src/chttpd/src/chttpd_view.erl - couchdb - Git at Google

 % 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(chttpd_view).
 -include_lib("couch/include/couch_db.hrl").
 -include_lib("couch_views/include/couch_views.hrl").

 -export([
     handle_view_req/3,
     validate_args/2,
     parse_queries/4,
     view_cb/2
 ]).

 -define(DEFAULT_ALL_DOCS_PAGE_SIZE, 2000).
 -define(DEFAULT_VIEWS_PAGE_SIZE, 2000).

 multi_query_view(Req, Db, DDoc, ViewName, Queries) ->
     Args = couch_views_http:parse_params(Req, undefined),
     case couch_views_util:is_paginated(Args) of
         false ->
             stream_multi_query_view(Req, Db, DDoc, ViewName, Args, Queries);
         true ->
             paginate_multi_query_view(Req, Db, DDoc, ViewName, Args, Queries)
     end.


 stream_multi_query_view(Req, Db, DDoc, ViewName, Args0, Queries) ->
     {ok, #mrst{views=Views}} = couch_views_util:ddoc_to_mrst(Db, DDoc),
     Args1 = couch_views_util:set_view_type(Args0, ViewName, Views),
     ArgQueries = parse_queries(Req, Args1, Queries, fun(QueryArg) ->
         couch_views_util:set_view_type(QueryArg, ViewName, Views)
     end),
     VAcc0 = #vacc{db=Db, req=Req, prepend="\r\n"},
     FirstChunk = "{\"results\":[",
     {ok, Resp0} = chttpd:start_delayed_json_response(VAcc0#vacc.req, 200, [], FirstChunk),
     VAcc1 = VAcc0#vacc{resp=Resp0},
     VAcc2 = lists:foldl(fun(Args, Acc0) ->
         Fun = fun view_cb/2,
         {ok, Acc1} = couch_views:query(Db, DDoc, ViewName, Fun, Acc0, Args),
         Acc1
     end, VAcc1, ArgQueries),
     {ok, Resp1} = chttpd:send_delayed_chunk(VAcc2#vacc.resp, "\r\n]}"),
     chttpd:end_delayed_json_response(Resp1).


 paginate_multi_query_view(Req, Db, DDoc, ViewName, Args0, Queries) ->
     {ok, #mrst{views=Views}} = couch_views_util:ddoc_to_mrst(Db, DDoc),
     ArgQueries = parse_queries(Req, Args0, Queries, fun(QueryArg) ->
         couch_views_util:set_view_type(QueryArg, ViewName, Views)
     end),
     KeyFun = fun({Props}) ->
         {couch_util:get_value(id, Props), couch_util:get_value(key, Props)}
     end,
     #mrargs{page_size = PageSize} = Args0,
     #httpd{path_parts = Parts} = Req,
     UpdateSeq = fabric2_db:get_update_seq(Db),
     EtagTerm = {Parts, UpdateSeq, Args0},
     Response = couch_views_http:paginated(
         Req, EtagTerm, PageSize, ArgQueries, KeyFun,
         fun(Args) ->
            {ok, #vacc{meta=MetaMap, buffer=Items}} = couch_views:query(
                Db, DDoc, ViewName, fun view_cb/2, #vacc{paginated=true}, Args),
            {MetaMap, Items}
         end),
     chttpd:send_json(Req, Response).


 design_doc_post_view(Req, Props, Db, DDoc, ViewName, Keys) ->
     Args = couch_views_http_util:parse_body_and_query(Req, Props, Keys),
     fabric_query_view(Db, Req, DDoc, ViewName, Args).

 design_doc_view(Req, Db, DDoc, ViewName, Keys) ->
     Args = couch_views_http:parse_params(Req, Keys),
     fabric_query_view(Db, Req, DDoc, ViewName, Args).


 fabric_query_view(Db, Req, DDoc, ViewName, Args) ->
     case couch_views_util:is_paginated(Args) of
         false ->
             stream_fabric_query_view(Db, Req, DDoc, ViewName, Args);
         true ->
             paginate_fabric_query_view(Db, Req, DDoc, ViewName, Args)
     end.


 stream_fabric_query_view(Db, Req, DDoc, ViewName, Args) ->
     Max = chttpd:chunked_response_buffer_size(),
     Fun = fun view_cb/2,
     VAcc = #vacc{db=Db, req=Req, threshold=Max},
     {ok, Resp} = couch_views:query(Db, DDoc, ViewName, Fun, VAcc, Args),
     {ok, Resp#vacc.resp}.


