lint guided refactor in dht source code (#2516)

src/kademlia/dht_tracker.cpp

@@ -575,7 +575,7 @@ namespace libtorrent { namespace dht {
 		, dht_observer* observer, counters& cnt
 		, get_foreign_node_t get_foreign_node
 		, dht_storage_interface& storage)
-		: dht(s, sock, settings, nid, observer, cnt, get_foreign_node, storage)
+		: dht(s, sock, settings, nid, observer, cnt, std::move(get_foreign_node), storage)
 		, connection_timer(ios)
 	{}
 
@@ -616,7 +616,7 @@ namespace libtorrent { namespace dht {
 		{
 			// use the local rather than external address because if the user is behind NAT
 			// we won't know the external IP on startup
-			ret.nids.push_back(std::make_pair(n.first.get_local_endpoint().address(), n.second.dht.nid()));
+			ret.nids.emplace_back(n.first.get_local_endpoint().address(), n.second.dht.nid());
 			auto nodes = save_nodes(n.second.dht);
 			ret.nodes.insert(ret.nodes.end(), nodes.begin(), nodes.end());
 		}

src/kademlia/dos_blocker.cpp

@@ -50,7 +50,7 @@ namespace libtorrent { namespace dht {
 		}
 	}
 
-	bool dos_blocker::incoming(address const& addr, time_point now, dht_logger* logger)
+	bool dos_blocker::incoming(address const& addr, time_point const now, dht_logger* logger)
 	{
 		node_ban_entry* match = nullptr;
 		node_ban_entry* min = m_ban_nodes;

src/kademlia/find_data.cpp

@@ -147,7 +147,7 @@ void find_data::done()
 
 	std::vector<std::pair<node_entry, std::string>> results;
 	int num_results = m_node.m_table.bucket_size();
-	for (std::vector<observer_ptr>::iterator i = m_results.begin()
+	for (auto i = m_results.begin()
 		, end(m_results.end()); i != end && num_results > 0; ++i)
 	{
 		observer_ptr const& o = *i;
@@ -174,7 +174,7 @@ void find_data::done()
 #endif
 			continue;
 		}
-		results.push_back(std::make_pair(node_entry(o->id(), o->target_ep()), j->second));
+		results.emplace_back(node_entry(o->id(), o->target_ep()), j->second);
 #ifndef TORRENT_DISABLE_LOGGING
 		if (logger != nullptr && logger->should_log(dht_logger::traversal))
 		{

src/kademlia/get_peers.cpp

@@ -275,7 +275,7 @@ void obfuscated_get_peers::done()
 #endif
 
 	int num_added = 0;
-	for (std::vector<observer_ptr>::iterator i = m_results.begin()
+	for (auto i = m_results.begin()
 		, end(m_results.end()); i != end && num_added < 16; ++i)
 	{
 		observer_ptr o = *i;

src/kademlia/item.cpp

@@ -62,7 +62,7 @@ namespace {
 		char* ptr = out.data();
 
 		std::size_t left = out.size() - aux::numeric_cast<std::size_t>(ptr - out.data());
-		if (salt.size() > 0)
+		if (!salt.empty())
 		{
 			ptr += std::snprintf(ptr, left, "4:salt%d:", int(salt.size()));
 			left = out.size() - aux::numeric_cast<std::size_t>(ptr - out.data());
@@ -90,7 +90,7 @@ sha1_hash item_target_id(span<char const> salt
 	, public_key const& pk)
 {
 	hasher h(pk.bytes);
-	if (salt.size() > 0) h.update(salt);
+	if (!salt.empty()) h.update(salt);
 	return h.final();
 }
 
@@ -188,7 +188,7 @@ bool item::assign(bdecode_node const& v, span<char const> salt
 		return false;
 	m_pk = pk;
 	m_sig = sig;
-	if (salt.size() > 0)
+	if (!salt.empty())
 		m_salt.assign(salt.data(), salt.size());
 	else
 		m_salt.clear();

src/kademlia/node.cpp

@@ -96,8 +96,8 @@ void incoming_error(entry& e, char const* msg, int error_code = 203)
 {
 	e["y"] = "e";
 	entry::list_type& l = e["e"].list();
-	l.push_back(entry(error_code));
-	l.push_back(entry(msg));
+	l.emplace_back(error_code);
+	l.emplace_back(msg);
 }
 
