diff --git a/sys_windows.go b/sys_windows.go new file mode 100644 index 0000000..15f9cf8 --- /dev/null +++ b/sys_windows.go @@ -0,0 +1,163 @@ +package sqlite3 + +import ( + "io/fs" + "os" + "path/filepath" + "syscall" +) + +// osOpenFile is the Windows implementation of OpenFile. +func osOpenFile(name string, flag int, perm fs.FileMode) (*os.File, error) { + if name == "" { + return nil, &os.PathError{Op: "open", Path: name, Err: syscall.ENOENT} + } + path := osFixLongPath(name) + r, e := syscallOpen(path, flag, syscallMode(perm)) + if e != nil { + return nil, &os.PathError{Op: "open", Path: name, Err: e} + } + return os.NewFile(uintptr(r), name), nil +} + +// fixLongPath returns the extended-length (\\?\-prefixed) form of +// path when needed, in order to avoid the default 260 character file +// path limit imposed by Windows. If path is not easily converted to +// the extended-length form (for example, if path is a relative path +// or contains .. elements), or is short enough, osFixLongPath returns +// path unmodified. +// +// See https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx#maxpath +func osFixLongPath(path string) string { + // Do nothing (and don't allocate) if the path is "short". + // Empirically (at least on the Windows Server 2013 builder), + // the kernel is arbitrarily okay with < 248 bytes. That + // matches what the docs above say: + // "When using an API to create a directory, the specified + // path cannot be so long that you cannot append an 8.3 file + // name (that is, the directory name cannot exceed MAX_PATH + // minus 12)." Since MAX_PATH is 260, 260 - 12 = 248. + // + // The MSDN docs appear to say that a normal path that is 248 bytes long + // will work; empirically the path must be less then 248 bytes long. + if len(path) < 248 { + // Don't fix. (This is how Go 1.7 and earlier worked, + // not automatically generating the \\?\ form) + return path + } + + // The extended form begins with \\?\, as in + // \\?\c:\windows\foo.txt or \\?\UNC\server\share\foo.txt. + // The extended form disables evaluation of . and .. path + // elements and disables the interpretation of / as equivalent + // to \. The conversion here rewrites / to \ and elides + // . elements as well as trailing or duplicate separators. For + // simplicity it avoids the conversion entirely for relative + // paths or paths containing .. elements. For now, + // \\server\share paths are not converted to + // \\?\UNC\server\share paths because the rules for doing so + // are less well-specified. + if len(path) >= 2 && path[:2] == `\\` { + // Don't canonicalize UNC paths. + return path + } + if !filepath.IsAbs(path) { + // Relative path + return path + } + + const prefix = `\\?` + + pathbuf := make([]byte, len(prefix)+len(path)+len(`\`)) + copy(pathbuf, prefix) + n := len(path) + r, w := 0, len(prefix) + for r < n { + switch { + case os.IsPathSeparator(path[r]): + // empty block + r++ + case path[r] == '.' && (r+1 == n || os.IsPathSeparator(path[r+1])): + // /./ + r++ + case r+1 < n && path[r] == '.' && path[r+1] == '.' && (r+2 == n || os.IsPathSeparator(path[r+2])): + // /../ is currently unhandled + return path + default: + pathbuf[w] = '\\' + w++ + for ; r < n && !os.IsPathSeparator(path[r]); r++ { + pathbuf[w] = path[r] + w++ + } + } + } + // A drive's root directory needs a trailing \ + if w == len(`\\?