func RegisterCompressor(method uint16, comp Compressor) {
	if _, dup := compressors.LoadOrStore(method, comp); dup {
		panic("compressor already registered")
	}
}

func compressor(method uint16) Compressor {
	ci, ok := compressors.Load(method)
	if !ok {
		return nil
	}
	return ci.(Compressor)
}

func decompressor(method uint16) Decompressor {
	di, ok := decompressors.Load(method)
	if !ok {
		return nil

// RegisterDecompressor registers or overrides a custom decompressor for a
// specific method ID. If a decompressor for a given method is not found,
// [Reader] will default to looking up the decompressor at the package level.
func (r *Reader) RegisterDecompressor(method uint16, dcomp Decompressor) {
	if r.decompressors == nil {
		r.decompressors = make(map[uint16]Decompressor)
	}
	r.decompressors[method] = dcomp
}

	return err
}

// RegisterCompressor registers or overrides a custom compressor for a specific
// method ID. If a compressor for a given method is not found, [Writer] will
// default to looking up the compressor at the package level.
func (w *Writer) RegisterCompressor(method uint16, comp Compressor) {
	if w.compressors == nil {
		w.compressors = make(map[uint16]Compressor)
	}
	w.compressors[method] = comp
}

			s3Select.progressReader.Close()

			var stErr bzip2.StructuralError
			if errors.As(err, &stErr) {
				return errInvalidCompression(err, s3Select.Input.CompressionType)
			}
			// Test these compressor errors
			errs := []error{
				gzip.ErrHeader, gzip.ErrChecksum,
				s2.ErrCorrupt, s2.ErrUnsupported, s2.ErrCRC,

// client closed the stream prematurely.
func newS2CompressReader(r io.Reader, on int64, encrypted bool) (rc io.ReadCloser, idx func() []byte) {
	pr, pw := io.Pipe()
	// Copy input to compressor
	opts := compressOpts
	if encrypted {
		// The values used for padding are not a security concern,
		// but we choose pseudo-random numbers instead of just zeros.