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|
% 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_httpd_view).
-include("couch_db.hrl").
-export([handle_view_req/2,handle_temp_view_req/2]).
-export([parse_view_query/1,parse_view_query/2,make_view_fold_fun/5,finish_view_fold/3]).
-import(couch_httpd,
[send_json/2,send_json/3,send_json/4,send_method_not_allowed/2,
start_json_response/2,send_chunk/2,end_json_response/1]).
design_doc_view(Req, Db, Id, ViewName, Keys) ->
case couch_view:get_map_view({couch_db:name(Db),
<<"_design/", Id/binary>>, ViewName}) of
{ok, View} ->
QueryArgs = parse_view_query(Req, Keys),
output_map_view(Req, View, Db, QueryArgs, Keys);
{not_found, Reason} ->
case couch_view:get_reduce_view({couch_db:name(Db),
<<"_design/", Id/binary>>, ViewName}) of
{ok, View} ->
#view_query_args{
reduce = Reduce
} = QueryArgs = parse_view_query(Req, Keys, true),
case Reduce of
false ->
{reduce, _N, _Lang, MapView} = View,
output_map_view(Req, MapView, Db, QueryArgs, Keys);
_ ->
output_reduce_view(Req, View, QueryArgs, Keys)
end;
_ ->
throw({not_found, Reason})
end
end.
handle_view_req(#httpd{method='GET',path_parts=[_,_, Id, ViewName]}=Req, Db) ->
design_doc_view(Req, Db, Id, ViewName, nil);
handle_view_req(#httpd{method='POST',path_parts=[_,_, Id, ViewName]}=Req, Db) ->
{Props} = couch_httpd:json_body(Req),
Keys = proplists:get_value(<<"keys">>, Props, nil),
design_doc_view(Req, Db, Id, ViewName, Keys);
handle_view_req(Req, _Db) ->
send_method_not_allowed(Req, "GET,POST,HEAD").
handle_temp_view_req(#httpd{method='POST'}=Req, Db) ->
QueryArgs = parse_view_query(Req),
case couch_httpd:primary_header_value(Req, "content-type") of
undefined -> ok;
"application/json" -> ok;
Else -> throw({incorrect_mime_type, Else})
end,
{Props} = couch_httpd:json_body(Req),
Language = proplists:get_value(<<"language">>, Props, <<"javascript">>),
MapSrc = proplists:get_value(<<"map">>, Props),
Keys = proplists:get_value(<<"keys">>, Props, nil),
case proplists:get_value(<<"reduce">>, Props, null) of
null ->
{ok, View} = couch_view:get_map_view({temp, couch_db:name(Db), Language, MapSrc}),
output_map_view(Req, View, Db, QueryArgs, Keys);
RedSrc ->
{ok, View} = couch_view:get_reduce_view(
{temp, couch_db:name(Db), Language, MapSrc, RedSrc}),
output_reduce_view(Req, View, QueryArgs, Keys)
end;
handle_temp_view_req(Req, _Db) ->
send_method_not_allowed(Req, "POST").
output_map_view(Req, View, Db, QueryArgs, nil) ->
#view_query_args{
count = Count,
direction = Dir,
skip = SkipCount,
start_key = StartKey,
start_docid = StartDocId
} = QueryArgs,
{ok, RowCount} = couch_view:get_row_count(View),
Start = {StartKey, StartDocId},
FoldlFun = make_view_fold_fun(Req, QueryArgs, Db, RowCount,
fun couch_view:reduce_to_count/1),
FoldAccInit = {Count, SkipCount, undefined, []},
FoldResult = couch_view:fold(View, Start, Dir, FoldlFun, FoldAccInit),
finish_view_fold(Req, RowCount, FoldResult);
output_map_view(Req, View, Db, QueryArgs, Keys) ->
#view_query_args{
count = Count,
direction = Dir,
skip = SkipCount,
start_docid = StartDocId
} = QueryArgs,
{ok, RowCount} = couch_view:get_row_count(View),
FoldAccInit = {Count, SkipCount, undefined, []},
FoldResult = lists:foldl(
fun(Key, {ok, FoldAcc}) ->
Start = {Key, StartDocId},
FoldlFun = make_view_fold_fun(Req,
QueryArgs#view_query_args{
start_key = Key,
end_key = Key
}, Db, RowCount, fun couch_view:reduce_to_count/1),
couch_view:fold(View, Start, Dir, FoldlFun, FoldAcc)
end, {ok, FoldAccInit}, Keys),
finish_view_fold(Req, RowCount, FoldResult).
