prevRune int   // index of previous rune; or < 0
}

// Len returns the number of bytes of the unread portion of the
// slice.
func (r *Reader) Len() int {
	if r.i >= int64(len(r.s)) {
		return 0
	}
	return int(int64(len(r.s)) - r.i)
}

// Size returns the original length of the underlying byte slice.
// Size is the number of bytes available for reading via [Reader.ReadAt].

//   - Exactly 0 bytes are read and EOF is hit.
//   - Exactly 1 block of zeros is read and EOF is hit.
//   - At least 2 blocks of zeros are read.
func (tr *Reader) readHeader() (*Header, *block, error) {
	// Two blocks of zero bytes marks the end of the archive.
	if _, err := io.ReadFull(tr.r, tr.blk[:]); err != nil {
		return nil, nil, err // EOF is okay here; exactly 0 bytes read
	}

			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])

//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package csv

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"runtime"
	"sync"
	"unicode/utf8"

	csv "github.com/minio/csvparser"
	"github.com/minio/minio/internal/s3select/sql"
)

// Reader - CSV record reader for S3Select.

//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package hash

import (
	"bytes"
	"context"
	"encoding/base64"
	"encoding/hex"
	"errors"
	"hash"
	"io"
	"net/http"

	"github.com/minio/minio/internal/etag"
	"github.com/minio/minio/internal/hash/sha256"

		return r.r.Read(buf)
	}
	if r.lastErr != nil {
		err = r.lastErr
		return
	}
	b := r.throttle.Burst()  // maximum available tokens
	need := len(buf)         // number of bytes requested by caller
	hdr := r.opts.HeaderSize // remaining header bytes
	var tokens int           // number of tokens to request

	if hdr > 0 { // available tokens go towards header first
		if hdr < b { // all of header can be accommodated

	//
	// dataDescriptorLen includes the size of the signature but
	// first read just those 4 bytes to see if it exists.
	if _, err := io.ReadFull(r, buf[:4]); err != nil {
		return err
	}
	off := 0
	maybeSig := readBuf(buf[:4])
	if maybeSig.uint32() != dataDescriptorSignature {
		// No data descriptor signature. Keep these four
		// bytes.
		off += 4
	}
	if _, err := io.ReadFull(r, buf[off:12]); err != nil {
		return err