// data returned to just N bytes. Each call to Read
// updates N to reflect the new amount remaining.
// Read returns EOF when N <= 0 or when the underlying R returns EOF.
type HardLimitedReader struct {
	R io.Reader // underlying reader
	N int64     // max bytes remaining
}

func (l *HardLimitedReader) Read(p []byte) (n int, err error) {
	if l.N < 0 {
		return 0, ErrOverread
	}

	recordDelimiter []byte
	oneByte         []byte
	useOneByte      bool
}

func (rr *recordTransform) Read(p []byte) (n int, err error) {
	if rr.useOneByte {
		p[0] = rr.oneByte[0]
		rr.useOneByte = false
		n, err = rr.reader.Read(p[1:])
		n++
	} else {
		n, err = rr.reader.Read(p)
	}

	if err != nil {
		return n, err
	}

	// Do nothing if record-delimiter is already newline.

@Named
@Singleton
public class DefaultMetadataReader implements MetadataReader {

    public Metadata read(File input, Map<String, ?> options) throws IOException {
        Objects.requireNonNull(input, "input cannot be null");

        return read(Files.newInputStream(input.toPath()), options);
    }

    public Metadata read(Reader input, Map<String, ?> options) throws IOException {

    assertTrue(source.wasStreamOpened());
    assertFalse(source.wasStreamClosed());

    StringWriter writer = new StringWriter();
    char[] buf = new char[64];
    int read;
    while ((read = reader.read(buf)) != -1) {
      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertTrue(source.wasStreamClosed());
    assertEquals(STRING, writer.toString());
  }

            if (inputStream != null) {
                return xml.read(inputStream, request.isStrict());
            } else if (reader != null) {
                return xml.read(reader, request.isStrict());
            } else if (path != null) {
                try (InputStream is = Files.newInputStream(path)) {
                    return xml.read(is, request.isStrict());
                }
            } else {

 *       block indefinitely or fail if the source creates an infinite reader.
 *   <li><b>Non-destructive:</b> A <i>destructive</i> reader will consume or otherwise alter the
 *       source as they are read from it. A source that provides such readers will not be reusable,
 *       and operations that read from the stream (including {@link #length()}, in some

      @Throws(IOException::class)
      override fun read(
        sink: Buffer,
        byteCount: Long,
      ): Long {
        val buffer = Buffer()
        val read = delegate.read(buffer, byteCount)
        if (read != -1L) {
          sink.write(buffer.readByteString().toAsciiUppercase())
        }
        return read
      }
    }
  }

  private val countingSource: CountingSource = CountingSource(source)
  private val source: BufferedSource = countingSource.buffer()

  /** Total bytes read thus far. */
  private val byteCount: Long
    get() = countingSource.bytesRead - source.buffer.size

  /** How many bytes to read before [peekHeader] should return false, or -1L for no limit. */
  private var limit = -1L

		}
	}
	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])

	if err == io.EOF && len(r.checksum) != 0 {

* `write(data)`: Writes `data` (`str` or `bytes`) to the file.
* `read(size)`: Reads `size` (`int`) bytes/characters of the file.
* `seek(offset)`: Goes to the byte position `offset` (`int`) in the file.
    * E.g., `await myfile.seek(0)` would go to the start of the file.
    * This is especially useful if you run `await myfile.read()` once and then need to read the contents again.
* `close()`: Closes the file.