add function to get default settings

ChangeLog

@@ -1,3 +1,4 @@
+	* add function to get default settings
 	* updating super seeding would include the torrent in state_update_alert
 	* fix issue where num_seeds could be greater than num_peers in torrent_status
 	* finished non-seed torrents can also be in super-seeding mode

bindings/python/src/session.cpp

@@ -214,6 +214,11 @@ namespace
 		return make_dict(ret);
 	}
 
+	dict default_settings_wrapper()
+	{
+		return make_dict(default_settings());
+	}
+
 	dict high_performance_seed_wrapper()
 	{
 		settings_pack ret;
@@ -983,6 +988,7 @@ void bind_session()
 
     def("high_performance_seed", high_performance_seed_wrapper);
     def("min_memory_usage", min_memory_usage_wrapper);
+    def("default_settings", default_settings_wrapper);
 
 	class_<stats_metric>("stats_metric")
 		.def_readonly("name", &stats_metric::name)

bindings/python/test.py

@@ -267,6 +267,11 @@ class test_session(unittest.TestCase):
 		self.assertTrue('connection_speed' in seed_mode)
 		self.assertTrue('file_pool_size' in seed_mode)
 
+	def test_default_settings(self):
+
+		default = lt.default_settings()
+		print(default)
+
 if __name__ == '__main__':
 	print(lt.__version__)
 	shutil.copy(os.path.join('..', '..', 'test', 'test_torrents', 'url_seed_multi.torrent'), '.')

include/libtorrent/settings_pack.hpp

@@ -70,6 +70,9 @@ namespace libtorrent
 	TORRENT_EXPORT int setting_by_name(std::string const& name);
 	TORRENT_EXPORT char const* name_for_setting(int s);
 
+	// returns a settings_pack with every setting set to its default value
+	TORRENT_EXPORT settings_pack default_settings();
+
 #ifndef TORRENT_NO_DEPRECATE
 	struct session_settings;
 	settings_pack load_pack_from_struct(aux::session_settings const& current, session_settings const& s);

src/session.cpp

@@ -296,7 +296,6 @@ namespace libtorrent
 	TORRENT_EXPORT session_settings min_memory_usage()
 	{
 		aux::session_settings def;
-		initialize_default_settings(def);
 		settings_pack pack;
 		min_memory_usage(pack);
 		apply_pack(&pack, def, 0);
@@ -308,7 +307,6 @@ namespace libtorrent
 	TORRENT_EXPORT session_settings high_performance_seed()
 	{
 		aux::session_settings def;
-		initialize_default_settings(def);
 		settings_pack pack;
 		high_performance_seed(pack);
 		apply_pack(&pack, def, 0);
@@ -421,7 +419,6 @@ namespace libtorrent
 	session_settings::session_settings(std::string const& user_agent_)
 	{
 		aux::session_settings def;
-		initialize_default_settings(def);
 		def.set_str(settings_pack::user_agent, user_agent_);
 		load_struct_from_settings(def, *this);
 	}

src/settings_pack.cpp

@@ -56,6 +56,11 @@ namespace {
 		if (i != c.end() && i->first == v.first) i->second = v.second;
 		else c.insert(i, v);
 	}
+
+	// return the string, unless it's null, in which case the empty string is
+	// returned
+	char const* ensure_string(char const* str)
+	{ return str == NULL ? "" : str; }
 }
 
 namespace libtorrent
@@ -441,8 +446,7 @@ namespace libtorrent
 		// loop over all settings that differ from default
 		for (int i = 0; i < settings_pack::num_string_settings; ++i)
 		{
-			char const* cmp = str_settings[i].default_value == 0 ? "" : str_settings[i].default_value;
-			if (cmp == s.m_strings[i]) continue;
+			if (ensure_string(str_settings[i].default_value) == s.m_strings[i]) continue;
 			sett[str_settings[i].name] = s.m_strings[i];
 		}
 
