blob: 197788823d067b4522192555f7083356ff059c34 [file] [log] [blame]
% 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_view_map).
-export([go/6]).
-include_lib("fabric/include/fabric.hrl").
-include_lib("mem3/include/mem3.hrl").
-include_lib("couch/include/couch_db.hrl").
-include_lib("couch_mrview/include/couch_mrview.hrl").
go(DbName, GroupId, View, Args, Callback, Acc0) when is_binary(GroupId) ->
{ok, DDoc} = fabric:open_doc(DbName, <<"_design/", GroupId/binary>>, []),
go(DbName, DDoc, View, Args, Callback, Acc0);
go(DbName, DDoc, View, Args, Callback, Acc) ->
Shards = fabric_view:get_shards(DbName, Args),
Repls = fabric_view:get_shard_replacements(DbName, Shards),
RPCArgs = [fabric_util:doc_id_and_rev(DDoc), View, Args],
StartFun = fun(Shard) ->
hd(fabric_util:submit_jobs([Shard], fabric_rpc, map_view, RPCArgs))
end,
Workers0 = fabric_util:submit_jobs(Shards, fabric_rpc, map_view, RPCArgs),
RexiMon = fabric_util:create_monitors(Workers0),
try
case fabric_util:stream_start(Workers0, #shard.ref, StartFun, Repls) of
{ok, Workers} ->
try
go(DbName, Workers, Args, Callback, Acc)
after
fabric_util:cleanup(Workers)
end;
{timeout, NewState} ->
DefunctWorkers = fabric_util:remove_done_workers(
NewState#stream_acc.workers,
waiting
),
fabric_util:log_timeout(
DefunctWorkers,
"map_view"
),
Callback({error, timeout}, Acc);
{error, Error} ->
Callback({error, Error}, Acc)
end
after
rexi_monitor:stop(RexiMon)
end.
go(DbName, Workers, Args, Callback, Acc0) ->
#mrargs{limit = Limit, skip = Skip, keys = Keys} = Args,
State = #collector{
db_name=DbName,
query_args = Args,
callback = Callback,
counters = fabric_dict:init(Workers, 0),
skip = Skip,
limit = Limit,
keys = fabric_view:keydict(Keys),
sorted = Args#mrargs.sorted,
user_acc = Acc0
},
case rexi_utils:recv(Workers, #shard.ref, fun handle_message/3,
State, infinity, 1000 * 60 * 60) of
{ok, NewState} ->
{ok, NewState#collector.user_acc};
{timeout, NewState} ->
Callback({error, timeout}, NewState#collector.user_acc);
{error, Resp} ->
{ok, Resp}
end.
handle_message({rexi_DOWN, _, {_, NodeRef}, _}, _, State) ->
fabric_view:check_down_shards(State, NodeRef);
handle_message({rexi_EXIT, Reason}, Worker, State) ->
fabric_view:handle_worker_exit(State, Worker, Reason);
handle_message({meta, Meta0}, {Worker, From}, State) ->
Tot = couch_util:get_value(total, Meta0, 0),
Off = couch_util:get_value(offset, Meta0, 0),
#collector{
callback = Callback,
counters = Counters0,
total_rows = Total0,
offset = Offset0,
user_acc = AccIn
} = State,
% Assert that we don't have other messages from this
% worker when the total_and_offset message arrives.
0 = fabric_dict:lookup_element(Worker, Counters0),
rexi:stream_ack(From),
Counters1 = fabric_dict:update_counter(Worker, 1, Counters0),
Total = Total0 + Tot,
Offset = Offset0 + Off,
case fabric_dict:any(0, Counters1) of
true ->
{ok, State#collector{
counters = Counters1,
total_rows = Total,
offset = Offset
}};
false ->
FinalOffset = erlang:min(Total, Offset+State#collector.skip),
Meta = [{total, Total}, {offset, FinalOffset}],
{Go, Acc} = Callback({meta, Meta}, AccIn),
{Go, State#collector{
counters = fabric_dict:decrement_all(Counters1),
total_rows = Total,
offset = FinalOffset,
user_acc = Acc
}}
end;
handle_message(#view_row{}, {_, _}, #collector{limit=0} = State) ->
#collector{callback=Callback} = State,
{_, Acc} = Callback(complete, State#collector.user_acc),
{stop, State#collector{user_acc=Acc}};
handle_message(#view_row{} = Row, {_,From}, #collector{sorted=false} = St) ->
#collector{callback=Callback, user_acc=AccIn, limit=Limit} = St,
{Go, Acc} = Callback(fabric_view:transform_row(Row), AccIn),
rexi:stream_ack(From),
{Go, St#collector{user_acc=Acc, limit=Limit-1}};
handle_message(#view_row{} = Row, {Worker, From}, State) ->
#collector{
query_args = #mrargs{direction=Dir},
counters = Counters0,
rows = Rows0,
keys = KeyDict
} = State,
Rows = merge_row(Dir, KeyDict, Row#view_row{worker={Worker, From}}, Rows0),
Counters1 = fabric_dict:update_counter(Worker, 1, Counters0),
State1 = State#collector{rows=Rows, counters=Counters1},
fabric_view:maybe_send_row(State1);
handle_message(complete, Worker, State) ->
Counters = fabric_dict:update_counter(Worker, 1, State#collector.counters),
fabric_view:maybe_send_row(State#collector{counters = Counters}).
merge_row(fwd, undefined, Row, Rows) ->
lists:merge(fun(#view_row{key=KeyA, id=IdA}, #view_row{key=KeyB, id=IdB}) ->
couch_ejson_compare:less_json_ids({KeyA, IdA}, {KeyB, IdB})
end, [Row], Rows);
merge_row(rev, undefined, Row, Rows) ->
lists:merge(fun(#view_row{key=KeyA, id=IdA}, #view_row{key=KeyB, id=IdB}) ->
couch_ejson_compare:less_json_ids({KeyB, IdB}, {KeyA, IdA})
end, [Row], Rows);
merge_row(_, KeyDict, Row, Rows) ->
lists:merge(fun(#view_row{key=A, id=IdA}, #view_row{key=B, id=IdB}) ->
if A =:= B -> IdA < IdB; true ->
dict:fetch(A, KeyDict) < dict:fetch(B, KeyDict)
end
end, [Row], Rows).