### Is concurrency better than parallelism?

Nope! That's not the moral of the story.

Concurrency is different than parallelism. And it is better on **specific** scenarios that involve a lot of waiting. Because of that, it generally is a lot better than parallelism for web application development. But not for everything.

    @CanIgnoreReturnValue
    @Override
    public Hasher putBytes(ByteBuffer buffer) {
      ByteOrder bo = buffer.order();
      buffer.order(ByteOrder.LITTLE_ENDIAN);
      while (buffer.remaining() >= 4) {
        putInt(buffer.getInt());
      }
      while (buffer.hasRemaining()) {
        putByte(buffer.get());
      }
      buffer.order(bo);
      return this;
    }

    @CanIgnoreReturnValue

    int readBytesWireFormat( byte[] buffer, int bufferIndex ) {
        int start = bufferIndex;

        if (extendedSecurity) {
            System.arraycopy(buffer, bufferIndex, blob, 0, blob.length);
            bufferIndex += blob.length;
        }
        nativeOs = readString( buffer, bufferIndex );
        bufferIndex += stringWireLength( nativeOs, bufferIndex );

            int lLow = SMBUtil.readInt4(buffer, bufferIndex + 16);

            this.lengthInBytes = ( lHigh << 32 ) | lLow;
            return 20;
        }
        this.pid = SMBUtil.readInt2(buffer, bufferIndex);
        this.byteOffset = SMBUtil.readInt4(buffer, bufferIndex + 2);
        this.lengthInBytes = SMBUtil.readInt4(buffer, bufferIndex + 6);
        return 10;
    }

  private static final byte[] testBytes = new byte[] {'y', 'a', 'm', 's'};
  private ByteArrayInputStream buffer;

  @SuppressWarnings("DoNotMock")
  @Override
  protected void setUp() throws Exception {
    super.setUp();
    hasher = mock(Hasher.class);
    hashFunction = mock(HashFunction.class);
    buffer = new ByteArrayInputStream(testBytes);

    when(hashFunction.newHasher()).thenReturn(hasher);
  }

!!! check "Authorize button!"
    You already have a shiny new "Authorize" button.

    And your *path operation* has a little lock in the top-right corner that you can click.

And if you click it, you have a little authorization form to type a `username` and `password` (and other optional fields):

<img src="/img/tutorial/security/image02.png">

!!! note

        for (b in data.toByteArray()) {
          assertThat(b).isEqualTo(2.toByte())
        }
      }
    }
  }

  private fun gzip(data: ByteArray): Buffer {
    val buffer = Buffer()
    GzipSink(buffer).buffer().write(data).close()
    return buffer
  }

  /** Create a sufficiently large header set to overflow INITIAL_MAX_FRAME_SIZE bytes.  */
  private fun largeHeaders(): List<Header> {

import java.nio.Buffer;

/**
 * Wrappers around {@link Buffer} methods that are covariantly overridden in Java 9+. See
 * https://github.com/google/guava/issues/3990
 */
@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class Java8Compatibility {
  static void clear(Buffer b) {
    b.clear();
  }

  static void flip(Buffer b) {
    b.flip();
  }

    server = MockWebServer()
    server.serverSocketFactory =
      object : DelegatingServerSocketFactory(ServerSocketFactory.getDefault()) {
        @Throws(IOException::class)
        override fun configureServerSocket(serverSocket: ServerSocket): ServerSocket {
          serverSocket.receiveBufferSize = SOCKET_BUFFER_SIZE
          return serverSocket
        }

func NewBytePoolCap(maxSize uint64, width int, capwidth int) (bp *BytePoolCap) {
	if capwidth > 0 && capwidth < 64 {
		panic("buffer capped with smaller than 64 bytes is not supported")
	}
	if capwidth > 0 && width > capwidth {
		panic("buffer length cannot be > capacity of the buffer")
	}
	return &BytePoolCap{
		c:    make(chan []byte, maxSize),
		w:    width,
		wcap: capwidth,
	}
}