Use binary concatenation for segment filenames (#10628)

Author: mkuratczyk

deps/rabbit/src/rabbit_classic_queue_index_v2.erl

@@ -196,9 +196,10 @@ init_for_conversion(#resource{ virtual_host = VHost } = Name, OnSyncFun, OnSyncM
 
 init1(Name, Dir, OnSyncFun, OnSyncMsgFun) ->
     ensure_queue_name_stub_file(Name, Dir),
+    DirBin = rabbit_file:filename_to_binary(Dir),
     #qi{
         queue_name = Name,
-        dir = rabbit_file:filename_to_binary(Dir),
+        dir = << DirBin/binary, "/" >>,
         on_sync = OnSyncFun,
         on_sync_msg = OnSyncMsgFun
     }.
@@ -1277,8 +1278,8 @@ queue_name_to_dir_name(#resource { kind = queue,
     rabbit_misc:format("~.36B", [Num]).
 
 segment_file(Segment, #qi{ dir = Dir }) ->
-    filename:join(rabbit_file:binary_to_filename(Dir),
-                  integer_to_list(Segment) ++ ?SEGMENT_EXTENSION).
+    N = integer_to_binary(Segment),
+    <<Dir/binary, N/binary, ?SEGMENT_EXTENSION>>.
 
 highest_continuous_seq_id([SeqId|Tail], EndSeqId)
         when (1 + SeqId) =:= EndSeqId ->

deps/rabbit/src/rabbit_classic_queue_store_v2.erl

@@ -118,7 +118,8 @@ init(#resource{ virtual_host = VHost } = Name) ->
     ?DEBUG("~0p", [Name]),
     VHostDir = rabbit_vhost:msg_store_dir_path(VHost),
     Dir = rabbit_classic_queue_index_v2:queue_dir(VHostDir, Name),
-    #qs{dir = rabbit_file:filename_to_binary(Dir)}.
+    DirBin = rabbit_file:filename_to_binary(Dir),
+    #qs{dir = << DirBin/binary, "/" >>}.
 
 -spec terminate(State) -> State when State::state().
 
@@ -570,6 +571,6 @@ check_crc32() ->
 
 %% Same implementation as rabbit_classic_queue_index_v2:segment_file/2,
 %% but with a different state record.
-segment_file(Segment, #qs{ dir = Dir }) ->
-    filename:join(rabbit_file:binary_to_filename(Dir),
-                  integer_to_list(Segment) ++ ?SEGMENT_EXTENSION).
+segment_file(Segment, #qs{dir = Dir}) ->
+    N = integer_to_binary(Segment),
+    <<Dir/binary, N/binary, ?SEGMENT_EXTENSION>>.