blob: caa85edba4b3dfc3fd7d5fefaf7130f85894bf4c [file] [log] [blame]
% Licensed under the Apache License, Version 2.0 (the "License"); you may not
% use this file except in compliance with the License. You may obtain a copy of
% the License at
%
% http://www.apache.org/licenses/LICENSE-2.0
%
% Unless required by applicable law or agreed to in writing, software
% distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
% WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
% License for the specific language governing permissions and limitations under
% the License.
-module(mango_idx_special).
-export([
validate/1,
add/2,
remove/2,
from_ddoc/1,
to_json/1,
columns/1,
is_usable/3,
start_key/1,
end_key/1
]).
-include_lib("couch/include/couch_db.hrl").
-include("mango.hrl").
validate(_) ->
erlang:exit(invalid_call).
add(_, _) ->
erlang:exit(invalid_call).
remove(_, _) ->
erlang:exit(invalid_call).
from_ddoc(_) ->
erlang:exit(invalid_call).
to_json(#idx{def = all_docs}) ->
{[
{ddoc, null},
{name, <<"_all_docs">>},
{type, <<"special">>},
{def,
{[
{<<"fields">>, [
{[
{<<"_id">>, <<"asc">>}
]}
]}
]}}
]}.
columns(#idx{def = all_docs}) ->
[<<"_id">>].
is_usable(#idx{def = all_docs}, _Selector, []) ->
{true, #{reason => []}};
is_usable(#idx{def = all_docs} = Idx, Selector, SortFields) ->
Fields = mango_idx_view:indexable_fields(Selector),
SelectorHasRequiredFields = lists:member(<<"_id">>, Fields),
CanUseSort = can_use_sort(Idx, SortFields, Selector),
Reason =
[field_mismatch || not SelectorHasRequiredFields] ++
[sort_order_mismatch || not CanUseSort],
Details = #{reason => Reason},
{SelectorHasRequiredFields and CanUseSort, Details}.
start_key([{'$gt', Key, _, _}]) ->
case mango_json:special(Key) of
true ->
?MIN_STR;
false ->
Key
end;
start_key([{'$gte', Key, _, _}]) ->
false = mango_json:special(Key),
Key;
start_key([{'$eq', Key, '$eq', Key}]) ->
false = mango_json:special(Key),
Key.
end_key([{_, _, '$lt', Key}]) ->
case mango_json:special(Key) of
true ->
?MAX_STR;
false ->
Key
end;
end_key([{_, _, '$lte', Key}]) ->
false = mango_json:special(Key),
Key;
end_key([{'$eq', Key, '$eq', Key}]) ->
false = mango_json:special(Key),
Key.
can_use_sort(_Idx, [], _Selector) ->
true;
can_use_sort(Idx, SortFields, _Selector) ->
Cols = columns(Idx),
lists:prefix(SortFields, Cols).
-ifdef(TEST).
-include_lib("couch/include/couch_eunit.hrl").
usable(Index, undefined, Fields) ->
is_usable(Index, undefined, Fields);
usable(Index, Selector, Fields) ->
is_usable(Index, test_util:as_selector(Selector), Fields).
is_usable_test() ->
Usable = {true, #{reason => []}},
FieldMismatch = {false, #{reason => [field_mismatch]}},
SortOrderMismatch = {false, #{reason => [sort_order_mismatch]}},
Index = #idx{def = all_docs},
?assertEqual(FieldMismatch, usable(Index, #{}, [<<"_id">>])),
?assertEqual(SortOrderMismatch, usable(Index, #{<<"_id">> => 11}, [<<"field3">>])),
?assertEqual(Usable, usable(Index, #{}, [])).
-endif.