| % 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_changes). |
| -include("couch_db.hrl"). |
| |
| -export([handle_changes/3]). |
| |
| %% @type Req -> #httpd{} | {json_req, JsonObj()} |
| handle_changes(#changes_args{style=Style}=Args1, Req, Db) -> |
| #changes_args{feed = Feed} = Args = Args1#changes_args{ |
| filter = make_filter_fun(Args1#changes_args.filter, Style, Req, Db) |
| }, |
| StartSeq = case Args#changes_args.dir of |
| rev -> |
| couch_db:get_update_seq(Db); |
| fwd -> |
| Args#changes_args.since |
| end, |
| if Feed == "continuous" orelse Feed == "longpoll" -> |
| fun(CallbackAcc) -> |
| {Callback, UserAcc} = get_callback_acc(CallbackAcc), |
| Self = self(), |
| {ok, Notify} = couch_db_update_notifier:start_link( |
| fun({_, DbName}) when DbName == Db#db.name -> |
| Self ! db_updated; |
| (_) -> |
| ok |
| end |
| ), |
| UserAcc2 = start_sending_changes(Callback, UserAcc, Feed), |
| {Timeout, TimeoutFun} = get_changes_timeout(Args, Callback), |
| try |
| keep_sending_changes( |
| Args, |
| Callback, |
| UserAcc2, |
| Db, |
| StartSeq, |
| <<"">>, |
| Timeout, |
| TimeoutFun |
| ) |
| after |
| couch_db_update_notifier:stop(Notify), |
| get_rest_db_updated(ok) % clean out any remaining update messages |
| end |
| end; |
| true -> |
| fun(CallbackAcc) -> |
| {Callback, UserAcc} = get_callback_acc(CallbackAcc), |
| UserAcc2 = start_sending_changes(Callback, UserAcc, Feed), |
| {ok, {_, LastSeq, _Prepend, _, _, UserAcc3, _, _, _, _}} = |
| send_changes( |
| Args#changes_args{feed="normal"}, |
| Callback, |
| UserAcc2, |
| Db, |
| StartSeq, |
| <<>> |
| ), |
| end_sending_changes(Callback, UserAcc3, LastSeq, Feed) |
| end |
| end. |
| |
| get_callback_acc({Callback, _UserAcc} = Pair) when is_function(Callback, 3) -> |
| Pair; |
| get_callback_acc(Callback) when is_function(Callback, 2) -> |
| {fun(Ev, Data, _) -> Callback(Ev, Data) end, ok}. |
| |
| %% @type Req -> #httpd{} | {json_req, JsonObj()} |
| make_filter_fun([$_ | _] = FilterName, Style, Req, Db) -> |
| builtin_filter_fun(FilterName, Style, Req, Db); |
| make_filter_fun(FilterName, Style, Req, Db) -> |
| os_filter_fun(FilterName, Style, Req, Db). |
| |
| os_filter_fun(FilterName, Style, Req, Db) -> |
| case [list_to_binary(couch_httpd:unquote(Part)) |
| || Part <- string:tokens(FilterName, "/")] of |
| [] -> |
| fun(_Db2, #doc_info{revs=Revs}) -> |
| builtin_results(Style, Revs) |
| end; |
| [DName, FName] -> |
| DesignId = <<"_design/", DName/binary>>, |
| DDoc = couch_httpd_db:couch_doc_open(Db, DesignId, nil, []), |
| % validate that the ddoc has the filter fun |
| #doc{body={Props}} = DDoc, |
| couch_util:get_nested_json_value({Props}, [<<"filters">>, FName]), |
| fun(Db2, DocInfo) -> |
| DocInfos = |
| case Style of |
| main_only -> |
| [DocInfo]; |
| all_docs -> |
| [DocInfo#doc_info{revs=[Rev]}|| Rev <- DocInfo#doc_info.revs] |
| end, |
| Docs = [Doc || {ok, Doc} <- [ |
| couch_db:open_doc(Db2, DocInfo2, [deleted, conflicts]) |
| || DocInfo2 <- DocInfos]], |
| {ok, Passes} = couch_query_servers:filter_docs( |
| Req, Db2, DDoc, FName, Docs |
| ), |
| [{[{<<"rev">>, couch_doc:rev_to_str({RevPos,RevId})}]} |
| || {Pass, #doc{revs={RevPos,[RevId|_]}}} |
| <- lists:zip(Passes, Docs), Pass == true] |
| end; |
| _Else -> |
| throw({bad_request, |
| "filter parameter must be of the form `designname/filtername`"}) |
| end. |
| |
| builtin_filter_fun("_doc_ids", Style, {json_req, {Props}}, _Db) -> |
| filter_docids(couch_util:get_value(<<"doc_ids">>, Props), Style); |
