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
|
// distribution boxbackup-0.10 (svn version: 494)
//
// Copyright (c) 2003 - 2006
// Ben Summers and contributors. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// 3. All use of this software and associated advertising materials must
// display the following acknowledgment:
// This product includes software developed by Ben Summers.
// 4. The names of the Authors may not be used to endorse or promote
// products derived from this software without specific prior written
// permission.
//
// [Where legally impermissible the Authors do not disclaim liability for
// direct physical injury or death caused solely by defects in the software
// unless it is modified by a third party.]
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT,
// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
//
//
// --------------------------------------------------------------------------
//
// File
// Name: RaidFileUtil.cpp
// Purpose: Utilities for raid files
// Created: 2003/07/11
//
// --------------------------------------------------------------------------
#include "Box.h"
#include <sys/types.h>
#include <sys/stat.h>
#include "RaidFileUtil.h"
#include "FileModificationTime.h"
#include "RaidFileRead.h" // for type definition
#include "MemLeakFindOn.h"
// --------------------------------------------------------------------------
//
// Function
// Name: RaidFileUtil::RaidFileExists(RaidFileDiscSet &, const std::string &)
// Purpose: Check to see the state of a RaidFile on disc (doesn't look at contents,
// just at existense of files)
// Created: 2003/07/11
//
// --------------------------------------------------------------------------
RaidFileUtil::ExistType RaidFileUtil::RaidFileExists(RaidFileDiscSet &rDiscSet, const std::string &rFilename, int *pStartDisc, int *pExisitingFiles, int64_t *pRevisionID)
{
if(pExisitingFiles)
{
*pExisitingFiles = 0;
}
// For stat call, although the results are not examined
struct stat st;
// check various files
int startDisc = 0;
{
std::string writeFile(RaidFileUtil::MakeWriteFileName(rDiscSet, rFilename, &startDisc));
if(pStartDisc)
{
*pStartDisc = startDisc;
}
if(::stat(writeFile.c_str(), &st) == 0)
{
// write file exists, use that
// Get unique ID
if(pRevisionID != 0)
{
(*pRevisionID) = FileModificationTime(st);
#ifndef HAVE_STRUCT_STAT_ST_MTIMESPEC
// On linux, the time resolution is very low for modification times.
// So add the size to it to give a bit more chance of it changing.
// TODO: Make this better.
(*pRevisionID) += st.st_size;
#endif
}
// return non-raid file
return NonRaid;
}
}
// Now see how many of the raid components exist
int64_t revisionID = 0;
int setSize = rDiscSet.size();
int rfCount = 0;
#ifndef HAVE_STRUCT_STAT_ST_MTIMESPEC
// TODO: replace this with better linux revision ID detection
int64_t revisionIDplus = 0;
#endif
for(int f = 0; f < setSize; ++f)
{
std::string componentFile(RaidFileUtil::MakeRaidComponentName(rDiscSet, rFilename, (f + startDisc) % setSize));
if(::stat(componentFile.c_str(), &st) == 0)
{
// Component file exists, add to count
rfCount++;
// Set flags for existance?
if(pExisitingFiles)
{
(*pExisitingFiles) |= (1 << f);
}
// Revision ID
if(pRevisionID != 0)
{
int64_t rid = FileModificationTime(st);
if(rid > revisionID) revisionID = rid;
#ifndef HAVE_STRUCT_STAT_ST_MTIMESPEC
revisionIDplus += st.st_size;
#endif
}
}
}
if(pRevisionID != 0)
{
(*pRevisionID) = revisionID;
#ifndef HAVE_STRUCT_STAT_ST_MTIMESPEC
(*pRevisionID) += revisionIDplus;
#endif
}
// Return a status based on how many parts are available
if(rfCount == setSize)
{
return AsRaid;
}
else if((setSize > 1) && rfCount == (setSize - 1))
{
return AsRaidWithMissingReadable;
}
else if(rfCount > 0)
{
return AsRaidWithMissingNotRecoverable;
}
return NoFile; // Obviously doesn't exist
}
// --------------------------------------------------------------------------
//
// Function
// Name: RaidFileUtil::DiscUsageInBlocks(int64_t, const RaidFileDiscSet &)
// Purpose: Returns the size of the file in blocks, given the file size and disc set
// Created: 2003/09/03
//
// --------------------------------------------------------------------------
int64_t RaidFileUtil::DiscUsageInBlocks(int64_t FileSize, const RaidFileDiscSet &rDiscSet)
{
// Get block size
int blockSize = rDiscSet.GetBlockSize();
// OK... so as the size of the file is always sizes of stripe1 + stripe2, we can
// do a very simple calculation for the main data.
int64_t blocks = (FileSize + (((int64_t)blockSize) - 1)) / ((int64_t)blockSize);
// It's just that simple calculation for non-RAID disc sets
if(rDiscSet.IsNonRaidSet())
{
return blocks;
}
// It's the parity which is mildly complex.
// First of all, add in size for all but the last two blocks.
int64_t parityblocks = (FileSize / ((int64_t)blockSize)) / 2;
blocks += parityblocks;
// Work out how many bytes are left
int bytesOver = (int)(FileSize - (parityblocks * ((int64_t)(blockSize*2))));
// Then... (let compiler optimise this out)
if(bytesOver == 0)
{
// Extra block for the size info
blocks++;
}
else if(bytesOver == sizeof(RaidFileRead::FileSizeType))
{
// For last block of parity, plus the size info
blocks += 2;
}
else if(bytesOver < blockSize)
{
// Just want the parity block
blocks += 1;
}
else if(bytesOver == blockSize || bytesOver >= ((blockSize*2)-((int)sizeof(RaidFileRead::FileSizeType))))
{
// Last block, plus size info
blocks += 2;
}
else
{
// Just want parity block
blocks += 1;
}
return blocks;
}
|
