Function readHeader

cache/filesystem_cache.go:331–342

readHeader decodes headers to big endian

(r io.Reader)

// readHeader decodes headers to big endian
func readHeader(r io.Reader) (string, error) {
	b := make([]byte, 4)
	if _, err := io.ReadFull(r, b); err != nil {
		return "", fmt.Errorf("cannot read header length: %w", err)
	}
	n := uint32(b[3]) | (uint32(b[2]) << 8) | (uint32(b[1]) << 16) | (uint32(b[0]) << 24)
	s := make([]byte, n)
	if _, err := io.ReadFull(r, s); err != nil {
		return "", fmt.Errorf("cannot read header value with length %d: %w", n, err)
	}
	return string(s), nil
}