| builtin_filter_fun("_doc_ids", Style, #httpd{method='POST'}=Req, _Db) -> |
| {Props} = couch_httpd:json_body_obj(Req), |
| DocIds = couch_util:get_value(<<"doc_ids">>, Props, nil), |
| filter_docids(DocIds, Style); |
| builtin_filter_fun("_doc_ids", Style, #httpd{method='GET'}=Req, _Db) -> |
| DocIds = ?JSON_DECODE(couch_httpd:qs_value(Req, "doc_ids", "null")), |
| filter_docids(DocIds, Style); |
| builtin_filter_fun("_design", Style, _Req, _Db) -> |
| filter_designdoc(Style); |
| builtin_filter_fun(_FilterName, _Style, _Req, _Db) -> |
| throw({bad_request, "unknown builtin filter name"}). |
| |
| filter_docids(DocIds, Style) when is_list(DocIds)-> |
| fun(_Db, #doc_info{id=DocId, revs=Revs}) -> |
| case lists:member(DocId, DocIds) of |
| true -> |
| builtin_results(Style, Revs); |
| _ -> [] |
| end |
| end; |
| filter_docids(_, _) -> |
| throw({bad_request, "`doc_ids` filter parameter is not a list."}). |
| |
| filter_designdoc(Style) -> |
| fun(_Db, #doc_info{id=DocId, revs=Revs}) -> |
| case DocId of |
| <<"_design", _/binary>> -> |
| builtin_results(Style, Revs); |
| _ -> [] |
| end |
| end. |
| |
| builtin_results(Style, [#rev_info{rev=Rev}|_]=Revs) -> |
| case Style of |
| main_only -> |
| [{[{<<"rev">>, couch_doc:rev_to_str(Rev)}]}]; |
| all_docs -> |
| [{[{<<"rev">>, couch_doc:rev_to_str(R)}]} |
| || #rev_info{rev=R} <- Revs] |
| end. |
| |
| get_changes_timeout(Args, Callback) -> |
| #changes_args{ |
| heartbeat = Heartbeat, |
| timeout = Timeout, |
| feed = ResponseType |
| } = Args, |
| DefaultTimeout = list_to_integer( |
| couch_config:get("httpd", "changes_timeout", "60000") |
| ), |
| case Heartbeat of |
| undefined -> |
| case Timeout of |
| undefined -> |
| {DefaultTimeout, fun(UserAcc) -> {stop, UserAcc} end}; |
| infinity -> |
| {infinity, fun(UserAcc) -> {stop, UserAcc} end}; |
| _ -> |
| {lists:min([DefaultTimeout, Timeout]), |
| fun(UserAcc) -> {stop, UserAcc} end} |
| end; |
| true -> |
| {DefaultTimeout, |
| fun(UserAcc) -> {ok, Callback(timeout, ResponseType, UserAcc)} end}; |
| _ -> |
| {lists:min([DefaultTimeout, Heartbeat]), |
| fun(UserAcc) -> {ok, Callback(timeout, ResponseType, UserAcc)} end} |
| end. |
| |
| start_sending_changes(_Callback, UserAcc, "continuous") -> |
| UserAcc; |
| start_sending_changes(Callback, UserAcc, ResponseType) -> |
| Callback(start, ResponseType, UserAcc). |
| |
| send_changes(Args, Callback, UserAcc, Db, StartSeq, Prepend) -> |
| #changes_args{ |
| style = Style, |
| include_docs = IncludeDocs, |
| conflicts = Conflicts, |
| limit = Limit, |
| feed = ResponseType, |
| dir = Dir, |
| filter = FilterFun |
| } = Args, |
| couch_db:changes_since( |
| Db, |
| Style, |
| StartSeq, |
| fun changes_enumerator/2, |
| [{dir, Dir}], |
| {Db, StartSeq, Prepend, FilterFun, Callback, UserAcc, ResponseType, |
| Limit, IncludeDocs, Conflicts} |
| ). |
| |
| keep_sending_changes(Args, Callback, UserAcc, Db, StartSeq, Prepend, Timeout, |
| TimeoutFun) -> |
| #changes_args{ |
| feed = ResponseType, |
| limit = Limit, |
| db_open_options = DbOptions |
| } = Args, |
| % ?LOG_INFO("send_changes start ~p",[StartSeq]), |
| {ok, {_, EndSeq, Prepend2, _, _, UserAcc2, _, NewLimit, _, _}} = send_changes( |
| Args#changes_args{dir=fwd}, Callback, UserAcc, Db, StartSeq, Prepend |
| ), |
| % ?LOG_INFO("send_changes last ~p",[EndSeq]), |
| couch_db:close(Db), |
| if Limit > NewLimit, ResponseType == "longpoll" -> |
