allow specifying which tracker to scrape in torrent_hadnle::scrape_tracker

ChangeLog

@@ -1,6 +1,7 @@
 
 1.1.0 release
 
+	* allow specifying which tracker to scrape in scrape_tracker
 	* tracker response alerts from user initiated announces/scrapes are now
 	  posted regardless of alert mask
 	* improve DHT performance when changing external IP (primarily affects

include/libtorrent/torrent.hpp

@@ -722,7 +722,7 @@ namespace libtorrent
 
 		// forcefully sets next_announce to the current time
 		void force_tracker_request(time_point, int tracker_idx);
-		void scrape_tracker(bool user_triggered);
+		void scrape_tracker(int idx, bool user_triggered);
 		void announce_with_tracker(boost::uint8_t e
 			= tracker_request::none
 			, address const& bind_interface = address_v4::any());

include/libtorrent/torrent_handle.hpp

@@ -1085,15 +1085,18 @@ namespace libtorrent
 		void force_reannounce(boost::posix_time::time_duration) const;
 #endif
 
-		// ``scrape_tracker()`` will send a scrape request to the tracker. A
-		// scrape request queries the tracker for statistics such as total number
-		// of incomplete peers, complete peers, number of downloads etc.
+		// ``scrape_tracker()`` will send a scrape request to a tracker. By
+		// default (``idx`` = -1) it will scrape the last working tracker. If
+		// ``idx`` is >= 0, the tracker with the specified index will scraped.
+		// 
+		// A scrape request queries the tracker for statistics such as total
+		// number of incomplete peers, complete peers, number of downloads etc.
 		// 
 		// This request will specifically update the ``num_complete`` and
 		// ``num_incomplete`` fields in the torrent_status struct once it
 		// completes. When it completes, it will generate a scrape_reply_alert.
 		// If it fails, it will generate a scrape_failed_alert.
-		void scrape_tracker() const;
+		void scrape_tracker(int idx = -1) const;
 
 		// ``set_upload_limit`` will limit the upload bandwidth used by this
 		// particular torrent to the limit you set. It is given as the number of

simulation/test_tracker.cpp

@@ -363,8 +363,8 @@ TORRENT_TEST(ipv6_support)
 	TEST_EQUAL(v6_announces, 2);
 }
 
-template <typename Announce, typename Test>
-void announce_entry_test(Announce a, Test t)
+template <typename Announce, typename Test1, typename Test2>
+void tracker_test(Announce a, Test1 test1, Test2 test2, char const* url_path = "/announce")
 {
 	using sim::asio::ip::address_v4;
 	sim_config network_cfg;
@@ -375,7 +375,7 @@ void announce_entry_test(Announce a, Test t)
 	// listen on port 8080
 	sim::http_server http(tracker_ios, 8080);
 
-	http.register_handler("/announce", a);
+	http.register_handler(url_path, a);
 
 	lt::session_proxy zombie;
 
@@ -393,26 +393,31 @@ void announce_entry_test(Announce a, Test t)
 	p.trackers.push_back("http://tracker.com:8080/announce");
 	ses->async_add_torrent(p);
 
-	// stop the torrent 5 seconds in
+	// run the test 5 seconds in
 	asio::high_resolution_timer t1(ios);
 	t1.expires_from_now(chrono::seconds(5));
-	t1.async_wait([&ses,&t](boost::system::error_code const& ec)
+	t1.async_wait([&ses,&test1](boost::system::error_code const& ec)
 	{
 		std::vector<lt::torrent_handle> torrents = ses->get_torrents();
 		TEST_EQUAL(torrents.size(), 1);
 		torrent_handle h = torrents.front();
+		test1(h);
+	});
 
-		std::vector<announce_entry> tr = h.trackers();
-
-		TEST_EQUAL(tr.size(), 1);
-		announce_entry const& ae = tr[0];
-		t(ae);
+	asio::high_resolution_timer t2(ios);
+	t2.expires_from_now(chrono::seconds(9));
+	t2.async_wait([&ses,&test2](boost::system::error_code const& ec)
+	{
+		std::vector<lt::torrent_handle> torrents = ses->get_torrents();
+		TEST_EQUAL(torrents.size(), 1);
+		torrent_handle h = torrents.front();
+		test2(h);
 	});
 
