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
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
|
// --------------------------------------------------------------------------
//
// File
// Name: BackupStoreRefCountDatabase.cpp
// Purpose: Backup store object reference count database storage
// Created: 2009/06/01
//
// --------------------------------------------------------------------------
#include "Box.h"
#include <algorithm>
#include "BackupStoreRefCountDatabase.h"
#include "BackupStoreException.h"
#include "BackupStoreAccountDatabase.h"
#include "BackupStoreAccounts.h"
#include "RaidFileController.h"
#include "RaidFileUtil.h"
#include "RaidFileException.h"
#include "Utils.h"
#include "MemLeakFindOn.h"
#define REFCOUNT_MAGIC_VALUE 0x52656643 // RefC
#define REFCOUNT_FILENAME "refcount"
// --------------------------------------------------------------------------
//
// Function
// Name: BackupStoreRefCountDatabase::BackupStoreRefCountDatabase()
// Purpose: Default constructor
// Created: 2003/08/28
//
// --------------------------------------------------------------------------
BackupStoreRefCountDatabase::BackupStoreRefCountDatabase(const
BackupStoreAccountDatabase::Entry& rAccount)
: mAccount(rAccount),
mFilename(GetFilename(rAccount)),
mReadOnly(true),
mIsModified(false)
{
}
// --------------------------------------------------------------------------
//
// Function
// Name: BackupStoreRefCountDatabase::~BackupStoreRefCountDatabase
// Purpose: Destructor
// Created: 2003/08/28
//
// --------------------------------------------------------------------------
BackupStoreRefCountDatabase::~BackupStoreRefCountDatabase()
{
}
std::string BackupStoreRefCountDatabase::GetFilename(const
BackupStoreAccountDatabase::Entry& rAccount)
{
std::string RootDir = BackupStoreAccounts::GetAccountRoot(rAccount);
ASSERT(RootDir[RootDir.size() - 1] == '/' ||
RootDir[RootDir.size() - 1] == DIRECTORY_SEPARATOR_ASCHAR);
std::string fn(RootDir + REFCOUNT_FILENAME ".db");
RaidFileController &rcontroller(RaidFileController::GetController());
RaidFileDiscSet rdiscSet(rcontroller.GetDiscSet(rAccount.GetDiscSet()));
return RaidFileUtil::MakeWriteFileName(rdiscSet, fn);
}
// --------------------------------------------------------------------------
//
// Function
// Name: BackupStoreRefCountDatabase::Create(int32_t,
// const std::string &, int, bool)
// Purpose: Create a new database, overwriting an existing
// one only if AllowOverwrite is true.
// Created: 2003/08/28
//
// --------------------------------------------------------------------------
void BackupStoreRefCountDatabase::Create(const
BackupStoreAccountDatabase::Entry& rAccount, bool AllowOverwrite)
{
// Initial header
refcount_StreamFormat hdr;
hdr.mMagicValue = htonl(REFCOUNT_MAGIC_VALUE);
hdr.mAccountID = htonl(rAccount.GetID());
// Generate the filename
std::string Filename = GetFilename(rAccount);
// Open the file for writing
if (FileExists(Filename) && !AllowOverwrite)
{
THROW_FILE_ERROR("Failed to overwrite refcount database: "
"not allowed here", Filename, RaidFileException,
CannotOverwriteExistingFile);
}
int flags = O_CREAT | O_BINARY | O_RDWR;
if (!AllowOverwrite)
{
flags |= O_EXCL;
}
std::auto_ptr<FileStream> DatabaseFile(new FileStream(Filename, flags));
// Write header
DatabaseFile->Write(&hdr, sizeof(hdr));
}
// --------------------------------------------------------------------------
//
// Function
// Name: BackupStoreRefCountDatabase::Load(int32_t AccountID,
// BackupStoreAccountDatabase& rAccountDatabase,
// bool ReadOnly);
// Purpose: Loads the info from disc, given the root
// information. Can be marked as read only.