| end_sending_changes(Callback, UserAcc2, EndSeq, ResponseType); |
| true -> |
| case wait_db_updated(Timeout, TimeoutFun, UserAcc2) of |
| {updated, UserAcc3} -> |
| % ?LOG_INFO("wait_db_updated updated ~p",[{Db#db.name, EndSeq}]), |
| DbOptions1 = [{user_ctx, Db#db.user_ctx} | DbOptions], |
| case couch_db:open(Db#db.name, DbOptions1) of |
| {ok, Db2} -> |
| keep_sending_changes( |
| Args#changes_args{limit=NewLimit}, |
| Callback, |
| UserAcc3, |
| Db2, |
| EndSeq, |
| Prepend2, |
| Timeout, |
| TimeoutFun |
| ); |
| _Else -> |
| end_sending_changes(Callback, UserAcc2, EndSeq, ResponseType) |
| end; |
| {stop, UserAcc3} -> |
| % ?LOG_INFO("wait_db_updated stop ~p",[{Db#db.name, EndSeq}]), |
| end_sending_changes(Callback, UserAcc3, EndSeq, ResponseType) |
| end |
| end. |
| |
| end_sending_changes(Callback, UserAcc, EndSeq, ResponseType) -> |
| Callback({stop, EndSeq}, ResponseType, UserAcc). |
| |
| changes_enumerator(DocInfo, {Db, _, _, FilterFun, Callback, UserAcc, |
| "continuous", Limit, IncludeDocs, Conflicts}) -> |
| |
| #doc_info{high_seq = Seq} = DocInfo, |
| Results0 = FilterFun(Db, DocInfo), |
| Results = [Result || Result <- Results0, Result /= null], |
| Go = if Limit =< 1 -> stop; true -> ok end, |
| case Results of |
| [] -> |
| {Go, {Db, Seq, nil, FilterFun, Callback, UserAcc, "continuous", Limit, |
| IncludeDocs, Conflicts} |
| }; |
| _ -> |
| ChangesRow = changes_row(Db, Results, DocInfo, IncludeDocs, Conflicts), |
| UserAcc2 = Callback({change, ChangesRow, <<>>}, "continuous", UserAcc), |
| {Go, {Db, Seq, nil, FilterFun, Callback, UserAcc2, "continuous", |
| Limit - 1, IncludeDocs, Conflicts} |
| } |
| end; |
| changes_enumerator(DocInfo, {Db, _, Prepend, FilterFun, Callback, UserAcc, |
| ResponseType, Limit, IncludeDocs, Conflicts}) -> |
| |
| #doc_info{high_seq = Seq} = DocInfo, |
| Results0 = FilterFun(Db, DocInfo), |
| Results = [Result || Result <- Results0, Result /= null], |
| Go = if (Limit =< 1) andalso Results =/= [] -> stop; true -> ok end, |
| case Results of |
| [] -> |
| {Go, {Db, Seq, Prepend, FilterFun, Callback, UserAcc, ResponseType, |
| Limit, IncludeDocs, Conflicts} |
| }; |
| _ -> |
| ChangesRow = changes_row(Db, Results, DocInfo, IncludeDocs, Conflicts), |
| UserAcc2 = Callback({change, ChangesRow, Prepend}, ResponseType, UserAcc), |
| {Go, {Db, Seq, <<",\n">>, FilterFun, Callback, UserAcc2, ResponseType, |
| Limit - 1, IncludeDocs, Conflicts} |
| } |
| end. |
| |
| |
| changes_row(Db, Results, DocInfo, IncludeDoc, Conflicts) -> |
| #doc_info{ |
| id = Id, high_seq = Seq, revs = [#rev_info{deleted = Del} | _] |
| } = DocInfo, |
| {[{<<"seq">>, Seq}, {<<"id">>, Id}, {<<"changes">>, Results}] ++ |
| deleted_item(Del) ++ case IncludeDoc of |
| true -> |
| Options = if Conflicts -> [conflicts]; true -> [] end, |
| couch_httpd_view:doc_member(Db, DocInfo, Options); |
| false -> |
| [] |
| end}. |
| |
| deleted_item(true) -> [{<<"deleted">>, true}]; |
| deleted_item(_) -> []. |
| |
| % waits for a db_updated msg, if there are multiple msgs, collects them. |
| wait_db_updated(Timeout, TimeoutFun, UserAcc) -> |
| receive |
| db_updated -> |
| get_rest_db_updated(UserAcc) |
| after Timeout -> |
| {Go, UserAcc2} = TimeoutFun(UserAcc), |
| case Go of |
| ok -> |
| wait_db_updated(Timeout, TimeoutFun, UserAcc2); |
| stop -> |
| {stop, UserAcc2} |
| end |
| end. |
| |
| get_rest_db_updated(UserAcc) -> |
| receive |
| db_updated -> |
| get_rest_db_updated(UserAcc) |
| after 0 -> |
| {updated, UserAcc} |
| end. |