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
145
146
147
148
149
150
|
% 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(couch_rep_writer).
-export([start_link/4]).
-include("couch_db.hrl").
-define (MAX_BYTES, 10000000).
-define (MAX_CHUNK_SIZE, 65535).
start_link(Parent, Target, Reader, _PostProps) ->
{ok, spawn_link(fun() -> writer_loop(Parent, Reader, Target) end)}.
make_chunk(Data) when is_list(Data) ->
make_chunk(list_to_binary(Data));
make_chunk(Data) when size(Data) > ?MAX_CHUNK_SIZE ->
<<ChunkData:?MAX_CHUNK_SIZE/binary, Rest/binary>> = Data,
Chunk = {?MAX_CHUNK_SIZE, [ibrowse_lib:dec2hex(4, ?MAX_CHUNK_SIZE), "\r\n",
ChunkData, "\r\n"]},
[Chunk, Rest];
make_chunk(Data) ->
Size = size(Data),
[{Size, [ibrowse_lib:dec2hex(4, Size), "\r\n", Data, "\r\n"]}].
upload_docs({start, Buffer}) ->
[{Size, Chunk}] = make_chunk(<<"{\"new_edits\":false, \"docs\":[">>),
% Buffer ! {self(), next_doc},
{ok, Chunk, {continue, Buffer, "", Size}};
upload_docs({continue, _Buf, _Pre, ByteCount}) when ByteCount > ?MAX_BYTES ->
{ok, "2\r\n]}\r\n0\r\n\r\n", finish};
upload_docs({continue, Buffer, Prepend, ByteCount}) ->
Buffer ! {self(), next_doc},
receive
{ok, JsonDoc} ->
[{Size, Chunk} | MoreData] = make_chunk([Prepend, JsonDoc]),
{ok, Chunk, {multi_chunk, MoreData, Buffer, ",", ByteCount+Size}};
eof ->
{ok, "2\r\n]}\r\n0\r\n\r\n", finish};
timeout ->
?LOG_DEBUG("sending a heartbeat to keep the connection open", []),
{ok, "1\r\n \r\n", {continue, Buffer, Prepend, ByteCount}}
end;
upload_docs({multi_chunk, [], Buffer, Prepend, ByteCount}) ->
% Buffer ! {self(), next_doc},
upload_docs({continue, Buffer, Prepend, ByteCount});
upload_docs({multi_chunk, [Data], Buffer, Prepend, ByteCount}) ->
[{Size, Chunk} | MoreData] = make_chunk(Data),
{ok, Chunk, {multi_chunk, MoreData, Buffer, Prepend, ByteCount+Size}};
upload_docs(finish) ->
couch_util:should_flush(),
eof.
encoding_worker([]) ->
receive {MiddleMan, next_doc} -> MiddleMan ! eof end,
ok;
encoding_worker([Doc|Rest]) ->
JsonDoc = ?l2b(?JSON_ENCODE(couch_doc:to_json_obj(Doc,[revs,attachments]))),
receive {MiddleMan, next_doc} -> MiddleMan ! {ok, JsonDoc} end,
encoding_worker(Rest).
% needed because upload_docs is inside a gen_server so it can't have a mailbox
middle_man(EncodingWorker) ->
receive {Uploader, next_doc} ->
receive
{ok, JsonDoc} ->
EncodingWorker ! {self(), next_doc},
Uploader ! {ok, JsonDoc},
middle_man(EncodingWorker);
eof ->
Uploader ! eof,
ok
after 5000 ->
Uploader ! timeout,
middle_man(EncodingWorker)
end
end.
request_loop(Ref, Request, Acc) ->
receive
{'DOWN', Ref, _, _, normal} ->
lists:flatten(lists:reverse(Acc));
{'DOWN', Ref, _, _, Reason} ->
exit(Reason)
after 0 ->
ErrorsJson = couch_rep_httpc:request(Request),
request_loop(Ref, Request, [ErrorsJson|Acc])
end.
writer_loop(Parent, Reader, Target) ->
case couch_rep_reader:next(Reader) of
{complete, FinalSeq} ->
Parent ! {writer_checkpoint, FinalSeq},
ok;
{HighSeq, Docs} ->
DocCount = length(Docs),
try write_docs(Target, Docs) of
{ok, []} ->
Parent ! {update_stats, docs_written, DocCount};
{ok, Errors} ->
ErrorCount = length(Errors),
Parent ! {update_stats, doc_write_failures, ErrorCount},
Parent ! {update_stats, docs_written, DocCount - ErrorCount}
catch
{attachment_request_failed, Err} ->
?LOG_DEBUG("writer failed to write an attachment ~p", [Err]),
exit({attachment_request_failed, Err, Docs})
end,
Parent ! {writer_checkpoint, HighSeq},
couch_rep_att:cleanup(),
couch_util:should_flush(),
writer_loop(Parent, Reader, Target)
end.
write_docs(#http_db{} = Db, Docs) ->
{Worker, Ref} = spawn_monitor(fun() -> encoding_worker(Docs) end),
Pid = spawn_link(fun() -> Worker ! {self(),next_doc}, middle_man(Worker) end),
Request = Db#http_db{
resource = "_bulk_docs",
method = post,
body = {fun upload_docs/1, {start, Pid}},
headers = [{"transfer-encoding", "chunked"} | Db#http_db.headers]
},
ErrorsJson = request_loop(Ref, Request, []),
ErrorsList =
lists:map(
fun({Props}) ->
Id = proplists:get_value(<<"id">>, Props),
Rev = couch_doc:parse_rev(proplists:get_value(<<"rev">>, Props)),
ErrId = couch_util:to_existing_atom(
proplists:get_value(<<"error">>, Props)),
Reason = proplists:get_value(<<"reason">>, Props),
{{Id, Rev}, {ErrId, Reason}}
end, ErrorsJson),
{ok, ErrorsList};
write_docs(Db, Docs) ->
couch_db:update_docs(Db, Docs, [], replicated_changes).
|
