make the save path for part files configurable

Author: arvidn

ChangeLog

@@ -1,5 +1,6 @@
 2.1.0 not released
 
+	* make the save path for part files configurable
 	* retry failed SAM connection (for i2p)
 	* deprecated remap_files(), and prevent it from breaking v2 torrents
 	* fix peer_info holding an i2p destination

bindings/python/src/session.cpp

@@ -339,6 +339,11 @@ namespace
                 p.save_path = extract<std::string>(value);
                 continue;
             }
+            else if(key == "part_file_dir")
+            {
+                p.part_file_dir = extract<std::string>(value);
+                continue;
+            }
 #if TORRENT_ABI_VERSION == 1
             else if(key == "resume_data")
             {
@@ -1006,6 +1011,7 @@ void bind_session()
         .add_property("dht_nodes", PROP(&add_torrent_params::dht_nodes))
         .def_readwrite("name", &add_torrent_params::name)
         .def_readwrite("save_path", &add_torrent_params::save_path)
+        .def_readwrite("part_file_dir", &add_torrent_params::part_file_dir)
         .def_readwrite("storage_mode", &add_torrent_params::storage_mode)
 //        .def_readwrite("storage", &add_torrent_params::storage)
         .add_property("file_priorities", PROP(&add_torrent_params::file_priorities))

examples/connection_tester.cpp

@@ -939,6 +939,7 @@ void generate_data(std::string const path, torrent_info const& ti)
 		fs,
 		rf,
 		path,
+		{},
 		storage_mode_sparse,
 		priorities,
 		info_hash,

include/libtorrent/add_torrent_params.hpp

@@ -145,7 +145,7 @@ TORRENT_VERSION_NAMESPACE_3
 		// The name out of the torrent_info object takes precedence if available.
 		std::string name;
 
-		// the path where the torrent is or will be stored.
+		// The path to the directory where the torrent is or will be stored.
 		//
 		// .. note::
 		// 	On windows this path (and other paths) are interpreted as UNC
@@ -156,6 +156,17 @@ TORRENT_VERSION_NAMESPACE_3
 		// relative path.
 		std::string save_path;
 
+		// This is an optional field. If set, the part-file for this torrent
+		// will be stored in the specified subdirectory, still inside its
+		// download directory. The part file name is the info-hash, in hexadecimal
+		// form. By default it's stored directly in the download directory.
+		// If the storage for a torrent is moved, the part file is also moved
+		// along with it, to the new download directory.
+		// A part file contains partial pieces that
+		// need to be downloaded in order to verify hashes and seeding, but are
+		// part of files whose priority is zero.
+		std::string part_file_dir;
+
 		// One of the values from storage_mode_t. For more information, see
 		// storage-allocation_.
 		storage_mode_t storage_mode = storage_mode_sparse;

include/libtorrent/aux_/mmap_storage.hpp

@@ -153,6 +153,7 @@ namespace libtorrent::aux {
 
 		aux::vector<download_priority_t, file_index_t> m_file_priority;
 		std::string m_save_path;
+		std::string m_part_file_dir;
 		std::string m_part_file_name;
 
 		// this this is an array indexed by file-index. Each slot represents

include/libtorrent/aux_/posix_storage.hpp

@@ -76,6 +76,7 @@ namespace aux {
 		file_storage const& m_files;
 		renamed_files m_renamed_files;
 		std::string m_save_path;
+		std::string m_part_file_dir;
 		stat_cache m_stat_cache;
 
 		aux::vector<download_priority_t, file_index_t> m_file_priority;

include/libtorrent/aux_/storage_utils.hpp

@@ -41,7 +41,7 @@ namespace libtorrent::aux {
 	// opt to only delete the partfile
 	TORRENT_EXTRA_EXPORT void
 	delete_files(filenames const& fs, std::string const& save_path
-		, std::string const& part_file_name, remove_flags_t options, storage_error& ec);
+		, std::string const& part_file, remove_flags_t options, storage_error& ec);
 
 	TORRENT_EXTRA_EXPORT bool
 	verify_resume_data(add_torrent_params const& rd

include/libtorrent/aux_/torrent.hpp

@@ -1401,6 +1401,7 @@ namespace libtorrent::aux {
 #endif
 
 		std::string m_save_path;
+		std::string m_part_file_dir;
 		aux::cached_slot m_name_idx;
 
 #ifndef TORRENT_DISABLE_PREDICTIVE_PIECES

include/libtorrent/storage_defs.hpp

@@ -18,6 +18,7 @@ see LICENSE file.
 #include "libtorrent/aux_/vector.hpp"
 #include "libtorrent/sha1_hash.hpp"
 #include "libtorrent/download_priority.hpp"
+#include "libtorrent/string_view.hpp"
 #include <functional>
 #include <string>
 
@@ -82,12 +83,13 @@ namespace libtorrent {
 	struct TORRENT_EXPORT storage_params
 	{
 		storage_params(file_storage const& f, lt::renamed_files const& mf
-			, std::string const& sp, storage_mode_t const sm
+			, string_view sp, string_view pfd, storage_mode_t const sm
 			, aux::vector<download_priority_t, file_index_t> const& prio
 			, sha1_hash const& ih, bool v1_torrent, bool v2_torrent)
 			: files(f)
 			, renamed_files(mf)
 			, path(sp)
+			, part_file_dir(pfd)
 			, mode(sm)
 			, priorities(prio)
 			, info_hash(ih)
@@ -96,7 +98,8 @@ namespace libtorrent {
 		{}
 		file_storage const& files;
 		lt::renamed_files const& renamed_files;
-		std::string const& path;
+		string_view path;
+		string_view part_file_dir;
 		storage_mode_t mode{storage_mode_sparse};
 		aux::vector<download_priority_t, file_index_t> const& priorities;
 		sha1_hash info_hash;

src/create_torrent.cpp

@@ -483,6 +483,7 @@ namespace {
 			fs,
 			rf,
 			path,
+			{},
 			storage_mode_t::storage_mode_sparse,
 			priorities,
 			sha1_hash{},