optimized dht_get_peers_reply_alert storage and created alerts unit test (#1714)

optimized dht_get_peers_reply_alert storage and created alerts unit test

include/libtorrent/alert_types.hpp

@@ -2404,8 +2404,10 @@ namespace libtorrent
 
 	private:
 		std::reference_wrapper<aux::stack_allocator> m_alloc;
-		int const m_num_peers;
-		aux::allocation_slot m_peers_idx;
+		int m_v4_num_peers = 0;
+		int m_v6_num_peers = 0;
+		aux::allocation_slot m_v4_peers_idx;
+		aux::allocation_slot m_v6_peers_idx;
 	};
 
 	// This is posted exactly once for every call to session_handle::dht_direct_request.

include/libtorrent/stack_allocator.hpp

@@ -125,7 +125,7 @@ namespace libtorrent { namespace aux
 		allocation_slot allocate(int const bytes)
 		{
 			if (bytes < 1) return allocation_slot();
-			int const ret = int(m_storage.size());
+			int const ret = m_storage.end_index();
 			m_storage.resize(ret + bytes);
 			return allocation_slot(ret);
 		}

src/alert.cpp

@@ -1922,37 +1922,46 @@ namespace libtorrent
 		, std::vector<tcp::endpoint> const& peers)
 		: info_hash(ih)
 		, m_alloc(alloc)
-		, m_num_peers(int(peers.size()))
 	{
-		std::size_t total_size = peers.size(); // num bytes for sizes
 		for (auto const& endp : peers)
 		{
-			total_size += endp.size();
+			if (endp.protocol() == tcp::v4())
+				m_v4_num_peers++;
+#if TORRENT_USE_IPV6
+			else
+				m_v6_num_peers++;
+#endif
 		}
 
-		m_peers_idx = alloc.allocate(int(total_size));
+		m_v4_peers_idx = alloc.allocate(m_v4_num_peers * 6);
+		m_v6_peers_idx = alloc.allocate(m_v6_num_peers * 18);
 
-		char *ptr = alloc.ptr(m_peers_idx);
+		char* v4_ptr = alloc.ptr(m_v4_peers_idx);
+#if TORRENT_USE_IPV6
+		char* v6_ptr = alloc.ptr(m_v6_peers_idx);
+#endif
 		for (auto const& endp : peers)
 		{
-			std::size_t const size = endp.size();
-			TORRENT_ASSERT(size < 0x100);
-			detail::write_uint8(size, ptr);
-			std::memcpy(ptr, endp.data(), size);
-			ptr += size;
+			if (endp.protocol() == tcp::v4())
+				detail::write_endpoint(endp, v4_ptr);
+#if TORRENT_USE_IPV6
+			else
+				detail::write_endpoint(endp, v6_ptr);
+#endif
 		}
 	}
 
 	std::string dht_get_peers_reply_alert::message() const
 	{
 		char msg[200];
-		std::snprintf(msg, sizeof(msg), "incoming dht get_peers reply: %s, peers %d", aux::to_hex(info_hash).c_str(), m_num_peers);
+		std::snprintf(msg, sizeof(msg), "incoming dht get_peers reply: %s, peers %d"
+			, aux::to_hex(info_hash).c_str(), num_peers());
 		return msg;
 	}
 
 	int dht_get_peers_reply_alert::num_peers() const
 	{
-		return m_num_peers;
+		return m_v4_num_peers + m_v6_num_peers;
 	}
 
 #ifndef TORRENT_NO_DEPRECATE
@@ -1965,16 +1974,17 @@ namespace libtorrent
 #endif
 	std::vector<tcp::endpoint> dht_get_peers_reply_alert::peers() const
 	{
-		std::size_t const num_peers = aux::numeric_cast<std::size_t>(m_num_peers);
-		std::vector<tcp::endpoint> peers(num_peers);
+		aux::vector<tcp::endpoint> peers;
+		peers.reserve(num_peers());
 
-		const char *ptr = m_alloc.get().ptr(m_peers_idx);
-		for (std::size_t i = 0; i < num_peers; i++)
-		{
-			std::size_t const size = detail::read_uint8(ptr);
-			std::memcpy(peers[i].data(), ptr, size);
-			ptr += size;
-		}
+		char const* v4_ptr = m_alloc.get().ptr(m_v4_peers_idx);
+		for (int i = 0; i < m_v4_num_peers; i++)
+			peers.push_back(detail::read_v4_endpoint<tcp::endpoint>(v4_ptr));
+#if TORRENT_USE_IPV6
+		char const* v6_ptr = m_alloc.get().ptr(m_v6_peers_idx);
+		for (int i = 0; i < m_v6_num_peers; i++)
+			peers.push_back(detail::read_v6_endpoint<tcp::endpoint>(v6_ptr));
+#endif
 
