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
|
// mmap_v1_extent_manager.h
/**
* Copyright (C) 2014 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 <string>
#include <vector>
#include <boost/filesystem/path.hpp>
#include "mongo/base/status.h"
#include "mongo/base/string_data.h"
#include "mongo/db/diskloc.h"
#include "mongo/db/storage/extent_manager.h"
namespace mongo {
class DataFile;
class Record;
class TransactionExperiment;
struct Extent;
/**
* ExtentManager basics
* - one per database
* - responsible for managing <db>.# files
* - NOT responsible for .ns file
* - gives out extents
* - responsible for figuring out how to get a new extent
* - can use any method it wants to do so
* - this structure is NOT stored on disk
* - this class is NOT thread safe, locking should be above (for now)
*
* implementation:
* - ExtentManager holds a list of DataFile
*/
class MmapV1ExtentManager : public ExtentManager {
MONGO_DISALLOW_COPYING( MmapV1ExtentManager );
public:
/**
* @param freeListDetails this is a reference into the .ns file
* while a bit odd, this is not a layer violation as extents
* are a peer to the .ns file, without any layering
*/
MmapV1ExtentManager( const StringData& dbname, const StringData& path,
bool directoryPerDB );
virtual ~MmapV1ExtentManager();
/**
* deletes all state and puts back to original state
*/
void reset();
/**
* opens all current files
*/
Status init(TransactionExperiment* txn);
size_t numFiles() const;
long long fileSize() const;
// TODO: make private
DataFile* getFile( TransactionExperiment* txn,
int n,
int sizeNeeded = 0,
bool preallocateOnly = false );
void flushFiles( bool sync );
// must call Extent::reuse on the returned extent
DiskLoc allocateExtent( TransactionExperiment* txn,
bool capped,
int size,
int quotaMax );
/**
* firstExt has to be == lastExt or a chain
*/
void freeExtents( TransactionExperiment* txn, DiskLoc firstExt, DiskLoc lastExt );
/**
* frees a single extent
* ignores all fields in the Extent except: magic, myLoc, length
*/
void freeExtent( TransactionExperiment* txn, DiskLoc extent );
void printFreeList() const;
void freeListStats( int* numExtents, int64_t* totalFreeSize ) const;
/**
* @param loc - has to be for a specific Record
* Note(erh): this sadly cannot be removed.
* A Record DiskLoc has an offset from a file, while a RecordStore really wants an offset
* from an extent. This intrinsically links an original record store to the original extent
* manager.
*/
Record* recordForV1( const DiskLoc& loc ) const;
/**
* @param loc - has to be for a specific Record (not an Extent)
* Note(erh) see comment on recordFor
*/
Extent* extentForV1( const DiskLoc& loc ) const;
/**
* @param loc - has to be for a specific Record (not an Extent)
* Note(erh) see comment on recordFor
*/
DiskLoc extentLocForV1( const DiskLoc& loc ) const;
/**
* @param loc - has to be for a specific Extent
*/
Extent* getExtent( const DiskLoc& loc, bool doSanityCheck = true ) const;
virtual int maxSize() const;
virtual CacheHint* cacheHint( const DiskLoc& extentLoc, const HintType& hint );
private:
/**
* will return NULL if nothing suitable in free list
*/
DiskLoc _allocFromFreeList( TransactionExperiment* txn, int approxSize, bool capped );
/* allocate a new Extent, does not check free list
* @param maxFileNoForQuota - 0 for unlimited
*/
DiskLoc _createExtent( TransactionExperiment* txn, int approxSize, int maxFileNoForQuota );
DataFile* _addAFile( TransactionExperiment* txn, int sizeNeeded, bool preallocateNextFile );
DiskLoc _getFreeListStart() const;
DiskLoc _getFreeListEnd() const;
void _setFreeListStart( TransactionExperiment* txn, DiskLoc loc );
void _setFreeListEnd( TransactionExperiment* txn, DiskLoc loc );
const DataFile* _getOpenFile( int n ) const;
DiskLoc _createExtentInFile( TransactionExperiment* txn,
int fileNo,
DataFile* f,
int size,
int maxFileNoForQuota );
boost::filesystem::path fileName( int n ) const;
// -----
std::string _dbname; // i.e. "test"
std::string _path; // i.e. "/data/db"
bool _directoryPerDB;
// must be in the dbLock when touching this (and write locked when writing to of course)
// however during Database object construction we aren't, which is ok as it isn't yet visible
// to others and we are in the dbholder lock then.
std::vector<DataFile*> _files;
};
}
|
