Blocking APIs may be inefficient because you hold a thread idle while waiting on the network. Threads are expensive because they have both a memory overhead and a context-switching overhead.

#### Framed protocols

  /** Returns the original request that initiated this web socket. */
  fun request(): Request

  /**
   * Returns the size in bytes of all messages enqueued to be transmitted to the server. This
   * doesn't include framing overhead. If compression is enabled, uncompressed messages size
   * is used to calculate this value. It also doesn't include any bytes buffered by the operating

   * intended to be used as a metric: smaller headers are more efficient to encode and transmit.
   */
  fun byteCount(): Long {
    // Each header name has 2 bytes of overhead for ': ' and every header value has 2 bytes of
    // overhead for '\r\n'.
    var result = (namesAndValues.size * 2).toLong()

    for (i in 0 until namesAndValues.size) {
      result += namesAndValues[i].length.toLong()
    }

  ) : Sink {
    /**
     * Buffer of outgoing data. This batches writes of small writes into this sink as larges frames
     * written to the outgoing connection. Batching saves the (small) framing overhead.
     */
    private val sendBuffer = Buffer()

    /** Trailers to send at the end of the stream. */
    var trailers: Headers? = null

    var closed: Boolean = false

 * is satisfied. The limit is not strict: the cache may temporarily exceed it while waiting for
 * files to be deleted. The limit does not include filesystem overhead or the cache journal so
 * space-sensitive applications should set a conservative limit.
 *
 * Clients call [edit] to create or update the values of an entry. An entry may have only one editor

    /**
     * The smallest message that will be compressed. We use 1024 because smaller messages already
     * fit comfortably within a single ethernet packet (1500 bytes) even with framing overhead.
     *
     * For tests this must be big enough to realize real compression on test messages like
     * 'aaaaaaaaaa...'. Our tests check if compression was applied just by looking at the size if
     * the inbound buffer.