From 505e1110371c6f88bfb4d293b68033a09284895b Mon Sep 17 00:00:00 2001 From: John Christopher Anderson Date: Wed, 16 Sep 2009 06:35:56 +0000 Subject: add limit to _changes git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@815629 13f79535-47bb-0310-9956-ffa450edef68 --- src/couchdb/couch_httpd_db.erl | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) (limited to 'src') diff --git a/src/couchdb/couch_httpd_db.erl b/src/couchdb/couch_httpd_db.erl index 2ff02654..03093c41 100644 --- a/src/couchdb/couch_httpd_db.erl +++ b/src/couchdb/couch_httpd_db.erl @@ -83,6 +83,7 @@ handle_changes_req(#httpd{method='GET',path_parts=[DbName|_]}=Req, Db) -> {rev, Seq}; _Bad -> throw({bad_request, "descending must be true or false"}) end, + Limit = list_to_integer(couch_httpd:qs_value(Req, "limit", "1000000000000000")), ResponseType = couch_httpd:qs_value(Req, "feed", "normal"), if ResponseType == "continuous" orelse ResponseType == "longpoll" -> {ok, Resp} = start_json_response(Req, 200), @@ -100,7 +101,7 @@ handle_changes_req(#httpd{method='GET',path_parts=[DbName|_]}=Req, Db) -> {httpd, clients_requesting_changes}), try keep_sending_changes(Req, Resp, Db, StartSeq, <<"">>, Timeout, - TimeoutFun, ResponseType, FilterFun, EndFilterFun) + TimeoutFun, ResponseType, Limit, FilterFun, EndFilterFun) after couch_db_update_notifier:stop(Notify), get_rest_db_updated() % clean out any remaining update messages @@ -111,9 +112,9 @@ handle_changes_req(#httpd{method='GET',path_parts=[DbName|_]}=Req, Db) -> % send the etag {ok, Resp} = start_json_response(Req, 200, [{"Etag", CurrentEtag}]), start_sending_changes(Resp, ResponseType), - {ok, {_, LastSeq, _Prepend, _, _, _, _}} = + {ok, {_, LastSeq, _Prepend, _, _, _, _, _}} = send_changes(Req, Resp, Db, Dir, StartSeq, <<"">>, "normal", - FilterFun, EndFilterFun), + Limit, FilterFun, EndFilterFun), end_sending_changes(Resp, LastSeq, ResponseType) end) end; @@ -144,9 +145,9 @@ end_sending_changes(Resp, EndSeq, _Else) -> end_json_response(Resp). keep_sending_changes(#httpd{user_ctx=UserCtx,path_parts=[DbName|_]}=Req, Resp, - Db, StartSeq, Prepend, Timeout, TimeoutFun, ResponseType, Filter, End) -> - {ok, {_, EndSeq, Prepend2, _, _, _, _}} = send_changes(Req, Resp, Db, fwd, StartSeq, - Prepend, ResponseType, Filter, End), + Db, StartSeq, Prepend, Timeout, TimeoutFun, ResponseType, Limit, Filter, End) -> + {ok, {_, EndSeq, Prepend2, _, _, _, NewLimit, _}} = send_changes(Req, Resp, Db, fwd, StartSeq, + Prepend, ResponseType, Limit, Filter, End), couch_db:close(Db), if EndSeq > StartSeq, ResponseType == "longpoll" -> @@ -156,35 +157,37 @@ keep_sending_changes(#httpd{user_ctx=UserCtx,path_parts=[DbName|_]}=Req, Resp, updated -> {ok, Db2} = couch_db:open(DbName, [{user_ctx, UserCtx}]), keep_sending_changes(Req, Resp, Db2, EndSeq, Prepend2, Timeout, - TimeoutFun, ResponseType, Filter, End); + TimeoutFun, ResponseType, NewLimit, Filter, End); stop -> end_sending_changes(Resp, EndSeq, ResponseType) end end. -changes_enumerator(DocInfos, {Db, _, _, FilterFun, Resp, "continuous", IncludeDocs}) -> +changes_enumerator(DocInfos, {Db, _, _, FilterFun, Resp, "continuous", Limit, IncludeDocs}) -> [#doc_info{id=Id, high_seq=Seq, revs=[#rev_info{deleted=Del,rev=Rev}|_]}|_] = DocInfos, Results0 = [FilterFun(DocInfo) || DocInfo <- DocInfos], Results = [Result || Result <- Results0, Result /= null], + Go = if Limit =< 1 -> stop; true -> ok end, case Results of [] -> - {ok, {Db, Seq, nil, FilterFun, Resp, "continuous", IncludeDocs}}; + {Go, {Db, Seq, nil, FilterFun, Resp, "continuous", Limit, IncludeDocs}}; _ -> send_chunk(Resp, [?JSON_ENCODE(changes_row(Db, Seq, Id, Del, Results, Rev, IncludeDocs)) |"\n"]), - {ok, {Db, Seq, nil, FilterFun, Resp, "continuous", IncludeDocs}} + {Go, {Db, Seq, nil, FilterFun, Resp, "continuous", Limit-1, IncludeDocs}} end; -changes_enumerator(DocInfos, {Db, _, Prepend, FilterFun, Resp, _, IncludeDocs}) -> +changes_enumerator(DocInfos, {Db, _, Prepend, FilterFun, Resp, _, Limit, IncludeDocs}) -> [#doc_info{id=Id, high_seq=Seq, revs=[#rev_info{deleted=Del,rev=Rev}|_]}|_] = DocInfos, Results0 = [FilterFun(DocInfo) || DocInfo <- DocInfos], Results = [Result || Result <- Results0, Result /= null], + Go = if Limit =< 1 -> stop; true -> ok end, case Results of [] -> - {ok, {Db, Seq, Prepend, FilterFun, Resp, nil, IncludeDocs}}; + {Go, {Db, Seq, Prepend, FilterFun, Resp, nil, Limit, IncludeDocs}}; _ -> send_chunk(Resp, [Prepend, ?JSON_ENCODE( changes_row(Db, Seq, Id, Del, Results, Rev, IncludeDocs))]), - {ok, {Db, Seq, <<",\n">>, FilterFun, Resp, nil, IncludeDocs}} + {Go, {Db, Seq, <<",\n">>, FilterFun, Resp, nil, Limit-1, IncludeDocs}} end. changes_row(Db, Seq, Id, Del, Results, Rev, true) -> @@ -196,14 +199,14 @@ changes_row(_, Seq, Id, Del, Results, _, false) -> deleted_item(true) -> [{deleted,true}]; deleted_item(_) -> []. -send_changes(Req, Resp, Db, Dir, StartSeq, Prepend, ResponseType, FilterFun, End) -> +send_changes(Req, Resp, Db, Dir, StartSeq, Prepend, ResponseType, Limit, FilterFun, End) -> Style = list_to_existing_atom( couch_httpd:qs_value(Req, "style", "main_only")), IncludeDocs = list_to_existing_atom( couch_httpd:qs_value(Req, "include_docs", "false")), try couch_db:changes_since(Db, Style, StartSeq, fun changes_enumerator/2, - [{dir, Dir}], {Db, StartSeq, Prepend, FilterFun, Resp, ResponseType, IncludeDocs}) + [{dir, Dir}], {Db, StartSeq, Prepend, FilterFun, Resp, ResponseType, Limit, IncludeDocs}) after End() end. -- cgit v1.2.3