updated file_win and file_pool error handling

include/libtorrent/file.hpp

@@ -109,7 +109,7 @@ namespace libtorrent
 		file(fs::path const& p, open_mode m);
 		~file();
 
-		void open(fs::path const& p, open_mode m);
+		bool open(fs::path const& p, open_mode m);
 		void close();
 		bool set_size(size_type size);
 

include/libtorrent/file_pool.hpp

@@ -65,7 +65,8 @@ namespace libtorrent
 	{
 		file_pool(int size = 40): m_size(size) {}
 
-		boost::shared_ptr<file> open_file(void* st, fs::path const& p, file::open_mode m);
+		boost::shared_ptr<file> open_file(void* st, fs::path const& p
+			, file::open_mode m, std::string& error);
 		void release(void* st);
 		void resize(int size);
 
@@ -74,9 +75,7 @@ namespace libtorrent
 
 		struct lru_file_entry
 		{
-			lru_file_entry(boost::shared_ptr<file> const& f)
-				: file_ptr(f)
-				, last_use(time_now()) {}
+			lru_file_entry(): last_use(time_now()) {}
 			mutable boost::shared_ptr<file> file_ptr;
 			fs::path file_path;
 			void* key;

src/file.cpp

@@ -158,7 +158,7 @@ namespace libtorrent
 			close();
 		}
 
-		void open(fs::path const& path, int mode)
+		bool open(fs::path const& path, int mode)
 		{
 			TORRENT_ASSERT(path.is_complete());
 			close();
@@ -189,8 +189,10 @@ namespace libtorrent
 					<< std::strerror(errno);
 				if (!m_error) m_error.reset(new std::string);
 				*m_error = msg.str();
+				return false;
 			}
 			m_open_mode = mode;
+			return true;
 		}
 
 		void close()
@@ -330,9 +332,9 @@ namespace libtorrent
 
 	file::~file() {}
 
-	void file::open(fs::path const& p, file::open_mode m)
+	bool file::open(fs::path const& p, file::open_mode m)
 	{
-		m_impl->open(p, m.m_mask);
+		return m_impl->open(p, m.m_mask);
 	}
 
 	void file::close()

src/file_pool.cpp

@@ -41,7 +41,8 @@ namespace libtorrent
 	using boost::multi_index::nth_index;
 	using boost::multi_index::get;
 
-	boost::shared_ptr<file> file_pool::open_file(void* st, fs::path const& p, file::open_mode m)
+	boost::shared_ptr<file> file_pool::open_file(void* st, fs::path const& p
+		, file::open_mode m, std::string& error)
 	{
 		TORRENT_ASSERT(st != 0);
 		TORRENT_ASSERT(p.is_complete());
@@ -57,14 +58,11 @@ namespace libtorrent
 
 			if (e.key != st)
 			{
-#ifdef BOOST_NO_EXCEPTIONS
-				return boost::shared_ptr<file>();
-#else
 				// this means that another instance of the storage
 				// is using the exact same file.
-				throw file_error("torrent uses the same file as another torrent "
-					"(" + p.string() + ")");
-#endif
+				error = "torrent uses the same file as another torrent "
+					"(" + p.string() + ")";
+				return boost::shared_ptr<file>();
 			}
 
 			e.key = st;
@@ -74,8 +72,13 @@ namespace libtorrent
 				// the new read/write privilages
 				i->file_ptr.reset();
 				TORRENT_ASSERT(e.file_ptr.unique());
-				e.file_ptr.reset();
-				e.file_ptr.reset(new file(p, m));
+				e.file_ptr->close();
+				if (!e.file_ptr->open(p, m))
+				{
+					error = e.file_ptr->error();
+					m_files.erase(i);
+					return boost::shared_ptr<file>();
+				}
 				e.mode = m;
 			}
 			pt.replace(i, e);
@@ -93,7 +96,18 @@ namespace libtorrent
 			TORRENT_ASSERT(lt.size() == 1 || (i->last_use <= boost::next(i)->last_use));
 			lt.erase(i);
 		}
-		lru_file_entry e(boost::shared_ptr<file>(new file(p, m)));
+		lru_file_entry e;
+		e.file_ptr.reset(new file);
+		if (!e.file_ptr)
+		{
+			error = "no memory";
+			return e.file_ptr;
+		}
+		if (!e.file_ptr->open(p, m))
+		{
+			error = e.file_ptr->error();
+			return boost::shared_ptr<file>();
+		}
 		e.mode = m;
 		e.key = st;
 		e.file_path = p;

