[wpinet] Move network portions of wpiutil into new wpinet library (#4077)

wpinet/src/main/native/cpp/uv/GetAddrInfo.cpp

@@ -0,0 +1,52 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include "wpinet/uv/GetAddrInfo.h"
+
+#include <wpi/SmallString.h>
+
+#include "wpinet/uv/Loop.h"
+#include "wpinet/uv/util.h"
+
+namespace wpi::uv {
+
+GetAddrInfoReq::GetAddrInfoReq() {
+  error = [this](Error err) { GetLoop().error(err); };
+}
+
+void GetAddrInfo(Loop& loop, const std::shared_ptr<GetAddrInfoReq>& req,
+                 std::string_view node, std::string_view service,
+                 const addrinfo* hints) {
+  SmallString<128> nodeStr{node};
+  SmallString<128> serviceStr{service};
+  int err = uv_getaddrinfo(
+      loop.GetRaw(), req->GetRaw(),
+      [](uv_getaddrinfo_t* req, int status, addrinfo* res) {
+        auto& h = *static_cast<GetAddrInfoReq*>(req->data);
+        if (status < 0) {
+          h.ReportError(status);
+        } else {
+          h.resolved(*res);
+        }
+        uv_freeaddrinfo(res);
+        h.Release();  // this is always a one-shot
+      },
+      node.empty() ? nullptr : nodeStr.c_str(),
+      service.empty() ? nullptr : serviceStr.c_str(), hints);
+  if (err < 0) {
+    loop.ReportError(err);
+  } else {
+    req->Keep();
+  }
+}
+
+void GetAddrInfo(Loop& loop, std::function<void(const addrinfo&)> callback,
+                 std::string_view node, std::string_view service,
+                 const addrinfo* hints) {
+  auto req = std::make_shared<GetAddrInfoReq>();
+  req->resolved.connect(std::move(callback));
+  GetAddrInfo(loop, req, node, service, hints);
+}
+
+}  // namespace wpi::uv