Framing rules make it impractical to implement http/2 correctly on a single blocking thread. The flow-control features introduce feedback between reads and writes, requiring writes to acknowledge reads and reads to throttle writes.

In OkHttp we expose a blocking API over a framed protocol. This document explains the code and policy that makes that work.

### Threads

#### Application's calling thread

    return (int) in.skip(n);
  }

  @CanIgnoreReturnValue // to skip a byte
  @Override
  public int readUnsignedByte() throws IOException {
    int b1 = in.read();
    if (b1 < 0) {
      throw new EOFException();
    }

    return b1;
  }

  /**
   * Reads an unsigned {@code short} as specified by {@link DataInputStream#readUnsignedShort()},
   * except using little-endian byte order.
   *

        }
    }

    /**
     * Reads the contents of the file channel into a byte buffer.
     *
     * @param channel
     *            The file channel. Must not be {@literal null}.
     * @param buffer
     *            The byte buffer. Must not be {@literal null}.
     * @return The number of bytes read.
     */
    public static int read(final FileChannel channel, final ByteBuffer buffer) {

        }
    }

    /**
     * Reads text from the given {@link Reader}.
     * <p>
     * The {@link Reader} is not closed by this method.
     * </p>
     *
     * @param reader
     *            the character input stream to read from (must not be {@literal null})
     * @return the text read from the reader
     */
    public static String readText(final Reader reader) {

			return n - remain, b.readErr()
		}
	}
}

// Read reads data into p.
// It returns the number of bytes read into p.
// The bytes are taken from at most one Read on the underlying [Reader],
// hence n may be less than len(p).
// To read exactly len(p) bytes, use io.ReadFull(b, p).
// If the underlying [Reader] can return a non-zero count with io.EOF,
// then this Read method can do so as well; see the [io.Reader] docs.

		sparseMap = sparseMap[2:]
	}
	return spd, nil
}

// Read reads from the current file in the tar archive.
// It returns (0, io.EOF) when it reaches the end of that file,
// until [Next] is called to advance to the next file.
//
// If the current file is sparse, then the regions marked as a hole
// are read back as NUL-bytes.
//
// Calling Read on special types like [TypeLink], [TypeSymlink], [TypeChar],

	"bytes"
	"fmt"
	"io"
	"net/http"
	"strings"
)

// newUnsignedV4ChunkedReader returns a new s3UnsignedChunkedReader that translates the data read from r
// out of HTTP "chunked" format before returning it.
// The s3ChunkedReader returns io.EOF when the final 0-length chunk is read.
func newUnsignedV4ChunkedReader(req *http.Request, trailer bool, signature bool) (io.ReadCloser, APIErrorCode) {
	if signature {

    val source = relay.newSource()
    val sourceBuffer = Buffer()
    assertThat(source!!.read(sourceBuffer, 5)).isEqualTo(5)
    assertThat(sourceBuffer.readUtf8()).isEqualTo("abcde")
    assertThat(source.read(sourceBuffer, 1024)).isEqualTo(8)
    assertThat(sourceBuffer.readUtf8()).isEqualTo("fghijklm")
    assertThat(source.read(sourceBuffer, 1024)).isEqualTo(-1)
    assertThat(sourceBuffer.size).isEqualTo(0)
    source.close()

      // The default implementation of Reader#read(CharBuffer) allocates a
      // temporary char[], so we call Reader#read(char[], int, int) instead.
      int read = (reader != null) ? reader.read(buf, 0, buf.length) : readable.read(cbuf);
      if (read == -1) {
        lineBuf.finish();
        break;
      }
      lineBuf.add(buf, 0, read);
    }
    return lines.poll();
  }

* `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.