Make check that compaction not ongoing before accepting new compaction

Respond 'busy' if compaction is ongoing

src/leveled_bookie.erl

@@ -1004,7 +1004,7 @@ book_snapshot(Pid, SnapType, Query, LongRunning) ->
     gen_server:call(Pid, {snapshot, SnapType, Query, LongRunning}, infinity).
 
 
--spec book_compactjournal(pid(), integer()) -> ok.
+-spec book_compactjournal(pid(), integer()) -> ok|busy.
 -spec book_islastcompactionpending(pid()) -> boolean().
 -spec book_trimjournal(pid()) -> ok.
 
@@ -1371,10 +1371,10 @@ handle_call({return_runner, QueryType}, _From, State) ->
                                 fold_countdown = CountDown}};
 handle_call({compact_journal, Timeout}, _From, State)
                                         when State#state.head_only == false ->
-    ok = leveled_inker:ink_compactjournal(State#state.inker,
+    R = leveled_inker:ink_compactjournal(State#state.inker,
                                           self(),
                                           Timeout),
-    {reply, ok, State};
+    {reply, R, State};
 handle_call(confirm_compact, _From, State)
                                         when State#state.head_only == false ->
     {reply, leveled_inker:ink_compactionpending(State#state.inker), State};

src/leveled_inker.erl

@@ -348,7 +348,7 @@ ink_loadpcl(Pid, MinSQN, FilterFun, Penciller) ->
                         as_ink},
                     infinity).
 
--spec ink_compactjournal(pid(), pid(), integer()) -> ok.
+-spec ink_compactjournal(pid(), pid(), integer()) -> ok|busy.
 %% @doc
 %% Trigger a compaction event.  the compaction event will use a sqn check
 %% against the Ledger to see if a value can be compacted - if the penciller
@@ -605,14 +605,19 @@ handle_call({compact,
                 FilterFun,
                 Timeout},
                     _From, State) ->
-    leveled_iclerk:clerk_compact(State#state.clerk,
-                                    Checker,
-                                    InitiateFun,
-                                    CloseFun,
-                                    FilterFun,
-                                    self(),
-                                    Timeout),
-    {reply, ok, State#state{compaction_pending=true}};
+    case State#state.compaction_pending of
+        true ->
+            {reply, busy, State};
+        false ->
+            leveled_iclerk:clerk_compact(State#state.clerk,
+                                            Checker,
+                                            InitiateFun,
+                                            CloseFun,
+                                            FilterFun,
+                                            self(),
+                                            Timeout),
+            {reply, ok, State#state{compaction_pending=true}}
+    end;
 handle_call(compaction_complete, _From, State) ->
     {reply, ok, State#state{compaction_pending=false}};
 handle_call(compaction_pending, _From, State) ->

test/end_to_end/basic_SUITE.erl

@@ -300,6 +300,7 @@ journal_compaction_tester(Restart, WRP) ->
                     {sync_strategy, testutil:sync_strategy()}],
     {ok, Bookie3} = leveled_bookie:book_start(StartOpts2),
     ok = leveled_bookie:book_compactjournal(Bookie3, 30000),
+    busy = leveled_bookie:book_compactjournal(Bookie3, 30000),
     testutil:wait_for_compaction(Bookie3),
     ok = leveled_bookie:book_close(Bookie3),