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
|
/* @file dbhelpers.h
db helpers are helper functions and classes that let us easily manipulate the local
database instance in-proc.
*/
/**
* Copyright (C) 2008 10gen 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/>.
*/
#pragma once
#include "mongo/pch.h"
#include "client.h"
#include "db.h"
namespace mongo {
extern const BSONObj reverseNaturalObj; // {"$natural": -1 }
class Cursor;
class CoveredIndexMatcher;
/**
all helpers assume locking is handled above them
*/
struct Helpers {
/* ensure the specified index exists.
@param keyPattern key pattern, e.g., { ts : 1 }
@param name index name, e.g., "name_1"
This method can be a little (not much) cpu-slow, so you may wish to use
OCCASIONALLY ensureIndex(...);
Note: use ensureHaveIdIndex() for the _id index: it is faster.
Note: does nothing if collection does not yet exist.
*/
static void ensureIndex(const char *ns, BSONObj keyPattern, bool unique, const char *name);
/* fetch a single object from collection ns that matches query.
set your db SavedContext first.
@param query - the query to perform. note this is the low level portion of query so "orderby : ..."
won't work.
@param requireIndex if true, assert if no index for the query. a way to guard against
writing a slow query.
@return true if object found
*/
static bool findOne(const StringData& ns, const BSONObj &query, BSONObj& result, bool requireIndex = false);
static DiskLoc findOne(const StringData& ns, const BSONObj &query, bool requireIndex);
/**
* have to be locked already
*/
static vector<BSONObj> findAll( const string& ns , const BSONObj& query );
/**
* @param foundIndex if passed in will be set to 1 if ns and index found
* @return true if object found
*/
static bool findById(Client&, const char *ns, BSONObj query, BSONObj& result ,
bool * nsFound = 0 , bool * indexFound = 0 );
/* uasserts if no _id index.
@return null loc if not found */
static DiskLoc findById(NamespaceDetails *d, BSONObj query);
/** Get/put the first (or last) object from a collection. Generally only useful if the collection
only ever has a single object -- which is a "singleton collection".
You do not need to set the database (Context) before calling.
@return true if object exists.
*/
static bool getSingleton(const char *ns, BSONObj& result);
static void putSingleton(const char *ns, BSONObj obj);
static void putSingletonGod(const char *ns, BSONObj obj, bool logTheOp);
static bool getFirst(const char *ns, BSONObj& result) { return getSingleton(ns, result); }
static bool getLast(const char *ns, BSONObj& result); // get last object int he collection; e.g. {$natural : -1}
/**
* you have to lock
* you do not have to have Context set
* o has to have an _id field or will assert
*/
static void upsert( const string& ns , const BSONObj& o, bool fromMigrate = false );
/** You do not need to set the database before calling.
@return true if collection is empty.
*/
static bool isEmpty(const char *ns, bool doAuth=true);
// 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. Also,
* fills in "key" with an ascending keyPattern that matches o
* Example:
* o = {a : 5 , b : 6} -->
* sets key= {a : 1, b :1}, returns {"" : 5, "" : 6}
*/
static BSONObj toKeyFormat( const BSONObj& o , BSONObj& key );
/* Takes a BSONObj indicating the min or max boundary of a range,
* and a keyPattern corresponding to an index that is useful
* for locating items in the range, and returns an "extension"
* of the bound, modified to fit the given pattern. In other words,
* it appends MinKey or MaxKey values to the bound, so that the extension
* has the same number of fields as keyPattern.
* minOrMax should be -1/+1 to indicate whether the extension
* corresponds to the min or max bound for the range.
* Also, strips out the field names to put the bound in key format.
* Examples:
* {a : 55}, {a :1}, -1 --> {"" : 55}
* {a : 55}, {a : 1, b : 1}, -1 -> {"" : 55, "" : minKey}
* {a : 55}, {a : 1, b : 1}, 1 -> {"" : 55, "" : maxKey}
* {a : 55}, {a : 1, b : -1}, -1 -> {"" : 55, "" : maxKey}
* {a : 55}, {a : 1, b : -1}, 1 -> {"" : 55, "" : minKey}
*
* This function is useful for modifying chunk ranges in sharding,
* when the shard key is a prefix of the index actually used
* (also useful when the shard key is equal to the index used,
* since it strips out the field names).
*/
static BSONObj modifiedRangeBound( const BSONObj& bound ,
const BSONObj& keyPattern ,
int minOrMax );
class RemoveCallback {
public:
virtual ~RemoveCallback() {}
virtual void goingToDelete( const BSONObj& o ) = 0;
};
/**
* Takes a range, specified by a min and max, and an index, specified by
* keyPattern, and removes all the documents in that range found by iterating
* over the given index. Caller is responsible for insuring that min/max are
* compatible with the given keyPattern (e.g min={a:100} is compatible with
* keyPattern={a:1,b:1} since it can be extended to {a:100,b:minKey}, but
* min={b:100} is not compatible).
*
* Caller must hold a write lock on 'ns'
*
* Does oplog the individual document deletions.
*/
static long long removeRange( const string& ns ,
const BSONObj& min ,
const BSONObj& max ,
const BSONObj& keyPattern ,
bool maxInclusive = false ,
bool secondaryThrottle = false ,
RemoveCallback * callback = 0,
bool fromMigrate = false );
/**
* Remove all documents from a collection.
* You do not need to set the database before calling.
* Does not oplog the operation.
*/
static void emptyCollection(const char *ns);
};
/**
* user for saving deleted bson objects to a flat file
*/
class RemoveSaver : public Helpers::RemoveCallback , boost::noncopyable {
public:
RemoveSaver( const string& type , const string& ns , const string& why);
~RemoveSaver();
void goingToDelete( const BSONObj& o );
private:
boost::filesystem::path _root;
boost::filesystem::path _file;
ofstream* _out;
};
} // namespace mongo
|
