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

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

@@ -0,0 +1,35 @@
+// 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/Handle.h"
+
+using namespace wpi::uv;
+
+Handle::~Handle() noexcept {
+  if (!m_closed && m_uv_handle->type != UV_UNKNOWN_HANDLE) {
+    uv_close(m_uv_handle, [](uv_handle_t* uv_handle) { std::free(uv_handle); });
+  } else {
+    std::free(m_uv_handle);
+  }
+}
+
+void Handle::Close() noexcept {
+  if (!IsClosing()) {
+    uv_close(m_uv_handle, [](uv_handle_t* handle) {
+      Handle& h = *static_cast<Handle*>(handle->data);
+      h.closed();
+      h.Release();  // free ourselves
+    });
+    m_closed = true;
+  }
+}
+
+void Handle::AllocBuf(uv_handle_t* handle, size_t size, uv_buf_t* buf) {
+  auto& h = *static_cast<Handle*>(handle->data);
+  *buf = h.m_allocBuf(size);
+}
+
+void Handle::DefaultFreeBuf(Buffer& buf) {
+  buf.Deallocate();
+}