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
142
143
144
|
-module(mem3_rep).
-export([go/2, changes_enumerator/3, make_local_id/2]).
-include("mem3.hrl").
-include_lib("couch/include/couch_db.hrl").
-define(CTX, #user_ctx{roles = [<<"_admin">>]}).
-record(acc, {revcount = 0, infos = [], seq, localid, source, target}).
go(DbName, Node) when is_binary(DbName), is_atom(Node) ->
go(#shard{name=DbName, node=node()}, #shard{name=DbName, node=Node});
go(#shard{} = Source, #shard{} = Target) ->
LocalId = make_local_id(Source, Target),
case couch_db:open(Source#shard.name, [{user_ctx,?CTX}]) of
{ok, Db} ->
try
go(Db, Target, LocalId)
catch error:{not_found, no_db_file} ->
{error, missing_target}
after
couch_db:close(Db)
end;
{not_found, no_db_file} ->
{error, missing_source}
end.
go(#db{name = DbName, seq_tree = Bt} = Db, #shard{} = Target, LocalId) ->
erlang:put(io_priority, {internal_repl, DbName}),
Seq = calculate_start_seq(Db, Target, LocalId),
Acc0 = #acc{source=Db, target=Target, seq=Seq, localid=LocalId},
Fun = fun ?MODULE:changes_enumerator/3,
{ok, _, AccOut} = couch_btree:fold(Bt, Fun, Acc0, [{start_key, Seq + 1}]),
{ok, #acc{seq = LastSeq}} = replicate_batch(AccOut),
case couch_db:count_changes_since(Db, LastSeq) of
0 ->
ok;
N ->
exit({pending_changes, N})
end.
make_local_id(#shard{node=SourceNode}, #shard{node=TargetNode}) ->
S = couch_util:encodeBase64Url(couch_util:md5(term_to_binary(SourceNode))),
T = couch_util:encodeBase64Url(couch_util:md5(term_to_binary(TargetNode))),
<<"_local/shard-sync-", S/binary, "-", T/binary>>.
changes_enumerator(FullDocInfo, _, #acc{revcount = C} = Acc) when C >= 99 ->
#doc_info{high_seq = Seq} = couch_doc:to_doc_info(FullDocInfo),
{stop, Acc#acc{seq = Seq, infos = [FullDocInfo | Acc#acc.infos]}};
changes_enumerator(FullDocInfo, _, #acc{revcount = C, infos = Infos} = Acc) ->
#doc_info{high_seq = Seq, revs = Revs} = couch_doc:to_doc_info(FullDocInfo),
Count = C + length(Revs),
{ok, Acc#acc{seq = Seq, revcount = Count, infos = [FullDocInfo | Infos]}}.
replicate_batch(#acc{target = #shard{node=Node, name=Name}} = Acc) ->
case find_missing_revs(Acc) of
[] ->
ok;
Missing ->
ok = save_on_target(Node, Name, open_docs(Acc, Missing))
end,
update_locals(Acc),
{ok, Acc#acc{revcount=0, infos=[]}}.
find_missing_revs(Acc) ->
#acc{target = #shard{node=Node, name=Name}, infos = Infos} = Acc,
IdsRevs = lists:map(fun(FDI) ->
#doc_info{id=Id, revs=RevInfos} = couch_doc:to_doc_info(FDI),
{Id, [R || #rev_info{rev=R} <- RevInfos]}
end, Infos),
Options = [{io_priority, {internal_repl, Name}}, {user_ctx, ?CTX}],
rexi_call(Node, {fabric_rpc, get_missing_revs, [Name, IdsRevs, Options]}).
open_docs(#acc{source=Source, infos=Infos}, Missing) ->
lists:flatmap(fun({Id, Revs, _}) ->
FDI = lists:keyfind(Id, #full_doc_info.id, Infos),
open_doc_revs(Source, FDI, Revs)
end, Missing).
save_on_target(Node, Name, Docs) ->
Options = [replicated_changes, full_commit, {user_ctx, ?CTX},
{io_priority, {internal_repl, Name}}],
rexi_call(Node, {fabric_rpc, update_docs, [Name, Docs, Options]}),
ok.
update_locals(Acc) ->
#acc{seq=Seq, source=Db, target=Target, localid=Id} = Acc,
#shard{name=Name, node=Node} = Target,
Doc = #doc{id = Id, body = {[
{<<"seq">>, Seq},
{<<"node">>, list_to_binary(atom_to_list(Node))},
{<<"timestamp">>, list_to_binary(iso8601_timestamp())}
]}},
{ok, _} = couch_db:update_doc(Db, Doc, []),
Options = [{user_ctx, ?CTX}, {io_priority, {internal_repl, Name}}],
rexi_call(Node, {fabric_rpc, update_docs, [Name, [Doc], Options]}).
rexi_call(Node, MFA) ->
Mon = rexi_monitor:start([{rexi_server, Node}]),
Ref = rexi:cast(Node, MFA),
try
receive {Ref, {ok, Reply}} ->
Reply;
{Ref, Error} ->
erlang:error(Error);
{rexi_DOWN, Mon, _, Reason} ->
erlang:error({rexi_DOWN, Reason})
after 600000 ->
erlang:error(timeout)
end
after
rexi_monitor:stop(Mon)
end.
calculate_start_seq(Db, #shard{node=Node, name=Name}, LocalId) ->
case couch_db:open_doc(Db, LocalId, []) of
{ok, #doc{body = {SProps}}} ->
Opts = [{user_ctx, ?CTX}, {io_priority, {internal_repl, Name}}],
try rexi_call(Node, {fabric_rpc, open_doc, [Name, LocalId, Opts]}) of
#doc{body = {TProps}} ->
SourceSeq = couch_util:get_value(<<"seq">>, SProps, 0),
TargetSeq = couch_util:get_value(<<"seq">>, TProps, 0),
erlang:min(SourceSeq, TargetSeq)
catch error:{not_found, _} ->
0
end;
{not_found, _} ->
0
end.
open_doc_revs(Db, #full_doc_info{id=Id, rev_tree=RevTree}, Revs) ->
{FoundRevs, _} = couch_key_tree:get_key_leafs(RevTree, Revs),
lists:map(fun({#leaf{deleted=IsDel, ptr=SummaryPtr}, FoundRevPath}) ->
couch_db:make_doc(Db, Id, IsDel, SummaryPtr, FoundRevPath)
end, FoundRevs).
iso8601_timestamp() ->
{_,_,Micro} = Now = os:timestamp(),
{{Year,Month,Date},{Hour,Minute,Second}} = calendar:now_to_datetime(Now),
Format = "~4.10.0B-~2.10.0B-~2.10.0BT~2.10.0B:~2.10.0B:~2.10.0B.~6.10.0BZ",
io_lib:format(Format, [Year, Month, Date, Hour, Minute, Second, Micro]).
|
