From 5b88a71e1de5e50ce7f2cc4e81b86560a0b0fbbd Mon Sep 17 00:00:00 2001
From: Kresten Krab Thorup <krab@trifork.com>
Date: Sun, 6 May 2012 19:49:53 +0200
Subject: [PATCH] Simplify riak_kv_hanoi_backend:is_empty/1

Do range fold with limit=1, rather than throw
exception.
---
 src/riak_kv_hanoi_backend.erl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/riak_kv_hanoi_backend.erl b/src/riak_kv_hanoi_backend.erl
index 37640d4..080b005 100644
--- a/src/riak_kv_hanoi_backend.erl
+++ b/src/riak_kv_hanoi_backend.erl
@@ -303,10 +303,10 @@ drop(#state{ tree=Tree, partition=Partition, config=Config }=State) ->
 %% non-tombstone values; otherwise returns false.
 -spec is_empty(state()) -> boolean().
 is_empty(#state{tree=Tree}) ->
-    FoldFun = fun(_K, _V, _Acc) -> throw(ok) end,
+    FoldFun = fun(K, _V, Acc) -> [K|Acc] end,
     try
         Range = to_key_range(undefined),
-        [] =:= hanoi:fold_range(Tree, FoldFun, [], Range)
+        [] =:= hanoi:fold_range(Tree, FoldFun, [], Range#btree_range{ limit=1 })
     catch
         _:ok ->
             false