Merge pull request #5 from beman-project/cppcon-2024

adding the code created during the cppcon-2024 presentation

examples/CMakeLists.txt

@@ -18,6 +18,7 @@ set(EXAMPLES
   server
   client
   task
+  cppcon-2024
 )
 
 set(DATA

examples/cppcon-2024.cpp

@@ -0,0 +1,108 @@
+// examples/http-server.cpp                                           -*-C++-*-
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include <beman/net29/net.hpp>
+#include <beman/execution26/execution.hpp>
+#include "demo_algorithm.hpp"
+#include "demo_error.hpp"
+#include "demo_scope.hpp"
+#include "demo_task.hpp"
+#include <iostream>
+#include <string>
+#include <fstream>
+#include <sstream>
+#include <string_view>
+#include <unordered_map>
+
+namespace ex  = beman::execution26;
+namespace net = beman::net29;
+using namespace std::chrono_literals;
+
+// ----------------------------------------------------------------------------
+
+std::unordered_map<std::string, std::string> files{
+    {"/", "examples/data/index.html"},
+    {"/favicon.ico", "examples/data/favicon.ico"},
+    {"/logo.png", "examples/data/logo.png"},
+};
+
+auto process(auto& stream, auto const& request) -> demo::task<>
+{
+    std::cout << "request=" << request << "\n";
+    std::string method, url, version;
+    std::string body;
+    std::ostringstream out;
+    if (std::istringstream(request) >> method >> url >> version
+        && files.contains(url))
+    {
+    std::cout << "url=" << url << "\n";
+        out << std::ifstream(files[url]).rdbuf();
+        body = out.str();
+        out.str({});
+    }
+
+    out << "HTTP/1.1 " << (body.empty()? "404 not found": "200 found") << "\r\n"
+        << "Content-Length: " << body.size() << "\r\n"
+        << "\r\n"
+        << body;
+    auto response{out.str()};
+    co_await net::async_send(stream, net::buffer(response));
+}
+
+auto timeout(auto scheduler, auto duration, auto sender)
+{
+    return demo::when_any(
+        std::move(sender),
+        net::resume_after(scheduler, duration)
+           | demo::into_error([]{ return std::error_code(demo::timeout, demo::category()); })
+    );
+}
+
+auto make_client_handler(auto scheduler, auto stream) -> demo::task<>
+{
+    char buffer[16];
+    std::string request;
+    while (true)
+       try {
+       if (auto n = co_await timeout(scheduler, 2s, net::async_receive(stream, net::buffer(buffer)))) {
+           std::string_view data(buffer, n);
+           request += data;
+           if (request.find("\r\n\r\n") != request.npos)
+           {
+               co_await process(stream, request);
+               break;
+           }
+       }
+       else {
+        //std::cout << "ERROR (via expected): " << std::get<0>(n.error()).message() << "\n";
+        break;
+       }
+       }
+       catch (std::variant<std::error_code> const& ex) {
+        std::cout << "ERROR: " << std::get<0>(ex).message() << "\n";
+        break;
+       }
+
+
+    co_return;
+}
+
+auto main() -> int
+{
+    demo::scope scope;
+
+    net::io_context context;
+    net::ip::tcp::endpoint endpoint(net::ip::address_v4::any(), 12345);
+    net::ip::tcp::acceptor acceptor(context, endpoint);
+
+    scope.spawn(std::invoke([](auto scheduler, auto& scope, auto& acceptor)->demo::task<> {
+         while (true)
+         {
+            auto[stream, address] = co_await net::async_accept(acceptor);
+            std::cout << "received client: " << address << "\n";
+            scope.spawn(make_client_handler(scheduler, std::move(stream)));
+         }
+    }, context.get_scheduler(), scope, acceptor));
+
+    context.run();
+}