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
|
/***************************************************************************
* Copyright (C) 2005 by Joris Guisson *
* [email protected] *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* 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 General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. *
***************************************************************************/
#ifndef BTMMAPFILE_H
#define BTMMAPFILE_H
#include <tqstring.h>
#include <util/constants.h>
namespace bt
{
/**
* @author Joris Guisson
* @brief Memory mapped file
*
* This class allows to access memory mapped files. It's pretty similar to
* File.
* TODO: make sure large files work (not really needed for the blocklist)
*/
class MMapFile
{
public:
MMapFile();
virtual ~MMapFile();
enum Mode
{
READ,WRITE, RW
};
/**
* Open the file. If mode is write and the file doesn't exist, it will
* be created.
* @param file Filename
* @param mode Mode (READ, WRITE or RW)
* @return true upon succes
*/
bool open(const TQString & file,Mode mode);
/**
* Open the file. If mode is write and the file doesn't exist, it will
* be created.
* @param file Filename
* @param mode Mode (READ, WRITE or RW)
* @param size Size of the memory mapping (the file will be enlarged to this value)
* @return true upon succes
*/
bool open(const TQString & file,Mode mode,Uint64 size);
/**
* Close the file. Undoes the memory mapping.
*/
void close();
/**
* Flush the file.
*/
void flush();
/**
* Write a bunch of data.
* @param buf The data
* @param size Size of the data
* @return The number of bytes written
*/
Uint32 write(const void* buf,Uint32 size);
/**
* Read a bunch of data
* @param buf The buffer to store the data
* @param size Size of the buffer
* @return The number of bytes read
*/
Uint32 read(void* buf,Uint32 size);
enum SeekPos
{
BEGIN,
END,
CURRENT
};
/**
* Seek in the file.
* @param from Position to seek from
* @param num Number of bytes to move
* @return New position
*/
Uint64 seek(SeekPos from,Int64 num);
/// Check to see if we are at the end of the file.
bool eof() const;
/// Get the current position in the file.
Uint64 tell() const;
/// Get the error string.
TQString errorString() const;
/// Get the file size
Uint64 getSize() const;
/**
* Get a pointer to the mmapped region of data.
* @param off Offset into buffer, if invalid 0 will be returned
* @return Pointer to a location in the mmapped region
*/
Uint8* getData(Uint64 off);
/// Gets the data pointer
void* getDataPointer() { return data; }
private:
void growFile(Uint64 new_size);
private:
int fd;
Uint8* data;
Uint64 size; // size of mmapping
Uint64 file_size; // size of file
Uint64 ptr;
TQString filename;
Mode mode;
};
}
#endif
|