 paginate_fabric_query_view(Db, Req, DDoc, ViewName, Args0) ->
     KeyFun = fun({Props}) ->
         {couch_util:get_value(id, Props), couch_util:get_value(key, Props)}
     end,
     #httpd{path_parts = Parts} = Req,
     UpdateSeq = fabric2_db:get_update_seq(Db),
     ETagTerm = {Parts, UpdateSeq, Args0},
     Response = couch_views_http:paginated(
         Req, ETagTerm, Args0, KeyFun,
         fun(Args) ->
             VAcc0 = #vacc{paginated=true},
             {ok, VAcc1} = couch_views:query(Db, DDoc, ViewName, fun view_cb/2, VAcc0, Args),
             #vacc{meta=Meta, buffer=Items} = VAcc1,
             {Meta, Items}
         end),
     chttpd:send_json(Req, Response).

 view_cb({row, Row} = Msg, Acc) ->
     case lists:keymember(doc, 1, Row) of
         true -> chttpd_stats:incr_reads();
         false -> ok
     end,
     chttpd_stats:incr_rows(),
     couch_views_http:view_cb(Msg, Acc);

 view_cb(Msg, Acc) ->
     couch_views_http:view_cb(Msg, Acc).


 handle_view_req(#httpd{method='POST',
     path_parts=[_, _, _, _, ViewName, <<"queries">>]}=Req, Db, DDoc) ->
     chttpd:validate_ctype(Req, "application/json"),
     Props = couch_httpd:json_body_obj(Req),
     case couch_views_util:get_view_queries(Props) of
         undefined ->
             throw({bad_request,
                 <<"POST body must include `queries` parameter.">>});
         Queries ->
             multi_query_view(Req, Db, DDoc, ViewName, Queries)
     end;

 handle_view_req(#httpd{path_parts=[_, _, _, _, _, <<"queries">>]}=Req,
     _Db, _DDoc) ->
     chttpd:send_method_not_allowed(Req, "POST");

 handle_view_req(#httpd{method='GET',
         path_parts=[_, _, _, _, ViewName]}=Req, Db, DDoc) ->
     couch_stats:increment_counter([couchdb, httpd, view_reads]),
     Keys = chttpd:qs_json_value(Req, "keys", undefined),
     design_doc_view(Req, Db, DDoc, ViewName, Keys);

 handle_view_req(#httpd{method='POST',
         path_parts=[_, _, _, _, ViewName]}=Req, Db, DDoc) ->
     chttpd:validate_ctype(Req, "application/json"),
     Props = couch_httpd:json_body_obj(Req),
     assert_no_queries_param(couch_views_util:get_view_queries(Props)),
     Keys = couch_views_util:get_view_keys(Props),
     couch_stats:increment_counter([couchdb, httpd, view_reads]),
     design_doc_post_view(Req, Props, Db, DDoc, ViewName, Keys);

 handle_view_req(Req, _Db, _DDoc) ->
     chttpd:send_method_not_allowed(Req, "GET,POST,HEAD").


 % See https://github.com/apache/couchdb/issues/2168
 assert_no_queries_param(undefined) ->
     ok;
 assert_no_queries_param(_) ->
     throw({
         bad_request,
         "The `queries` parameter is no longer supported at this endpoint"
     }).


 validate_args(Req, #mrargs{page_size = PageSize} = Args) when is_integer(PageSize) ->
     MaxPageSize = max_page_size(Req),
     couch_views_util:validate_args(Args, [{page_size, MaxPageSize}]);

 validate_args(_Req, #mrargs{} = Args) ->
     couch_views_util:validate_args(Args, []).


 max_page_size(#httpd{path_parts=[_Db, <<"_all_docs">>, <<"queries">>]}) ->
     config:get_integer(
         "request_limits", "_all_docs/queries", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

 max_page_size(#httpd{path_parts=[_Db, <<"_all_docs">>]}) ->
     config:get_integer(
         "request_limits", "_all_docs", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

 max_page_size(#httpd{path_parts=[_Db, <<"_local_docs">>, <<"queries">>]}) ->
     config:get_integer(
         "request_limits", "_all_docs/queries", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

 max_page_size(#httpd{path_parts=[_Db, <<"_local_docs">>]}) ->
     config:get_integer(
         "request_limits", "_all_docs", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