\c:`) { + pathbuf[w] = '\\' + w++ + } + return string(pathbuf[:w]) +} + +// syscallMode returns the syscall-specific mode bits from Go's portable mode bits. +func syscallMode(i fs.FileMode) (o uint32) { + o |= uint32(i.Perm()) + if i&fs.ModeSetuid != 0 { + o |= syscall.S_ISUID + } + if i&fs.ModeSetgid != 0 { + o |= syscall.S_ISGID + } + if i&fs.ModeSticky != 0 { + o |= syscall.S_ISVTX + } + // No mapping for Go's ModeTemporary (plan9 only). + return +} + +func syscallOpen(path string, mode int, perm uint32) (fd syscall.Handle, err error) { + if len(path) == 0 { + return syscall.InvalidHandle, syscall.ERROR_FILE_NOT_FOUND + } + pathp, err := syscall.UTF16PtrFromString(path) + if err != nil { + return syscall.InvalidHandle, err + } + var access uint32 + switch mode & (syscall.O_RDONLY | syscall.O_WRONLY | syscall.O_RDWR) { + case syscall.O_RDONLY: + access = syscall.GENERIC_READ + case syscall.O_WRONLY: + access = syscall.GENERIC_WRITE + case syscall.O_RDWR: + access = syscall.GENERIC_READ | syscall.GENERIC_WRITE + } + if mode&syscall.O_CREAT != 0 { + access |= syscall.GENERIC_WRITE + } + if mode&syscall.O_APPEND != 0 { + access &^= syscall.GENERIC_WRITE + access |= syscall.FILE_APPEND_DATA + } + sharemode := uint32(syscall.FILE_SHARE_READ | syscall.FILE_SHARE_WRITE | syscall.FILE_SHARE_DELETE) + var createmode uint32 + switch { + case mode&(syscall.O_CREAT|syscall.O_EXCL) == (syscall.O_CREAT | syscall.O_EXCL): + createmode = syscall.CREATE_NEW + case mode&(syscall.O_CREAT|syscall.O_TRUNC) == (syscall.O_CREAT | syscall.O_TRUNC): + createmode = syscall.CREATE_ALWAYS + case mode&syscall.O_CREAT == syscall.O_CREAT: + createmode = syscall.OPEN_ALWAYS + case mode&syscall.O_TRUNC == syscall.O_TRUNC: + createmode = syscall.TRUNCATE_EXISTING + default: + createmode = syscall.OPEN_EXISTING + } + var attrs uint32 = syscall.FILE_ATTRIBUTE_NORMAL + if perm&syscall.S_IWRITE == 0 { + attrs = syscall.FILE_ATTRIBUTE_READONLY + } + h, e := syscall.CreateFile(pathp, access, sharemode, nil, createmode, attrs, 0) + return h, e +} diff --git a/vfs.go b/vfs.go index fd37d2d..db59852 100644 --- a/vfs.go +++ b/vfs.go @@ -169,8 +169,6 @@ func vfsDelete(ctx context.Context, mod api.Module, pVfs, zPath, syncDir uint32) return _OK } if err != nil { - // TODO: fix windows.ERROR_SHARING_VIOLATION - // https://github.com/golang/go/issues/32088 return uint32(IOERR_DELETE) } if runtime.GOOS != "windows" && syncDir != 0 { @@ -251,14 +249,14 @@ func vfsOpen(ctx context.Context, mod api.Module, pVfs, zName, pFile uint32, fla file, err = os.CreateTemp("", "*.db") } else { name := memory{mod}.readString(zName, _MAX_PATHNAME) - file, err = os.OpenFile(name, oflags, 0600) + file, err = vfsOS.OpenFile(name, oflags, 0600) } if err != nil { return uint32(CANTOPEN) } if flags&OPEN_DELETEONCLOSE != 0 { - vfsOS.DeleteOnClose(file) + os.Remove(file.Name()) } vfsFile.Open(ctx, mod, pFile, file) diff --git a/vfs_unix.go b/vfs_unix.go index be7607b..1469c0a 100644 --- a/vfs_unix.go +++ b/vfs_unix.go @@ -8,8 +8,8 @@ import ( "syscall" ) -func (vfsOSMethods) DeleteOnClose(file *os.File) { - _ = os.Remove(file.Name()) +func (vfsOSMethods) OpenFile(name string, flag int, perm os.FileMode) (*os.File, error) { + return os.OpenFile(name, flag, perm) } func (vfsOSMethods) GetExclusiveLock(file *os.File) xErrorCode { diff --git a/vfs_windows.go b/vfs_windows.go index 6148d8b..73be2a9 100644 --- a/vfs_windows.go +++ b/vfs_windows.go @@ -7,7 +7,9 @@ import ( "golang.org/x/sys/windows" ) -func (vfsOSMethods) DeleteOnClose(file *os.File) {} +func (vfsOSMethods) OpenFile(name string, flag int, perm os.FileMode) (*os.File, error) { + return osOpenFile(name, flag, perm) +} func (vfsOSMethods) GetExclusiveLock(file *os.File) xErrorCode { // Release the SHARED lock.