GC manifest files when numbers skipped

Otherwise list of old files perpetually grows

src/leveled_pmanifest.erl

@@ -208,6 +208,13 @@ save_manifest(Manifest, RootPath) ->
         % delete the previous one straight away.  Retain until enough have been
         % kept to make the probability of all being independently corrupted 
         % through separate events negligible
+    ok = remove_manifest(RootPath, GC_SQN),
+        % Sometimes we skip a SQN, so to GC all may need to clear up previous
+        % as well
+    ok = remove_manifest(RootPath, GC_SQN - 1).
+
+-spec remove_manifest(string(), integer()) -> ok.
+remove_manifest(RootPath, GC_SQN) ->
     LFP = filepath(RootPath, GC_SQN, current_manifest),
     ok = 
         case filelib:is_file(LFP) of
@@ -217,6 +224,7 @@ save_manifest(Manifest, RootPath) ->
                 ok
         end.
 
+
 -spec replace_manifest_entry(manifest(), integer(), integer(),
                                     list()|manifest_entry(),
                                     list()|manifest_entry()) -> manifest().

test/end_to_end/basic_SUITE.erl

@@ -618,6 +618,14 @@ load_and_count(JournalSize, BookiesMemSize, PencillerMemSize) ->
     {ok, Bookie2} = leveled_bookie:book_start(StartOpts1),
     {_, 300000} = testutil:check_bucket_stats(Bookie2, "Bucket"),
     ok = leveled_bookie:book_close(Bookie2),
+    ManifestFP =
+        leveled_pmanifest:filepath(filename:join(RootPath, ?LEDGER_FP),
+                                    manifest),
+    IsManifest = fun(FN) -> filename:extension(FN) == ".man" end,
+    {ok, RawManList} = file:list_dir(ManifestFP),
+    ManList = lists:filter(IsManifest, RawManList),
+    io:format("Length of manifest file list ~w~n", [length(ManList)]),
+    true = length(ManList) =< 5,
     testutil:reset_filestructure().
 
 load_and_count_withdelete(_Config) ->