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
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
/**
* 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 "mongo/db/namespace_string.h"
#include "mongo/db/ops/update_result.h"
#include "mongo/db/record_id.h"
namespace mongo {
class Collection;
class CollectionPtr;
class Database;
class OperationContext;
class FindCommandRequest;
/**
* db helpers are helper functions and classes that let us easily manipulate the local
* database instance in-proc.
*
* all helpers assume locking is handled above them
*/
struct Helpers {
/**
* Executes the given match expression ('query') and returns true if there is at least one
* one matching document. The first found matching document is returned via the 'result' output
* parameter.
*
* If 'requireIndex' is true, then this forces the query system to choose an indexed plan. An
* exception is thrown if no 'requireIndex' is set to true but no indexed plan exists.
*
* Performs the read successfully regardless of a replica set node's state, meaning that the
* node does not need to be primary or secondary.
*/
static bool findOne(OperationContext* opCtx,
const CollectionPtr& collection,
const BSONObj& query,
BSONObj& result,
bool requireIndex = false);
/**
* If `invariantOnError` is true, an error (e.g: no document found) will crash the
* process. Otherwise the empty BSONObj will be returned.
*/
static BSONObj findOneForTesting(OperationContext* opCtx,
const CollectionPtr& collection,
const BSONObj& query,
bool invariantOnError = true);
/**
* Similar to the 'findOne()' overload above, except returns the RecordId of the first matching
* document, or a null RecordId if no such document exists.
*/
static RecordId findOne(OperationContext* opCtx,
const CollectionPtr& collection,
const BSONObj& query,
bool requireIndex);
static RecordId findOne(OperationContext* opCtx,
const CollectionPtr& collection,
std::unique_ptr<FindCommandRequest> qr,
bool requireIndex);
/**
* @param foundIndex if passed in will be set to 1 if ns and index found
* @return true if object found
*/
static bool findById(OperationContext* opCtx,
Database* db,
StringData ns,
BSONObj query,
BSONObj& result,
bool* nsFound = nullptr,
bool* indexFound = nullptr);
/* TODO: should this move into Collection?
* uasserts if no _id index.
* @return null loc if not found */
static RecordId findById(OperationContext* opCtx,
const CollectionPtr& collection,
const BSONObj& query);
/**
* Get the first object generated from a forward natural-order scan on "ns". Callers do not
* have to lock "ns".
*
* Returns true if there is such an object. An owned copy of the object is placed into the
* out-argument "result".
*
* Returns false if there is no such object.
*/
static bool getSingleton(OperationContext* opCtx, const char* ns, BSONObj& result);
/**
* Same as getSingleton, but with a reverse natural-order scan on "ns".
*/
static bool getLast(OperationContext* opCtx, const char* ns, BSONObj& result);
/**
* Performs an upsert of "obj" into the collection "ns", with an empty update predicate.
* Callers must have "ns" locked.
*/
static void putSingleton(OperationContext* opCtx, const char* ns, BSONObj obj);
/**
* Callers are expected to hold the collection lock.
* you do not have to have Context set
* o has to have an _id field or will assert
*/
static UpdateResult upsert(OperationContext* opCtx,
const std::string& ns,
const BSONObj& o,
bool fromMigrate = false);
/**
* Performs an upsert of 'updateMod' if we don't match the given 'filter'.
* Callers are expected to hold the collection lock.
* Note: Query yielding is turned off, so both read and writes are performed
* on the same storage snapshot.
*/
static UpdateResult upsert(OperationContext* opCtx,
const std::string& ns,
const BSONObj& filter,
const BSONObj& updateMod,
bool fromMigrate = false);
/**
* Performs an update of 'updateMod' for the entry matching the given 'filter'.
* Callers are expected to hold the collection lock.
* Note: Query yielding is turned off, so both read and writes are performed
* on the same storage snapshot.
*/
static void update(OperationContext* opCtx,
const std::string& ns,
const BSONObj& filter,
const BSONObj& updateMod,
bool fromMigrate = false);
// TODO: this should be somewhere else probably
/* Takes object o, and returns a new object with the
* same field elements but the names stripped out.
* Example:
* o = {a : 5 , b : 6} --> {"" : 5, "" : 6}
*/
static BSONObj toKeyFormat(const BSONObj& o);
/* Takes object o, and infers an ascending keyPattern with the same fields as o
* Example:
* o = {a : 5 , b : 6} --> {a : 1 , b : 1 }
*/
static BSONObj inferKeyPattern(const BSONObj& o);
/**
* Remove all documents from a collection.
* You do not need to set the database before calling.
* Does not oplog the operation.
*/
static void emptyCollection(OperationContext* opCtx, const NamespaceString& nss);
/*
* Finds the doc and then runs a no-op update by running an update using the doc just read. Used
* in order to force a conflict if a concurrent storage transaction writes to the doc we're
* reading.
* Callers must hold the collection lock in MODE_IX.
* Uasserts if no _id index.
* Returns true if object found
*/
static bool findByIdAndNoopUpdate(OperationContext* opCtx,
const CollectionPtr& collection,
const BSONObj& idQuery,
BSONObj& result);
};
} // namespace mongo
|
