src/couch_mrview_http.erl - couchdb-couch-mrview - 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(couch_mrview_http).

 -export([
     handle_all_docs_req/2,
     handle_view_req/3,
     handle_temp_view_req/2,
     handle_info_req/3,
     handle_compact_req/3,
     handle_cleanup_req/2,
     parse_qs/2
 ]).


 -include_lib("couch/include/couch_db.hrl").
 -include_lib("couch_mrview/include/couch_mrview.hrl").


 -record(vacc, {
     db,
     req,
     resp,
     prepend,
     etag
 }).


 handle_all_docs_req(#httpd{method='GET'}=Req, Db) ->
     all_docs_req(Req, Db, undefined);
 handle_all_docs_req(#httpd{method='POST'}=Req, Db) ->
     Keys = get_view_keys(couch_httpd:json_body_obj(Req)),
     all_docs_req(Req, Db, Keys);
 handle_all_docs_req(Req, _Db) ->
     couch_httpd:send_method_not_allowed(Req, "GET,POST,HEAD").


 handle_view_req(#httpd{method='GET'}=Req, Db, DDoc) ->
     [_, _, _, _, ViewName] = Req#httpd.path_parts,
     couch_stats_collector:increment({httpd, view_reads}),
     design_doc_view(Req, Db, DDoc, ViewName, undefined);
 handle_view_req(#httpd{method='POST'}=Req, Db, DDoc) ->
     [_, _, _, _, ViewName] = Req#httpd.path_parts,
     Keys = get_view_keys(couch_httpd:json_body_obj(Req)),
     couch_stats_collector:increment({httpd, view_reads}),
     design_doc_view(Req, Db, DDoc, ViewName, Keys);
 handle_view_req(Req, _Db, _DDoc) ->
     couch_httpd:send_method_not_allowed(Req, "GET,POST,HEAD").


 handle_temp_view_req(#httpd{method='POST'}=Req, Db) ->
     couch_httpd:validate_ctype(Req, "application/json"),
     ok = couch_db:check_is_admin(Db),
     {Body} = couch_httpd:json_body_obj(Req),
     DDoc = couch_mrview_util:temp_view_to_ddoc({Body}),
     Keys = get_view_keys({Body}),
     couch_stats_collector:increment({httpd, temporary_view_reads}),
     design_doc_view(Req, Db, DDoc, <<"temp">>, Keys);
 handle_temp_view_req(Req, _Db) ->
     couch_httpd:send_method_not_allowed(Req, "POST").


 handle_info_req(#httpd{method='GET'}=Req, Db, DDoc) ->
     [_, _, Name, _] = Req#httpd.path_parts,
     {ok, Info} = couch_mrview:get_info(Db, DDoc),
     couch_httpd:send_json(Req, 200, {[
         {name, Name},
         {view_index, {Info}}
     ]});
 handle_info_req(Req, _Db, _DDoc) ->
     couch_httpd:send_method_not_allowed(Req, "GET").


 handle_compact_req(#httpd{method='POST'}=Req, Db, DDoc) ->
     ok = couch_db:check_is_admin(Db),
     couch_httpd:validate_ctype(Req, "application/json"),
     ok = couch_mrview:compact(Db, DDoc),
     couch_httpd:send_json(Req, 202, {[{ok, true}]});
 handle_compact_req(Req, _Db, _DDoc) ->
     couch_httpd:send_method_not_allowd(Req, "POST").


 handle_cleanup_req(#httpd{method='POST'}=Req, Db) ->
     ok = couch_db:check_is_admin(Db),
     couch_httpd:validate_ctype(Req, "application/json"),
     ok = couch_mrview:cleanup(Db),
     couch_httpd:send_json(Req, 202, {[{ok, true}]});
 handle_cleanup_req(Req, _Db) ->
     couch_httpd:send_method_not_allowed(Req, "POST").


