Rename to _approx_count_distinct and return an int

src/couch/src/couch_query_servers.erl

@@ -91,7 +91,7 @@ finalize(Reductions) ->
  {ok, lists:map(fun(Reduction) ->
  case hyper:is_hyper(Reduction) of
  true ->
- hyper:card(Reduction);
+ round(hyper:card(Reduction));
  false ->
  Reduction
  end
@@ -183,8 +183,8 @@ builtin_reduce(rereduce, [<<"_count",_/binary>>|BuiltinReds], KVs, Acc) ->
 builtin_reduce(Re, [<<"_stats",_/binary>>|BuiltinReds], KVs, Acc) ->
  Stats = builtin_stats(Re, KVs),
  builtin_reduce(Re, BuiltinReds, KVs, [Stats|Acc]);
-builtin_reduce(Re, [<<"_distinct",_/binary>>|BuiltinReds], KVs, Acc) ->
- Distinct = count_distinct_keys(Re, KVs),
+builtin_reduce(Re, [<<"_approx_count_distinct",_/binary>>|BuiltinReds], KVs, Acc) ->
+ Distinct = approx_count_distinct(Re, KVs),
  builtin_reduce(Re, BuiltinReds, KVs, [Distinct|Acc]).
 
 
@@ -318,11 +318,11 @@ get_number(Key, Props) ->
  end.
 
 % TODO allow customization of precision in the ddoc.
-count_distinct_keys(reduce, KVs) ->
+approx_count_distinct(reduce, KVs) ->
  lists:foldl(fun([[Key, _Id], _Value], Filter) ->
  hyper:insert(term_to_binary(Key), Filter)
  end, hyper:new(11), KVs);
-count_distinct_keys(rereduce, Reds) ->
+approx_count_distinct(rereduce, Reds) ->
  hyper:union([Filter || [_, Filter] <- Reds]).
 
 % use the function stored in ddoc.validate_doc_update to test an update.

src/couch_mrview/src/couch_mrview.erl

@@ -184,7 +184,7 @@ validate(DbName, DDoc) ->
  ok;
  ({_RedName, <<"_stats", _/binary>>}) ->
  ok;
- ({_RedName, <<"_distinct", _/binary>>}) ->
+ ({_RedName, <<"_approx_count_distinct", _/binary>>}) ->
  ok;
  ({_RedName, <<"_", _/binary>> = Bad}) ->
  Msg = ["`", Bad, "` is not a supported reduce function."],