diff options
Diffstat (limited to 'src/couch/src/couch_query_servers.erl')
| -rw-r--r-- | src/couch/src/couch_query_servers.erl | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/src/couch/src/couch_query_servers.erl b/src/couch/src/couch_query_servers.erl index f31d24c6c..de8ef1e15 100644 --- a/src/couch/src/couch_query_servers.erl +++ b/src/couch/src/couch_query_servers.erl @@ -17,6 +17,7 @@ -export([reduce/3, rereduce/3,validate_doc_update/5]). -export([filter_docs/5]). -export([filter_view/3]). +-export([finalize/2]). -export([rewrite/3]). -export([with_ddoc_proc/2, proc_prompt/2, ddoc_prompt/3, ddoc_proc_prompt/3, json_doc/1]). @@ -86,6 +87,17 @@ group_reductions_results(List) -> [Heads | group_reductions_results(Tails)] end. +finalize(<<"_approx_count_distinct",_/binary>>, Reduction) -> + true = hyper:is_hyper(Reduction), + {ok, round(hyper:card(Reduction))}; +finalize(<<"_stats",_/binary>>, {_, _, _, _, _} = Unpacked) -> + {ok, pack_stats(Unpacked)}; +finalize(<<"_stats",_/binary>>, {Packed}) -> + % Legacy code path before we had the finalize operation + {ok, {Packed}}; +finalize(_RedSrc, Reduction) -> + {ok, Reduction}. + rereduce(_Lang, [], _ReducedValues) -> {ok, []}; rereduce(Lang, RedSrcs, ReducedValues) -> @@ -171,7 +183,10 @@ builtin_reduce(rereduce, [<<"_count",_/binary>>|BuiltinReds], KVs, Acc) -> builtin_reduce(rereduce, BuiltinReds, KVs, [Count|Acc]); builtin_reduce(Re, [<<"_stats",_/binary>>|BuiltinReds], KVs, Acc) -> Stats = builtin_stats(Re, KVs), - builtin_reduce(Re, BuiltinReds, KVs, [Stats|Acc]). + builtin_reduce(Re, BuiltinReds, KVs, [Stats|Acc]); +builtin_reduce(Re, [<<"_approx_count_distinct",_/binary>>|BuiltinReds], KVs, Acc) -> + Distinct = approx_count_distinct(Re, KVs), + builtin_reduce(Re, BuiltinReds, KVs, [Distinct|Acc]). builtin_sum_rows([], Acc) -> @@ -236,11 +251,11 @@ sum_arrays(Else, _) -> throw_sum_error(Else). builtin_stats(_, []) -> - {[{sum,0}, {count,0}, {min,0}, {max,0}, {sumsqr,0}]}; + {0, 0, 0, 0, 0}; builtin_stats(_, [[_,First]|Rest]) -> - Unpacked = lists:foldl(fun([_Key, Value], Acc) -> stat_values(Value, Acc) end, - build_initial_accumulator(First), Rest), - pack_stats(Unpacked). + lists:foldl(fun([_Key, Value], Acc) -> + stat_values(Value, Acc) + end, build_initial_accumulator(First), Rest). stat_values(Value, Acc) when is_list(Value), is_list(Acc) -> lists:zipwith(fun stat_values/2, Value, Acc); @@ -267,6 +282,8 @@ build_initial_accumulator(L) when is_list(L) -> [build_initial_accumulator(X) || X <- L]; build_initial_accumulator(X) when is_number(X) -> {X, 1, X, X, X*X}; +build_initial_accumulator({_, _, _, _, _} = AlreadyUnpacked) -> + AlreadyUnpacked; build_initial_accumulator({Props}) -> unpack_stats({Props}); build_initial_accumulator(Else) -> @@ -303,6 +320,13 @@ get_number(Key, Props) -> throw({invalid_value, iolist_to_binary(Msg)}) end. +% TODO allow customization of precision in the ddoc. +approx_count_distinct(reduce, KVs) -> + lists:foldl(fun([[Key, _Id], _Value], Filter) -> + hyper:insert(term_to_binary(Key), Filter) + end, hyper:new(11), KVs); +approx_count_distinct(rereduce, Reds) -> + hyper:union([Filter || [_, Filter] <- Reds]). % use the function stored in ddoc.validate_doc_update to test an update. -spec validate_doc_update(DDoc, EditDoc, DiskDoc, Ctx, SecObj) -> ok when |