Repo created

libs/storage/pinger.cpp

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+#include "storage/pinger.hpp"
+
+#include "platform/http_client.hpp"
+
+#include "base/assert.hpp"
+#include "base/logging.hpp"
+#include "base/thread_pool_delayed.hpp"
+
+#include <chrono>
+
+namespace pinger
+{
+auto constexpr kTimeoutInSeconds = 4.0;
+int64_t constexpr kInvalidPing = -1;
+
+int64_t DoPing(std::string const & url)
+{
+  using namespace std::chrono;
+
+  if (url.empty())
+  {
+    ASSERT(false, ("Metaserver returned an empty url."));
+    return kInvalidPing;
+  }
+
+  LOG(LDEBUG, ("Pinging server", url));
+  platform::HttpClient request(url);
+  request.SetHttpMethod("HEAD");
+  request.SetTimeout(kTimeoutInSeconds);
+  auto const begin = high_resolution_clock::now();
+  if (request.RunHttpRequest() && !request.WasRedirected() && request.ErrorCode() == 200)
+  {
+    return duration_cast<milliseconds>(high_resolution_clock::now() - begin).count();
+  }
+  else
+  {
+    LOG(LWARNING, ("Ping to server", url, "failed with code =", request.ErrorCode(),
+                   "; wasRedirected =", request.WasRedirected()));
+  }
+
+  return kInvalidPing;
+}
+}  // namespace pinger
+
+namespace storage
+{
+// static
+Pinger::Endpoints Pinger::ExcludeUnavailableAndSortEndpoints(Endpoints const & urls)
+{
+  auto const size = urls.size();
+  CHECK_GREATER(size, 0, ());
+
+  using EntryT = std::pair<int64_t, size_t>;
+  std::vector<EntryT> timeUrls(size, {pinger::kInvalidPing, 0});
+  {
+    base::DelayedThreadPool pool(size, base::DelayedThreadPool::Exit::ExecPending);
+    for (size_t i = 0; i < size; ++i)
+      pool.Push([&urls, &timeUrls, i] { timeUrls[i] = {pinger::DoPing(urls[i]), i}; });
+  }
+
+  std::sort(timeUrls.begin(), timeUrls.end(), [](EntryT const & e1, EntryT const & e2) { return e1.first < e2.first; });
+
+  Endpoints readyUrls;
+  for (auto const & [ping, index] : timeUrls)
+    if (ping >= 0)
+      readyUrls.push_back(urls[index]);
+
+  return readyUrls;
+}
+}  // namespace storage