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
|
#ifndef REORDERED_FILE_BUFFER_H
#define REORDERED_FILE_BUFFER_H
#include <fstream>
#include <vector>
#include <set>
#include "../util/logger.h"
class ReorderedFileBuffer
{
public:
ReorderedFileBuffer(std::ofstream* stream, size_t maxSize) :
_nextWritePos(0), _unflushedSize(0), _maxSize(maxSize), _stream(stream)
{
}
~ReorderedFileBuffer()
{
flush();
}
void seekp(size_t offset)
{
_nextWritePos = offset;
}
void write(const char* data, size_t length)
{
_buffer.insert(BufferEntry(_nextWritePos, data, length));
_nextWritePos += length;
_unflushedSize += length + sizeof(_nextWritePos)*2;
if(_unflushedSize > _maxSize)
flush();
}
void flush()
{
Logger::Debug << "Flushing reordered file buffer...\n";
for(std::set<BufferEntry>::const_iterator i=_buffer.begin(); i!=_buffer.end(); ++i)
{
_stream->seekp(i->position, std::ios_base::beg);
_stream->write(i->data.data(), i->data.size());
if(_stream->fail())
throw std::runtime_error("Error: failed to write to reordered file! Check access rights and free disk space.");
}
_buffer.clear();
_unflushedSize = 0;
}
std::ofstream& stream() { return *_stream; }
private:
struct BufferEntry {
BufferEntry(size_t pos_, const char* data_, size_t length_) :
position(pos_),
data(data_, data_ + length_)
{ }
bool operator<(const BufferEntry& other) const
{
return position < other.position;
}
size_t position;
std::vector<char> data;
};
std::set<BufferEntry> _buffer;
size_t _nextWritePos;
size_t _unflushedSize;
size_t _maxSize;
std::ofstream* _stream;
};
#endif
|
