| #include <atomic> |
| #include <chrono> |
| #include <condition_variable> |
| #include <httplib.h> |
| #include <iostream> |
| #include <mutex> |
| #include <sstream> |
| #include <thread> |
| |
| using namespace httplib; |
| using namespace std; |
| |
| class EventDispatcher { |
| public: |
| EventDispatcher() { |
| } |
| |
| void wait_event(DataSink *sink) { |
| unique_lock<mutex> lk(m_); |
| int id = id_; |
| cv_.wait(lk, [&] { return cid_ == id; }); |
| sink->write(message_.data(), message_.size()); |
| } |
| |
| void send_event(const string &message) { |
| lock_guard<mutex> lk(m_); |
| cid_ = id_++; |
| message_ = message; |
| cv_.notify_all(); |
| } |
| |
| private: |
| mutex m_; |
| condition_variable cv_; |
| atomic_int id_{0}; |
| atomic_int cid_{-1}; |
| string message_; |
| }; |
| |
| const auto html = R"( |
| <!DOCTYPE html> |
| <html lang="en"> |
| <head> |
| <meta charset="UTF-8"> |
| <title>SSE demo</title> |
| </head> |
| <body> |
| <script> |
| const ev1 = new EventSource("event1"); |
| ev1.onmessage = function(e) { |
| console.log('ev1', e.data); |
| } |
| const ev2 = new EventSource("event2"); |
| ev2.onmessage = function(e) { |
| console.log('ev2', e.data); |
| } |
| </script> |
| </body> |
| </html> |
| )"; |
| |
| int main(void) { |
| EventDispatcher ed; |
| |
| Server svr; |
| |
| svr.Get("/", [&](const Request & /*req*/, Response &res) { |
| res.set_content(html, "text/html"); |
| }); |
| |
| svr.Get("/event1", [&](const Request & /*req*/, Response &res) { |
| cout << "connected to event1..." << endl; |
| res.set_chunked_content_provider("text/event-stream", |
| [&](size_t /*offset*/, DataSink &sink) { |
| ed.wait_event(&sink); |
| return true; |
| }); |
| }); |
| |
| svr.Get("/event2", [&](const Request & /*req*/, Response &res) { |
| cout << "connected to event2..." << endl; |
| res.set_chunked_content_provider("text/event-stream", |
| [&](size_t /*offset*/, DataSink &sink) { |
| ed.wait_event(&sink); |
| return true; |
| }); |
| }); |
| |
| thread t([&] { |
| int id = 0; |
| while (true) { |
| this_thread::sleep_for(chrono::seconds(1)); |
| cout << "send event: " << id << std::endl; |
| std::stringstream ss; |
| ss << "data: " << id << "\n\n"; |
| ed.send_event(ss.str()); |
| id++; |
| } |
| }); |
| |
| svr.listen("localhost", 1234); |
| } |
