Requests library (#1140)

For #51.

First part of improving forwarding - library for easy async requests.

unittests/util/TestHttpServer.cpp

@@ -0,0 +1,124 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "util/TestHttpServer.h"
+
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/detached.hpp>
+#include <boost/asio/io_context.hpp>
+#include <boost/asio/ip/address.hpp>
+#include <boost/asio/ip/tcp.hpp>
+#include <boost/asio/socket_base.hpp>
+#include <boost/asio/spawn.hpp>
+#include <boost/beast.hpp>
+#include <boost/beast/core/error.hpp>
+#include <boost/beast/core/flat_buffer.hpp>
+#include <boost/beast/core/tcp_stream.hpp>
+#include <boost/beast/http/error.hpp>
+#include <boost/beast/http/field.hpp>
+#include <boost/beast/http/message.hpp>
+#include <boost/beast/http/message_generator.hpp>
+#include <boost/beast/http/string_body.hpp>
+#include <gtest/gtest.h>
+
+#include <chrono>
+#include <string>
+#include <utility>
+
+namespace beast = boost::beast;
+namespace http = beast::http;
+namespace asio = boost::asio;
+using tcp = boost::asio::ip::tcp;
+
+namespace {
+
+void
+doSession(beast::tcp_stream stream, TestHttpServer::RequestHandler requestHandler, asio::yield_context yield)
+{
+    beast::error_code errorCode;
+
+    // This buffer is required to persist across reads
+    beast::flat_buffer buffer;
+
+    // This lambda is used to send messages
+    // Set the timeout.
+    stream.expires_after(std::chrono::seconds(5));
+
+    // Read a request
+    http::request<http::string_body> req;
+    http::async_read(stream, buffer, req, yield[errorCode]);
+    if (errorCode == http::error::end_of_stream)
+        return;
+
+    ASSERT_FALSE(errorCode) << errorCode.message();
+
+    auto response = requestHandler(req);
+
+    if (not response)
+        return;
+
+    bool const keep_alive = response->keep_alive();
+
+    http::message_generator messageGenerator{std::move(response).value()};
+
+    // Send the response
+    beast::async_write(stream, std::move(messageGenerator), yield[errorCode]);
+
+    ASSERT_FALSE(errorCode) << errorCode.message();
+
+    if (!keep_alive) {
+        // This means we should close the connection, usually because
+        // the response indicated the "Connection: close" semantic.
+        return;
+    }
+
+    // Send a TCP shutdown
+    stream.socket().shutdown(tcp::socket::shutdown_send, errorCode);
+
+    // At this point the connection is closed gracefully
+}
+
+}  // namespace
+
+TestHttpServer::TestHttpServer(boost::asio::io_context& context, std::string host, int const port) : acceptor_(context)
+{
+    boost::asio::ip::tcp::endpoint endpoint(boost::asio::ip::make_address(host), port);
+    acceptor_.open(endpoint.protocol());
+    acceptor_.set_option(asio::socket_base::reuse_address(true));
+    acceptor_.bind(endpoint);
+    acceptor_.listen(asio::socket_base::max_listen_connections);
+}
+
+void
+TestHttpServer::handleRequest(TestHttpServer::RequestHandler handler)
+{
+    boost::asio::spawn(
+        acceptor_.get_executor(),
+        [this, handler = std::move(handler)](asio::yield_context yield) mutable {
+            boost::beast::error_code errorCode;
+            tcp::socket socket(this->acceptor_.get_executor());
+            acceptor_.async_accept(socket, yield[errorCode]);
+
+            [&]() { ASSERT_FALSE(errorCode) << errorCode.message(); }();
+
+            doSession(beast::tcp_stream{std::move(socket)}, std::move(handler), yield);
+        },
+        boost::asio::detached
+    );
+}