 		return peers;
 	}

test/Jamfile

@@ -169,6 +169,7 @@ test-suite libtorrent :
 	[ run test_gzip.cpp ]
 	[ run test_receive_buffer.cpp ]
 	[ run test_alert_manager.cpp ]
+	[ run test_alert_types.cpp ]
 	[ run test_magnet.cpp ]
 	[ run test_storage.cpp ]
 	[ run test_session.cpp ]

test/Makefile.am

@@ -152,6 +152,7 @@ test_primitives_SOURCES = \
   test_identify_client.cpp \
   test_merkle.cpp \
   test_alert_manager.cpp \
+  test_alert_types.cpp \
   test_resolve_links.cpp \
   test_crc32.cpp \
   test_heterogeneous_queue.cpp \

test/setup_transfer.cpp

@@ -121,11 +121,11 @@ address rand_v6()
 
 static std::uint16_t g_port = 0;
 
-tcp::endpoint rand_tcp_ep()
+tcp::endpoint rand_tcp_ep(libtorrent::address(&rand_addr)())
 {
-	// make sure we don't procude the same "random" port twice
+	// make sure we don't produce the same "random" port twice
 	g_port = (g_port + 1) % 14038;
-	return tcp::endpoint(rand_v4(), g_port + 1024);
+	return tcp::endpoint(rand_addr(), g_port + 1024);
 }
 
 udp::endpoint rand_udp_ep(libtorrent::address(&rand_addr)())

test/setup_transfer.hpp

@@ -58,7 +58,7 @@ EXPORT libtorrent::address rand_v4();
 #if TORRENT_USE_IPV6
 EXPORT libtorrent::address rand_v6();
 #endif
-EXPORT libtorrent::tcp::endpoint rand_tcp_ep();
+EXPORT libtorrent::tcp::endpoint rand_tcp_ep(libtorrent::address(&rand_addr)() = rand_v4);
 EXPORT libtorrent::udp::endpoint rand_udp_ep(libtorrent::address(&rand_addr)() = rand_v4);
 
 EXPORT libtorrent::sha1_hash rand_hash();

test/test_alert_types.cpp

@@ -0,0 +1,73 @@
+/*
+
+Copyright (c) 2017, Arvid Norberg, Alden Torres
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in
+      the documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#include "libtorrent/alert_manager.hpp"
+#include "libtorrent/alert_types.hpp"
+#include "test.hpp"
+#include "setup_transfer.hpp"
+
+#include <algorithm>
+
+using namespace libtorrent;
+
+TORRENT_TEST(dht_get_peers_reply_alert)
+{
+	alert_manager mgr(1, dht_get_peers_reply_alert::static_category);
+
+	TEST_EQUAL(mgr.should_post<dht_get_peers_reply_alert>(), true);
+
+	sha1_hash const ih = rand_hash();
+	tcp::endpoint const ep1 = rand_tcp_ep(rand_v4);
+	tcp::endpoint const ep2 = rand_tcp_ep(rand_v4);
+	tcp::endpoint const ep3 = rand_tcp_ep(rand_v4);
+#if TORRENT_USE_IPV6
+	tcp::endpoint const ep4 = rand_tcp_ep(rand_v6);
+	tcp::endpoint const ep5 = rand_tcp_ep(rand_v6);
+#else
+	tcp::endpoint const ep4 = rand_tcp_ep(rand_v4);
+	tcp::endpoint const ep5 = rand_tcp_ep(rand_v4);
+#endif
+	std::vector<tcp::endpoint> v = {ep1, ep2, ep3, ep4, ep5};
+
+	mgr.emplace_alert<dht_get_peers_reply_alert>(ih, v);
+
+	auto const* a = alert_cast<dht_get_peers_reply_alert>(mgr.wait_for_alert(seconds(0)));
+	TEST_CHECK(a != nullptr);
+
+	TEST_EQUAL(a->info_hash, ih);
+	TEST_EQUAL(a->num_peers(), 5);
+
+	std::vector<tcp::endpoint> peers = a->peers();
+	std::sort(v.begin(), v.end());
+	std::sort(peers.begin(), peers.end());
+	TEST_CHECK(v == peers);
+}

tools/test_coverage.sh

@@ -46,6 +46,7 @@ run_test test_packet_buffer "*/packet_buffer.*"
 run_test test_ip_voter "*/ip_voter.*"
 run_test test_bitfield "*/bitfield.*"
 run_test test_alert_manager "*/alert_manager.*"
+run_test test_alert_types "*/alert_types.*"
 run_test test_dht "*/kademlia/*"
 run_test test_bdecode "*/bdecode.*"
 run_test test_piece_picker "*/piece_picker.*"