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
|
/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include <boost/optional.hpp>
#include <vector>
#include "mongo/base/status_with.h"
#include "mongo/bson/bsonobj.h"
#include "mongo/db/cursor_id.h"
#include "mongo/executor/task_executor.h"
#include "mongo/s/client/shard.h"
#include "mongo/s/query/async_results_merger_params_gen.h"
#include "mongo/stdx/mutex.h"
#include "mongo/util/net/hostandport.h"
#include "mongo/util/time_support.h"
namespace mongo {
class CursorResponse;
/**
* Establishes cursors on the remote shards by issuing requests in parallel, using the readPref to
* select a host within each shard.
*
* If any of the cursors fail to be established, this function performs cleanup by sending
* killCursors to any cursors that were established, then throws the error. If the namespace
* represents a view, an exception containing a ResolvedView is thrown. Calling code can then
* attempt to establish cursors against the base collection using this view.
*
* On success, the ownership of the cursors is transferred to the caller. This means the caller is
* now responsible for either exhausting the cursors or sending killCursors to them.
*
* @param allowPartialResults: If true, unreachable hosts are ignored, and only cursors established
* on reachable hosts are returned.
*
*/
std::vector<RemoteCursor> establishCursors(
OperationContext* opCtx,
executor::TaskExecutor* executor,
const NamespaceString& nss,
const ReadPreferenceSetting readPref,
const std::vector<std::pair<ShardId, BSONObj>>& remotes,
bool allowPartialResults,
Shard::RetryPolicy retryPolicy = Shard::RetryPolicy::kIdempotent);
/**
* Schedules a remote killCursor command for each of the cursors in 'remoteCursors'.
*
* Note that this method is optimistic and does not check the return status for the killCursors
* commands.
*/
void killRemoteCursors(OperationContext* opCtx,
executor::TaskExecutor* executor,
std::vector<RemoteCursor>&& remoteCursors,
const NamespaceString& nss);
void killRemoteCursor(OperationContext* opCtx,
executor::TaskExecutor* executor,
RemoteCursor&& cursor,
const NamespaceString& nss);
} // namespace mongo
|