src/file_win.cpp

@@ -81,36 +81,7 @@ namespace
 			return s;
 		}
 	}
-	
-	void throw_exception(const char* thrower)
-	{
-		DWORD err = GetLastError();
-
-#ifdef UNICODE
-		wchar_t *wbuffer = 0;
-		FormatMessage(
-			FORMAT_MESSAGE_FROM_SYSTEM
-			|FORMAT_MESSAGE_ALLOCATE_BUFFER
-			, 0, err, 0, (LPWSTR)&wbuffer, 0, 0);
-		auto_localfree auto_free(wbuffer);
-		std::string tmp_utf8;
-		libtorrent::wchar_utf8(wbuffer, tmp_utf8);
-		char const* buffer = tmp_utf8.c_str();
-#else
-		char* buffer = 0;
-		FormatMessage(
-			FORMAT_MESSAGE_FROM_SYSTEM
-			|FORMAT_MESSAGE_ALLOCATE_BUFFER
-			, 0, err, 0, (LPSTR)&buffer, 0, 0);
-		auto_localfree auto_free(buffer);
-#endif
-
-		std::stringstream s;
-		s << (thrower ? thrower : "NULL") << ": " << (buffer ? buffer : "NULL");
-
-		throw libtorrent::file_error(s.str());
 	}
-}
 
 namespace libtorrent
 {
@@ -130,12 +101,42 @@ namespace libtorrent
 			seek_end = FILE_END
 		};
 
+		void set_error(const char* thrower)
+		{
+			DWORD err = GetLastError();
+
+#ifdef UNICODE
+			wchar_t *wbuffer = 0;
+			FormatMessage(
+				FORMAT_MESSAGE_FROM_SYSTEM
+				|FORMAT_MESSAGE_ALLOCATE_BUFFER
+				, 0, err, 0, (LPWSTR)&wbuffer, 0, 0);
+			auto_localfree auto_free(wbuffer);
+			std::string tmp_utf8;
+			libtorrent::wchar_utf8(wbuffer, tmp_utf8);
+			char const* buffer = tmp_utf8.c_str();
+#else
+			char* buffer = 0;
+			FormatMessage(
+				FORMAT_MESSAGE_FROM_SYSTEM
+				|FORMAT_MESSAGE_ALLOCATE_BUFFER
+				, 0, err, 0, (LPSTR)&buffer, 0, 0);
+			auto_localfree auto_free(buffer);
+#endif
+
+			std::stringstream s;
+			s << (thrower ? thrower : "NULL") << ": " << (buffer ? buffer : "NULL");
+
+			if (!m_error) m_error.reset(new std::string);
+			*m_error = s.str();
+		}
+
 		impl()
 		{
 			m_file_handle = INVALID_HANDLE_VALUE;
 		}
 
-		void open(const char *file_name, open_flags flags)
+		bool open(const char *file_name, open_flags flags)
 		{
 			TORRENT_ASSERT(file_name);
 			TORRENT_ASSERT(flags & (read_flag | write_flag));
@@ -170,7 +171,10 @@ namespace libtorrent
 		#endif
 
 			if (new_handle == INVALID_HANDLE_VALUE)
-				throw_exception(file_name);
+			{
+				set_error(file_name);
+				return false;
+			}
 			// try to make the file sparse if supported
 			if (access_mask & GENERIC_WRITE)
 			{
@@ -181,6 +185,7 @@ namespace libtorrent
 			// will only close old file if the open succeeded
 			close();
 			m_file_handle = new_handle;
+			return true;
 		}
 
 		void close()
@@ -211,7 +216,8 @@ namespace libtorrent
 					, &bytes_written
 					, 0))
 				{
-					throw_exception("file::write");
+					set_error("file::write");
+					return -1;
 				}
 			}
 			return bytes_written;
@@ -233,20 +239,23 @@ namespace libtorrent
 					, &bytes_read
 					, 0))
 				{
-					throw_exception("file::read");
+					set_error("file::set_size");
+					return -1;
 				}
 			}
 			return bytes_read;
 		}
 
-		void set_size(size_type s)
+		bool set_size(size_type s)
 		{
 			size_type pos = tell();
 			seek(s, seek_begin);
 			if (FALSE == ::SetEndOfFile(m_file_handle))
-				throw_exception("file::set_size");
-
-			seek(pos, seek_begin);
+			{
+				set_error("file::set_size");
+				return false;
+			}
+			return true;
 		}
 
 		size_type seek(size_type pos, seek_mode from_where)
@@ -261,7 +270,8 @@ namespace libtorrent
 				, &offs
 				, from_where))
 			{
-				throw_exception("file::seek");
+				set_error("file::seek");
+				return -1;
 			}
 			return offs.QuadPart;
 		}
@@ -278,7 +288,8 @@ namespace libtorrent
 				, &offs
 				, FILE_CURRENT))
 			{
-				throw_exception("file::tell");
+				set_error("file::tell");
+				return -1;
 			}
 
 			size_type pos = offs.QuadPart;
@@ -299,9 +310,17 @@ namespace libtorrent
 			return size;
 		}
 */
+
+		std::string const& error() const
+		{
+			if (!m_error) m_error.reset(new std::string);
+			return *m_error;
+		}
+
 	private:
 
 		HANDLE m_file_handle;
+		mutable boost::scoped_ptr<std::string> m_error;
 