output_reduce_view(Req, View, QueryArgs, nil) ->
#view_query_args{
start_key = StartKey,
end_key = EndKey,
count = Count,
skip = Skip,
direction = Dir,
start_docid = StartDocId,
end_docid = EndDocId,
group_level = GroupLevel
} = QueryArgs,
{ok, Resp} = start_json_response(Req, 200),
{ok, GroupRowsFun, RespFun} = make_reduce_fold_funs(Resp, GroupLevel),
send_chunk(Resp, "{\"rows\":["),
{ok, _} = couch_view:fold_reduce(View, Dir, {StartKey, StartDocId},
{EndKey, EndDocId}, GroupRowsFun, RespFun, {"", Skip, Count}),
send_chunk(Resp, "]}"),
end_json_response(Resp);
output_reduce_view(Req, View, QueryArgs, Keys) ->
#view_query_args{
count = Count,
skip = Skip,
direction = Dir,
start_docid = StartDocId,
end_docid = EndDocId,
group_level = GroupLevel
} = QueryArgs,
{ok, Resp} = start_json_response(Req, 200),
{ok, GroupRowsFun, RespFun} = make_reduce_fold_funs(Resp, GroupLevel),
send_chunk(Resp, "{\"rows\":["),
lists:foldl(
fun(Key, AccSeparator) ->
{ok, _} = couch_view:fold_reduce(View, Dir, {Key, StartDocId},
{Key, EndDocId}, GroupRowsFun, RespFun,
{AccSeparator, Skip, Count}),
"," % Switch to comma
end,
"", Keys), % Start with no comma
send_chunk(Resp, "]}"),
end_json_response(Resp).
make_reduce_fold_funs(Resp, GroupLevel) ->
GroupRowsFun =
fun({_Key1,_}, {_Key2,_}) when GroupLevel == 0 ->
true;
({Key1,_}, {Key2,_})
when is_integer(GroupLevel) and is_list(Key1) and is_list(Key2) ->
lists:sublist(Key1, GroupLevel) == lists:sublist(Key2, GroupLevel);
({Key1,_}, {Key2,_}) ->
Key1 == Key2
end,
RespFun = fun(_Key, _Red, {AccSeparator,AccSkip,AccCount}) when AccSkip > 0 ->
{ok, {AccSeparator,AccSkip-1,AccCount}};
(_Key, _Red, {AccSeparator,0,AccCount}) when AccCount == 0 ->
{stop, {AccSeparator,0,AccCount}};
(_Key, Red, {AccSeparator,0,AccCount}) when GroupLevel == 0 ->
Json = ?JSON_ENCODE({[{key, null}, {value, Red}]}),
send_chunk(Resp, AccSeparator ++ Json),
{ok, {",",0,AccCount-1}};
(Key, Red, {AccSeparator,0,AccCount})
when is_integer(GroupLevel)
andalso is_list(Key) ->
Json = ?JSON_ENCODE(
{[{key, lists:sublist(Key, GroupLevel)},{value, Red}]}),
send_chunk(Resp, AccSeparator ++ Json),
{ok, {",",0,AccCount-1}};
(Key, Red, {AccSeparator,0,AccCount}) ->
Json = ?JSON_ENCODE({[{key, Key}, {value, Red}]}),
send_chunk(Resp, AccSeparator ++ Json),
{ok, {",",0,AccCount-1}}
end,
{ok, GroupRowsFun, RespFun}.
reverse_key_default(nil) -> {};
reverse_key_default({}) -> nil;
reverse_key_default(Key) -> Key.
parse_view_query(Req) ->
parse_view_query(Req, nil, nil).
parse_view_query(Req, Keys) ->
parse_view_query(Req, Keys, nil).
