make resolver_flags use enum class for improved type-safety

include/libtorrent/http_connection.hpp

@@ -57,6 +57,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/session_settings.hpp"
 #include "libtorrent/i2p_stream.hpp"
 #include "libtorrent/aux_/vector.hpp"
+#include "libtorrent/resolver_interface.hpp"
 
 namespace libtorrent {
 
@@ -103,7 +104,7 @@ struct TORRENT_EXTRA_EXPORT http_connection
 		, int prio = 0, aux::proxy_settings const* ps = NULL, int handle_redirects = 5
 		, std::string const& user_agent = std::string()
 		, boost::optional<address> const& bind_addr = boost::optional<address>()
-		, int resolve_flags = 0, std::string const& auth_ = std::string()
+		, resolver_flags resolve_flags = resolver_flags::none, std::string const& auth_ = std::string()
 #if TORRENT_USE_I2P
 		, i2p_connection* i2p_conn = 0
 #endif
@@ -113,7 +114,7 @@ struct TORRENT_EXTRA_EXPORT http_connection
 		, time_duration timeout, int prio = 0, aux::proxy_settings const* ps = NULL
 		, bool ssl = false, int handle_redirect = 5
 		, boost::optional<address> const& bind_addr = boost::optional<address>()
-		, int resolve_flags = 0
+		, resolver_flags resolve_flags = resolver_flags::none
 #if TORRENT_USE_I2P
 		, i2p_connection* i2p_conn = 0
 #endif
@@ -215,7 +216,7 @@ private:
 	int m_priority;
 
 	// used for DNS lookups
-	int m_resolve_flags;
+	resolver_flags m_resolve_flags;
 
 	std::uint16_t m_port;
 

include/libtorrent/resolver.hpp

@@ -52,7 +52,7 @@ struct TORRENT_EXTRA_EXPORT resolver final : resolver_interface
 {
 	explicit resolver(io_service& ios);
 
-	virtual void async_resolve(std::string const& host, int flags
+	virtual void async_resolve(std::string const& host, resolver_flags flags
 		, callback_t const& h) override;
 
 	virtual void abort() override;

include/libtorrent/resolver_interface.hpp

@@ -39,27 +39,37 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/error_code.hpp"
 #include "libtorrent/address.hpp"
 #include "libtorrent/time.hpp"
+#include "libtorrent/flags.hpp"
 
 namespace libtorrent {
 
+enum class resolver_flags : std::uint8_t
+{
+	none = 0,
+
+	// this flag will make async_resolve() only use the cache and fail if we
+	// don't have a cache entry, regardless of how old it is. This is usefull
+	// when completing the lookup quickly is more important than accuracy,
+	// like on shutdown
+	cache_only = 1,
+
+	// set this flag for lookups that are not critical during shutdown. i.e.
+	// for looking up tracker names _except_ when stopping a tracker.
+	abort_on_shutdown = 2
+};
+
+namespace flags {
+	template <>
+	struct enable_flag_operators<resolver_flags> : std::true_type {};
+}
+
+using namespace flags;
+
 struct TORRENT_EXTRA_EXPORT resolver_interface
 {
 	using callback_t = std::function<void(error_code const&, std::vector<address> const&)>;
 
-	enum flags_t
+	virtual void async_resolve(std::string const& host, resolver_flags flags
-	{
-		// this flag will make async_resolve() only use the cache and fail if we
-		// don't have a cache entry, regardless of how old it is. This is usefull
-		// when completing the lookup quickly is more important than accuracy,
-		// like on shutdown
-		cache_only = 1,
-
-		// set this flag for lookups that are not critical during shutdown. i.e.
-		// for looking up tracker names _except_ when stopping a tracker.
-		abort_on_shutdown = 2
-	};
-
-	virtual void async_resolve(std::string const& host, int flags
 		, callback_t const& h) = 0;
 
 	virtual void abort() = 0;

simulation/test_http_connection.cpp

@@ -179,7 +179,7 @@ std::shared_ptr<http_connection> test_request(io_service& ios
 		});
 
