Easy HTTP (Header-only) library implemented using minimum C++11 and Boost.Beast. Allows you to get or provide REST resources available from an application in C ++. Use all the features of the Boost.Beast when constructing queries and answers.
- HTTP 1.0 / 1.1
- TLS/SSL
- Pipeline request
- Used I/O multiplexing model (Asio library implementation)
- Timer manage (default action: Closing connection)
- Server-Sent Events
- Simple way to dynamic add REST resources using regex for path, and anonymous functions
- Support accepted plain and SSL session on the same port
- Boost Libraries >= 1.70.0
Boost.Asio,Boost.BeastOpenSSL(optional)Boost.LexicalCast(optional)
More examples is here...
The following notes show the standard syntax for setting up routes and starting a server!
Alias's represent instances of default classes for reactive (select/epool) design.
using namespace _0xdead4ead;
namespace beast = boost::beast;
using http_session = http::reactor::_default::session_type;
using http_listener = http::reactor::_default::listener_type;
Creating a new callback functions storage and route path for GET request with "/" resource:
static const std::regex::flag_type regex_flags = std::regex::ECMAScript;
http::basic_router<http_session> router{regex_flags};
router.get("^/$", [](auto beast_http_request, auto context) {
context.send(make_200<beast::http::string_body>(beast_http_request, "Main page\n", "text/html"));
});
router.all("^.*$", [](auto beast_http_request, auto context) {
context.send(make_404<beast::http::string_body>(beast_http_request, "Resource is not found\n", "text/html"));
});
// or so ...
using http::literals::operator""_get;
"^/$"_get.advance(router, [](auto beast_http_request, auto context) {
// as above...
});
"^.*$"_all.advance(router, [](auto beast_http_request, auto context) {
// as above...
});
It is possible to add multiple handlers for one route. For movement on them std::next or std::advance is used:
router.get("^/a/b$",
[](auto /*beast_http_request*/, auto /*context*/, auto iterator){
// process /a
std::next(iterator)();
}, [](auto /*beast_http_request*/, auto /*context*/){
// process /b
});
Getting a parameter from a URI. Request send example curl localhost --request 'GET' --request-target '/user/param?y=1992':
using pack = http::param::pack<int>;
router.param<pack>().get("^/user/param[?]y=(\\d+)$",
[](auto /*beast_http_request*/, auto /*context*/, auto args){
assert(std::get<0>(args) == 1992);
});
// or
router.param<pack>().get("^/user/param[?]y=(\\d+)$",
[](auto /*beast_http_request*/, auto /*context*/, auto iterator, auto /*args*/){
// process /user
std::next(iterator)();
}, [](auto /*beast_http_request*/, auto /*context*/, auto args){
// process /param
assert(std::get<0>(args) == 1992);
});
Getting a parameter using a string literal (as above) :
// For value f'n is required c++14
using http::literals::value;
using http::literals::operator""_c;
auto param = router.param<pack>();
"^/user/param[?]y=(\\d+)$"_get.advance(std::move(param),
[](auto /*beast_http_request*/, auto /*context*/, auto args){
assert(value(args, 0_c) == 1992);
});
Create modular, mounted route handlers:
http::basic_router<http_session> animals{regex_flags};
animals.get("^/cat$", [](auto beast_http_request, auto context){ // '/animals/cat'
context.send(make_200<beast::http::string_body>(beast_http_request, "me-ow\n", "text/html"));
});
animals.get("^/dog$", [](auto beast_http_request, auto context){ // '/animals/dog'
context.send(make_200<beast::http::string_body>(beast_http_request, "aw! aw! Rrrrr\n", "text/html"));
});
animals.get("^/mouse$", [](auto beast_http_request, auto context){ // '/animals/mouse'
context.send(make_200<beast::http::string_body>(beast_http_request, "...\n", "text/html"));
});
animals.get("^[/]??$", [](auto beast_http_request, auto context){ // '/animals' or '/animals/'
context.send(make_200<beast::http::string_body>(beast_http_request, "animals home page\n", "text/html"));
});
router.use("^/animals$", animals);
Create handlers routes, forming a chain, for the route path:
http::chain_router<http_session> books{regex_flags};
books.route("^/book$")
.get([](auto beast_http_request, auto context) {
context.send(make_200<beast::http::string_body>(beast_http_request, "get a random book\n", "text/html"));
})
.post([](auto beast_http_request, auto context) {
context.send(make_200<beast::http::string_body>(beast_http_request, "add a book\n", "text/html"));
})
.put([](auto beast_http_request, auto context) {
context.send(make_200<beast::http::string_body>(beast_http_request, "update the book\n", "text/html"));
});
router.use("^/books$", books);
Start listening on 0.0.0.0:8080
// global namespace
static boost::asio::io_context ioc;
static boost::asio::posix::stream_descriptor out{ioc, ::dup(STDERR_FILENO)};
//
const auto& onError = [](auto system_error_code, auto from){
http::out::pushn<std::ostream>(
out, "From:", from, "Info:", system_error_code.message());
};
const auto& onAccept = [&](auto asio_socket){
auto endpoint = asio_socket.remote_endpoint();
http::out::prefix::version::time::pushn<std::ostream>(
out, endpoint.address().to_string() + ':' + std::to_string(endpoint.port()), "connected!");
http_session::recv(std::move(asio_socket), router, onError);
};
auto const address = boost::asio::ip::address_v4::any();
auto const port = static_cast<unsigned short>(8080);
http_listener::launch(ioc, {address, port}, onAccept, onError);
Run the I/O service on the requested number of threads:
std::thread t{[](){
ioc.run();
}};
// do other work...
t.join();
- Copyright (c) @Evgeny Tixonow 2018-2019