uvco::Resolver Class Reference

Asynchronous name resolution using the libuv getaddrinfo(3) interface. More...

#include <name_resolution.h>

Collaboration diagram for uvco::Resolver:

Public Member Functions
	Resolver (const Loop &loop)
	Instantiate a resolver based on an event loop.
Promise< AddressHandle >	gai (std::string_view host, std::string_view port, int af_hint=AF_UNSPEC)
	Resolve a host and port string. Throws an UvcoException upon error.
Promise< AddressHandle >	gai (std::string_view host, uint16_t port, int af_hint=AF_UNSPEC)

Static Private Member Functions
static void	onAddrinfo (uv_getaddrinfo_t *req, uv_status status, struct addrinfo *result)
	Called after finishing a getaddrinfo call.

Private Attributes
const Loop *	loop_

Detailed Description

Asynchronous name resolution using the libuv getaddrinfo(3) interface.

Constructor & Destructor Documentation

Resolver()

uvco::Resolver::Resolver ( const Loop & loop )

inlineexplicit

Instantiate a resolver based on an event loop.

: loop_{&loop} {}

Member Function Documentation

gai() [1/2]

Promise< AddressHandle > uvco::Resolver::gai	(	std::string_view	host,
		std::string_view	port,
		int	af_hint = AF_UNSPEC )

Resolve a host and port string. Throws an UvcoException upon error.

                                                                       {
  AddrinfoAwaiter_ awaiter;
  struct addrinfo hints{};
  hints.ai_family = af_hint;
  hints.ai_socktype = SOCK_STREAM;
 
  uv_getaddrinfo(loop_->uvloop(), awaiter.req_.get(), onAddrinfo, host.data(),
                 port.data(), &hints);
  // Npte: we rely on libuv not resuming before awaiting the result.
  struct addrinfo *result = co_await awaiter;
 
  const uv_status status = awaiter.status_.value();
  if (status != 0) {
    throw UvcoException{status, "getaddrinfo()"};
  }
 
  co_return AddressHandle{result};
}

gai() [2/2]

Promise< AddressHandle > uvco::Resolver::gai	(	std::string_view	host,
		uint16_t	port,
		int	af_hint = AF_UNSPEC )

Resolve a host string and numeric port. Throws an UvcoException upon error.

                                                  {
  const std::string portStr = std::to_string(port);
  co_return (co_await gai(host, portStr, af_hint));
}

onAddrinfo()

void uvco::Resolver::onAddrinfo ( uv_getaddrinfo_t * req, uv_status status, struct addrinfo * result )

staticprivate

Called after finishing a getaddrinfo call.

                                                   {
  // asserts request data not null; the only time this could be the case is
  // after a lookup is cancelled.
  auto *awaiter = getRequestDataOrNull<AddrinfoAwaiter_>(req);
  if (awaiter == nullptr) {
    // cancelled
    delete req;
    uv_freeaddrinfo(result);
    return;
  }
  if (status == UV_ECANCELED) {
    return;
  }
  awaiter->addrinfo_ = result;
  awaiter->status_ = status;
  BOOST_ASSERT(awaiter->handle_ != nullptr);
  Loop::enqueue(awaiter->handle_);
}

Member Data Documentation

loop_

const Loop* uvco::Resolver::loop_

private

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The documentation for this class was generated from the following files:

• uvco/name_resolution.h
• uvco/name_resolution.cc