 	// then shut down 10 seconds in
-	asio::high_resolution_timer t2(ios);
-	t2.expires_from_now(chrono::seconds(10));
-	t2.async_wait([&ses,&zombie](boost::system::error_code const& ec)
+	asio::high_resolution_timer t3(ios);
+	t3.expires_from_now(chrono::seconds(10));
+	t3.async_wait([&ses,&zombie](boost::system::error_code const& ec)
 	{
 		zombie = ses->abort();
 		ses->set_alert_notify([]{});
@@ -422,6 +427,21 @@ void announce_entry_test(Announce a, Test t)
 	sim.run();
 }
 
+template <typename Announce, typename Test>
+void announce_entry_test(Announce a, Test t, char const* url_path = "/announce")
+{
+	tracker_test(a
+		, [&t] (torrent_handle h) {
+			std::vector<announce_entry> tr = h.trackers();
+
+			TEST_EQUAL(tr.size(), 1);
+			announce_entry const& ae = tr[0];
+			t(ae);
+		}
+		, [](torrent_handle){}
+		, url_path);
+}
+
 TORRENT_TEST(test_error)
 {
 	announce_entry_test(
@@ -467,7 +487,7 @@ TORRENT_TEST(test_warning)
 		});
 }
 
-TORRENT_TEST(test_scrape)
+TORRENT_TEST(test_scrape_data_in_announce)
 {
 	announce_entry_test(
 		[](std::string method, std::string req
@@ -493,6 +513,36 @@ TORRENT_TEST(test_scrape)
 		});
 }
 
+TORRENT_TEST(test_scrape)
+{
+	tracker_test(
+		[](std::string method, std::string req
+			, std::map<std::string, std::string>& headers)
+		{
+			TEST_EQUAL(method, "GET");
+
+			char response[500];
+			int size = snprintf(response, sizeof(response),
+				"d5:filesd20:ababababababababababd8:completei1e10:downloadedi3e10:incompletei2eeee");
+			return sim::send_response(200, "OK", size) + response;
+		}
+		, [](torrent_handle h)
+		{
+			h.scrape_tracker();
+		}
+		, [](torrent_handle h)
+		{
+			std::vector<announce_entry> tr = h.trackers();
+
+			TEST_EQUAL(tr.size(), 1);
+			announce_entry const& ae = tr[0];
+			TEST_EQUAL(ae.scrape_incomplete, 2);
+			TEST_EQUAL(ae.scrape_complete, 1);
+			TEST_EQUAL(ae.scrape_downloaded, 3);
+		}
+		, "/scrape");
+}
+
 TORRENT_TEST(test_http_status)
 {
 	announce_entry_test(

src/session_impl.cpp

@@ -3220,7 +3220,7 @@ retry:
 
 					// false means it's not triggered by the user, but automatically
 					// by libtorrent
-					t.scrape_tracker(false);
+					t.scrape_tracker(-1, false);
 
 					++m_next_scrape_torrent;
 					if (m_next_scrape_torrent >= int(want_scrape.size()))

src/torrent.cpp

@@ -3279,15 +3279,15 @@ namespace libtorrent
 		update_tracker_timer(now);
 	}
 
-	void torrent::scrape_tracker(bool user_triggered)
+	void torrent::scrape_tracker(int idx, bool user_triggered)
 	{
 		TORRENT_ASSERT(is_single_thread());
 		m_last_scrape = m_ses.session_time();
 
 		if (m_trackers.empty()) return;
 
-		int i = m_last_working_tracker;
-		if (i == -1) i = 0;
+		if (idx < 0 || idx >= int(m_trackers.size())) idx = m_last_working_tracker;
+		if (idx < 0) idx = 0;
 
 		tracker_request req;
 		if (settings().get_bool(settings_pack::apply_ip_filter_to_trackers)
@@ -3296,7 +3296,7 @@ namespace libtorrent
 
 		req.info_hash = m_torrent_file->info_hash();
 		req.kind |= tracker_request::scrape_request;
-		req.url = m_trackers[i].url;
+		req.url = m_trackers[idx].url;
 #ifndef TORRENT_NO_DEPRECATE
 		req.auth = tracker_login();
 #endif

src/torrent_handle.cpp

@@ -800,9 +800,9 @@ namespace libtorrent
 		ses.disk_thread().files().get_status(&status, &t->storage());
 	}
 
-	void torrent_handle::scrape_tracker() const
+	void torrent_handle::scrape_tracker(int idx) const
 	{
-		TORRENT_ASYNC_CALL1(scrape_tracker, true);
+		TORRENT_ASYNC_CALL2(scrape_tracker, idx, true);
 	}
 
 	void torrent_handle::super_seeding(bool on) const