Add wpi::HttpServerConnection and an example of its use (#1281)

2026-06-20 00:51:42 +00:00 · 2018-08-20 13:11:39 -07:00
parent 7b95c5341a
commit 9e37ee13de
4 changed files with 362 additions and 0 deletions
--- a/wpiutil/src/main/native/cpp/HttpServerConnection.cpp
+++ b/wpiutil/src/main/native/cpp/HttpServerConnection.cpp
@@ -0,0 +1,126 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2018 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "wpi/HttpServerConnection.h"
+
+#include "wpi/SmallString.h"
+#include "wpi/SmallVector.h"
+#include "wpi/raw_uv_ostream.h"
+
+using namespace wpi;
+
+HttpServerConnection::HttpServerConnection(std::shared_ptr<uv::Stream> stream)
+    : m_stream(*stream) {
+  // process HTTP messages
+  m_request.messageComplete.connect([this](bool keepAlive) {
+    m_keepAlive = keepAlive;
+    ProcessRequest();
+  });
+
+  // pass incoming data to HTTP parser
+  stream->data.connect([this](uv::Buffer& buf, size_t size) {
+    m_request.Execute(StringRef{buf.base, size});
+    if (m_request.HasError()) {
+      // could not parse; just close the connection
+      m_stream.Close();
+    }
+  });
+
+  // close when remote side closes
+  stream->end.connect([h = stream.get()] { h->Close(); });
+
+  // start reading
+  stream->StartRead();
+}
+
+void HttpServerConnection::BuildCommonHeaders(raw_ostream& os) {
+  os << "Server: WebServer/1.0\r\n"
+        "Cache-Control: no-store, no-cache, must-revalidate, pre-check=0, "
+        "post-check=0, max-age=0\r\n"
+        "Pragma: no-cache\r\n"
+        "Expires: Mon, 3 Jan 2000 12:34:56 GMT\r\n";
+}
+
+void HttpServerConnection::BuildHeader(raw_ostream& os, int code,
+                                       const Twine& codeText,
+                                       const Twine& contentType,
+                                       uint64_t contentLength,
+                                       const Twine& extra) {
+  os << "HTTP/" << m_request.GetMajor() << '.' << m_request.GetMinor() << ' '
+     << code << ' ' << codeText << "\r\n";
+  if (contentLength == 0) m_keepAlive = false;
+  if (!m_keepAlive) os << "Connection: close\r\n";
+  BuildCommonHeaders(os);
+  os << "Content-Type: " << contentType << "\r\n";
+  if (contentLength != 0) os << "Content-Length: " << contentLength << "\r\n";
+  os << "Access-Control-Allow-Origin: *\r\nAccess-Control-Allow-Methods: *\r\n";
+  SmallString<128> extraBuf;
+  StringRef extraStr = extra.toStringRef(extraBuf);
+  if (!extraStr.empty()) os << extraStr << "\r\n";
+  os << "\r\n";  // header ends with a blank line
+}
+
+void HttpServerConnection::SendData(ArrayRef<uv::Buffer> bufs,
+                                    bool closeAfter) {
+  m_stream.Write(bufs, [ closeAfter, stream = &m_stream ](
+                           MutableArrayRef<uv::Buffer> bufs, uv::Error) {
+    for (auto&& buf : bufs) buf.Deallocate();
+    if (closeAfter) stream->Close();
+  });
+}
+
+void HttpServerConnection::SendResponse(int code, const Twine& codeText,
+                                        const Twine& contentType,
+                                        StringRef content,
+                                        const Twine& extraHeader) {
+  SmallVector<uv::Buffer, 4> toSend;
+  raw_uv_ostream os{toSend, 4096};
+  BuildHeader(os, code, codeText, contentType, content.size(), extraHeader);
+  os << content;
+  // close after write completes if we aren't keeping alive
+  SendData(os.bufs(), !m_keepAlive);
+}
+
+void HttpServerConnection::SendError(int code, const Twine& message) {
+  StringRef codeText, extra, baseMessage;
+  switch (code) {
+    case 401:
+      codeText = "Unauthorized";
+      extra = "WWW-Authenticate: Basic realm=\"CameraServer\"";
+      baseMessage = "401: Not Authenticated!";
+      break;
+    case 404:
+      codeText = "Not Found";
+      baseMessage = "404: Not Found!";
+      break;
+    case 500:
+      codeText = "Internal Server Error";
+      baseMessage = "500: Internal Server Error!";
+      break;
+    case 400:
+      codeText = "Bad Request";
+      baseMessage = "400: Not Found!";
+      break;
+    case 403:
+      codeText = "Forbidden";
+      baseMessage = "403: Forbidden!";
+      break;
+    case 503:
+      codeText = "Service Unavailable";
+      baseMessage = "503: Service Unavailable";
+      break;
+    default:
+      code = 501;
+      codeText = "Not Implemented";
+      baseMessage = "501: Not Implemented!";
+      break;
+  }
+  SmallString<256> content = baseMessage;
+  content += "\r\n";
+  message.toVector(content);
+  SendResponse(code, codeText, "text/plain", content, extra);
+}