 all_docs_req(Req, Db, Keys) ->
     case couch_db:is_system_db(Db) of
     true ->
         case (catch couch_db:check_is_admin(Db)) of
         ok ->
             do_all_docs_req(Req, Db, Keys);
         _ ->
             throw({forbidden, <<"Only admins can access _all_docs",
                 " of system databases.">>})
         end;
     false ->
         do_all_docs_req(Req, Db, Keys)
     end.


 do_all_docs_req(Req, Db, Keys) ->
     Args0 = parse_qs(Req, Keys),
     ETagFun = fun(Sig, Acc0) ->
         ETag = couch_httpd:make_etag(Sig),
         case couch_httpd:etag_match(Req, ETag) of
             true -> throw({etag_match, ETag});
             false -> {ok, Acc0#vacc{etag=ETag}}
         end
     end,
     Args = Args0#mrargs{preflight_fun=ETagFun},
     {ok, Resp} = couch_httpd:etag_maybe(Req, fun() ->
         VAcc0 = #vacc{db=Db, req=Req},
         couch_mrview:query_all_docs(Db, Args, fun view_cb/2, VAcc0)
     end),
     case is_record(Resp, vacc) of
         true -> {ok, Resp#vacc.resp};
         _ -> {ok, Resp}
     end.


 design_doc_view(Req, Db, DDoc, ViewName, Keys) ->
     Args0 = parse_qs(Req, Keys),
     ETagFun = fun(Sig, Acc0) ->
         ETag = couch_httpd:make_etag(Sig),
         case couch_httpd:etag_match(Req, ETag) of
             true -> throw({etag_match, ETag});
             false -> {ok, Acc0#vacc{etag=ETag}}
         end
     end,
     Args = Args0#mrargs{preflight_fun=ETagFun},
     {ok, Resp} = couch_httpd:etag_maybe(Req, fun() ->
         VAcc0 = #vacc{db=Db, req=Req},
         couch_mrview:query_view(Db, DDoc, ViewName, Args, fun view_cb/2, VAcc0)
     end),
     case is_record(Resp, vacc) of
         true -> {ok, Resp#vacc.resp};
         _ -> {ok, Resp}
     end.


 view_cb({meta, Meta}, #vacc{resp=undefined}=Acc) ->
     Headers = [{"ETag", Acc#vacc.etag}],
     {ok, Resp} = couch_httpd:start_json_response(Acc#vacc.req, 200, Headers),
     % Map function starting
     Parts = case couch_util:get_value(total, Meta) of
         undefined -> [];
         Total -> [io_lib:format("\"total_rows\":~p", [Total])]
     end ++ case couch_util:get_value(offset, Meta) of
         undefined -> [];
         Offset -> [io_lib:format("\"offset\":~p", [Offset])]
     end ++ case couch_util:get_value(update_seq, Meta) of
         undefined -> [];
         UpdateSeq -> [io_lib:format("\"update_seq\":~p", [UpdateSeq])]
     end ++ ["\"rows\":["],
     Chunk = lists:flatten("{" ++ string:join(Parts, ",") ++ "\r\n"),
     couch_httpd:send_chunk(Resp, Chunk),
     {ok, Acc#vacc{resp=Resp, prepend=""}};
 view_cb({row, Row}, #vacc{resp=undefined}=Acc) ->
     % Reduce function starting
     Headers = [{"ETag", Acc#vacc.etag}],
     {ok, Resp} = couch_httpd:start_json_response(Acc#vacc.req, 200, Headers),
     couch_httpd:send_chunk(Resp, ["{\"rows\":[\r\n", row_to_json(Row)]),
     {ok, #vacc{resp=Resp, prepend=",\r\n"}};
 view_cb({row, Row}, Acc) ->
     % Adding another row
     couch_httpd:send_chunk(Acc#vacc.resp, [Acc#vacc.prepend, row_to_json(Row)]),
     {ok, Acc#vacc{prepend=",\r\n"}};
 view_cb(complete, #vacc{resp=undefined}=Acc) ->
     % Nothing in view
     {ok, Resp} = couch_httpd:send_json(Acc#vacc.req, 200, {[{rows, []}]}),
     {ok, Acc#vacc{resp=Resp}};
 view_cb(complete, Acc) ->
     % Finish view output
     couch_httpd:send_chunk(Acc#vacc.resp, "\r\n]}"),
     couch_httpd:end_json_response(Acc#vacc.resp),
     {ok, Acc}.


