couchdb-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From rnew...@apache.org
Subject [08/50] [abbrv] git commit: updated refs/heads/1843-feature-bigcouch to cba2e81
Date Sat, 29 Jun 2013 15:17:49 GMT
Extend _sum to operate on JSON Objects

A map function that emits JSON objects as values can now be used with
the builtin _sum function.  In contrast to our support for JSON arrays
(which can be freely mixed with numbers), this extension requires an
all-or-nothing approach - either emit only objects or do not emit any at
all.  Moreover, all the fields inside the object must have values that
are numbers or arrays of numbers.

TODO use proper instead of writing explicit unit test cases

BugzID: 14798


Project: http://git-wip-us.apache.org/repos/asf/couchdb/repo
Commit: http://git-wip-us.apache.org/repos/asf/couchdb/commit/98a0cfa7
Tree: http://git-wip-us.apache.org/repos/asf/couchdb/tree/98a0cfa7
Diff: http://git-wip-us.apache.org/repos/asf/couchdb/diff/98a0cfa7

Branch: refs/heads/1843-feature-bigcouch
Commit: 98a0cfa798fd3a1aad03488a83ddc0f028a30cc8
Parents: 24f77c0
Author: Adam Kocoloski <adam@cloudant.com>
Authored: Fri Dec 7 11:07:20 2012 -0800
Committer: Paul J. Davis <paul.joseph.davis@gmail.com>
Committed: Wed Mar 20 06:02:51 2013 -0500

----------------------------------------------------------------------
 src/couch/src/couch_query_servers.erl | 73 ++++++++++++++++++++++--------
 1 file changed, 53 insertions(+), 20 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/couchdb/blob/98a0cfa7/src/couch/src/couch_query_servers.erl
----------------------------------------------------------------------
diff --git a/src/couch/src/couch_query_servers.erl b/src/couch/src/couch_query_servers.erl
index eb41e27..e420ce9 100644
--- a/src/couch/src/couch_query_servers.erl
+++ b/src/couch/src/couch_query_servers.erl
@@ -24,6 +24,11 @@
 
 -include_lib("couch/include/couch_db.hrl").
 
+-define(SUMERROR, <<"The _sum function requires that map values be numbers, "
+    "arrays of numbers, or objects. Objects cannot be mixed with other data "
+    "structures. Objects can be arbitrarily nested, provided that the values "
+    "for all fields are themselves numbers, arrays of numbers, or objects.">>).
+
 % https://gist.github.com/df10284c76d85f988c3f
 -define(SUMREGEX, {re_pattern,3,0,<<69,82,67,80,194,0,0,0,8,0,0,0,5,0,0,0,3,0,
 2,0,0,0,125,2,48,0,9,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,118,97,108,
@@ -204,29 +209,42 @@ builtin_reduce(Re, [<<"_stats",_/binary>>|BuiltinReds],
KVs, Acc) ->
     builtin_reduce(Re, BuiltinReds, KVs, [Stats|Acc]).
 
 builtin_sum_rows(KVs) ->
-    lists:foldl(fun
-        ([_Key, Value], Acc) when is_number(Value), is_number(Acc) ->
-            Acc + Value;
-        ([_Key, Value], Acc) when is_list(Value), is_list(Acc) ->
-            sum_terms(Acc, Value);
-        ([_Key, Value], Acc) when is_number(Value), is_list(Acc) ->
-            sum_terms(Acc, [Value]);
-        ([_Key, Value], Acc) when is_list(Value), is_number(Acc) ->
-            sum_terms([Acc], Value);
-        (_Else, _Acc) ->
-            throw({invalid_value, <<"builtin _sum function requires map values to be
numbers or lists of numbers">>})
-    end, 0, KVs).
-
-sum_terms([], []) ->
+    lists:foldl(fun([_Key, Value], Acc) -> sum_values(Value, Acc) end, 0, KVs).
+
+sum_values({Props}, {AccProps}) ->
+    {sum_objects(lists:sort(Props), lists:sort(AccProps))};
+sum_values(Value, Acc) when is_number(Value), is_number(Acc) ->
+    Acc + Value;
+sum_values(Value, Acc) when is_list(Value), is_list(Acc) ->
+    sum_arrays(Acc, Value);
+sum_values(Value, Acc) when is_number(Value), is_list(Acc) ->
+    sum_arrays(Acc, [Value]);
+sum_values(Value, Acc) when is_list(Value), is_number(Acc) ->
+    sum_arrays([Acc], Value);
+sum_values(_Else, _Acc) ->
+    throw({invalid_value, ?SUMERROR}).
+
+sum_objects([{K1, V1} | Rest1], [{K1, V2} | Rest2]) ->
+    [{K1, sum_values(V1, V2)} | sum_objects(Rest1, Rest2)];
+sum_objects([{K1, V1} | Rest1], [{K2, V2} | Rest2]) when K1 < K2 ->
+    [{K1, V1}, {K2, V2} | sum_objects(Rest1, Rest2)];
+sum_objects([{K1, V1} | Rest1], [{K2, V2} | Rest2]) when K1 > K2 ->
+    [{K2, V2}, {K1, V1} | sum_objects(Rest1, Rest2)];
+sum_objects([], Rest) ->
+    Rest;
+sum_objects(Rest, []) ->
+    Rest.
+
+sum_arrays([], []) ->
     [];
-sum_terms([_|_]=Xs, []) ->
+sum_arrays([_|_]=Xs, []) ->
     Xs;
-sum_terms([], [_|_]=Ys) ->
+sum_arrays([], [_|_]=Ys) ->
     Ys;
-sum_terms([X|Xs], [Y|Ys]) when is_number(X), is_number(Y) ->
-    [X+Y | sum_terms(Xs,Ys)];
-sum_terms(_, _) ->
-    throw({invalid_value, <<"builtin _sum function requires map values to be numbers
or lists of numbers">>}).
+sum_arrays([X|Xs], [Y|Ys]) when is_number(X), is_number(Y) ->
+    [X+Y | sum_arrays(Xs,Ys)];
+sum_arrays(_, _) ->
+    throw({invalid_value, ?SUMERROR}).
 
 
 builtin_stats(reduce, [[_,First]|Rest]) ->
@@ -397,3 +415,18 @@ ret_os_process(Proc) ->
     true = gen_server:call(couch_proc_manager, {ret_proc, Proc}, infinity),
     catch unlink(Proc#proc.pid),
     ok.
+
+-ifdef(TEST).
+-include_lib("eunit/include/eunit.hrl").
+
+sum_values_test() ->
+    ?assertEqual(3, sum_values(1, 2)),
+    ?assertEqual([2,4,6], sum_values(1, [1,4,6])),
+    ?assertEqual([3,5,7], sum_values([3,2,4], [0,3,3])),
+    X = {[{<<"a">>,1}, {<<"b">>,[1,2]}, {<<"c">>, {[{<<"d">>,3}]}}]},
+    Y = {[{<<"a">>,2}, {<<"b">>,3}, {<<"c">>, {[{<<"e">>,
5}]}}]},
+    Z = {[{<<"a">>,3}, {<<"b">>,[4,2]}, {<<"c">>, {[{<<"d">>,3},{<<"e">>,5}]}}]},
+    ?assertEqual(Z, sum_values(X, Y)),
+    ?assertEqual(Z, sum_values(Y, X)).
+
+-endif.


Mime
View raw message