 max_page_size(#httpd{path_parts=[_Db, <<"_design_docs">>, <<"queries">>]}) ->
     config:get_integer(
         "request_limits", "_all_docs/queries", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

 max_page_size(#httpd{path_parts=[_Db, <<"_design_docs">>]}) ->
     config:get_integer(
         "request_limits", "_all_docs", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

 max_page_size(#httpd{path_parts=[
         _Db, <<"_design">>, _DDocName, <<"_view">>, _View, <<"queries">>]}) ->
     config:get_integer(
         "request_limits", "_view/queries", ?DEFAULT_VIEWS_PAGE_SIZE);

 max_page_size(#httpd{path_parts=[
         _Db, <<"_design">>, _DDocName, <<"_view">>, _View]}) ->
     config:get_integer(
         "request_limits", "_view", ?DEFAULT_VIEWS_PAGE_SIZE).


 parse_queries(Req, #mrargs{page_size = PageSize} = Args0, Queries, Fun)
         when is_integer(PageSize) ->
     MaxPageSize = max_page_size(Req),
     if length(Queries) < PageSize -> ok; true ->
         throw({
             query_parse_error,
             <<"Provided number of queries is more than given page_size">>
         })
     end,
     couch_views_util:validate_args(Fun(Args0), [{page_size, MaxPageSize}]),
     Args = Args0#mrargs{page_size = undefined},
     lists:map(fun({Query}) ->
         Args1 = couch_views_http:parse_params(Query, undefined, Args, [decoded]),
         if not is_integer(Args1#mrargs.page_size) -> ok; true ->
             throw({
                query_parse_error,
                 <<"You cannot specify `page_size` inside the query">>
             })
         end,
         Args2 = maybe_set_page_size(Args1, MaxPageSize),
         couch_views_util:validate_args(Fun(Args2), [{page_size, MaxPageSize}])
     end, Queries);

 parse_queries(_Req, #mrargs{} = Args, Queries, Fun) ->
     lists:map(fun({Query}) ->
         Args1 = couch_views_http:parse_params(Query, undefined, Args, [decoded]),
         couch_views_util:validate_args(Fun(Args1))
     end, Queries).


 maybe_set_page_size(#mrargs{page_size = undefined} = Args, MaxPageSize) ->
     Args#mrargs{page_size = MaxPageSize};

 maybe_set_page_size(#mrargs{} = Args, _MaxPageSize) ->
     Args.


 -ifdef(TEST).

 -include_lib("eunit/include/eunit.hrl").


 check_multi_query_reduce_view_overrides_test_() ->
     {
         setup,
         fun setup_all/0,
         fun teardown_all/1,
         {
             foreach,
             fun setup/0,
             fun teardown/1,
             [
                 t_check_include_docs_throw_validation_error(),
                 t_check_user_can_override_individual_query_type()
             ]
         }
     }.


 t_check_include_docs_throw_validation_error() ->
     ?_test(begin
         Req = #httpd{qs = []},
         Db = #{name => <<"foo">>},
         Query = {[{<<"include_docs">>, true}]},
         Throw = {query_parse_error, <<"`include_docs` is invalid for reduce">>},
         ?assertThrow(Throw, multi_query_view(Req, Db, ddoc, <<"v">>, [Query]))
     end).


 t_check_user_can_override_individual_query_type() ->
     ?_test(begin
         Req = #httpd{qs = []},
         Db = #{name => <<"foo">>},
         Query = {[{<<"include_docs">>, true}, {<<"reduce">>, false}]},
         multi_query_view(Req, Db, ddoc, <<"v">>, [Query]),
         ?assertEqual(1, meck:num_calls(chttpd, start_delayed_json_response, '_'))
     end).


 setup_all() ->
     Views = [#mrview{reduce_funs = [{<<"v">>, <<"_count">>}]}],
     meck:expect(couch_views_util, ddoc_to_mrst, 2, {ok, #mrst{views = Views}}),
     meck:expect(chttpd, start_delayed_json_response, 4, {ok, resp}),
     meck:expect(couch_views, query, 6, {ok, #vacc{}}),
     meck:expect(chttpd, send_delayed_chunk, 2, {ok, resp}),
     meck:expect(chttpd, end_delayed_json_response, 1, ok).


 teardown_all(_) ->
     meck:unload().


 setup() ->
     meck:reset([
         chttpd,
         couch_views,
         couch_views_util
     ]).


 teardown(_) ->
     ok.


