best method for SSE

example/server_sse.cc

@@ -0,0 +1,59 @@
+#include <filesystem>
+#include <getopt.h>
+#include <httplib.h>
+#include <iostream>
+#include <map>
+#include <nlohmann/json.hpp>
+#include <unistd.h>
+
+#define HTTP_SERVER_PORT 1234
+
+using namespace std;
+
+map<socket_t, httplib::detail::SseEmitter> sseEmitterMap;
+
+int main(int argc, char *argv[]) {
+
+  httplib::Server svr;
+  svr.set_default_headers({
+      {"Access-Control-Allow-Origin", "*"},
+      {"Access-Control-Allow-Methods", "POST, GET, PUT, OPTIONS,PATCH, DELETE"},
+      {"Access-Control-Max-Age", "3600"},
+      {"Access-Control-Allow-Headers", "*"},
+  });
+
+  svr.Options(R"(/.+)", [](const auto &req, auto &res) {
+    res.set_header("Allow", "GET, POST, HEAD,PATCH, OPTIONS");
+  });
+
+  svr.Get("/sse", [](const httplib::Request &req, httplib::Response &res) {
+    string data = "event: log\nid: 0\ndata: sse test\nretry: 3000\n\n\n";
+    res.set_content(data, "text/event-stream; charset=UTF-8");
+    httplib::detail::SseEmitter sseEmitter(req.sock_fd);
+    sseEmitterMap[req.sock_fd] = sseEmitter;
+  });
+  thread t([] {
+    int id = 1;
+    while (true) {
+      this_thread::sleep_for(chrono::seconds(1));
+      if (sseEmitterMap.size() < 1) { continue; }
+      cout << "send event: " << id << std::endl;
+      vector<socket_t> clearSocktFds;
+      for (auto sseEmitter : sseEmitterMap) {
+        sseEmitter.second.id = id;
+        sseEmitter.second.event = "message";
+        sseEmitter.second.data = "test ==> " + to_string(id);
+        if (sseEmitter.second.send() == -1) {
+          clearSocktFds.push_back(sseEmitter.first);
+        }
+      }
+      for (auto k : clearSocktFds) {
+        sseEmitterMap.erase(k);
+      }
+      id++;
+    }
+  });
+  t.detach();
+  svr.listen("0.0.0.0", HTTP_SERVER_PORT);
+  return 0;
+}