remove support for BEP 30 merkle tree torrents

With the adoption of BEP 52, BEP 30 is now obsolete. This code has also
been broken for some time. The merkle_* functions have been retained because
they will probably be usefull for BEP 52.

examples/make_torrent.cpp

@@ -117,10 +117,6 @@ or directory and writes it to standard out
 
 
 OPTIONS:
--m file       generate a merkle hash tree torrent.
-              merkle torrents require client support
-              the resulting full merkle tree is written to
-              the specified file
 -w url        adds a web seed to the torrent with
               the specified url
 -t url        adds the specified tracker to the
@@ -173,7 +169,6 @@ int main(int argc_, char const* argv_[]) try
 	std::string root_cert;
 
 	std::string outfile;
-	std::string merklefile;
 #ifdef TORRENT_WINDOWS
 	// don't ever write binary data to the console on windows
 	// it will just be interpreted as text and corrupted
@@ -221,10 +216,6 @@ int main(int argc_, char const* argv_[]) try
 				pad_file_limit = atoi(args[1]);
 				flags |= lt::create_torrent::optimize_alignment;
 				break;
-			case 'm':
-				merklefile = args[1];
-				flags |= lt::create_torrent::merkle;
-				break;
 			case 'S': {
 				if (strlen(args[1]) != 40) {
 					std::cerr << "invalid info-hash for -S. "
@@ -331,13 +322,6 @@ int main(int argc_, char const* argv_[]) try
 		std::cout.write(torrent.data(), torrent.size());
 	}
 
-	if (!merklefile.empty()) {
-		std::fstream merkle;
-		merkle.exceptions(std::ifstream::failbit);
-		merkle.open(merklefile.c_str(), std::ios_base::out | std::ios_base::binary);
-		auto const& tree = t.merkle_tree();
-		merkle.write(reinterpret_cast<char const*>(tree.data()), tree.size() * 20);
-	}
 	return 0;
 }
 catch (std::exception& e) {

include/libtorrent/add_torrent_params.hpp

@@ -312,10 +312,18 @@ TORRENT_VERSION_NAMESPACE_2
 		// precedence.
 		aux::noexcept_movable<std::vector<download_priority_t>> piece_priorities;
 
+#if TORRENT_ABI_VERSION <= 2
+		// support for BEP 30 merkle torrents has been removed
+
 		// if this is a merkle tree torrent, and you're seeding, this field must
 		// be set. It is all the hashes in the binary tree, with the root as the
 		// first entry. See torrent_info::set_merkle_tree() for more info.
-		aux::noexcept_movable<std::vector<sha1_hash>> merkle_tree;
+		aux::noexcept_movable<std::vector<sha1_hash>> TORRENT_DEPRECATED_MEMBER merkle_tree;
+#else
+		// hidden
+		// to maintain ABI compatibility
+		aux::noexcept_movable<std::vector<sha1_hash>> deprecated6;
+#endif
 
 		// this is a map of file indices in the torrent and new filenames to be
 		// applied before the torrent is added.

include/libtorrent/create_torrent.hpp

@@ -119,7 +119,10 @@ namespace libtorrent {
 		// When creating merkle torrents, the full hash tree is also generated
 		// and should be saved off separately. It is accessed through the
 		// create_torrent::merkle_tree() function.
-		static constexpr create_flags_t merkle = 1_bit;
+#ifndef TORRENT_NO_DEPRECATE
+		// support for BEP 30 merkle torrents has been removed
+		static constexpr create_flags_t TORRENT_DEPRECATED_MEMBER merkle = 1_bit;
+#endif
 
 		// This will include the file modification time as part of the torrent.
 		// This is not enabled by default, as it might cause problems when you
@@ -272,13 +275,18 @@ namespace libtorrent {
 		int piece_length() const { return m_files.piece_length(); }
 		int piece_size(piece_index_t i) const { return m_files.piece_size(i); }
 
+#ifndef TORRENT_NO_DEPRECATE
+		// support for BEP 30 merkle torrents has been removed
+
 		// This function returns the merkle hash tree, if the torrent was created as a merkle
 		// torrent. The tree is created by ``generate()`` and won't be valid until that function
 		// has been called. When creating a merkle tree torrent, the actual tree itself has to
 		// be saved off separately and fed into libtorrent the first time you start seeding it,
 		// through the ``torrent_info::set_merkle_tree()`` function. From that point onwards, the
 		// tree will be saved in the resume data.
-		std::vector<sha1_hash> const& merkle_tree() const { return m_merkle_tree; }
+		TORRENT_DEPRECATED
+		std::vector<sha1_hash> merkle_tree() const { return std::vector<sha1_hash>(); }
+#endif
 
 		// Add similar torrents (by info-hash) or collections of similar torrents.
 		// Similar torrents are expected to share some files with this torrent.
@@ -312,11 +320,6 @@ namespace libtorrent {
 		std::vector<sha1_hash> m_similar;
 		std::vector<std::string> m_collections;
 
-		// if we're generating a merkle torrent, this is the
-		// merkle tree we got. This should be saved in fast-resume
-		// in order to start seeding the torrent
-		mutable aux::vector<sha1_hash> m_merkle_tree;
-
 		// dht nodes to add to the routing table/bootstrap from
 		std::vector<std::pair<std::string, int>> m_nodes;
 
@@ -347,9 +350,6 @@ namespace libtorrent {
 		// advertise itself on the DHT for this torrent
 		bool m_private:1;
 
-		// if set to one, a merkle torrent will be generated
-		bool m_merkle_torrent:1;
-
 		// if set, include the 'mtime' modification time in the
 		// torrent file
 		bool m_include_mtime:1;

include/libtorrent/settings_pack.hpp

@@ -642,9 +642,15 @@ namespace aux {
 			// if false, prevents libtorrent to advertise share-mode support
 			support_share_mode,
 
