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
151
152
153
154
|
/**
* Copyright (C) 2015 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* 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 GNU Affero General 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 <memory>
#include <vector>
#include "mongo/bson/bsonobj.h"
#include "mongo/client/read_preference.h"
#include "mongo/db/auth/user_name.h"
#include "mongo/db/cursor_id.h"
#include "mongo/db/namespace_string.h"
#include "mongo/s/client/shard.h"
#include "mongo/util/net/hostandport.h"
namespace mongo {
class OperationContext;
struct ClusterClientCursorParams {
// When mongos has to do a merge in order to return results to the client in the correct sort
// order, it requests a sortKey meta-projection using this field name.
static const char kSortKeyField[];
/**
* Contains any CCC parameters that are specified per-remote node.
*/
struct Remote {
/**
* Use when a new cursor should be created on the remote.
*/
Remote(ShardId sid, BSONObj cmdObj) : shardId(std::move(sid)), cmdObj(std::move(cmdObj)) {}
/**
* Use when an a cursor already exists on the remote. The resulting CCC will take ownership
* of the existing remote cursor, generating results based on its current state.
*
* Note that any results already generated from this cursor will not be returned by the
* resulting CCC. The caller is responsible for ensuring that results previously generated
* by this cursor have been processed.
*/
Remote(HostAndPort hostAndPort, CursorId cursorId)
: hostAndPort(std::move(hostAndPort)), cursorId(cursorId) {}
// If this is a regular query cursor, this value will be set and shard id retargeting may
// occur on certain networking or replication errors.
//
// If this is an externally-prepared cursor (as is in the case of aggregation cursors),
// this value will never be set and no retargeting will occur.
boost::optional<ShardId> shardId;
// If this is an externally-specified cursor (e.g. aggregation), this value will be set and
// used directly and no re-targeting may happen on errors.
boost::optional<HostAndPort> hostAndPort;
// The raw command parameters to send to this remote (e.g. the find command specification).
//
// Exactly one of 'cmdObj' or 'cursorId' must be set.
boost::optional<BSONObj> cmdObj;
// The cursorId for the remote node, if one already exists.
//
// Exactly one of 'cmdObj' or 'cursorId' must be set.
boost::optional<CursorId> cursorId;
};
/**
* Read preference must be provided if initial shard host targeting is necessary (i.e., we don't
* know yet the remote cursor id).
*/
ClusterClientCursorParams(NamespaceString nss,
UserNameIterator authenticatedUsersIter,
boost::optional<ReadPreferenceSetting> readPref = boost::none)
: nsString(std::move(nss)) {
while (authenticatedUsersIter.more()) {
authenticatedUsers.emplace_back(authenticatedUsersIter.next());
}
if (readPref) {
readPreference = std::move(readPref.get());
}
}
// Namespace against which to query.
NamespaceString nsString;
// The set of authenticated users when this cursor was created.
std::vector<UserName> authenticatedUsers;
// Per-remote node data.
std::vector<Remote> remotes;
// The sort specification. Leave empty if there is no sort.
BSONObj sort;
// The number of results to skip. Optional. Should not be forwarded to the remote hosts in
// 'cmdObj'.
boost::optional<long long> skip;
// The number of results per batch. Optional. If specified, will be specified as the batch for
// each getMore.
boost::optional<long long> batchSize;
// Limits the number of results returned by the ClusterClientCursor to this many. Optional.
// Should be forwarded to the remote hosts in 'cmdObj'.
boost::optional<long long> limit;
// Whether this cursor is tailing a capped collection.
bool isTailable = false;
// Whether this cursor has the awaitData option set.
bool isAwaitData = false;
// Read preference for where to target the query. This value is only set if initial shard host
// targeting is necessary and not used if using externally prepared cursor ids.
boost::optional<ReadPreferenceSetting> readPreference;
// Whether the client indicated that it is willing to receive partial results in the case of an
// unreachable host.
bool isAllowPartialResults = false;
// If the read is done against a view, an error is returned along with the view definition in
// the first response from the primary shard for the base collection. Calling code can re-run
// the read against the base collection by using this returned view definition.
boost::optional<BSONObj> viewDefinition;
};
} // mongo
|