 	h->get(url, seconds(1), 0, &ps, 5, "test/user-agent", boost::optional<address>()
-		, 0, auth);
+		, resolver_flags::none, auth);
 	return h;
 }
 

src/http_connection.cpp

@@ -88,7 +88,7 @@ http_connection::http_connection(io_service& ios
 	, m_rate_limit(0)
 	, m_download_quota(0)
 	, m_priority(0)
-	, m_resolve_flags(0)
+	, m_resolve_flags(resolver_flags::none)
 	, m_port(0)
 	, m_bottled(bottled)
 	, m_called(false)
@@ -109,7 +109,7 @@ http_connection::~http_connection()
 
 void http_connection::get(std::string const& url, time_duration timeout, int prio
 	, aux::proxy_settings const* ps, int handle_redirects, std::string const& user_agent
-	, boost::optional<address> const& bind_addr, int resolve_flags, std::string const& auth_
+	, boost::optional<address> const& bind_addr, resolver_flags const resolve_flags, std::string const& auth_
 #if TORRENT_USE_I2P
 	, i2p_connection* i2p_conn
 #endif
@@ -226,7 +226,7 @@ void http_connection::start(std::string const& hostname, int port
 	, time_duration timeout, int prio, aux::proxy_settings const* ps, bool ssl
 	, int handle_redirects
 	, boost::optional<address> const& bind_addr
-	, int resolve_flags
+	, resolver_flags const resolve_flags
 #if TORRENT_USE_I2P
 	, i2p_connection* i2p_conn
 #endif

src/http_tracker_connection.cpp

@@ -223,9 +223,9 @@ namespace libtorrent {
 			, tracker_req().event == tracker_request::stopped ? 2 : 1
 			, ps.proxy_tracker_connections ? &ps : nullptr
 			, 5, user_agent, bind_interface()
-			, tracker_req().event == tracker_request::stopped
+			, (tracker_req().event == tracker_request::stopped
-				? resolver_interface::cache_only : 0
+				? resolver_flags::cache_only : resolver_flags::none)
-				| resolver_interface::abort_on_shutdown
+				| resolver_flags::abort_on_shutdown
 #ifndef TORRENT_NO_DEPRECATE
 			, tracker_req().auth
 #else

src/resolver.cpp

@@ -83,7 +83,7 @@ namespace libtorrent {
 		}
 	}
 
-	void resolver::async_resolve(std::string const& host, int const flags
+	void resolver::async_resolve(std::string const& host, resolver_flags const flags
 		, resolver_interface::callback_t const& h)
 	{
 		// special handling for raw IP addresses. There's no need to get in line
@@ -103,7 +103,7 @@ namespace libtorrent {
 		if (i != m_cache.end())
 		{
 			// keep cache entries valid for m_timeout seconds
-			if ((flags & resolver_interface::cache_only)
+			if (test(flags & resolver_flags::cache_only)
 				|| i->second.last_seen + m_timeout >= aux::time_now())
 			{
 				m_ios.post(std::bind(h, ec, i->second.addresses));
@@ -111,7 +111,7 @@ namespace libtorrent {
 			}
 		}
 
-		if (flags & resolver_interface::cache_only)
+		if (test(flags & resolver_flags::cache_only))
 		{
 			// we did not find a cache entry, fail the lookup
 			m_ios.post(std::bind(h, boost::asio::error::host_not_found
@@ -124,7 +124,7 @@ namespace libtorrent {
 
 		using namespace std::placeholders;
 		ADD_OUTSTANDING_ASYNC("resolver::on_lookup");
-		if (flags & resolver_interface::abort_on_shutdown)
+		if (test(flags & resolver_flags::abort_on_shutdown))
 		{
 			m_resolver.async_resolve(q, std::bind(&resolver::on_lookup, this, _1, _2
 				, h, host));

