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-module(fabric_db_doc_count).
-export([go/1]).
-include("fabric.hrl").
go(DbName) ->
Shards = mem3:shards(DbName),
Workers = fabric_util:submit_jobs(Shards, get_doc_count, []),
Acc0 = {length(Workers), [{Beg,nil} || #shard{range=[Beg,_]} <- Workers]},
fabric_util:recv(Workers, #shard.ref, fun handle_message/3, Acc0).
handle_message({ok, Count}, #shard{range=[Beg,_]}, {N, Infos0}) ->
case couch_util:get_value(Beg, Infos0) of
nil ->
Infos = lists:keyreplace(Beg, 1, Infos0, {Beg, Count}),
case is_complete(Infos) of
true ->
{stop, lists:sum([C || {_, C} <- Infos])};
false ->
if N > 1 ->
{ok, {N-1, Infos}};
true ->
report_error(Infos),
{error, missing_shards}
end
end;
_ ->
{ok, {N-1, Infos0}}
end;
handle_message(_, _, {1, Infos}) ->
report_error(Infos),
{error, missing_shards};
handle_message(_Other, _, {N, Infos0}) ->
{ok, {N-1, Infos0}}.
report_error(Infos) ->
MissingShards = [S || {S,nil} <- Infos],
?LOG_ERROR("doc_count error, missing shards: ~p", [MissingShards]).
is_complete(List) ->
not lists:keymember(nil, 2, List).
|
