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
|
// #include "../lz4/lz4.h"
#include <cstddef>
#include <vector>
#include <iostream>
#include <cstdlib>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <cstring>
const std::size_t S = 1 << 20;
void fill_seq(std::vector<char>& buf) {
unsigned char c = 0;
char* p = buf.data();
for( std::size_t i = 0; i < S; ++i ) {
*p = c++;
}
}
void fill_random(std::vector<char>& buf) {
int fd = open("/dev/urandom", O_RDONLY);
if( fd == -1 ) {
std::cerr << "failed to open /dev/urandom" << std::endl;
std::exit(1);
}
std::size_t to_read = S;
char* p = buf.data();
while( to_read != 0 ) {
ssize_t n = read(fd, p, to_read);
if( n == -1 ) {
std::cerr << "failed to read from /dev/urandom" << std::endl;
std::exit(1);
}
p += n;
to_read -= n;
}
close(fd);
}
int main(int argc, char** argv) {
// std::vector<char> buf1(S);
// fill_seq(buf1);
// //fill_random(buf1);
// std::vector<char> buf2(S);
// std::vector<char> cbuf(LZ4_COMPRESSBOUND(S));
// std::cout << "cbuf size = " << cbuf.size() << std::endl;
// int csize = LZ4_compress(buf1.data(), cbuf.data(), S);
// if( csize == 0 ) {
// std::cerr << "compression failed." << std::endl;
// return 1;
// }
// std::cout << "compressed: " << csize << " bytes." << std::endl;
// // beware that the third parameter is the *uncompressed* size.
// int csize2 = LZ4_decompress_fast(cbuf.data(), buf2.data(), S);
// if( csize != csize2 ) {
// std::cerr << "wtf!?" << std::endl;
// return 1;
// }
// if( std::memcmp(buf1.data(), buf2.data(), S) != 0 ) {
// std::cerr << "verify failed." << std::endl;
// return 1;
// }
// std::cout << "verify ok." << std::endl;
return 0;
}
|
