split out non-HTTP server parts

Author: arnej27959

tools/server/http-utils.hpp

@@ -0,0 +1,19 @@
+
+// increase max payload length to allow use of larger context size
+#define CPPHTTPLIB_FORM_URL_ENCODED_PAYLOAD_MAX_LENGTH 1048576
+// increase backlog size to avoid connection resets for >> 1 slots
+#define CPPHTTPLIB_LISTEN_BACKLOG 512
+// disable Nagle's algorithm
+#define CPPHTTPLIB_TCP_NODELAY true
+#include <cpp-httplib/httplib.h>
+
+static bool server_sent_event(httplib::DataSink & sink, const json & data) {
+    const std::string str =
+        "data: " +
+        data.dump(-1, ' ', false, json::error_handler_t::replace) +
+        "\n\n"; // required by RFC 8895 - A message is terminated by a blank line (two line terminators in a row).
+
+    LOG_DBG("data stream, to_send: %s", str.c_str());
+
+    return sink.write(str.c_str(), str.size());
+}