% 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_util). -export([submit_jobs/3, cleanup/1, recv/4, get_db/1, get_db/2, error_info/1, update_counter/3, remove_ancestors/2, create_monitors/1, kv/2, remove_down_workers/2]). -include("fabric.hrl"). -include_lib("mem3/include/mem3.hrl"). -include_lib("couch/include/couch_db.hrl"). -include_lib("eunit/include/eunit.hrl"). remove_down_workers(Workers, BadNode) -> Filter = fun(#shard{node = Node}, _) -> Node =/= BadNode end, NewWorkers = fabric_dict:filter(Filter, Workers), case fabric_view:is_progress_possible(NewWorkers) of true -> {ok, NewWorkers}; false -> error end. submit_jobs(Shards, EndPoint, ExtraArgs) -> lists:map(fun(#shard{node=Node, name=ShardName} = Shard) -> Ref = rexi:cast(Node, {fabric_rpc, EndPoint, [ShardName | ExtraArgs]}), Shard#shard{ref = Ref} end, Shards). cleanup(Workers) -> [rexi:kill(Node, Ref) || #shard{node=Node, ref=Ref} <- Workers]. recv(Workers, Keypos, Fun, Acc0) -> Timeout = case couch_config:get("fabric", "request_timeout", "60000") of "infinity" -> infinity; N -> list_to_integer(N) end, rexi_utils:recv(Workers, Keypos, Fun, Acc0, Timeout, infinity). get_db(DbName) -> get_db(DbName, []). get_db(DbName, Options) -> % prefer local shards {Local, Remote} = lists:partition(fun(S) -> S#shard.node =:= node() end, mem3:shards(DbName)), % suppress shards from down nodes Nodes = erlang:nodes(), Live = [S || #shard{node = N} = S <- Remote, lists:member(N, Nodes)], % sort the live remote shards so that we don't repeatedly try the same node get_shard(Local ++ lists:keysort(#shard.name, Live), Options, 100). get_shard([], _Opts, _Timeout) -> erlang:error({internal_server_error, "No DB shards could be opened."}); get_shard([#shard{node = Node, name = Name} | Rest], Opts, Timeout) -> case rpc:call(Node, couch_db, open, [Name, [{timeout, Timeout} | Opts]]) of {ok, Db} -> {ok, Db}; {unauthorized, _} = Error -> throw(Error); {badrpc, {'EXIT', {timeout, _}}} -> get_shard(Rest, Opts, 2*Timeout); _Else -> get_shard(Rest, Opts, Timeout) end. error_info({{<<"reduce_overflow_error">>, _} = Error, _Stack}) -> Error; error_info({{timeout, _} = Error, _Stack}) -> Error; error_info({{Error, Reason}, Stack}) -> {Error, Reason, Stack}; error_info({Error, Stack}) -> {Error, nil, Stack}. update_counter(Item, Incr, D) -> UpdateFun = fun ({Old, Count}) -> {Old, Count + Incr} end, orddict:update(make_key(Item), UpdateFun, {Item, Incr}, D). make_key({ok, L}) when is_list(L) -> make_key(L); make_key([]) -> []; make_key([{ok, #doc{revs= {Pos,[RevId | _]}}} | Rest]) -> [{ok, {Pos, RevId}} | make_key(Rest)]; make_key([{{not_found, missing}, Rev} | Rest]) -> [{not_found, Rev} | make_key(Rest)]; make_key({ok, #doc{id=Id,revs=Revs}}) -> {Id, Revs}; make_key(Else) -> Else. % this presumes the incoming list is sorted, i.e. shorter revlists come first remove_ancestors([], Acc) -> lists:reverse(Acc); remove_ancestors([{_, {{not_found, _}, Count}} = Head | Tail], Acc) -> % any document is a descendant case lists:filter(fun({_,{{ok, #doc{}}, _}}) -> true; (_) -> false end, Tail) of [{_,{{ok, #doc{}} = Descendant, _}} | _] -> remove_ancestors(update_counter(Descendant, Count, Tail), Acc); [] -> remove_ancestors(Tail, [Head | Acc]) end; remove_ancestors([{_,{{ok, #doc{revs = {Pos, Revs}}}, Count}} = Head | Tail], Acc) -> Descendants = lists:dropwhile(fun ({_,{{ok, #doc{revs = {Pos2, Revs2}}}, _}}) -> case lists:nthtail(erlang:min(Pos2 - Pos, length(Revs2)), Revs2) of [] -> % impossible to tell if Revs2 is a descendant - assume no true; History -> % if Revs2 is a descendant, History is a prefix of Revs not lists:prefix(History, Revs) end end, Tail), case Descendants of [] -> remove_ancestors(Tail, [Head | Acc]); [{Descendant, _} | _] -> remove_ancestors(update_counter(Descendant, Count, Tail), Acc) end; remove_ancestors([Error | Tail], Acc) -> remove_ancestors(Tail, [Error | Acc]). create_monitors(Shards) -> MonRefs = lists:usort([{rexi_server, N} || #shard{node=N} <- Shards]), rexi_monitor:start(MonRefs). %% verify only id and rev are used in key. update_counter_test() -> Reply = {ok, #doc{id = <<"id">>, revs = <<"rev">>, body = <<"body">>, atts = <<"atts">>}}, ?assertEqual([{{<<"id">>,<<"rev">>}, {Reply, 1}}], update_counter(Reply, 1, [])). remove_ancestors_test() -> Foo1 = {ok, #doc{revs = {1, [<<"foo">>]}}}, Foo2 = {ok, #doc{revs = {2, [<<"foo2">>, <<"foo">>]}}}, Bar1 = {ok, #doc{revs = {1, [<<"bar">>]}}}, Bar2 = {not_found, {1,<<"bar">>}}, ?assertEqual( [kv(Bar1,1), kv(Foo1,1)], remove_ancestors([kv(Bar1,1), kv(Foo1,1)], []) ), ?assertEqual( [kv(Bar1,1), kv(Foo2,2)], remove_ancestors([kv(Bar1,1), kv(Foo1,1), kv(Foo2,1)], []) ), ?assertEqual( [kv(Bar1,2)], remove_ancestors([kv(Bar2,1), kv(Bar1,1)], []) ). %% test function kv(Item, Count) -> {make_key(Item), {Item,Count}}.