blob: 7ea1c9f700f36a1f3c15d196a498d6f6a20cc61e (
plain)
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
|
#ifndef UTIL_STREAM_STREAM_H
#define UTIL_STREAM_STREAM_H
#include "util/stream/chain.hh"
#include <boost/noncopyable.hpp>
#include <assert.h>
#include <stdint.h>
namespace util {
namespace stream {
class Stream : boost::noncopyable {
public:
Stream() : current_(NULL), end_(NULL) {}
void Init(const ChainPosition &position) {
entry_size_ = position.GetChain().EntrySize();
block_size_ = position.GetChain().BlockSize();
block_it_.Init(position);
StartBlock();
}
explicit Stream(const ChainPosition &position) {
Init(position);
}
operator bool() const { return current_ != NULL; }
bool operator!() const { return current_ == NULL; }
const void *Get() const { return current_; }
void *Get() { return current_; }
void Poison() {
block_it_->SetValidSize(current_ - static_cast<uint8_t*>(block_it_->Get()));
++block_it_;
block_it_.Poison();
}
Stream &operator++() {
assert(*this);
assert(current_ < end_);
current_ += entry_size_;
if (current_ == end_) {
++block_it_;
StartBlock();
}
return *this;
}
private:
void StartBlock() {
for (; block_it_ && !block_it_->ValidSize(); ++block_it_) {}
current_ = static_cast<uint8_t*>(block_it_->Get());
end_ = current_ + block_it_->ValidSize();
}
// The following are pointers to raw memory
// current_ is the current record
// end_ is the end of the block (so we know when to move to the next block)
uint8_t *current_, *end_;
std::size_t entry_size_;
std::size_t block_size_;
Link block_it_;
};
inline Chain &operator>>(Chain &chain, Stream &stream) {
stream.Init(chain.Add());
return chain;
}
} // namespace stream
} // namespace util
#endif // UTIL_STREAM_STREAM_H
|