 -endif.
	% 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(chttpd_view).
	-include_lib("couch/include/couch_db.hrl").
	-include_lib("couch_views/include/couch_views.hrl").

	-export([
	handle_view_req/3,
	validate_args/2,
	parse_queries/4,
	view_cb/2
	]).

	-define(DEFAULT_ALL_DOCS_PAGE_SIZE, 2000).
	-define(DEFAULT_VIEWS_PAGE_SIZE, 2000).

	multi_query_view(Req, Db, DDoc, ViewName, Queries) ->
	Args = couch_views_http:parse_params(Req, undefined),
	case couch_views_util:is_paginated(Args) of
	false ->
	stream_multi_query_view(Req, Db, DDoc, ViewName, Args, Queries);
	true ->
	paginate_multi_query_view(Req, Db, DDoc, ViewName, Args, Queries)
	end.


	stream_multi_query_view(Req, Db, DDoc, ViewName, Args0, Queries) ->
	{ok, #mrst{views=Views}} = couch_views_util:ddoc_to_mrst(Db, DDoc),
	Args1 = couch_views_util:set_view_type(Args0, ViewName, Views),
	ArgQueries = parse_queries(Req, Args1, Queries, fun(QueryArg) ->
	couch_views_util:set_view_type(QueryArg, ViewName, Views)
	end),
	VAcc0 = #vacc{db=Db, req=Req, prepend="\r\n"},
	FirstChunk = "{\"results\":[",
	{ok, Resp0} = chttpd:start_delayed_json_response(VAcc0#vacc.req, 200, [], FirstChunk),
	VAcc1 = VAcc0#vacc{resp=Resp0},
	VAcc2 = lists:foldl(fun(Args, Acc0) ->
	Fun = fun view_cb/2,
	{ok, Acc1} = couch_views:query(Db, DDoc, ViewName, Fun, Acc0, Args),
	Acc1
	end, VAcc1, ArgQueries),
	{ok, Resp1} = chttpd:send_delayed_chunk(VAcc2#vacc.resp, "\r\n]}"),
	chttpd:end_delayed_json_response(Resp1).


	paginate_multi_query_view(Req, Db, DDoc, ViewName, Args0, Queries) ->
	{ok, #mrst{views=Views}} = couch_views_util:ddoc_to_mrst(Db, DDoc),
	ArgQueries = parse_queries(Req, Args0, Queries, fun(QueryArg) ->
	couch_views_util:set_view_type(QueryArg, ViewName, Views)
	end),
	KeyFun = fun({Props}) ->
	{couch_util:get_value(id, Props), couch_util:get_value(key, Props)}
	end,
	#mrargs{page_size = PageSize} = Args0,
	#httpd{path_parts = Parts} = Req,
	UpdateSeq = fabric2_db:get_update_seq(Db),
	EtagTerm = {Parts, UpdateSeq, Args0},
	Response = couch_views_http:paginated(
	Req, EtagTerm, PageSize, ArgQueries, KeyFun,
	fun(Args) ->
	{ok, #vacc{meta=MetaMap, buffer=Items}} = couch_views:query(
	Db, DDoc, ViewName, fun view_cb/2, #vacc{paginated=true}, Args),
	{MetaMap, Items}
	end),
	chttpd:send_json(Req, Response).


	design_doc_post_view(Req, Props, Db, DDoc, ViewName, Keys) ->
	Args = couch_views_http_util:parse_body_and_query(Req, Props, Keys),
	fabric_query_view(Db, Req, DDoc, ViewName, Args).

	design_doc_view(Req, Db, DDoc, ViewName, Keys) ->
	Args = couch_views_http:parse_params(Req, Keys),
	fabric_query_view(Db, Req, DDoc, ViewName, Args).


	fabric_query_view(Db, Req, DDoc, ViewName, Args) ->
	case couch_views_util:is_paginated(Args) of
	false ->
	stream_fabric_query_view(Db, Req, DDoc, ViewName, Args);
	true ->
	paginate_fabric_query_view(Db, Req, DDoc, ViewName, Args)
	end.


	stream_fabric_query_view(Db, Req, DDoc, ViewName, Args) ->
	Max = chttpd:chunked_response_buffer_size(),
	Fun = fun view_cb/2,
	VAcc = #vacc{db=Db, req=Req, threshold=Max},
	{ok, Resp} = couch_views:query(Db, DDoc, ViewName, Fun, VAcc, Args),
	{ok, Resp#vacc.resp}.