 row_to_json(Row) ->
     Id = couch_util:get_value(id, Row),
     row_to_json(Id, Row).


 row_to_json(error, Row) ->
     % Special case for _all_docs request with KEYS to
     % match prior behavior.
     Key = couch_util:get_value(key, Row),
     Val = couch_util:get_value(value, Row),
     Obj = {[{key, Key}, {error, Val}]},
     ?JSON_ENCODE(Obj);
 row_to_json(Id0, Row) ->
     Id = case Id0 of
         undefined -> [];
         Id0 -> [{id, Id0}]
     end,
     Key = couch_util:get_value(key, Row, null),
     Val = couch_util:get_value(value, Row),
     Doc = case couch_util:get_value(doc, Row) of
         undefined -> [];
         Doc0 -> [{doc, Doc0}]
     end,
     Obj = {Id ++ [{key, Key}, {value, Val}] ++ Doc},
     ?JSON_ENCODE(Obj).


 get_view_keys({Props}) ->
     case couch_util:get_value(<<"keys">>, Props) of
         undefined ->
             ?LOG_DEBUG("POST with no keys member.", []),
             undefined;
         Keys when is_list(Keys) ->
             Keys;
         _ ->
             throw({bad_request, "`keys` member must be a array."})
     end.


 parse_qs(Req, Keys) ->
     Args = #mrargs{keys=Keys},
     lists:foldl(fun({K, V}, Acc) ->
         parse_qs(K, V, Acc)
     end, Args, couch_httpd:qs(Req)).


 parse_qs(Key, Val, Args) ->
     case Key of
         "" ->
             Args;
         "reduce" ->
             Args#mrargs{reduce=parse_boolean(Val)};
         "key" ->
             JsonKey = ?JSON_DECODE(Val),
             Args#mrargs{start_key=JsonKey, end_key=JsonKey};
         "keys" ->
             Args#mrargs{keys=?JSON_DECODE(Val)};
         "startkey" ->
             Args#mrargs{start_key=?JSON_DECODE(Val)};
         "start_key" ->
             Args#mrargs{start_key=?JSON_DECODE(Val)};
         "startkey_docid" ->
             Args#mrargs{start_key_docid=list_to_binary(Val)};
         "start_key_doc_id" ->
             Args#mrargs{start_key_docid=list_to_binary(Val)};
         "endkey" ->
             Args#mrargs{end_key=?JSON_DECODE(Val)};
         "end_key" ->
             Args#mrargs{end_key=?JSON_DECODE(Val)};
         "endkey_docid" ->
             Args#mrargs{end_key_docid=list_to_binary(Val)};
         "end_key_doc_id" ->
             Args#mrargs{end_key_docid=list_to_binary(Val)};
         "limit" ->
             Args#mrargs{limit=parse_pos_int(Val)};
         "count" ->
             throw({query_parse_error, <<"QS param `count` is not `limit`">>});
         "stale" when Val == "ok" ->
             Args#mrargs{stale=ok};
         "stale" when Val == "update_after" ->
             Args#mrargs{stale=update_after};
         "stale" ->
             throw({query_parse_error, <<"Invalid value for `stale`.">>});
         "descending" ->
             case parse_boolean(Val) of
                 true -> Args#mrargs{direction=rev};
                 _ -> Args#mrargs{direction=fwd}
             end;
         "skip" ->
             Args#mrargs{skip=parse_pos_int(Val)};
         "group" ->
             case parse_boolean(Val) of
                 true -> Args#mrargs{group_level=exact};
                 _ -> Args#mrargs{group_level=0}
             end;
         "group_level" ->
             Args#mrargs{group_level=parse_pos_int(Val)};
         "inclusive_end" ->
             Args#mrargs{inclusive_end=parse_boolean(Val)};
         "include_docs" ->
             Args#mrargs{include_docs=parse_boolean(Val)};
         "update_seq" ->
             Args#mrargs{update_seq=parse_boolean(Val)};
         "conflicts" ->
             Args#mrargs{conflicts=parse_boolean(Val)};
         "list" ->
             Args#mrargs{list=list_to_binary(Val)};
         "callback" ->
             Args#mrargs{callback=list_to_binary(Val)};
         _ ->
             BKey = list_to_binary(Key),
             BVal = list_to_binary(Val),
             Args#mrargs{extra=[{BKey, BVal} | Args#mrargs.extra]}
     end.