 	};
 }
@@ -329,10 +348,10 @@ namespace libtorrent
 	{
 	}
 
-	void file::open(boost::filesystem::path const& p, open_mode m)
+	bool file::open(boost::filesystem::path const& p, open_mode m)
 	{
 		TORRENT_ASSERT(p.is_complete());
-		m_impl->open(p.native_file_string().c_str(), impl::open_flags(m.m_mask));
+		return m_impl->open(p.native_file_string().c_str(), impl::open_flags(m.m_mask));
 	}
 
 	void file::close()
@@ -350,9 +369,9 @@ namespace libtorrent
 		return m_impl->read(buffer, num_bytes);
 	}
 
-	void file::set_size(size_type s)
+	bool file::set_size(size_type s)
 	{
-		m_impl->set_size(s);
+		return m_impl->set_size(s);
 	}
 
 	size_type file::seek(size_type pos, seek_mode m)
@@ -364,4 +383,9 @@ namespace libtorrent
 	{
 		return m_impl->tell();
 	}
+
+	std::string const& file::error() const
+	{
+		return m_impl->error();
+	}
 }

src/storage.cpp

@@ -472,8 +472,10 @@ namespace libtorrent
 #endif
 			if (allocate_files)
 			{
+				std::string error;
 				boost::shared_ptr<file> f = m_files.open_file(this
-					, m_save_path / file_iter->path, file::in | file::out);
+					, m_save_path / file_iter->path, file::in | file::out
+					, error);
 				if (f && f->error().empty())
 					f->set_size(file_iter->size);
 			}
@@ -829,21 +831,20 @@ namespace libtorrent
 		}
 
 		int buf_pos = 0;
+		std::string error;
 		boost::shared_ptr<file> in(m_files.open_file(
-			this, m_save_path / file_iter->path, file::in));
+			this, m_save_path / file_iter->path, file::in
+			, error));
 		if (!in)
 		{
-			m_error = "failed to open file " + (m_save_path / file_iter->path).string();
+			m_error = "failed to open file ";
+			m_error += (m_save_path / file_iter->path).string();
+			m_error += ": ";
+			m_error += error;
 			return -1;
 		}
-		if (!in->error().empty())
-		{
-			m_error = in->error();
-			return -1;
-		}
-
+		TORRENT_ASSERT(in->error().empty());
 		TORRENT_ASSERT(file_offset < file_iter->size);
-
 		TORRENT_ASSERT(slices[0].offset == file_offset + file_iter->file_base);
 
 		size_type new_pos = in->seek(file_offset + file_iter->file_base);
@@ -927,18 +928,18 @@ namespace libtorrent
 				fs::path path = m_save_path / file_iter->path;
 
 				file_offset = 0;
+				std::string error;
 				in = m_files.open_file(
-					this, path, file::in);
+					this, path, file::in, error);
 				if (!in)
 				{
-					m_error = "failed to open file " + (m_save_path / file_iter->path).string();
-					return -1;
-				}
-				if (!in->error().empty())
-				{
-					m_error = in->error();
+					m_error = "failed to open file ";
+					m_error += path.string();
+					m_error += ": ";
+					m_error += error;
 					return -1;
 				}
+				TORRENT_ASSERT(in->error().empty());
 				in->seek(file_iter->file_base);
 			}
 		}
@@ -981,19 +982,19 @@ namespace libtorrent
 		}
 
 		fs::path p(m_save_path / file_iter->path);
+		std::string error;
 		boost::shared_ptr<file> out = m_files.open_file(
-			this, p, file::out | file::in);
+			this, p, file::out | file::in, error);
+
 		if (!out)
 		{
-			m_error = "failed to open file " + (m_save_path / file_iter->path).string();
+			m_error = "failed to open file ";
+			m_error += p.string();
+			m_error += ": ";
+			m_error += error;
 			return -1;
 		}
-		if (!out->error().empty())
-		{
-			m_error = out->error();
-			return -1;
-		}
-
+		TORRENT_ASSERT(out->error().empty());
 		TORRENT_ASSERT(file_offset < file_iter->size);
 		TORRENT_ASSERT(slices[0].offset == file_offset + file_iter->file_base);
 
@@ -1060,18 +1061,19 @@ namespace libtorrent
 				TORRENT_ASSERT(file_iter != m_info->end_files(true));
 				fs::path p = m_save_path / file_iter->path;
 				file_offset = 0;
+				std::string error;
 				out = m_files.open_file(
-					this, p, file::out | file::in);
+					this, p, file::out | file::in, error);
+
 				if (!out)
 				{
-					m_error = "failed to open file " + (m_save_path / file_iter->path).string();
-					return -1;
-				}
-				if (!out->error().empty())
-				{
-					m_error = out->error();
+					m_error = "failed to open file ";
+					m_error += p.string();
+					m_error += ": ";
+					m_error += error;
 					return -1;
 				}
+				TORRENT_ASSERT(out->error().empty());
 
 				out->seek(file_iter->file_base);
 			}