// Created: 2003/08/28
//
// --------------------------------------------------------------------------
std::auto_ptr<BackupStoreRefCountDatabase> BackupStoreRefCountDatabase::Load(
const BackupStoreAccountDatabase::Entry& rAccount, bool ReadOnly)
{
// Generate the filename
std::string filename = GetFilename(rAccount);
int flags = ReadOnly ? O_RDONLY : O_RDWR;
// Open the file for read/write
std::auto_ptr<FileStream> dbfile(new FileStream(filename,
flags | O_BINARY));
// Read in a header
refcount_StreamFormat hdr;
if(!dbfile->ReadFullBuffer(&hdr, sizeof(hdr), 0 /* not interested in bytes read if this fails */))
{
THROW_FILE_ERROR("Failed to read refcount database: "
"short read", filename, BackupStoreException,
CouldNotLoadStoreInfo);
}
// Check it
if(ntohl(hdr.mMagicValue) != REFCOUNT_MAGIC_VALUE ||
(int32_t)ntohl(hdr.mAccountID) != rAccount.GetID())
{
THROW_FILE_ERROR("Failed to read refcount database: "
"bad magic number", filename, BackupStoreException,
BadStoreInfoOnLoad);
}
// Make new object
std::auto_ptr<BackupStoreRefCountDatabase> refcount(new BackupStoreRefCountDatabase(rAccount));
// Put in basic location info
refcount->mReadOnly = ReadOnly;
refcount->mapDatabaseFile = dbfile;
// return it to caller
return refcount;
}
// --------------------------------------------------------------------------
//
// Function
// Name: BackupStoreRefCountDatabase::GetRefCount(int64_t
// ObjectID)
// Purpose: Get the number of references to the specified object
// out of the database
// Created: 2009/06/01
//
// --------------------------------------------------------------------------
BackupStoreRefCountDatabase::refcount_t
BackupStoreRefCountDatabase::GetRefCount(int64_t ObjectID) const
{
IOStream::pos_type offset = GetOffset(ObjectID);
if (GetSize() < offset + GetEntrySize())
{
THROW_FILE_ERROR("Failed to read refcount database: "
"attempted read of unknown refcount for object " <<
BOX_FORMAT_OBJECTID(ObjectID), mFilename,
BackupStoreException, UnknownObjectRefCountRequested);
}
mapDatabaseFile->Seek(offset, SEEK_SET);
refcount_t refcount;
if (mapDatabaseFile->Read(&refcount, sizeof(refcount)) !=
sizeof(refcount))
{
THROW_FILE_ERROR("Failed to read refcount database: "
"short read at offset " << offset, mFilename,
BackupStoreException, CouldNotLoadStoreInfo);
}
return ntohl(refcount);
}
int64_t BackupStoreRefCountDatabase::GetLastObjectIDUsed() const
{
return (GetSize() - sizeof(refcount_StreamFormat)) /
sizeof(refcount_t);
}
void BackupStoreRefCountDatabase::AddReference(int64_t ObjectID)
{
refcount_t refcount;
if (ObjectID > GetLastObjectIDUsed())
{
// new object, assume no previous references
refcount = 0;
}
else
{
// read previous value from database
refcount = GetRefCount(ObjectID);
}
refcount++;
SetRefCount(ObjectID, refcount);
}
void BackupStoreRefCountDatabase::SetRefCount(int64_t ObjectID,
refcount_t NewRefCount)
{
IOStream::pos_type offset = GetOffset(ObjectID);
mapDatabaseFile->Seek(offset, SEEK_SET);
refcount_t RefCountNetOrder = htonl(NewRefCount);
mapDatabaseFile->Write(&RefCountNetOrder, sizeof(RefCountNetOrder));
}
bool BackupStoreRefCountDatabase::RemoveReference(int64_t ObjectID)
{
refcount_t refcount = GetRefCount(ObjectID); // must exist in database
ASSERT(refcount > 0);
refcount--;
SetRefCount(ObjectID, refcount);
return (refcount > 0);
}
|
