SocketWrapperBase (Apache Tomcat 8.5.84 API Documentation)

Package org.apache.tomcat.util.net

## Class SocketWrapperBase<E>

- java.lang.Object
- - org.apache.tomcat.util.net.SocketWrapperBase<E>

- Direct Known Subclasses:
    `AprEndpoint.AprSocketWrapper`, `Nio2Endpoint.Nio2SocketWrapper`, `NioEndpoint.NioSocketWrapper`

      public abstract class SocketWrapperBase<E>
      extends java.lang.Object

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Class | Description
    --- | --- | ---
    `static class` | `SocketWrapperBase.BlockingMode` |
    `static interface` | `SocketWrapperBase.CompletionCheck` |
    `static class` | `SocketWrapperBase.CompletionHandlerCall` |
    `static class` | `SocketWrapperBase.CompletionState` |
    `protected class` | `SocketWrapperBase.OperationState<A>` | Internal state tracker for vectored operations.
    `protected class` | `SocketWrapperBase.VectoredIOCompletionHandler<A>` | Completion handler for vectored operations.

  - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `protected int` | `bufferedWriteSize` | The max size of the individual buffered write buffers
    `protected java.util.concurrent.atomic.AtomicBoolean` | `closed` |
    `static SocketWrapperBase.CompletionCheck` | `COMPLETE_READ` | This utility CompletionCheck will cause the completion handler to be called once the given buffers are full.
    `static SocketWrapperBase.CompletionCheck` | `COMPLETE_READ_WITH_COMPLETION` | This utility CompletionCheck will cause the completion handler to be called once the given buffers are full.
    `static SocketWrapperBase.CompletionCheck` | `COMPLETE_WRITE` | This utility CompletionCheck will cause the write to fully write all remaining data.
    `static SocketWrapperBase.CompletionCheck` | `COMPLETE_WRITE_WITH_COMPLETION` | This utility CompletionCheck will cause the write to fully write all remaining data.
    `protected java.lang.String` | `localAddr` |
    `protected java.lang.String` | `localName` |
    `protected int` | `localPort` |
    `protected WriteBuffer` | `nonBlockingWriteBuffer` | Additional buffer used for non-blocking writes.
    `protected java.io.IOException` | `previousIOException` |
    `static SocketWrapperBase.CompletionCheck` | `READ_DATA` | This utility CompletionCheck will cause the completion handler to be called once some data has been read.
    `protected SocketWrapperBase.OperationState<?>` | `readOperation` |
    `protected java.util.concurrent.Semaphore` | `readPending` |
    `protected java.lang.String` | `remoteAddr` |
    `protected java.lang.String` | `remoteHost` |
    `protected int` | `remotePort` |
    `protected static StringManager` | `sm` |
    `protected SocketBufferHandler` | `socketBufferHandler` | The buffers used for communicating with the socket.
    `protected SocketWrapperBase.OperationState<?>` | `writeOperation` |
    `protected java.util.concurrent.Semaphore` | `writePending` |

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `SocketWrapperBase​(E socket, AbstractEndpoint<E,​?> endpoint)` |