src/session_impl.cpp

@@ -5766,7 +5766,7 @@ namespace {
 	void session_impl::add_dht_node_name(std::pair<std::string, int> const& node)
 	{
 		ADD_OUTSTANDING_ASYNC("session_impl::on_dht_name_lookup");
-		m_host_resolver.async_resolve(node.first, resolver_interface::abort_on_shutdown
+		m_host_resolver.async_resolve(node.first, resolver_flags::abort_on_shutdown
 			, std::bind(&session_impl::on_dht_name_lookup
 				, this, _1, _2, node.second));
 	}
@@ -5795,7 +5795,7 @@ namespace {
 	{
 		ADD_OUTSTANDING_ASYNC("session_impl::on_dht_router_name_lookup");
 		++m_outstanding_router_lookups;
-		m_host_resolver.async_resolve(node.first, resolver_interface::abort_on_shutdown
+		m_host_resolver.async_resolve(node.first, resolver_flags::abort_on_shutdown
 			, std::bind(&session_impl::on_dht_router_name_lookup
 				, this, _1, _2, node.second));
 	}

src/torrent.cpp

@@ -3140,7 +3140,7 @@ namespace libtorrent {
 #endif
 			{
 				ADD_OUTSTANDING_ASYNC("torrent::on_peer_name_lookup");
-				m_ses.get_resolver().async_resolve(i.hostname, resolver_interface::abort_on_shutdown
+				m_ses.get_resolver().async_resolve(i.hostname, resolver_flags::abort_on_shutdown
 					, std::bind(&torrent::on_peer_name_lookup, shared_from_this(), _1, _2, i.port));
 			}
 		}
@@ -5621,7 +5621,7 @@ namespace libtorrent {
 
 			// use proxy
 			web->resolving = true;
-			m_ses.get_resolver().async_resolve(ps.hostname, resolver_interface::abort_on_shutdown
+			m_ses.get_resolver().async_resolve(ps.hostname, resolver_flags::abort_on_shutdown
 				, [self, web, proxy_port](error_code const& e, std::vector<address> const& addrs)
 				{
 					self->wrap(&torrent::on_proxy_name_lookup, e, addrs, web, proxy_port);
@@ -5643,7 +5643,7 @@ namespace libtorrent {
 			auto self = shared_from_this();
 			web->resolving = true;
 
-			m_ses.get_resolver().async_resolve(hostname, resolver_interface::abort_on_shutdown
+			m_ses.get_resolver().async_resolve(hostname, resolver_flags::abort_on_shutdown
 				, [self, web, port](error_code const& e, std::vector<address> const& addrs)
 				{
 					self->wrap(&torrent::on_name_lookup, e, addrs, port, web);
@@ -5728,7 +5728,7 @@ namespace libtorrent {
 
 		auto self = shared_from_this();
 		web->resolving = true;
-		m_ses.get_resolver().async_resolve(hostname, resolver_interface::abort_on_shutdown
+		m_ses.get_resolver().async_resolve(hostname, resolver_flags::abort_on_shutdown
 			, [self, web, port](error_code const& err, std::vector<address> const& addr)
 			{
 				self->wrap(&torrent::on_name_lookup, err, addr, port, web);

src/udp_tracker_connection.cpp

@@ -106,9 +106,9 @@ namespace libtorrent {
 			// when stopping, pass in the cache-only flag, because we
 			// don't want to get stuck on DNS lookups when shutting down
 			m_man.host_resolver().async_resolve(hostname
-				, tracker_req().event == tracker_request::stopped
+				, (tracker_req().event == tracker_request::stopped
-					? resolver_interface::cache_only : 0
+					? resolver_flags::cache_only : resolver_flags::none)
-					| resolver_interface::abort_on_shutdown
+					| resolver_flags::abort_on_shutdown
 				, std::bind(&udp_tracker_connection::name_lookup
 					, shared_from_this(), _1, _2, port));
 

test/test_http_connection.cpp

@@ -121,7 +121,7 @@ void run_test(std::string const& url, int size, int status, int connected
 	std::shared_ptr<http_connection> h = std::make_shared<http_connection>(ios
 		, res, &::http_handler, true, 1024*1024, &::http_connect_handler);
 	h->get(url, seconds(1), 0, &ps, 5, "test/user-agent", address(address_v4::any())
-		, 0, auth);
+		, resolver_flags::none, auth);
 	ios.reset();
 	error_code e;
 	ios.run(e);