	paginate_fabric_query_view(Db, Req, DDoc, ViewName, Args0) ->
	KeyFun = fun({Props}) ->
	{couch_util:get_value(id, Props), couch_util:get_value(key, Props)}
	end,
	#httpd{path_parts = Parts} = Req,
	UpdateSeq = fabric2_db:get_update_seq(Db),
	ETagTerm = {Parts, UpdateSeq, Args0},
	Response = couch_views_http:paginated(
	Req, ETagTerm, Args0, KeyFun,
	fun(Args) ->
	VAcc0 = #vacc{paginated=true},
	{ok, VAcc1} = couch_views:query(Db, DDoc, ViewName, fun view_cb/2, VAcc0, Args),
	#vacc{meta=Meta, buffer=Items} = VAcc1,
	{Meta, Items}
	end),
	chttpd:send_json(Req, Response).

	view_cb({row, Row} = Msg, Acc) ->
	case lists:keymember(doc, 1, Row) of
	true -> chttpd_stats:incr_reads();
	false -> ok
	end,
	chttpd_stats:incr_rows(),
	couch_views_http:view_cb(Msg, Acc);

	view_cb(Msg, Acc) ->
	couch_views_http:view_cb(Msg, Acc).


	handle_view_req(#httpd{method='POST',
	path_parts=[_, _, _, _, ViewName, <<"queries">>]}=Req, Db, DDoc) ->
	chttpd:validate_ctype(Req, "application/json"),
	Props = couch_httpd:json_body_obj(Req),
	case couch_views_util:get_view_queries(Props) of
	undefined ->
	throw({bad_request,
	<<"POST body must include `queries` parameter.">>});
	Queries ->
	multi_query_view(Req, Db, DDoc, ViewName, Queries)
	end;

	handle_view_req(#httpd{path_parts=[_, _, _, _, _, <<"queries">>]}=Req,
	_Db, _DDoc) ->
	chttpd:send_method_not_allowed(Req, "POST");

	handle_view_req(#httpd{method='GET',
	path_parts=[_, _, _, _, ViewName]}=Req, Db, DDoc) ->
	couch_stats:increment_counter([couchdb, httpd, view_reads]),
	Keys = chttpd:qs_json_value(Req, "keys", undefined),
	design_doc_view(Req, Db, DDoc, ViewName, Keys);

	handle_view_req(#httpd{method='POST',
	path_parts=[_, _, _, _, ViewName]}=Req, Db, DDoc) ->
	chttpd:validate_ctype(Req, "application/json"),
	Props = couch_httpd:json_body_obj(Req),
	assert_no_queries_param(couch_views_util:get_view_queries(Props)),
	Keys = couch_views_util:get_view_keys(Props),
	couch_stats:increment_counter([couchdb, httpd, view_reads]),
	design_doc_post_view(Req, Props, Db, DDoc, ViewName, Keys);

	handle_view_req(Req, _Db, _DDoc) ->
	chttpd:send_method_not_allowed(Req, "GET,POST,HEAD").


	% See https://github.com/apache/couchdb/issues/2168
	assert_no_queries_param(undefined) ->
	ok;
	assert_no_queries_param(_) ->
	throw({
	bad_request,
	"The `queries` parameter is no longer supported at this endpoint"
	}).


	validate_args(Req, #mrargs{page_size = PageSize} = Args) when is_integer(PageSize) ->
	MaxPageSize = max_page_size(Req),
	couch_views_util:validate_args(Args, [{page_size, MaxPageSize}]);

	validate_args(_Req, #mrargs{} = Args) ->
	couch_views_util:validate_args(Args, []).


	max_page_size(#httpd{path_parts=[_Db, <<"_all_docs">>, <<"queries">>]}) ->
	config:get_integer(
	"request_limits", "_all_docs/queries", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

	max_page_size(#httpd{path_parts=[_Db, <<"_all_docs">>]}) ->
	config:get_integer(
	"request_limits", "_all_docs", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

	max_page_size(#httpd{path_parts=[_Db, <<"_local_docs">>, <<"queries">>]}) ->
	config:get_integer(
	"request_limits", "_all_docs/queries", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

	max_page_size(#httpd{path_parts=[_Db, <<"_local_docs">>]}) ->
	config:get_integer(
	"request_limits", "_all_docs", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

