% Copyright 2010 Cloudant % % 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(fabric_doc_missing_revs). -export([go/2, go/3]). -include("fabric.hrl"). -include_lib("mem3/include/mem3.hrl"). go(DbName, AllIdsRevs) -> go(DbName, AllIdsRevs, []). go(DbName, AllIdsRevs, Options) -> Workers = lists:map(fun({#shard{name=Name, node=Node} = Shard, IdsRevs}) -> Ref = rexi:cast(Node, {fabric_rpc, get_missing_revs, [Name, IdsRevs, Options]}), Shard#shard{ref=Ref} end, group_idrevs_by_shard(DbName, AllIdsRevs)), ResultDict = dict:from_list([{Id, {{nil,Revs},[]}} || {Id, Revs} <- AllIdsRevs]), RexiMon = fabric_util:create_monitors(Workers), Acc0 = {length(Workers), ResultDict, Workers}, try fabric_util:recv(Workers, #shard.ref, fun handle_message/3, Acc0) after rexi_monitor:stop(RexiMon) end. handle_message({rexi_DOWN, _, {_,NodeRef},_}, _Shard, {_WorkerLen, ResultDict, Workers}) -> NewWorkers = [W || #shard{node=Node} = W <- Workers, Node =/= NodeRef], skip_message({fabric_dict:size(NewWorkers), ResultDict, NewWorkers}); handle_message({rexi_EXIT, _}, Worker, {W, D, Workers}) -> skip_message({W-1,D,lists:delete(Worker, Workers)}); handle_message({ok, Results}, _Worker, {1, D0, _}) -> D = update_dict(D0, Results), {stop, dict:fold(fun force_reply/3, [], D)}; handle_message({ok, Results}, Worker, {WaitingCount, D0, Workers}) -> D = update_dict(D0, Results), case dict:fold(fun maybe_reply/3, {stop, []}, D) of continue -> % still haven't heard about some Ids {ok, {WaitingCount - 1, D, lists:delete(Worker,Workers)}}; {stop, FinalReply} -> % finished, stop the rest of the jobs fabric_util:cleanup(lists:delete(Worker,Workers)), {stop, FinalReply} end. force_reply(Id, {{nil,Revs}, Anc}, Acc) -> % never heard about this ID, assume it's missing [{Id, Revs, Anc} | Acc]; force_reply(_, {[], _}, Acc) -> Acc; force_reply(Id, {Revs, Anc}, Acc) -> [{Id, Revs, Anc} | Acc]. maybe_reply(_, _, continue) -> continue; maybe_reply(_, {{nil, _}, _}, _) -> continue; maybe_reply(_, {[], _}, {stop, Acc}) -> {stop, Acc}; maybe_reply(Id, {Revs, Anc}, {stop, Acc}) -> {stop, [{Id, Revs, Anc} | Acc]}. group_idrevs_by_shard(DbName, IdsRevs) -> dict:to_list(lists:foldl(fun({Id, Revs}, D0) -> lists:foldl(fun(Shard, D1) -> dict:append(Shard, {Id, Revs}, D1) end, D0, mem3:shards(DbName,Id)) end, dict:new(), IdsRevs)). update_dict(D0, KVs) -> lists:foldl(fun({K,V,A}, D1) -> dict:store(K, {V,A}, D1) end, D0, KVs). skip_message({0, Dict, _Workers}) -> {stop, dict:fold(fun force_reply/3, [], Dict)}; skip_message(Acc) -> {ok, Acc}.