 parse_boolean(Val) ->
     case string:to_lower(Val) of
     "true" -> true;
     "false" -> false;
     _ ->
         Msg = io_lib:format("Invalid boolean parameter: ~p", [Val]),
         throw({query_parse_error, ?l2b(Msg)})
     end.


 parse_int(Val) ->
     case (catch list_to_integer(Val)) of
     IntVal when is_integer(IntVal) ->
         IntVal;
     _ ->
         Msg = io_lib:format("Invalid value for integer: ~p", [Val]),
         throw({query_parse_error, ?l2b(Msg)})
     end.


 parse_pos_int(Val) ->
     case parse_int(Val) of
     IntVal when IntVal >= 0 ->
         IntVal;
     _ ->
         Fmt = "Invalid value for positive integer: ~p",
         Msg = io_lib:format(Fmt, [Val]),
         throw({query_parse_error, ?l2b(Msg)})
     end.
	% 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(couch_mrview_http).

	-export([
	handle_all_docs_req/2,
	handle_view_req/3,
	handle_temp_view_req/2,
	handle_info_req/3,
	handle_compact_req/3,
	handle_cleanup_req/2,
	parse_qs/2
	]).


	-include_lib("couch/include/couch_db.hrl").
	-include_lib("couch_mrview/include/couch_mrview.hrl").


	-record(vacc, {
	db,
	req,
	resp,
	prepend,
	etag
	}).


	handle_all_docs_req(#httpd{method='GET'}=Req, Db) ->
	all_docs_req(Req, Db, undefined);
	handle_all_docs_req(#httpd{method='POST'}=Req, Db) ->
	Keys = get_view_keys(couch_httpd:json_body_obj(Req)),
	all_docs_req(Req, Db, Keys);
	handle_all_docs_req(Req, _Db) ->
	couch_httpd:send_method_not_allowed(Req, "GET,POST,HEAD").


	handle_view_req(#httpd{method='GET'}=Req, Db, DDoc) ->
	[_, _, _, _, ViewName] = Req#httpd.path_parts,
	couch_stats_collector:increment({httpd, view_reads}),
	design_doc_view(Req, Db, DDoc, ViewName, undefined);
	handle_view_req(#httpd{method='POST'}=Req, Db, DDoc) ->
	[_, _, _, _, ViewName] = Req#httpd.path_parts,
	Keys = get_view_keys(couch_httpd:json_body_obj(Req)),
	couch_stats_collector:increment({httpd, view_reads}),
	design_doc_view(Req, Db, DDoc, ViewName, Keys);
	handle_view_req(Req, _Db, _DDoc) ->
	couch_httpd:send_method_not_allowed(Req, "GET,POST,HEAD").