	max_page_size(#httpd{path_parts=[_Db, <<"_design_docs">>, <<"queries">>]}) ->
	config:get_integer(
	"request_limits", "_all_docs/queries", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

	max_page_size(#httpd{path_parts=[_Db, <<"_design_docs">>]}) ->
	config:get_integer(
	"request_limits", "_all_docs", ?DEFAULT_ALL_DOCS_PAGE_SIZE);

	max_page_size(#httpd{path_parts=[
	_Db, <<"_design">>, _DDocName, <<"_view">>, _View, <<"queries">>]}) ->
	config:get_integer(
	"request_limits", "_view/queries", ?DEFAULT_VIEWS_PAGE_SIZE);

	max_page_size(#httpd{path_parts=[
	_Db, <<"_design">>, _DDocName, <<"_view">>, _View]}) ->
	config:get_integer(
	"request_limits", "_view", ?DEFAULT_VIEWS_PAGE_SIZE).


	parse_queries(Req, #mrargs{page_size = PageSize} = Args0, Queries, Fun)
	when is_integer(PageSize) ->
	MaxPageSize = max_page_size(Req),
	if length(Queries) < PageSize -> ok; true ->
	throw({
	query_parse_error,
	<<"Provided number of queries is more than given page_size">>
	})
	end,
	couch_views_util:validate_args(Fun(Args0), [{page_size, MaxPageSize}]),
	Args = Args0#mrargs{page_size = undefined},
	lists:map(fun({Query}) ->
	Args1 = couch_views_http:parse_params(Query, undefined, Args, [decoded]),
	if not is_integer(Args1#mrargs.page_size) -> ok; true ->
	throw({
	query_parse_error,
	<<"You cannot specify `page_size` inside the query">>
	})
	end,
	Args2 = maybe_set_page_size(Args1, MaxPageSize),
	couch_views_util:validate_args(Fun(Args2), [{page_size, MaxPageSize}])
	end, Queries);

	parse_queries(_Req, #mrargs{} = Args, Queries, Fun) ->
	lists:map(fun({Query}) ->
	Args1 = couch_views_http:parse_params(Query, undefined, Args, [decoded]),
	couch_views_util:validate_args(Fun(Args1))
	end, Queries).


	maybe_set_page_size(#mrargs{page_size = undefined} = Args, MaxPageSize) ->
	Args#mrargs{page_size = MaxPageSize};

	maybe_set_page_size(#mrargs{} = Args, _MaxPageSize) ->
	Args.


	-ifdef(TEST).

	-include_lib("eunit/include/eunit.hrl").


	check_multi_query_reduce_view_overrides_test_() ->
	{
	setup,
	fun setup_all/0,
	fun teardown_all/1,
	{
	foreach,
	fun setup/0,
	fun teardown/1,
	[
	t_check_include_docs_throw_validation_error(),
	t_check_user_can_override_individual_query_type()
	]
	}
	}.


	t_check_include_docs_throw_validation_error() ->
	?_test(begin
	Req = #httpd{qs = []},
	Db = #{name => <<"foo">>},
	Query = {[{<<"include_docs">>, true}]},
	Throw = {query_parse_error, <<"`include_docs` is invalid for reduce">>},
	?assertThrow(Throw, multi_query_view(Req, Db, ddoc, <<"v">>, [Query]))
	end).


	t_check_user_can_override_individual_query_type() ->
	?_test(begin
	Req = #httpd{qs = []},
	Db = #{name => <<"foo">>},
	Query = {[{<<"include_docs">>, true}, {<<"reduce">>, false}]},
	multi_query_view(Req, Db, ddoc, <<"v">>, [Query]),
	?assertEqual(1, meck:num_calls(chttpd, start_delayed_json_response, '_'))
	end).


	setup_all() ->
	Views = [#mrview{reduce_funs = [{<<"v">>, <<"_count">>}]}],
	meck:expect(couch_views_util, ddoc_to_mrst, 2, {ok, #mrst{views = Views}}),
	meck:expect(chttpd, start_delayed_json_response, 4, {ok, resp}),
	meck:expect(couch_views, query, 6, {ok, #vacc{}}),
	meck:expect(chttpd, send_delayed_chunk, 2, {ok, resp}),
	meck:expect(chttpd, end_delayed_json_response, 1, ok).


	teardown_all(_) ->
	meck:unload().


	setup() ->
	meck:reset([
	chttpd,
	couch_views,
	couch_views_util
	]).


	teardown(_) ->
	ok.


	-endif.