added torrent_info::remap_files()

ChangeLog

@@ -80,6 +80,7 @@
 	* automatically caps files and connections by default to rlimit
 	* added session::is_dht_running() function
 	* added torrent_handle::force_dht_announce()
+	* added torrent_info::remap_files()
 
 release 0.14.8
 

docs/manual.rst

@@ -1408,6 +1408,8 @@ The ``torrent_info`` has the following synopsis::
 		file_storage const& files() const;
 		file_storage const& orig_files() const;
 
+		void remap_files(file_storage const& f);
+
 		void rename_file(int index, std::string const& new_filename);
 		void rename_file(int index, std::wstring const& new_filename);
 
@@ -1528,6 +1530,19 @@ names. Filename may be chaged using ``torrent_info::rename_file()``.
 For more information on the ``file_storage`` object, see the separate document on how
 to create torrents.
 
+remap_files()
+-------------
+
+	::
+
+		void remap_files(file_storage const& f);
+
+Remaps the file storage to a new file layout. This can be used to, for instance,
+download all data in a torrent to a single file, or to a number of fixed size
+sector aligned files, regardless of the number and sizes of the files in the torrent.
+
+The new specified ``file_storage`` must have the exact same size as the current one.
+
 rename_file()
 -------------
 

include/libtorrent/torrent_info.hpp

@@ -195,6 +195,8 @@ namespace libtorrent
 		}
 #endif // TORRENT_USE_WSTRING
 
+		void remap_files(file_storage const& f);
+
 		void add_tracker(std::string const& url, int tier = 0);
 		std::vector<announce_entry> const& trackers() const { return m_urls; }
 

src/torrent_info.cpp

@@ -451,6 +451,17 @@ namespace libtorrent
 		}
 	}
 
+	void torrent_info::remap_files(file_storage const& f)
+	{
+		// the new specified file storage must have the exact
+		// same size as the current file storage
+		TORRENT_ASSERT(m_files.total_size() == f.total_size());
+
+		if (m_files.total_size() != f.total_size()) return;
+		copy_on_write();
+		m_files = f;
+	}
+
 #ifndef TORRENT_NO_DEPRECATE
 	// standard constructor that parses a torrent file
 	torrent_info::torrent_info(entry const& torrent_file)