type readOp int8

// Don't use iota for these, as the values need to correspond with the
// names and comments, which is easier to see when being explicit.
const (
	opRead      readOp = -1 // Any other read operation.
	opInvalid   readOp = 0  // Non-read operation.
	opReadRune1 readOp = 1  // Read rune of size 1.
	opReadRune2 readOp = 2  // Read rune of size 2.

func (r *Reader) Read(b []byte) (n int, err error) {
	if r.i >= int64(len(r.s)) {
		return 0, io.EOF
	}
	r.prevRune = -1
	n = copy(b, r.s[r.i:])
	r.i += int64(n)
	return
}

// ReadAt implements the [io.ReaderAt] interface.
func (r *Reader) ReadAt(b []byte, off int64) (n int, err error) {
	// cannot modify state - see io.ReaderAt
	if off < 0 {
		return 0, errors.New("bytes.Reader.ReadAt: negative offset")

}

// MonitorReaderOptions provides configurable options for monitor reader implementation.
type MonitorReaderOptions struct {
	BucketOptions
	HeaderSize int
}

// Read implements a throttled read
func (r *MonitoredReader) Read(buf []byte) (n int, err error) {
	if r.throttle == nil {
		return r.r.Read(buf)
	}
	if r.lastErr != nil {
		err = r.lastErr
		return
	}

// the [ErrInsecurePath] error and use the returned reader.
func NewReader(r io.ReaderAt, size int64) (*Reader, error) {
	if size < 0 {
		return nil, errors.New("zip: size cannot be negative")
	}
	zr := new(Reader)
	var err error
	if err = zr.init(r, size); err != nil && err != ErrInsecurePath {
		return nil, err
	}
	return zr, err
}

func (r *Reader) init(rdr io.ReaderAt, size int64) error {

	"strconv"
	"strings"
	"time"
)

// Reader provides sequential access to the contents of a tar archive.
// Reader.Next advances to the next file in the archive (including the first),
// and then Reader can be treated as an io.Reader to access the file's data.
type Reader struct {
	r    io.Reader
	pad  int64      // Amount of padding (ignored) after current file entry
	curr fileReader // Reader for current file entry

func (r *Reader) startReaders(newReader func(io.Reader) *csv.Reader) error {
	if r.args.FileHeaderInfo != none {
		// Read column names
		// Get one line.
		b, err := r.nextSplit(0, nil)
		if err != nil {
			r.err = err
			return err
		}
		if !utf8.Valid(b) {
			return errInvalidTextEncodingError()
		}
		reader := newReader(bytes.NewReader(b))

			src:      r,
			md5:      NewUUIDHash(forceMD5),
			checksum: etag,
		}
	}
	return &Reader{
		src:      r,
		md5:      md5.New(),
		checksum: etag,
	}
}

// Read reads up to len(p) bytes from the underlying
// io.Reader as specified by the io.Reader interface.
func (r *Reader) Read(p []byte) (int, error) {
	n, err := r.src.Read(p)
	r.readN += int64(n)
	r.md5.Write(p[:n])

)

// A Reader wraps an io.Reader and computes the MD5 checksum
// of the read content as ETag. Optionally, it also computes
// the SHA256 checksum of the content.
//
// If the reference values for the ETag and content SHA26
// are not empty then it will check whether the computed
// match the reference values.
type Reader struct {
	src         io.Reader
	bytesRead   int64
	expectedMin int64

	return &Reader{
		args:       args,
		decoded:    ch,
		err:        err,
		readCloser: nil,
	}
}

// safeCloser will wrap a Reader as a ReadCloser.
// It is safe to call Close while the reader is being used.
type safeCloser struct {
	closed uint32
	r      io.Reader
}

func (s *safeCloser) Read(p []byte) (n int, err error) {

Regular Reads will block until data is available, but not wait for a full buffer. 
Writes will block until there is space available and writes bigger than the buffer will wait for reads to make space.

`TryRead` and `TryWrite` are still available for non-blocking reads and writes.