switch src := r.src.(type) {
	case *lockedSource:
		return src.read(p, &r.readVal, &r.readPos)
	case *runtimeSource:
		return src.read(p, &r.readVal, &r.readPos)
	}
	return read(p, r.src, &r.readVal, &r.readPos)
}

func read(p []byte, src Source, readVal *int64, readPos *int8) (n int, err error) {
	pos := *readPos
	val := *readVal
	rng, _ := src.(*rngSource)
	for n = 0; n < len(p); n++ {
		if pos == 0 {

			if _, err := p.readVal(); err != nil {
				return errMalformedVarint
			}
			ln, err := p.readVal()
			if err != nil {
				return err
			}
			if !p.discard(ln) {
				return fmt.Errorf("failed to read trace: %w", io.EOF)
			}
		} else {
			// String dictionary entry [ID, length, string].
			id, err := p.readVal()
			if err != nil {
				return err
			}

	storageRESTMethodCreateFile     = "/createfile"
	storageRESTMethodWriteAll       = "/writeall"
	storageRESTMethodReadVersion    = "/readversion"
	storageRESTMethodReadXL         = "/readxl"
	storageRESTMethodReadAll        = "/readall"
	storageRESTMethodReadFile       = "/readfile"
	storageRESTMethodReadFileStream = "/readfilestream"
	storageRESTMethodListDir        = "/listdir"
	storageRESTMethodDeleteVersions = "/deleteverions"

// ReadAt blocks until either all the data is available or an error occurs.
// In this respect ReadAt is different from Read.
//
// If the n = len(p) bytes returned by ReadAt are at the end of the
// input source, ReadAt may return either err == EOF or err == nil.
//
// If ReadAt is reading from an input source with a seek offset,
// ReadAt should not affect nor be affected by the underlying

		return err
	}
	return d.disk.WriteAll(ctx, volume, path, b)
}

func (d *naughtyDisk) ReadAll(ctx context.Context, volume string, path string) (buf []byte, err error) {
	if err := d.calcError(); err != nil {
		return nil, err
	}
	return d.disk.ReadAll(ctx, volume, path)
}

func (d *naughtyDisk) ReadXL(ctx context.Context, volume string, path string, readData bool) (rf RawFileInfo, err error) {

	// Write all data, syncs the data to disk.
	// Should be used for smaller payloads.
	WriteAll(ctx context.Context, volume string, path string, b []byte) (err error)

	// Read all.
	ReadAll(ctx context.Context, volume string, path string) (buf []byte, err error)
	GetDiskLoc() (poolIdx, setIdx, diskIdx int) // Retrieve location indexes.

	// Read entire file.
	f, err := t.fsys.Open(file)
	if err != nil {
		t.errorf("%s: Open: %w", file, err)
		return
	}

	data, err := io.ReadAll(f)
	if err != nil {
		f.Close()
		t.errorf("%s: Open+ReadAll: %w", file, err)
		return
	}

	if err := f.Close(); err != nil {
		t.errorf("%s: Close: %w", file, err)
	}

	// Check that closing twice doesn't crash.

	"io/fs"
	"os"
	"slices"
	"strings"
)

// ReadAll reads from r until an error or EOF and returns the data it read.
// A successful call returns err == nil, not err == EOF. Because ReadAll is
// defined to read from src until EOF, it does not treat an EOF from Read
// as an error to be reported.
//
// Deprecated: As of Go 1.16, this function simply calls [io.ReadAll].
func ReadAll(r io.Reader) ([]byte, error) {
	return io.ReadAll(r)
}

		buf = make([]byte, sz)
	}

	// Read file...
	_, err = io.ReadFull(f, buf)

	return buf, stat.ModTime().UTC(), osErrToFileErr(err)
}

// ReadAll is a raw call, reads content at any path and returns the buffer.
func (s *xlStorage) ReadAll(ctx context.Context, volume string, path string) (buf []byte, err error) {
	// Specific optimization to avoid re-read from the drives for `format.json`

	if err != nil {
		t.Fatal(err)
	}
	firstRead = firstRead[:n]

	close(cancel)

	rest, err := io.ReadAll(res.Body)
	all := string(firstRead) + string(rest)
	if all != "Hello" {
		t.Errorf("Read %q (%q + %q); want Hello", all, firstRead, rest)
	}
	if err != ExportErrRequestCanceled {
		t.Errorf("ReadAll error = %v; want %v", err, ExportErrRequestCanceled)
	}
}