init(
-      test_queue(), false,
+      test_queue(), true, false,
       fun (Guid) ->
               rabbit_msg_store:contains(?PERSISTENT_MSG_STORE, Guid)
       end).
diff --git a/src/rabbit_variable_queue.erl b/src/rabbit_variable_queue.erl
index 92ffc511..0f52eee8 100644
--- a/src/rabbit_variable_queue.erl
+++ b/src/rabbit_variable_queue.erl
@@ -368,10 +368,10 @@ stop_msg_store() ->
     ok = rabbit_sup:stop_child(?PERSISTENT_MSG_STORE),
     ok = rabbit_sup:stop_child(?TRANSIENT_MSG_STORE).
 
-init(QueueName, IsDurable, _Recover) ->
+init(QueueName, IsDurable, Recover) ->
     {DeltaCount, Terms, IndexState} =
         rabbit_queue_index:init(
-          QueueName,
+          QueueName, Recover,
           rabbit_msg_store:successfully_recovered_state(?PERSISTENT_MSG_STORE),
           fun (Guid) ->
                   rabbit_msg_store:contains(?PERSISTENT_MSG_STORE, Guid)