fix issue of force-recheck or seeding from read-only media, torrents with empty files in them. Previously libtorrent would create empty files up-front unconditionally, now they won't be created if they already exist

ChangeLog

@@ -1,3 +1,4 @@
+	* don't attempt to create empty files on startup, if they already exist
 	* fix force-recheck issue (new files would not be picked up)
 	* fix inconsistency in file_priorities and override_resume_data behavior
 

src/storage.cpp

@@ -543,7 +543,8 @@ namespace libtorrent
 			// ignore pad files
 			if (files().pad_file_at(file_index)) continue;
 
-			if (m_stat_cache.get_filesize(file_index) == stat_cache::not_in_cache)
+			boost::int64_t cached_size = m_stat_cache.get_filesize(file_index);
+			if (cached_size == stat_cache::not_in_cache)
 			{
 				file_status s;
 				std::string file_path = files().file_path(file_index, m_save_path);
@@ -551,6 +552,7 @@ namespace libtorrent
 				if (!ec)
 				{
 					m_stat_cache.set_cache(file_index, s.file_size, s.mtime);
+					cached_size = s.file_size;
 				}
 				else if (ec.ec != boost::system::errc::no_such_file_or_directory)
 				{
@@ -559,13 +561,17 @@ namespace libtorrent
 					ec.operation = storage_error::stat;
 					break;
 				}
+				else
+				{
+					cached_size = stat_cache::no_exist;
+				}
 			}
 
 			// if the file already exists, but is larger than what
 			// it's supposed to be, truncate it
-			// if the file is empty, just create it either way.
-			if ((!ec && m_stat_cache.get_filesize(file_index) > files().file_size(file_index))
-				|| files().file_size(file_index) == 0)
+			// if the file is empty and doesn't already exist, create it
+			if ((!ec && cached_size > files().file_size(file_index))
+				|| (files().file_size(file_index) == 0 && cached_size == stat_cache::no_exist))
 			{
 				std::string file_path = files().file_path(file_index, m_save_path);
 				std::string dir = parent_path(file_path);

test/setup_transfer.cpp

@@ -595,7 +595,8 @@ boost::shared_ptr<T> clone_ptr(boost::shared_ptr<T> const& ptr)
 unsigned char random_byte()
 { return std::rand() & 0xff; }
 
-void create_random_files(std::string const& path, const int file_sizes[], int num_files)
+void create_random_files(std::string const& path, const int file_sizes[], int num_files
+	, file_storage* fs)
 {
 	error_code ec;
 	char* random_data = (char*)malloc(300000);
@@ -613,6 +614,7 @@ void create_random_files(std::string const& path, const int file_sizes[], int nu
 		full_path = combine_path(full_path, filename);
 
 		int to_write = file_sizes[i];
+		if (fs) fs->add_file(full_path, to_write);
 		file f(full_path, file::write_only, ec);
 		if (ec) fprintf(stderr, "failed to create file \"%s\": (%d) %s\n"
 			, full_path.c_str(), ec.value(), ec.message().c_str());

test/setup_transfer.hpp

@@ -41,6 +41,7 @@ namespace libtorrent
 {
 	class alert;
 	struct add_torrent_params;
+	class file_storage;
 }
 
 EXPORT int print_failures();
@@ -83,7 +84,8 @@ EXPORT void wait_for_listen(libtorrent::session& ses, char const* name);
 EXPORT void wait_for_downloading(libtorrent::session& ses, char const* name);
 EXPORT void test_sleep(int millisec);
 
-EXPORT void create_random_files(std::string const& path, const int file_sizes[], int num_files);
+EXPORT void create_random_files(std::string const& path, const int file_sizes[]
+	, int num_files, libtorrent::file_storage* fs = NULL);
 
 EXPORT boost::shared_ptr<libtorrent::torrent_info> create_torrent(std::ostream* file = 0
 	, char const* name = "temporary", int piece_size = 16 * 1024, int num_pieces = 13

test/test_checking.cpp

@@ -41,7 +41,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/torrent_status.hpp"
 
 static const int file_sizes[] =
-{ 5, 16 - 5, 16000, 17, 10, 8000, 8000, 1,1,1,1,1,100,1,1,1,1,100,1,1,1,1,1,1
+{ 0, 5, 16 - 5, 16000, 17, 10, 8000, 8000, 1,1,1,1,1,100,1,1,1,1,100,1,1,1,1,1,1
 	,1,1,1,1,1,1,13,65000,34,75,2,30,400,500,23000,900,43000,400,4300,6, 4};
 const int num_files = sizeof(file_sizes)/sizeof(file_sizes[0]);
 
@@ -83,9 +83,8 @@ void test_checking(int flags = read_only_files)
 	std::srand(10);
 	int piece_size = 0x4000;
 
-	create_random_files("test_torrent_dir", file_sizes, num_files);
+	create_random_files("test_torrent_dir", file_sizes, num_files, &fs);
 
-	add_files(fs, "test_torrent_dir");
 	lt::create_torrent t(fs, piece_size, 0x4000
 		, lt::create_torrent::optimize_alignment);
 
@@ -130,7 +129,7 @@ void test_checking(int flags = read_only_files)
 		// increase the size of some files. When they're read only that forces
 		// the checker to open them in write-mode to truncate them
 		static const int file_sizes2[] =
-		{ 5, 16 - 5, 16001, 30, 10, 8000, 8000, 1,1,1,1,1,100,1,1,1,1,100,1,1,1,1,1,1
+		{ 0, 5, 16 - 5, 16001, 30, 10, 8000, 8000, 1,1,1,1,1,100,1,1,1,1,100,1,1,1,1,1,1
 			,1,1,1,1,1,1,13,65000,34,75,2,30,400,500,23000,900,43000,400,4300,6, 4};
 		create_random_files("test_torrent_dir", file_sizes2, num_files);
 	}
@@ -160,6 +159,9 @@ void test_checking(int flags = read_only_files)
 
 	if (flags & force_recheck)
 	{
+		remove_all("test_torrent_dir_tmp", ec);
+		if (ec) fprintf(stdout, "ERROR: removing \"test_torrent_dir_tmp\": (%d) %s\n"
+			, ec.value(), ec.message().c_str());
 		rename("test_torrent_dir", "test_torrent_dir_tmp", ec);
 		if (ec) fprintf(stdout, "ERROR: renaming dir \"test_torrent_dir\": (%d) %s\n"
 			, ec.value(), ec.message().c_str());
@@ -196,6 +198,9 @@ void test_checking(int flags = read_only_files)
 
 		// now, move back the files and force-recheck. make sure we pick up the
 		// files this time
+		remove_all("test_torrent_dir", ec);
+		if (ec) fprintf(stdout, "ERROR: removing \"test_torrent_dir\": (%d) %s\n"
+			, ec.value(), ec.message().c_str());
 		rename("test_torrent_dir_tmp", "test_torrent_dir", ec);
 		if (ec) fprintf(stdout, "ERROR: renaming dir \"test_torrent_dir_tmp\": (%d) %s\n"
 			, ec.value(), ec.message().c_str());