1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
|
% 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_update).
-export([go/3]).
-include("fabric.hrl").
-include_lib("mem3/include/mem3.hrl").
-include_lib("couch/include/couch_db.hrl").
go(_, [], _) ->
{ok, []};
go(DbName, AllDocs, Opts) ->
validate_atomic_update(DbName, AllDocs, lists:member(all_or_nothing, Opts)),
Options = lists:delete(all_or_nothing, Opts),
GroupedDocs = lists:map(fun({#shard{name=Name, node=Node} = Shard, Docs}) ->
Ref = rexi:cast(Node, {fabric_rpc, update_docs, [Name, Docs, Options]}),
{Shard#shard{ref=Ref}, Docs}
end, group_docs_by_shard(DbName, AllDocs)),
{Workers, _} = lists:unzip(GroupedDocs),
W = couch_util:get_value(w, Options, couch_config:get("cluster","w","2")),
Acc0 = {length(Workers), length(AllDocs), list_to_integer(W), GroupedDocs,
dict:from_list([{Doc,[]} || Doc <- AllDocs])},
case fabric_util:recv(Workers, #shard.ref, fun handle_message/3, Acc0) of
{ok, Results} ->
Reordered = couch_util:reorder_results(AllDocs, Results),
{ok, [R || R <- Reordered, R =/= noreply]};
Else ->
Else
end.
handle_message({rexi_DOWN, _, _, _}, _Worker, Acc0) ->
skip_message(Acc0);
handle_message({rexi_EXIT, _}, _Worker, Acc0) ->
skip_message(Acc0);
handle_message({ok, Replies}, Worker, Acc0) ->
{WaitingCount, DocCount, W, GroupedDocs, DocReplyDict0} = Acc0,
Docs = couch_util:get_value(Worker, GroupedDocs),
DocReplyDict = append_update_replies(Docs, Replies, DocReplyDict0),
case {WaitingCount, dict:size(DocReplyDict)} of
{1, _} ->
% last message has arrived, we need to conclude things
{W, Reply} = dict:fold(fun force_reply/3, {W,[]}, DocReplyDict),
{stop, Reply};
{_, DocCount} ->
% we've got at least one reply for each document, let's take a look
case dict:fold(fun maybe_reply/3, {stop,W,[]}, DocReplyDict) of
continue ->
{ok, {WaitingCount - 1, DocCount, W, GroupedDocs, DocReplyDict}};
{stop, W, FinalReplies} ->
{stop, FinalReplies}
end;
{_, N} when N < DocCount ->
% no point in trying to finalize anything yet
{ok, {WaitingCount - 1, DocCount, W, GroupedDocs, DocReplyDict}}
end;
handle_message({missing_stub, Stub}, _, _) ->
throw({missing_stub, Stub});
handle_message({not_found, no_db_file} = X, Worker, Acc0) ->
{_, _, _, GroupedDocs, _} = Acc0,
Docs = couch_util:get_value(Worker, GroupedDocs),
handle_message({ok, [X || _D <- Docs]}, Worker, Acc0).
force_reply(Doc, [], {W, Acc}) ->
{W, [{Doc, {error, internal_server_error}} | Acc]};
force_reply(Doc, [FirstReply|_] = Replies, {W, Acc}) ->
case update_quorum_met(W, Replies) of
{true, Reply} ->
{W, [{Doc,Reply} | Acc]};
false ->
?LOG_ERROR("write quorum (~p) failed, reply ~p", [W, FirstReply]),
% TODO make a smarter choice than just picking the first reply
{W, [{Doc,FirstReply} | Acc]}
end.
maybe_reply(_, _, continue) ->
% we didn't meet quorum for all docs, so we're fast-forwarding the fold
continue;
maybe_reply(Doc, Replies, {stop, W, Acc}) ->
case update_quorum_met(W, Replies) of
{true, Reply} ->
{stop, W, [{Doc, Reply} | Acc]};
false ->
continue
end.
update_quorum_met(W, Replies) ->
Counters = lists:foldl(fun(R,D) -> orddict:update_counter(R,1,D) end,
orddict:new(), Replies),
case lists:dropwhile(fun({_, Count}) -> Count < W end, Counters) of
[] ->
false;
[{FinalReply, _} | _] ->
{true, FinalReply}
end.
-spec group_docs_by_shard(binary(), [#doc{}]) -> [{#shard{}, [#doc{}]}].
group_docs_by_shard(DbName, Docs) ->
dict:to_list(lists:foldl(fun(#doc{id=Id} = Doc, D0) ->
lists:foldl(fun(Shard, D1) ->
dict:append(Shard, Doc, D1)
end, D0, mem3:shards(DbName,Id))
end, dict:new(), Docs)).
append_update_replies([], [], DocReplyDict) ->
DocReplyDict;
append_update_replies([Doc|Rest], [], Dict0) ->
% icky, if replicated_changes only errors show up in result
append_update_replies(Rest, [], dict:append(Doc, noreply, Dict0));
append_update_replies([Doc|Rest1], [Reply|Rest2], Dict0) ->
% TODO what if the same document shows up twice in one update_docs call?
append_update_replies(Rest1, Rest2, dict:append(Doc, Reply, Dict0)).
skip_message(Acc0) ->
% TODO fix this
{ok, Acc0}.
validate_atomic_update(_, _, false) ->
ok;
validate_atomic_update(_DbName, AllDocs, true) ->
% TODO actually perform the validation. This requires some hackery, we need
% to basically extract the prep_and_validate_updates function from couch_db
% and only run that, without actually writing in case of a success.
Error = {not_implemented, <<"all_or_nothing is not supported yet">>},
PreCommitFailures = lists:map(fun(#doc{id=Id, revs = {Pos,Revs}}) ->
case Revs of [] -> RevId = <<>>; [RevId|_] -> ok end,
{{Id, {Pos, RevId}}, Error}
end, AllDocs),
throw({aborted, PreCommitFailures}).
|