parse_view_query(Req, Keys, IsReduce) ->
QueryList = couch_httpd:qs(Req),
#view_query_args{
group_level = GroupLevel
} = QueryArgs = lists:foldl(fun({Key,Value}, Args) ->
case {Key, Value} of
{"", _} ->
Args;
{"key", Value} ->
case Keys of
nil ->
JsonKey = ?JSON_DECODE(Value),
Args#view_query_args{start_key=JsonKey,end_key=JsonKey};
_ ->
Msg = io_lib:format("Query parameter \"~s\" not compatible with multi key mode.", [Key]),
throw({query_parse_error, Msg})
end;
{"startkey_docid", DocId} ->
Args#view_query_args{start_docid=list_to_binary(DocId)};
{"endkey_docid", DocId} ->
Args#view_query_args{end_docid=list_to_binary(DocId)};
{"startkey", Value} ->
case Keys of
nil ->
Args#view_query_args{start_key=?JSON_DECODE(Value)};
_ ->
Msg = io_lib:format("Query parameter \"~s\" not compatible with multi key mode.", [Key]),
throw({query_parse_error, Msg})
end;
{"endkey", Value} ->
case Keys of
nil ->
Args#view_query_args{end_key=?JSON_DECODE(Value)};
_ ->
Msg = io_lib:format("Query parameter \"~s\" not compatible with multi key mode.", [Key]),
throw({query_parse_error, Msg})
end;
{"count", Value} ->
case (catch list_to_integer(Value)) of
Count when is_integer(Count) ->
if Count < 0 ->
Msg = io_lib:format("Count must be a positive integer: count=~s", [Value]),
throw({query_parse_error, Msg});
true ->
Args#view_query_args{count=Count}
end;
_Error ->
Msg = io_lib:format("Bad URL query value, number expected: count=~s", [Value]),
throw({query_parse_error, Msg})
end;
{"update", "false"} ->
Args#view_query_args{update=false};
{"descending", "true"} ->
case Args#view_query_args.direction of
fwd ->
Args#view_query_args {
direction = rev,
start_key = reverse_key_default(Args#view_query_args.start_key),
start_docid = reverse_key_default(Args#view_query_args.start_docid),
end_key = reverse_key_default(Args#view_query_args.end_key),
end_docid = reverse_key_default(Args#view_query_args.end_docid)};
_ ->
Args %already reversed
end;
{"descending", "false"} ->
% The descending=false behaviour is the default behaviour, so we
% simpply ignore it. This is only for convenience when playing with
% the HTTP API, so that a user doesn't get served an error when
% flipping true to false in the descending option.
Args;
{"skip", Value} ->
case (catch list_to_integer(Value)) of
Count when is_integer(Count) ->
Args#view_query_args{skip=Count};
_Error ->
Msg = lists:flatten(io_lib:format(
"Bad URL query value, number expected: skip=~s", [Value])),
throw({query_parse_error, Msg})
end;
{"group", Value} ->
case Value of
"true" ->
Args#view_query_args{group_level=exact};
"false" ->
Args#view_query_args{group_level=0};
_ ->
Msg = "Bad URL query value for 'group' expected \"true\" or \"false\".",
throw({query_parse_error, Msg})
end;
{"group_level", LevelStr} ->
case Keys of
nil ->
Args#view_query_args{group_level=list_to_integer(LevelStr)};
_ ->
Msg = lists:flatten(io_lib:format("Multi-key fetches for a reduce view must include group=true", [])),
throw({query_parse_error, Msg})
end;
{"reduce", "true"} ->
Args#view_query_args{reduce=true};
{"reduce", "false"} ->
Args#view_query_args{reduce=false};
{"include_docs", Value} ->
case IsReduce of
true ->
Msg = lists:flatten(io_lib:format("Bad URL query key for reduce operation: ~s", [Key])),
throw({query_parse_error, Msg});
_ ->
ok
end,
case Value of
"true" ->
Args#view_query_args{include_docs=true};
"false" ->
Args#view_query_args{include_docs=false};
_ ->
Msg1 = "Bad URL query value for 'include_docs' expected \"true\" or \"false\".",
throw({query_parse_error, Msg1})
end;
_ -> % unknown key
Msg = lists:flatten(io_lib:format(
"Bad URL query key:~s", [Key])),
throw({query_parse_error, Msg})
end
end, #view_query_args{}, QueryList),
case Keys of
nil ->
QueryArgs;
_ ->
case IsReduce of
nil ->
QueryArgs;
_ ->
case GroupLevel of
exact ->
QueryArgs;
_ ->
Msg = lists:flatten(io_lib:format(
"Multi-key fetches for a reduce view must include group=true", [])),
throw({query_parse_error, Msg})
end
end
end.
