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| 1 | +// |
| 2 | +// sse.cc |
| 3 | +// |
| 4 | +// Copyright (c) 2020 Yuji Hirose. All rights reserved. |
| 5 | +// MIT License |
| 6 | +// |
| 7 | + |
| 8 | +#include <atomic> |
| 9 | +#include <chrono> |
| 10 | +#include <condition_variable> |
| 11 | +#include <httplib.h> |
| 12 | +#include <iostream> |
| 13 | +#include <mutex> |
| 14 | +#include <thread> |
| 15 | + |
| 16 | +using namespace httplib; |
| 17 | +using namespace std; |
| 18 | + |
| 19 | +class EventDispatcher { |
| 20 | +public: |
| 21 | + EventDispatcher() { |
| 22 | + id_ = 0; |
| 23 | + cid_ = -1; |
| 24 | + } |
| 25 | + |
| 26 | + void add_sink(DataSink *sink) { |
| 27 | + unique_lock<mutex> lk(m_); |
| 28 | + int id = id_; |
| 29 | + cv_.wait(lk, [&] { return cid_ == id; }); |
| 30 | + if (sink->is_writable()) { sink->write(message_.data(), message_.size()); } |
| 31 | + } |
| 32 | + |
| 33 | + void send_event(const string &message) { |
| 34 | + lock_guard<mutex> lk(m_); |
| 35 | + cid_ = id_++; |
| 36 | + message_ = message; |
| 37 | + cv_.notify_all(); |
| 38 | + } |
| 39 | + |
| 40 | +private: |
| 41 | + mutex m_; |
| 42 | + condition_variable cv_; |
| 43 | + atomic_int id_; |
| 44 | + atomic_int cid_; |
| 45 | + string message_; |
| 46 | +}; |
| 47 | + |
| 48 | +const auto html = R"( |
| 49 | +<!DOCTYPE html> |
| 50 | +<html lang="en"> |
| 51 | +<head> |
| 52 | +<meta charset="UTF-8"> |
| 53 | +<title>SSE demo</title> |
| 54 | +</head> |
| 55 | +<body> |
| 56 | +<script> |
| 57 | +const ev1 = new EventSource("event1"); |
| 58 | +ev1.onmessage = function(e) { |
| 59 | + console.log('ev1', e.data); |
| 60 | +} |
| 61 | +const ev2 = new EventSource("event2"); |
| 62 | +ev2.onmessage = function(e) { |
| 63 | + console.log('ev2', e.data); |
| 64 | +} |
| 65 | +</script> |
| 66 | +</body> |
| 67 | +</html> |
| 68 | +)"; |
| 69 | + |
| 70 | +int main(void) { |
| 71 | + EventDispatcher ed; |
| 72 | + |
| 73 | + Server svr; |
| 74 | + |
| 75 | + svr.Get("/", [&](const Request & /*req*/, Response &res) { |
| 76 | + res.set_content(html, "text/html"); |
| 77 | + }); |
| 78 | + |
| 79 | + svr.Get("/event1", [&](const Request & /*req*/, Response &res) { |
| 80 | + cout << "connected to event1..." << endl; |
| 81 | + res.set_header("Content-Type", "text/event-stream"); |
| 82 | + res.set_chunked_content_provider( |
| 83 | + [&](uint64_t /*offset*/, DataSink &sink) { ed.add_sink(&sink); }); |
| 84 | + }); |
| 85 | + |
| 86 | + svr.Get("/event2", [&](const Request & /*req*/, Response &res) { |
| 87 | + cout << "connected to event2..." << endl; |
| 88 | + res.set_header("Content-Type", "text/event-stream"); |
| 89 | + res.set_chunked_content_provider( |
| 90 | + [&](uint64_t /*offset*/, DataSink &sink) { ed.add_sink(&sink); }); |
| 91 | + }); |
| 92 | + |
| 93 | + thread t([&] { |
| 94 | + int id = 0; |
| 95 | + while (true) { |
| 96 | + this_thread::sleep_for(chrono::seconds(1)); |
| 97 | + cout << "send event: " << id << std::endl; |
| 98 | + std::stringstream ss; |
| 99 | + ss << "data: " << id << "\n\n"; |
| 100 | + ed.send_event(ss.str()); |
| 101 | + id++; |
| 102 | + } |
| 103 | + }); |
| 104 | + |
| 105 | + svr.listen("localhost", 1234); |
| 106 | +} |
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