Files
rippled/src/test/rpc/Handler_test.cpp

120 lines
3.4 KiB
C++

#include <test/jtx/TestHelpers.h>
#include <xrpld/rpc/detail/Handler.h>
#include <xrpl/beast/unit_test/suite.h>
#include <algorithm>
#include <array>
#include <cassert>
#include <chrono>
#include <cmath>
#include <cstddef>
#include <iostream>
#include <random>
#include <tuple>
#include <vector>
// cspell: words stdev
namespace xrpl::test {
// NOTE: there should be no need for this function;
// `std::cout << some_duration` should just work if built with a compliant
// C++20 compiler. Sadly, we are not using one, as of today
// TODO: remove this operator<< overload when we bump compiler version
std::ostream&
operator<<(std::ostream& os, std::chrono::nanoseconds ns)
{
return (os << ns.count() << "ns");
}
// NOTE This is a rather naive effort at a microbenchmark. Ideally we want
// Google Benchmark, or something similar. Also, this actually does not belong
// to unit tests, as it makes little sense to run it in conditions very
// dissimilar to how xrpld will normally work.
// TODO as https://github.com/XRPLF/rippled/issues/4765
class Handler_test : public beast::unit_test::Suite
{
auto
time(std::size_t n, auto f, auto prng) -> auto
{
using clock = std::chrono::steady_clock;
assert(n > 0);
double sum = 0;
double sumSquared = 0;
std::size_t j = 0;
while (j < n)
{
// Generate 100 inputs upfront, separated from the inner loop
std::array<decltype(prng()), 100> inputs = {};
for (auto& i : inputs)
{
i = prng();
}
// Take 100 samples, then sort and throw away 35 from each end,
// using only middle 30. This helps to reduce measurement noise.
std::array<long, 100> samples = {};
for (std::size_t k = 0; k < 100; ++k)
{
auto start = std::chrono::steady_clock::now();
f(inputs[k]);
samples[k] = (std::chrono::steady_clock::now() - start).count();
}
std::ranges::sort(samples);
for (std::size_t k = 35; k < 65; ++k)
{
j += 1;
sum += samples[k];
sumSquared += (samples[k] * samples[k]);
}
}
double const meanSquared = (sum * sum) / (j * j);
return std::make_tuple(
clock::duration{static_cast<long>(sum / j)},
clock::duration{static_cast<long>(std::sqrt((sumSquared / j) - meanSquared))},
j);
}
void
reportLookupPerformance()
{
testcase("Handler lookup performance");
std::random_device dev;
std::ranlux48 prng(dev());
std::vector<char const*> names = test::jtx::makeVector(xrpl::RPC::getHandlerNames());
std::uniform_int_distribution<std::size_t> distr{0, names.size() - 1};
std::size_t dummy = 0;
auto const [mean, stdev, n] = time(
1'000'000,
[&](std::size_t i) {
auto const d = RPC::getHandler(1, false, names[i]);
dummy = dummy + i + (int)d->role;
},
[&]() -> std::size_t { return distr(prng); });
std::cout << "mean=" << mean << " stdev=" << stdev << " N=" << n << '\n';
BEAST_EXPECT(dummy != 0);
}
public:
void
run() override
{
reportLookupPerformance();
}
};
BEAST_DEFINE_TESTSUITE_MANUAL(Handler, rpc, xrpl);
} // namespace xrpl::test