make_view_fold_fun(Req, QueryArgs, Db, TotalViewCount, ReduceCountFun) ->
#view_query_args{
end_key = EndKey,
end_docid = EndDocId,
include_docs = IncludeDocs,
direction = Dir
} = QueryArgs,
PassedEndFun =
case Dir of
fwd ->
fun(ViewKey, ViewId) ->
couch_view:less_json([EndKey, EndDocId], [ViewKey, ViewId])
end;
rev->
fun(ViewKey, ViewId) ->
couch_view:less_json([ViewKey, ViewId], [EndKey, EndDocId])
end
end,
fun({{Key, DocId}, Value}, OffsetReds,
{AccCount, AccSkip, Resp, AccRevRows}) ->
PassedEnd = PassedEndFun(Key, DocId),
case {PassedEnd, AccCount, AccSkip, Resp} of
{true, _, _, _} ->
% The stop key has been passed, stop looping.
{stop, {AccCount, AccSkip, Resp, AccRevRows}};
{_, 0, _, _} ->
% we've done "count" rows, stop foldling
{stop, {0, 0, Resp, AccRevRows}};
{_, _, AccSkip, _} when AccSkip > 0 ->
{ok, {AccCount, AccSkip - 1, Resp, AccRevRows}};
{_, _, _, undefined} ->
{ok, Resp2} = start_json_response(Req, 200),
Offset = ReduceCountFun(OffsetReds),
JsonBegin = io_lib:format("{\"total_rows\":~w,\"offset\":~w,\"rows\":[\r\n",
[TotalViewCount, Offset]),
JsonObj = view_row_obj(Db, {{Key, DocId}, Value}, IncludeDocs),
send_chunk(Resp2, JsonBegin ++ ?JSON_ENCODE(JsonObj)),
{ok, {AccCount - 1, 0, Resp2, AccRevRows}};
{_, AccCount, _, Resp} when (AccCount > 0) ->
JsonObj = view_row_obj(Db, {{Key, DocId}, Value}, IncludeDocs),
send_chunk(Resp, ",\r\n" ++ ?JSON_ENCODE(JsonObj)),
{ok, {AccCount - 1, 0, Resp, AccRevRows}}
end
end.
view_row_obj(Db, {{Key, DocId}, Value}, IncludeDocs) ->
case DocId of
error ->
{[{key, Key}, {error, Value}]};
_ ->
case IncludeDocs of
true ->
Rev = case Value of
{Props} ->
case is_list(Props) of
true ->
proplists:get_value(<<"_rev">>, Props, []);
_ ->
[]
end;
_ ->
[]
end,
?LOG_DEBUG("Include Doc: ~p ~p", [DocId, Rev]),
case (catch couch_httpd_db:couch_doc_open(Db, DocId,
Rev, [])) of
{{not_found, missing}, _} ->
{[{id, DocId}, {key, Key}, {value, Value}, {error, missing}]};
Doc ->
JsonDoc = couch_doc:to_json_obj(Doc, []),
{[{id, DocId}, {key, Key}, {value, Value}, {doc, JsonDoc}]}
end;
_ ->
{[{id, DocId}, {key, Key}, {value, Value}]}
end
end.
finish_view_fold(Req, TotalRows, FoldResult) ->
case FoldResult of
{ok, {_, _, undefined, _}} ->
% nothing found in the view, nothing has been returned
% send empty view
send_json(Req, 200, {[
{total_rows, TotalRows},
{rows, []}
]});
{ok, {_, _, Resp, AccRevRows}} ->
% end the view
send_chunk(Resp, AccRevRows ++ "\r\n]}"),
end_json_response(Resp);
Error ->
throw(Error)
end.
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