	handle_temp_view_req(#httpd{method='POST'}=Req, Db) ->
	couch_httpd:validate_ctype(Req, "application/json"),
	ok = couch_db:check_is_admin(Db),
	{Body} = couch_httpd:json_body_obj(Req),
	DDoc = couch_mrview_util:temp_view_to_ddoc({Body}),
	Keys = get_view_keys({Body}),
	couch_stats_collector:increment({httpd, temporary_view_reads}),
	design_doc_view(Req, Db, DDoc, <<"temp">>, Keys);
	handle_temp_view_req(Req, _Db) ->
	couch_httpd:send_method_not_allowed(Req, "POST").


	handle_info_req(#httpd{method='GET'}=Req, Db, DDoc) ->
	[_, _, Name, _] = Req#httpd.path_parts,
	{ok, Info} = couch_mrview:get_info(Db, DDoc),
	couch_httpd:send_json(Req, 200, {[
	{name, Name},
	{view_index, {Info}}
	]});
	handle_info_req(Req, _Db, _DDoc) ->
	couch_httpd:send_method_not_allowed(Req, "GET").


	handle_compact_req(#httpd{method='POST'}=Req, Db, DDoc) ->
	ok = couch_db:check_is_admin(Db),
	couch_httpd:validate_ctype(Req, "application/json"),
	ok = couch_mrview:compact(Db, DDoc),
	couch_httpd:send_json(Req, 202, {[{ok, true}]});
	handle_compact_req(Req, _Db, _DDoc) ->
	couch_httpd:send_method_not_allowd(Req, "POST").


	handle_cleanup_req(#httpd{method='POST'}=Req, Db) ->
	ok = couch_db:check_is_admin(Db),
	couch_httpd:validate_ctype(Req, "application/json"),
	ok = couch_mrview:cleanup(Db),
	couch_httpd:send_json(Req, 202, {[{ok, true}]});
	handle_cleanup_req(Req, _Db) ->
	couch_httpd:send_method_not_allowed(Req, "POST").


	all_docs_req(Req, Db, Keys) ->
	case couch_db:is_system_db(Db) of
	true ->
	case (catch couch_db:check_is_admin(Db)) of
	ok ->
	do_all_docs_req(Req, Db, Keys);
	_ ->
	throw({forbidden, <<"Only admins can access _all_docs",
	" of system databases.">>})
	end;
	false ->
	do_all_docs_req(Req, Db, Keys)
	end.


	do_all_docs_req(Req, Db, Keys) ->
	Args0 = parse_qs(Req, Keys),
	ETagFun = fun(Sig, Acc0) ->
	ETag = couch_httpd:make_etag(Sig),
	case couch_httpd:etag_match(Req, ETag) of
	true -> throw({etag_match, ETag});
	false -> {ok, Acc0#vacc{etag=ETag}}
	end
	end,
	Args = Args0#mrargs{preflight_fun=ETagFun},
	{ok, Resp} = couch_httpd:etag_maybe(Req, fun() ->
	VAcc0 = #vacc{db=Db, req=Req},
	couch_mrview:query_all_docs(Db, Args, fun view_cb/2, VAcc0)
	end),
	case is_record(Resp, vacc) of
	true -> {ok, Resp#vacc.resp};
	_ -> {ok, Resp}
	end.


	design_doc_view(Req, Db, DDoc, ViewName, Keys) ->
	Args0 = parse_qs(Req, Keys),
	ETagFun = fun(Sig, Acc0) ->
	ETag = couch_httpd:make_etag(Sig),
	case couch_httpd:etag_match(Req, ETag) of
	true -> throw({etag_match, ETag});
	false -> {ok, Acc0#vacc{etag=ETag}}
	end
	end,
	Args = Args0#mrargs{preflight_fun=ETagFun},
	{ok, Resp} = couch_httpd:etag_maybe(Req, fun() ->
	VAcc0 = #vacc{db=Db, req=Req},
	couch_mrview:query_view(Db, DDoc, ViewName, Args, fun view_cb/2, VAcc0)
	end),
	case is_record(Resp, vacc) of
	true -> {ok, Resp#vacc.resp};
	_ -> {ok, Resp}
	end.


