use ets internal counters for sample size and use lists:unzip for get…

…ting values

src/folsom_sample_exdec.erl

@@ -56,8 +56,7 @@ update(#exdec{reservoir = Reservoir, alpha = Alpha, start = Start, next = Next}
     update(Sample#exdec{reservoir = NewRes, next = NewNext, start = NewStart}, Value, Timestamp).
 
 get_values(#exdec{reservoir = Reservoir}) ->
-    ResList = ets:tab2list(Reservoir),
-    {_, Values} = lists:unzip(ResList),
+    {_, Values} = lists:unzip(ets:tab2list(Reservoir)),
     Values.
 
 % internal api

src/folsom_sample_none.erl

@@ -39,12 +39,13 @@ new(Size) ->
 update(#none{size = Size, reservoir = Reservoir, n = N} = Sample, Value)
   when N < Size ->
     ets:insert(Reservoir, {N, Value}),
-    Sample#none{n = N+1};
+    Sample#none{n = folsom_utils:get_ets_size(Reservoir) + 1};
 update(#none{reservoir = Reservoir, n = N} = Sample, Value) ->
     Oldest = ets:first(Reservoir),
     ets:delete(Reservoir, Oldest),
     ets:insert(Reservoir, {N, Value}),
-    Sample#none{n = N+1}.
+    Sample#none{n = folsom_utils:get_ets_size(Reservoir) + 1}.
 
 get_values(#none{reservoir = Reservoir}) ->
-    [Val || {_,Val} <- ets:tab2list(Reservoir)].
+    {_, Values} = lists:unzip(ets:tab2list(Reservoir)),
+    Values.

src/folsom_sample_uniform.erl

@@ -45,16 +45,17 @@ new(Size) ->
 
 update(#uniform{size = Size, reservoir = Reservoir, n = N} = Sample, Value) when N =< Size ->
     ets:insert(Reservoir, {N, Value}),
-    Sample#uniform{n = N+1};
+    Sample#uniform{n = folsom_utils:get_ets_size(Reservoir) + 1};
 
 update(#uniform{reservoir = Reservoir, size = Size, n = N, seed = Seed} = Sample,
        Value) ->
     {Rnd, New_seed} = random:uniform_s(N, Seed),
     maybe_update(Rnd, Size, Value, Reservoir),
-    Sample#uniform{n = N+1, seed=New_seed}.
+    Sample#uniform{n = folsom_utils:get_ets_size(Reservoir) + 1, seed=New_seed}.
 
 get_values(#uniform{reservoir = Reservoir}) ->
-    [Val || {_,Val} <- ets:tab2list(Reservoir)].
+    {_, Values} = lists:unzip(ets:tab2list(Reservoir)),
+    Values.
 
 maybe_update(Rnd, Size, Value, Reservoir) when Rnd < Size ->
     ets:insert(Reservoir, {Rnd, Value});