+#if TORRENT_ABI_VERSION <= 2
+			// support for BEP 30 merkle torrents has been removed
+
 			// if this is false, don't advertise support for the Tribler merkle
 			// tree piece message
-			support_merkle_torrents,
+			support_merkle_torrents TORRENT_DEPRECATED_ENUM,
+#else
+			deprecated_support_merkle_torrents,
+#endif
 
 			// if this is true, the number of redundant bytes is sent to the
 			// tracker

include/libtorrent/torrent.hpp

@@ -1067,8 +1067,6 @@ namespace libtorrent {
 		{ return m_verified.get_bit(piece); }
 		void verified(piece_index_t piece);
 
-		bool add_merkle_nodes(std::map<int, sha1_hash> const& n, piece_index_t piece);
-
 		// this is called once periodically for torrents
 		// that are not private
 		void lsd_announce();

include/libtorrent/torrent_info.hpp

@@ -458,22 +458,17 @@ namespace libtorrent {
 			TORRENT_ASSERT(index < m_files.end_piece());
 			TORRENT_ASSERT(is_loaded());
 			int const idx = static_cast<int>(index);
-			if (is_merkle_torrent())
-			{
-				TORRENT_ASSERT(idx < m_merkle_tree.end_index() - m_merkle_first_leaf);
-				return m_merkle_tree[m_merkle_first_leaf + idx].data();
-			}
-			else
-			{
-				TORRENT_ASSERT(m_piece_hashes);
-				TORRENT_ASSERT(m_piece_hashes >= m_info_section.get());
-				TORRENT_ASSERT(m_piece_hashes < m_info_section.get() + m_info_section_size);
-				TORRENT_ASSERT(idx < int(m_info_section_size / 20));
-				return &m_piece_hashes[idx * 20];
-			}
+			TORRENT_ASSERT(m_piece_hashes);
+			TORRENT_ASSERT(m_piece_hashes >= m_info_section.get());
+			TORRENT_ASSERT(m_piece_hashes < m_info_section.get() + m_info_section_size);
+			TORRENT_ASSERT(idx < int(m_info_section_size / 20));
+			return &m_piece_hashes[idx * 20];
 		}
 
-		bool is_loaded() const { return m_piece_hashes || !m_merkle_tree.empty(); }
+		bool is_loaded() const { return m_piece_hashes; }
+
+#if TORRENT_ABI_VERSION <= 2
+		// support for BEP 30 merkle torrents has been removed
 
 		// ``merkle_tree()`` returns a reference to the merkle tree for this
 		// torrent, if any.
@@ -484,9 +479,12 @@ namespace libtorrent {
 		// ``create_torrent::merkle_tree()`` function, and need to be saved
 		// separately from the torrent file itself. Once it's added to
 		// libtorrent, the merkle tree will be persisted in the resume data.
+		TORRENT_DEPRECATED
 		std::vector<sha1_hash> const& merkle_tree() const { return m_merkle_tree; }
+		TORRENT_DEPRECATED
 		void set_merkle_tree(std::vector<sha1_hash>& h)
 		{ TORRENT_ASSERT(h.size() == m_merkle_tree.size() ); m_merkle_tree.swap(h); }
+#endif
 
 		// ``name()`` returns the name of the torrent.
 		// name contains UTF-8 encoded string.
@@ -541,16 +539,26 @@ namespace libtorrent {
 		boost::shared_array<char> metadata() const
 		{ return m_info_section; }
 
+#if TORRENT_ABI_VERSION <= 2
+		// support for BEP 30 merkle torrents has been removed
+
 		// internal
-		bool add_merkle_nodes(std::map<int, sha1_hash> const& subtree
-			, piece_index_t piece);
-		std::map<int, sha1_hash> build_merkle_list(piece_index_t piece) const;
+		TORRENT_DEPRECATED
+		bool add_merkle_nodes(std::map<int, sha1_hash> const&
+			, piece_index_t) { return false; }
+		TORRENT_DEPRECATED
+		std::map<int, sha1_hash> build_merkle_list(piece_index_t) const
+		{
+			return std::map<int, sha1_hash>();
+		}
 
 		// returns whether or not this is a merkle torrent.
 		// see `BEP 30`__.
 		//
 		// __ http://bittorrent.org/beps/bep_0030.html
+		TORRENT_DEPRECATED
 		bool is_merkle_torrent() const { return !m_merkle_tree.empty(); }
+#endif
 
 		bool parse_torrent_file(bdecode_node const& libtorrent, error_code& ec);
 
@@ -608,10 +616,14 @@ namespace libtorrent {
 		// cannot be pointers into that buffer.
 		std::vector<std::string> m_owned_collections;
 
+#if TORRENT_ABI_VERSION <= 2
 		// if this is a merkle torrent, this is the merkle
 		// tree. It has space for merkle_num_nodes(merkle_num_leafs(num_pieces))
 		// hashes
 		aux::vector<sha1_hash> m_merkle_tree;
+#else
+		aux::vector<sha1_hash> deprecated1;
+#endif
 
 		// this is a copy of the info section from the torrent.
 		// it use maintained in this flat format in order to
@@ -646,9 +658,13 @@ namespace libtorrent {
 		// the number of bytes in m_info_section
 		std::int32_t m_info_section_size = 0;
 
+#if TORRENT_ABI_VERSION <= 2
 		// the index to the first leaf. This is where the hash for the
 		// first piece is stored
 		std::int32_t m_merkle_first_leaf = 0;
+#else
+		std::int32_t deprecated2 = 0;
+#endif
 
 		enum flags_t : std::uint8_t
 		{