	view_cb({meta, Meta}, #vacc{resp=undefined}=Acc) ->
	Headers = [{"ETag", Acc#vacc.etag}],
	{ok, Resp} = couch_httpd:start_json_response(Acc#vacc.req, 200, Headers),
	% Map function starting
	Parts = case couch_util:get_value(total, Meta) of
	undefined -> [];
	Total -> [io_lib:format("\"total_rows\":~p", [Total])]
	end ++ case couch_util:get_value(offset, Meta) of
	undefined -> [];
	Offset -> [io_lib:format("\"offset\":~p", [Offset])]
	end ++ case couch_util:get_value(update_seq, Meta) of
	undefined -> [];
	UpdateSeq -> [io_lib:format("\"update_seq\":~p", [UpdateSeq])]
	end ++ ["\"rows\":["],
	Chunk = lists:flatten("{" ++ string:join(Parts, ",") ++ "\r\n"),
	couch_httpd:send_chunk(Resp, Chunk),
	{ok, Acc#vacc{resp=Resp, prepend=""}};
	view_cb({row, Row}, #vacc{resp=undefined}=Acc) ->
	% Reduce function starting
	Headers = [{"ETag", Acc#vacc.etag}],
	{ok, Resp} = couch_httpd:start_json_response(Acc#vacc.req, 200, Headers),
	couch_httpd:send_chunk(Resp, ["{\"rows\":[\r\n", row_to_json(Row)]),
	{ok, #vacc{resp=Resp, prepend=",\r\n"}};
	view_cb({row, Row}, Acc) ->
	% Adding another row
	couch_httpd:send_chunk(Acc#vacc.resp, [Acc#vacc.prepend, row_to_json(Row)]),
	{ok, Acc#vacc{prepend=",\r\n"}};
	view_cb(complete, #vacc{resp=undefined}=Acc) ->
	% Nothing in view
	{ok, Resp} = couch_httpd:send_json(Acc#vacc.req, 200, {[{rows, []}]}),
	{ok, Acc#vacc{resp=Resp}};
	view_cb(complete, Acc) ->
	% Finish view output
	couch_httpd:send_chunk(Acc#vacc.resp, "\r\n]}"),
	couch_httpd:end_json_response(Acc#vacc.resp),
	{ok, Acc}.


	row_to_json(Row) ->
	Id = couch_util:get_value(id, Row),
	row_to_json(Id, Row).


	row_to_json(error, Row) ->
	% Special case for _all_docs request with KEYS to
	% match prior behavior.
	Key = couch_util:get_value(key, Row),
	Val = couch_util:get_value(value, Row),
	Obj = {[{key, Key}, {error, Val}]},
	?JSON_ENCODE(Obj);
	row_to_json(Id0, Row) ->
	Id = case Id0 of
	undefined -> [];
	Id0 -> [{id, Id0}]
	end,
	Key = couch_util:get_value(key, Row, null),
	Val = couch_util:get_value(value, Row),
	Doc = case couch_util:get_value(doc, Row) of
	undefined -> [];
	Doc0 -> [{doc, Doc0}]
	end,
	Obj = {Id ++ [{key, Key}, {value, Val}] ++ Doc},
	?JSON_ENCODE(Obj).


	get_view_keys({Props}) ->
	case couch_util:get_value(<<"keys">>, Props) of
	undefined ->
	?LOG_DEBUG("POST with no keys member.", []),
	undefined;
	Keys when is_list(Keys) ->
	Keys;
	_ ->
	throw({bad_request, "`keys` member must be a array."})
	end.


	parse_qs(Req, Keys) ->
	Args = #mrargs{keys=Keys},
	lists:foldl(fun({K, V}, Acc) ->
	parse_qs(K, V, Acc)
	end, Args, couch_httpd:qs(Req)).