 } // anonymous namespace
@@ -452,7 +452,7 @@ void node::announce(sha1_hash const& info_hash, int const listen_port, int const
 	}
 #endif
 
-	get_peers(info_hash, f
+	get_peers(info_hash, std::move(f)
 		, std::bind(&announce_fun, _1, std::ref(*this)
 		, listen_port, info_hash, flags), flags & node::flag_seed);
 }
@@ -995,7 +995,7 @@ void node::incoming_request(msg const& m, entry& e)
 
 		// pointer and length to the whole entry
 		span<char const> buf = msg_keys[1].data_section();
-		if (buf.size() > 1000 || buf.size() <= 0)
+		if (buf.size() > 1000 || buf.empty())
 		{
 			m_counters.inc_stats_counter(counters::dht_invalid_put);
 			incoming_error(e, "message too big", 205);

src/kademlia/node_entry.cpp

@@ -72,7 +72,7 @@ namespace libtorrent { namespace dht {
 #endif
 	}
 
-	void node_entry::update_rtt(int new_rtt)
+	void node_entry::update_rtt(int const new_rtt)
 	{
 		TORRENT_ASSERT(new_rtt <= 0xffff);
 		TORRENT_ASSERT(new_rtt >= 0);

src/kademlia/refresh.cpp

@@ -36,8 +36,6 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <libtorrent/kademlia/dht_observer.hpp>
 #include <libtorrent/performance_counters.hpp>
 
-#include <libtorrent/io.hpp>
-
 namespace libtorrent { namespace dht {
 
 observer_ptr bootstrap::new_observer(udp::endpoint const& ep

src/kademlia/routing_table.cpp

@@ -244,11 +244,9 @@ node_entry const* routing_table::next_refresh()
 	node_entry* candidate = nullptr;
 
 	// this will have a bias towards pinging nodes close to us first.
-	for (table_t::reverse_iterator i = m_buckets.rbegin()
-		, end(m_buckets.rend()); i != end; ++i)
+	for (auto i = m_buckets.rbegin(), end(m_buckets.rend()); i != end; ++i)
 	{
-		for (bucket_t::iterator j = i->live_nodes.begin()
-			, end2(i->live_nodes.end()); j != end2; ++j)
+		for (auto j = i->live_nodes.begin(), end2(i->live_nodes.end()); j != end2; ++j)
 		{
 			// this shouldn't happen
 			TORRENT_ASSERT(m_id != j->id);
@@ -1163,7 +1161,7 @@ bool routing_table::is_full(int const bucket) const
 	if (num_buckets == 0) return false;
 	if (bucket >= num_buckets) return false;
 
-	table_t::const_iterator i = m_buckets.begin();
+	auto i = m_buckets.cbegin();
 	std::advance(i, bucket);
 	return (int(i->live_nodes.size()) >= bucket_limit(bucket)
 		&& int(i->replacements.size()) >= m_bucket_size);

src/kademlia/rpc_manager.cpp

@@ -480,7 +480,7 @@ bool rpc_manager::invoke(entry& e, udp::endpoint const& target_addr
 	node& n = o->algorithm()->get_node();
 	if (!n.native_address(o->target_addr()))
 	{
-		a["want"].list().push_back(entry(n.protocol_family_name()));
+		a["want"].list().emplace_back(n.protocol_family_name());
 	}
 
 	o->set_target(target_addr);

src/kademlia/traversal_algorithm.cpp

@@ -186,7 +186,7 @@ void traversal_algorithm::add_entry(node_id const& id
 				if (o->target_addr().is_v6())
 				{
 					address_v6::bytes_type addr_bytes = o->target_addr().to_v6().to_bytes();
-					address_v6::bytes_type::const_iterator prefix_it = addr_bytes.begin();
+					auto prefix_it = addr_bytes.cbegin();
 					std::uint64_t const prefix6 = detail::read_uint64(prefix_it);
 
 					if (m_peer6_prefixes.insert(prefix6).second)
@@ -483,7 +483,7 @@ bool traversal_algorithm::add_requests()
 	// limits the number of outstanding requests, this limits the
 	// number of good outstanding requests. It will use more traffic,
 	// but is intended to speed up lookups
-	for (std::vector<observer_ptr>::iterator i = m_results.begin()
+	for (auto i = m_results.begin()
 		, end(m_results.end()); i != end
 		&& results_target > 0
 		&& (agg ? outstanding < m_branch_factor