@@ -553,7 +557,7 @@ namespace libtorrent
 	{
 		for (int i = 0; i < settings_pack::num_string_settings; ++i)
 		{
-			if (str_settings[i].default_value == 0) continue;
+			if (str_settings[i].default_value == NULL) continue;
 			s.set_str(settings_pack::string_type_base + i, str_settings[i].default_value);
 			TORRENT_ASSERT(s.get_str(settings_pack::string_type_base + i) == str_settings[i].default_value);
 		}
@@ -569,16 +573,28 @@ namespace libtorrent
 			s.set_bool(settings_pack::bool_type_base + i, bool_settings[i].default_value);
 			TORRENT_ASSERT(s.get_bool(settings_pack::bool_type_base + i) == bool_settings[i].default_value);
 		}
+	}
 
-		// this seems questionable...
-/*
-		// Some settings have dynamic defaults depending on the machine
-		// for instance, the disk cache size
+	settings_pack default_settings()
+	{
+		settings_pack ret;
+		// TODO: it would be nice to reserve() these vectors up front
+		for (int i = 0; i < settings_pack::num_string_settings; ++i)
+		{
+			if (str_settings[i].default_value == NULL) continue;
+			ret.set_str(settings_pack::string_type_base + i, str_settings[i].default_value);
+		}
 
-		// by default, set the cahe size to an 8:th of the total amount of physical RAM
-		boost::uint64_t phys_ram = total_physical_ram();
-		if (phys_ram > 0) s.set_int(settings_pack::cache_size, phys_ram / 16 / 1024 / 8);
-*/
+		for (int i = 0; i < settings_pack::num_int_settings; ++i)
+		{
+			ret.set_int(settings_pack::int_type_base + i, int_settings[i].default_value);
+		}
+
+		for (int i = 0; i < settings_pack::num_bool_settings; ++i)
+		{
+			ret.set_bool(settings_pack::bool_type_base + i, bool_settings[i].default_value);
+		}
+		return ret;
 	}
 
 	void apply_pack(settings_pack const* pack, aux::session_settings& sett

test/test_bandwidth_limiter.cpp

@@ -158,7 +158,6 @@ void run_test(connections_t& v
 		, boost::bind(&peer_connection::start, _1));
 
 	libtorrent::aux::session_settings s;
-	initialize_default_settings(s);
 	int tick_interval = s.get_int(settings_pack::tick_interval);
 
 	for (int i = 0; i < int(sample_time * 1000 / tick_interval); ++i)

test/test_settings_pack.cpp

@@ -43,7 +43,6 @@ using namespace libtorrent::aux;
 TORRENT_TEST(default_settings)
 {
 	aux::session_settings sett;
-	initialize_default_settings(sett);
 
 	entry e;
 	save_settings_to_dict(sett, e.dict());
@@ -57,10 +56,34 @@ TORRENT_TEST(default_settings)
 #endif
 }
 
+TORRENT_TEST(default_settings2)
+{
+	aux::session_settings sett;
+
+	settings_pack def = default_settings();
+
+	for (int i = 0; i < settings_pack::num_string_settings; ++i)
+	{
+		TEST_EQUAL(sett.get_str(settings_pack::string_type_base + i)
+			, def.get_str(settings_pack::string_type_base + i));
+	}
+
+	for (int i = 0; i < settings_pack::num_int_settings; ++i)
+	{
+		TEST_EQUAL(sett.get_int(settings_pack::int_type_base + i)
+			, def.get_int(settings_pack::int_type_base + i));
+	}
+
+	for (int i = 0; i < settings_pack::num_bool_settings; ++i)
+	{
+		TEST_EQUAL(sett.get_bool(settings_pack::bool_type_base + i)
+			, def.get_bool(settings_pack::bool_type_base + i));
+	}
+}
+
 TORRENT_TEST(apply_pack)
 {
 	aux::session_settings sett;
-	initialize_default_settings(sett);
 	settings_pack sp;
 	sp.set_int(settings_pack::max_out_request_queue, 1337);