import (
	"errors"
	"io"
	"unicode/utf8"
)

// A Reader implements the [io.Reader], [io.ReaderAt], [io.WriterTo], [io.Seeker],
// [io.ByteScanner], and [io.RuneScanner] interfaces by reading from
// a byte slice.
// Unlike a [Buffer], a Reader is read-only and supports seeking.
// The zero value for Reader operates like a Reader of an empty slice.
type Reader struct {
	s        []byte
	i        int64 // current reading index

// 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

// AWS Signature V4 chunked reader.
type s3UnsignedChunkedReader struct {
	reader   *bufio.Reader
	trailers http.Header

	buffer []byte
	offset int
	err    error
	debug  bool
}

func (cr *s3UnsignedChunkedReader) Close() (err error) {
	return cr.err
}

// Read - implements `io.Reader`, which transparently decodes
// the incoming AWS Signature V4 streaming signature.

   * independent reader each time it is called.
   *
   * <p>The caller is responsible for ensuring that the returned reader is closed.
   *
   * @throws IOException if an I/O error occurs while of opening the reader
   */
  public BufferedReader openBufferedStream() throws IOException {
    Reader reader = openStream();
    return (reader instanceof BufferedReader)
        ? (BufferedReader) reader

   * independent reader each time it is called.
   *
   * <p>The caller is responsible for ensuring that the returned reader is closed.
   *
   * @throws IOException if an I/O error occurs while of opening the reader
   */
  public BufferedReader openBufferedStream() throws IOException {
    Reader reader = openStream();
    return (reader instanceof BufferedReader)
        ? (BufferedReader) reader

)

var magicHeaders = []struct {
	header []byte
	f      format
}{
	{
		header: []byte{0x1f, 0x8b, 8},
		f:      formatGzip,
	},
	{
		// Zstd default header.
		header: []byte{0x28, 0xb5, 0x2f, 0xfd},
		f:      formatZstd,
	},
	{
		// Zstd skippable frame header.
		header: []byte{0x2a, 0x4d, 0x18},
		f:      formatZstd,
	},
	{
		// LZ4
		header: []byte{0x4, 0x22, 0x4d, 0x18},

    CharSequenceReader reader = new CharSequenceReader(string);
    assertTrue(reader.markSupported());

    assertEquals(string, readFully(reader));
    assertFullyRead(reader);

    // reset and read again
    reader.reset();
    assertEquals(string, readFully(reader));
    assertFullyRead(reader);

    // reset, skip, mark, then read the rest
    reader.reset();
    assertEquals(5, reader.skip(5));

        addDocument(indexName, client, num);

        ESSourceReader reader = new ESSourceReader(client, settings, indexName);
        reader.setScrollSize(1);
        reader.setLimitDocNumPercentage("1%");
        int count = 0;
        Set<String> valueSet = Collections.synchronizedSet(new HashSet<>());
        Map<String, Object> source;
        while ((source = reader.read()) != null) {

    // The most common case is that from is a Reader (like InputStreamReader or StringReader) so
    // take advantage of that.
    if (from instanceof Reader) {
      // optimize for common output types which are optimized to deal with char[]
      if (to instanceof StringBuilder) {
        return copyReaderToBuilder((Reader) from, (StringBuilder) to);
      } else {
        return copyReaderToWriter((Reader) from, asWriter(to));
      }
    }