nickva commented on code in PR #5466: URL: https://github.com/apache/couchdb/pull/5466#discussion_r2029531163
########## src/couch_scanner/src/couch_scanner_plugin_conflict_finder.erl: ########## @@ -0,0 +1,198 @@ +% 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_scanner_plugin_conflict_finder). +-behaviour(couch_scanner_plugin). + +-export([ + start/2, + resume/2, + complete/1, + checkpoint/1, + db/2, + doc_id/3 +]). + +-include_lib("couch_scanner/include/couch_scanner_plugin.hrl"). + +-record(st, { + sid, + opts = #{}, + dbname, + report = #{}, + doc_report = true +}). + +-define(CONFLICTS, <<"conflicts">>). +-define(DELETED_CONFLICTS, <<"deleted_conflicts">>). + +-define(OPTS, #{ + ?CONFLICTS => true, + ?DELETED_CONFLICTS => true +}). + +% Behavior callbacks + +start(SId, #{}) -> + St = init_config(#st{sid = SId}), + ?INFO("Starting.", [], #{sid => SId}), + {ok, St}. + +resume(SId, #{<<"opts">> := OldOpts}) -> + St = init_config(#st{sid = SId}), + case OldOpts == St#st.opts of + true -> + ?INFO("Resuming.", [], #{sid => SId}), + {ok, St}; + false -> + ?INFO("Resetting. Config changed.", [], #{sid => SId}), + reset + end. + +complete(#st{sid = SId, dbname = DbName, report = Report} = St) -> + report_per_db(St, DbName, Report), + ?INFO("Completed", [], #{sid => SId}), + {ok, #{}}. + +checkpoint(#st{sid = SId, opts = Opts}) -> + case Opts == opts() of + true -> + {ok, #{<<"opts">> => Opts}}; + false -> + ?INFO("Resetting. Config changed.", [], #{sid => SId}), + reset + end. + +db(#st{} = St, _DbName) -> + {ok, St}. + +doc_id(#st{} = St, <<?DESIGN_DOC_PREFIX, _/binary>>, _Db) -> + {skip, St}; +doc_id(#st{} = St, DocId, Db) -> + {ok, #doc_info{revs = Revs}} = couch_db:get_doc_info(Db, DocId), + DbName = mem3:dbname(couch_db:name(Db)), + {ok, check(St, DbName, DocId, Revs)}. + +% Private + +init_config(#st{} = St) -> + St#st{ + opts = opts(), + doc_report = cfg_bool("doc_report", St#st.doc_report) + }. + +opts() -> + Fun = fun(Key, Default) -> cfg_bool(binary_to_list(Key), Default) end, + maps:map(Fun, ?OPTS). + +cfg_bool(Key, Default) when is_list(Key), is_boolean(Default) -> + config:get_boolean(atom_to_list(?MODULE), Key, Default). + +check(#st{} = St, _, _, Revs) when length(Revs) =< 1 -> + St; +check(#st{doc_report = true, opts = Opts} = St, DbName, DocId, Revs) -> + {DeletedConflicts, Conflicts} = + lists:partition(fun(R) -> R#rev_info.deleted end, Revs), + ConflictsReport = gen_report(doc, ?CONFLICTS, Opts, Conflicts), + DeletedConflictsReport = gen_report(doc, ?DELETED_CONFLICTS, Opts, DeletedConflicts), + DocReport = maps:merge(ConflictsReport, DeletedConflictsReport), + report_per_doc(#st{} = St, DbName, DocId, DocReport), + DbReport = maps:map(fun(_K, V) when is_list(V) -> length(V) end, DocReport), + report(#st{} = St, DbName, DbReport); +check(#st{opts = Opts} = St, DbName, _DocId, Revs) -> + {DeletedConflicts, Conflicts} = + lists:partition(fun(R) -> R#rev_info.deleted end, Revs), + ConflictsReport = gen_report(db, ?CONFLICTS, Opts, Conflicts), + DeletedConflictsReport = gen_report(db, ?DELETED_CONFLICTS, Opts, DeletedConflicts), + DbReport = maps:merge(ConflictsReport, DeletedConflictsReport), + report(#st{} = St, DbName, DbReport). + +gen_report(db, ?CONFLICTS, #{?CONFLICTS := true}, Revs) -> + #{?CONFLICTS => length(Revs)}; +gen_report(db, ?DELETED_CONFLICTS, #{?DELETED_CONFLICTS := true}, Revs) -> + #{?DELETED_CONFLICTS => length(Revs)}; +gen_report(doc, ?CONFLICTS, #{?CONFLICTS := true}, Revs) -> + #{?CONFLICTS => [couch_doc:rev_to_str(R#rev_info.rev) || R <- Revs]}; +gen_report(doc, ?DELETED_CONFLICTS, #{?DELETED_CONFLICTS := true}, Revs) -> + #{?DELETED_CONFLICTS => [couch_doc:rev_to_str(R#rev_info.rev) || R <- Revs]}; +gen_report(_Type, _Key, #{} = _Opts, _Revs) -> + #{}. + +report(#st{} = St, DbName, Report) -> + #st{report = Total, dbname = PrevDbName} = St, + case is_binary(PrevDbName) andalso DbName =/= PrevDbName of + true -> + % We switched dbs, so report stats for old db + % and make the new one the current one + report_per_db(St, PrevDbName, Total), + St#st{report = Report, dbname = DbName}; + false -> + % Keep accumulating per-db stats + St#st{report = merge_report(Total, Report), dbname = DbName} + end. + +merge_report(#{} = Total, #{} = Update) -> + Fun = fun(_K, V1, V2) -> V1 + V2 end, + maps:merge_with(Fun, Total, Update). + +report_per_db(#st{sid = SId}, DbName, #{} = Report) when + map_size(Report) > 0, is_binary(DbName) +-> + {Fmt, Args} = report_fmt(Report), + Meta = #{sid => SId, db => DbName}, + ?WARN(Fmt, Args, Meta); +report_per_db(#st{}, _, _) -> + ok. + +report_per_doc(#st{sid = SId}, DbName, DocId, Report) when + map_size(Report) > 0, is_binary(DbName) +-> + {Fmt, Args} = report_fmt(Report), + Meta = #{sid => SId, db => DbName, doc => DocId}, + ?WARN(Fmt, Args, Meta); +report_per_doc(#st{}, _, _, _) -> + ok. + +report_fmt(Report) -> + Sorted = lists:sort(maps:to_list(Report)), + FmtArgs = [{"~s:~p ", [K, V]} || {K, V} <- Sorted], + {Fmt1, Args1} = lists:unzip(FmtArgs), + Fmt2 = lists:flatten(Fmt1), + Args2 = flatten_one_level(Args1), + {Fmt2, Args2}. + +flatten_one_level(List) when is_list(List) -> + case lists:flatten(List) =:= List of + true -> + List; + false -> + lists:append([ + case is_list(E) of Review Comment: I think here we're handling the case of list of binaries `[<<"2-y">>,<<"2-x">>]` vs a number say `2`? Perhaps we could shorten a bit the string by translating the binaries to strings so it would look like '["2-y", "2-x"]'? Another potential issues is if we have a large amount of revs, say a 1000 (we've seen documents like that), in that case often the log line gets cut, not sure what could do there, maybe nothing? We could emit it as a number then "we found conflicts but it's a 1000 so we'll just say 1000 instead of `[..., ..., ... x 1000]`? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: notifications-unsubscr...@couchdb.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