	parse_qs(Key, Val, Args) ->
	case Key of
	"" ->
	Args;
	"reduce" ->
	Args#mrargs{reduce=parse_boolean(Val)};
	"key" ->
	JsonKey = ?JSON_DECODE(Val),
	Args#mrargs{start_key=JsonKey, end_key=JsonKey};
	"keys" ->
	Args#mrargs{keys=?JSON_DECODE(Val)};
	"startkey" ->
	Args#mrargs{start_key=?JSON_DECODE(Val)};
	"start_key" ->
	Args#mrargs{start_key=?JSON_DECODE(Val)};
	"startkey_docid" ->
	Args#mrargs{start_key_docid=list_to_binary(Val)};
	"start_key_doc_id" ->
	Args#mrargs{start_key_docid=list_to_binary(Val)};
	"endkey" ->
	Args#mrargs{end_key=?JSON_DECODE(Val)};
	"end_key" ->
	Args#mrargs{end_key=?JSON_DECODE(Val)};
	"endkey_docid" ->
	Args#mrargs{end_key_docid=list_to_binary(Val)};
	"end_key_doc_id" ->
	Args#mrargs{end_key_docid=list_to_binary(Val)};
	"limit" ->
	Args#mrargs{limit=parse_pos_int(Val)};
	"count" ->
	throw({query_parse_error, <<"QS param `count` is not `limit`">>});
	"stale" when Val == "ok" ->
	Args#mrargs{stale=ok};
	"stale" when Val == "update_after" ->
	Args#mrargs{stale=update_after};
	"stale" ->
	throw({query_parse_error, <<"Invalid value for `stale`.">>});
	"descending" ->
	case parse_boolean(Val) of
	true -> Args#mrargs{direction=rev};
	_ -> Args#mrargs{direction=fwd}
	end;
	"skip" ->
	Args#mrargs{skip=parse_pos_int(Val)};
	"group" ->
	case parse_boolean(Val) of
	true -> Args#mrargs{group_level=exact};
	_ -> Args#mrargs{group_level=0}
	end;
	"group_level" ->
	Args#mrargs{group_level=parse_pos_int(Val)};
	"inclusive_end" ->
	Args#mrargs{inclusive_end=parse_boolean(Val)};
	"include_docs" ->
	Args#mrargs{include_docs=parse_boolean(Val)};
	"update_seq" ->
	Args#mrargs{update_seq=parse_boolean(Val)};
	"conflicts" ->
	Args#mrargs{conflicts=parse_boolean(Val)};
	"list" ->
	Args#mrargs{list=list_to_binary(Val)};
	"callback" ->
	Args#mrargs{callback=list_to_binary(Val)};
	_ ->
	BKey = list_to_binary(Key),
	BVal = list_to_binary(Val),
	Args#mrargs{extra=[{BKey, BVal} \| Args#mrargs.extra]}
	end.


	parse_boolean(Val) ->
	case string:to_lower(Val) of
	"true" -> true;
	"false" -> false;
	_ ->
	Msg = io_lib:format("Invalid boolean parameter: ~p", [Val]),
	throw({query_parse_error, ?l2b(Msg)})
	end.


	parse_int(Val) ->
	case (catch list_to_integer(Val)) of
	IntVal when is_integer(IntVal) ->
	IntVal;
	_ ->
	Msg = io_lib:format("Invalid value for integer: ~p", [Val]),
	throw({query_parse_error, ?l2b(Msg)})
	end.


	parse_pos_int(Val) ->
	case parse_int(Val) of
	IntVal when IntVal >= 0 ->
	IntVal;
	_ ->
	Fmt = "Invalid value for positive integer: ~p",
	Msg = io_lib:format(Fmt, [Val]),
	throw({query_parse_error, ?l2b(Msg)})
	end.