fs/io/FileOutputStream: move code to new class BaseFileOutputStream

src/fs/io/FileOutputStream.cxx

@@ -37,37 +37,33 @@ FileOutputStream::Create(Path path, Error &error)
 #ifdef WIN32
 
 FileOutputStream::FileOutputStream(Path _path, Error &error)
-	:path(_path),
-	 handle(CreateFile(path.c_str(), GENERIC_WRITE, 0, nullptr,
+	:BaseFileOutputStream(_path)
+{
+	SetHandle(CreateFile(_path.c_str(), GENERIC_WRITE, 0, nullptr,
 			     CREATE_ALWAYS,
 			     FILE_ATTRIBUTE_NORMAL|FILE_FLAG_WRITE_THROUGH,
-			   nullptr))
-{
-	if (handle == INVALID_HANDLE_VALUE) {
-		const auto path_utf8 = path.ToUTF8();
+			     nullptr));
+	if (!IsDefined())
 		error.FormatLastError("Failed to create %s",
-				      path_utf8.c_str());
-	}
+				      GetPath().ToUTF8().c_str());
 }
 
 bool
-FileOutputStream::Write(const void *data, size_t size, Error &error)
+BaseFileOutputStream::Write(const void *data, size_t size, Error &error)
 {
 	assert(IsDefined());
 
 	DWORD nbytes;
 	if (!WriteFile(handle, data, size, &nbytes, nullptr)) {
-		const auto path_utf8 = path.ToUTF8();
 		error.FormatLastError("Failed to write to %s",
-				      path_utf8.c_str());
+				      path.ToUTF8().c_str());
 		return false;
 	}
 
 	if (size_t(nbytes) != size) {
-		const auto path_utf8 = path.ToUTF8();
 		error.FormatLastError(ERROR_DISK_FULL,
 				      "Failed to write to %s",
-				      path_utf8.c_str());
+				      path.ToUTF8().c_str());
 		return false;
 	}
 
@@ -79,8 +75,7 @@ FileOutputStream::Commit(gcc_unused Error &error)
 {
 	assert(IsDefined());
 
-	CloseHandle(handle);
-	handle = INVALID_HANDLE_VALUE;
+	Close();
 	return true;
 }
 
@@ -89,9 +84,8 @@ FileOutputStream::Cancel()
 {
 	assert(IsDefined());
 
-	CloseHandle(handle);
-	handle = INVALID_HANDLE_VALUE;
-	RemoveFile(path);
+	Close();
+	RemoveFile(GetPath());
 }
 
 #else
@@ -124,35 +118,36 @@ OpenTempFile(FileDescriptor &fd, Path path)
 #endif /* HAVE_LINKAT */
 
 FileOutputStream::FileOutputStream(Path _path, Error &error)
-	:path(_path)
+	:BaseFileOutputStream(_path)
 {
 #ifdef HAVE_LINKAT
 	/* try Linux's O_TMPFILE first */
-	is_tmpfile = OpenTempFile(fd, path);
+	is_tmpfile = OpenTempFile(SetFD(), GetPath());
 	if (!is_tmpfile) {
 #endif
 		/* fall back to plain POSIX */
-		if (!fd.Open(path.c_str(),
+		if (!SetFD().Open(GetPath().c_str(),
 				  O_WRONLY|O_CREAT|O_TRUNC,
 				  0666))
-			error.FormatErrno("Failed to create %s", path.c_str());
+			error.FormatErrno("Failed to create %s",
+					  GetPath().c_str());
 #ifdef HAVE_LINKAT
 	}
 #endif
 }
 
 bool
-FileOutputStream::Write(const void *data, size_t size, Error &error)
+BaseFileOutputStream::Write(const void *data, size_t size, Error &error)
 {
 	assert(IsDefined());
 
 	ssize_t nbytes = fd.Write(data, size);
 	if (nbytes < 0) {
-		error.FormatErrno("Failed to write to %s", path.c_str());
+		error.FormatErrno("Failed to write to %s", GetPath().c_str());
 		return false;
 	} else if ((size_t)nbytes < size) {
 		error.FormatErrno(ENOSPC,
-				  "Failed to write to %s", path.c_str());
+				  "Failed to write to %s", GetPath().c_str());
 		return false;
 	}
 
