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
|
#include <chrono>
#include <cstdlib>
#include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include "gsd.h"
int main(int argc, char** argv) // NOLINT
{
const size_t n_keys = 2048;
const size_t max_frames = 100;
std::vector<char> data;
std::vector<std::string> names;
for (size_t i = 0; i < n_keys; i++)
{
std::ostringstream s;
s << "key " << i;
names.push_back(s.str());
}
gsd_handle handle;
auto t1 = std::chrono::high_resolution_clock::now();
gsd_open(&handle, "test.gsd", GSD_OPEN_READONLY);
auto t2 = std::chrono::high_resolution_clock::now();
auto const open_time = std::chrono::duration_cast<std::chrono::duration<double>>(t2 - t1);
std::cout << "Time to open: " << open_time.count() / 1e-6 << " microseconds\n";
size_t const n_frames = gsd_get_nframes(&handle);
size_t n_read = n_frames;
if (n_read > max_frames)
{
n_read = max_frames;
}
std::cout << "Reading test.gsd with: " << n_keys << " keys and " << n_frames << " frames."
<< '\n';
t1 = std::chrono::high_resolution_clock::now();
size_t total_bytes = 0;
for (size_t frame = 0; frame < n_read; frame++)
{
for (auto const& name : names)
{
const gsd_index_entry* e;
e = gsd_find_chunk(&handle, frame, name.c_str());
if (e == nullptr)
{
std::cout << "ERROR: Chunk `" << name << "` not found\n";
exit(1);
}
if (data.empty())
{
data.resize(e->N * e->M * gsd_sizeof_type((gsd_type)e->type));
}
total_bytes += e->N * e->M * gsd_sizeof_type((gsd_type)e->type);
gsd_read_chunk(&handle, data.data(), e);
}
}
t2 = std::chrono::high_resolution_clock::now();
auto const time_span = std::chrono::duration_cast<std::chrono::duration<double>>(t2 - t1);
double const time_per_key = time_span.count() / double(n_keys) / double(n_read);
double const us_per_key = time_per_key / 1e-6;
std::cout << "Sequential latency : " << us_per_key << " microseconds/key.\n";
std::cout << "Sequential throughput: "
<< double(total_bytes) / 1024.0 / 1024.0 / time_span.count() << " MB/s\n";
gsd_close(&handle);
}
|
