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

wpinet/src/main/native/cpp/raw_socket_istream.cpp

@@ -0,0 +1,33 @@
+// 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/raw_socket_istream.h"
+
+#include "wpinet/NetworkStream.h"
+
+using namespace wpi;
+
+void raw_socket_istream::read_impl(void* data, size_t len) {
+  char* cdata = static_cast<char*>(data);
+  size_t pos = 0;
+
+  while (pos < len) {
+    NetworkStream::Error err;
+    size_t count = m_stream.receive(&cdata[pos], len - pos, &err, m_timeout);
+    if (count == 0) {
+      error_detected();
+      break;
+    }
+    pos += count;
+  }
+  set_read_count(pos);
+}
+
+void raw_socket_istream::close() {
+  m_stream.close();
+}
+
+size_t raw_socket_istream::in_avail() const {
+  return 0;
+}