@@ -166,24 +161,25 @@ FileOutputStream::Commit(Error &error)
 
 #if HAVE_LINKAT
 	if (is_tmpfile) {
-		RemoveFile(path);
+		RemoveFile(GetPath());
 
 		/* hard-link the temporary file to the final path */
 		char fd_path[64];
 		snprintf(fd_path, sizeof(fd_path), "/proc/self/fd/%d",
-			 fd.Get());
-		if (linkat(AT_FDCWD, fd_path, AT_FDCWD, path.c_str(),
+			 GetFD().Get());
+		if (linkat(AT_FDCWD, fd_path, AT_FDCWD, GetPath().c_str(),
 			   AT_SYMLINK_FOLLOW) < 0) {
-			error.FormatErrno("Failed to commit %s", path.c_str());
-			fd.Close();
+			error.FormatErrno("Failed to commit %s",
+					  GetPath().c_str());
+			Close();
 			return false;
 		}
 	}
 #endif
 
-	bool success = fd.Close();
+	bool success = Close();
 	if (!success)
-		error.FormatErrno("Failed to commit %s", path.c_str());
+		error.FormatErrno("Failed to commit %s", GetPath().c_str());
 
 	return success;
 }
@@ -193,12 +189,12 @@ FileOutputStream::Cancel()
 {
 	assert(IsDefined());
 
-	fd.Close();
+	Close();
 
 #ifdef HAVE_LINKAT
 	if (!is_tmpfile)
 #endif
-		RemoveFile(path);
+		RemoveFile(GetPath());
 }
 
 #endif

src/fs/io/FileOutputStream.hxx

@@ -37,7 +37,7 @@
 
 class Path;
 
-class FileOutputStream final : public OutputStream {
+class BaseFileOutputStream : public OutputStream {
 	const AllocatedPath path;
 
 #ifdef WIN32
@@ -46,6 +46,73 @@ class FileOutputStream final : public OutputStream {
 	FileDescriptor fd;
 #endif
 
+protected:
+#ifdef WIN32
+	template<typename P>
+	BaseFileOutputStream(P &&_path)
+		:path(std::forward<P>(_path)),
+		 handle(INVALID_HANDLE_VALUE) {}
+#else
+	template<typename P>
+	BaseFileOutputStream(P &&_path)
+		:path(std::forward<P>(_path)),
+		 fd(FileDescriptor::Undefined()) {}
+#endif
+
+	~BaseFileOutputStream() {
+		assert(!IsDefined());
+	}
+
+#ifdef WIN32
+	void SetHandle(HANDLE _handle) {
+		assert(!IsDefined());
+
+		handle = _handle;
+
+		assert(IsDefined());
+	}
+#else
+	FileDescriptor &SetFD() {
+		assert(!IsDefined());
+
+		return fd;
+	}
+
+	const FileDescriptor &GetFD() const {
+		return fd;
+	}
+#endif
+
+	bool Close() {
+		assert(IsDefined());
+
+#ifdef WIN32
+		CloseHandle(handle);
+		handle = INVALID_HANDLE_VALUE;
+		return true;
+#else
+		return fd.Close();
+#endif
+	}
+
+public:
+	bool IsDefined() const {
+#ifdef WIN32
+		return handle != INVALID_HANDLE_VALUE;
+#else
+		return fd.IsDefined();
+#endif
+	}
+
+	Path GetPath() const {
+		return path;
+	}
+
+	/* virtual methods from class OutputStream */
+	bool Write(const void *data, size_t size, Error &error) override;
+};
+
+class FileOutputStream final : public BaseFileOutputStream {
 #ifdef HAVE_LINKAT
 	/**
 	 * Was O_TMPFILE used?  If yes, then linkat() must be used to
@@ -64,19 +131,8 @@ public:
 
 	static FileOutputStream *Create(Path path, Error &error);
 
-	bool IsDefined() const {
-#ifdef WIN32
-		return handle != INVALID_HANDLE_VALUE;
-#else
-		return fd.IsDefined();
-#endif
-	}
-
 	bool Commit(Error &error);
 	void Cancel();
-
-	/* virtual methods from class OutputStream */
-	bool Write(const void *data, size_t size, Error &error) override;
 };
 
 #endif