  - ### Method Summary

    All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `boolean` | `awaitReadComplete​(long timeout, java.util.concurrent.TimeUnit unit)` | Deprecated.
    `boolean` | `awaitWriteComplete​(long timeout, java.util.concurrent.TimeUnit unit)` | Deprecated.
    `protected static boolean` | `buffersArrayHasRemaining​(java.nio.ByteBuffer[] buffers, int offset, int length)` |
    `boolean` | `canWrite()` |
    `void` | `checkError()` |
    `void` | `close()` | Close the socket wrapper.
    `abstract SendfileDataBase` | `createSendfileData​(java.lang.String filename, long pos, long length)` |
    `int` | `decrementKeepAlive()` |
    `abstract void` | `doClientAuth​(SSLSupport sslSupport)` | Require the client to perform CLIENT-CERT authentication if it hasn't already done so.
    `protected abstract void` | `doClose()` | Perform the actual close.
    `protected void` | `doWrite​(boolean block)` | Write the contents of the socketWriteBuffer to the socket.
    `protected abstract void` | `doWrite​(boolean block, java.nio.ByteBuffer from)` | Write the contents of the ByteBuffer to the socket.
    `void` | `execute​(java.lang.Runnable runnable)` | Transfers processing to a container thread.
    `boolean` | `flush​(boolean block)` | Writes as much data as possible from any that remains in the buffers.
    `protected void` | `flushBlocking()` | Writes all remaining data from the buffers and blocks until the write is complete.
    `protected abstract boolean` | `flushNonBlocking()` | Writes as much data as possible from any that remains in the buffers.
    `java.lang.Object` | `getCurrentProcessor()` |
    `AbstractEndpoint<E,​?>` | `getEndpoint()` |
    `java.io.IOException` | `getError()` |
    `java.lang.String` | `getLocalAddr()` |
    `java.lang.String` | `getLocalName()` |
    `int` | `getLocalPort()` |
    `java.lang.String` | `getNegotiatedProtocol()` |
    `long` | `getReadTimeout()` |
    `java.lang.String` | `getRemoteAddr()` |
    `java.lang.String` | `getRemoteHost()` |
    `int` | `getRemotePort()` |
    `E` | `getSocket()` |
    `SocketBufferHandler` | `getSocketBufferHandler()` |
    `abstract SSLSupport` | `getSslSupport​(java.lang.String clientCertProvider)` |
    `long` | `getWriteTimeout()` |
    `boolean` | `hasAsyncIO()` | Allows using NIO2 style read/write.
    `boolean` | `hasDataToRead()` |
    `boolean` | `hasDataToWrite()` |
    `boolean` | `hasPerOperationTimeout()` | Allows indicating if the connector supports per operation timeout.
    `boolean` | `isClosed()` |
    `boolean` | `isReadPending()` | Allows checking if an asynchronous read operation is currently pending.
    `abstract boolean` | `isReadyForRead()` |
    `boolean` | `isReadyForWrite()` | Checks to see if there are any writes pending and if there are calls `registerWriteInterest()` to trigger a callback once the pending writes have completed.
    `boolean` | `isSecure()` | Deprecated. Unused.
    `boolean` | `isUpgraded()` | Deprecated. Unused.
    `boolean` | `isWritePending()` | Allows checking if an asynchronous write operation is currently pending.
    `boolean` | `needSemaphores()` | Allows indicating if the connector needs semaphores.
    `protected abstract <A> SocketWrapperBase.OperationState<A>` | `newOperationState​(boolean read, java.nio.ByteBuffer[] buffers, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, java.util.concurrent.TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler, java.util.concurrent.Semaphore semaphore, SocketWrapperBase.VectoredIOCompletionHandler<A> completion)` |
    `protected abstract void` | `populateLocalAddr()` |
    `protected abstract void` | `populateLocalName()` |
    `protected abstract void` | `populateLocalPort()` |
    `protected int` | `populateReadBuffer​(byte[] b, int off, int len)` |
    `protected int` | `populateReadBuffer​(java.nio.ByteBuffer to)` |
    `protected abstract void` | `populateRemoteAddr()` |
    `protected abstract void` | `populateRemoteHost()` |
    `protected abstract void` | `populateRemotePort()` |
    `abstract SendfileState` | `processSendfile​(SendfileDataBase sendfileData)` | Starts the sendfile process.
    `void` | `processSocket​(SocketEvent socketStatus, boolean dispatch)` |
    `abstract int` | `read​(boolean block, byte[] b, int off, int len)` |
    `abstract int` | `read​(boolean block, java.nio.ByteBuffer to)` |
    `<A> SocketWrapperBase.CompletionState` | `read​(long timeout, java.util.concurrent.TimeUnit unit, A attachment, java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler, java.nio.ByteBuffer... dsts)` | Scatter read.
    `<A> SocketWrapperBase.CompletionState` | `read​(java.nio.ByteBuffer[] dsts, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, java.util.concurrent.TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler)` | Scatter read.
    `<A> SocketWrapperBase.CompletionState` | `read​(SocketWrapperBase.BlockingMode block, long timeout, java.util.concurrent.TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler, java.nio.ByteBuffer... dsts)` | Scatter read.
    `abstract void` | `registerReadInterest()` |
    `abstract void` | `registerWriteInterest()` |
    `protected void` | `reset​(E closedSocket)` |
    `abstract void` | `setAppReadBufHandler​(ApplicationBufferHandler handler)` |
    `void` | `setCurrentProcessor​(java.lang.Object currentProcessor)` |
    `void` | `setError​(java.io.IOException error)` |
    `void` | `setKeepAliveLeft​(int keepAliveLeft)` |
    `void` | `setNegotiatedProtocol​(java.lang.String negotiatedProtocol)` |
    `void` | `setReadTimeout​(long readTimeout)` | Set the timeout for reading.
    `void` | `setSecure​(boolean secure)` | Deprecated. Unused.
    `void` | `setUpgraded​(boolean upgraded)` | Deprecated. Unused.
    `void` | `setWriteTimeout​(long writeTimeout)` | Set the timeout for writing.
    `java.lang.Object` | `takeCurrentProcessor()` |
    `java.lang.String` | `toString()` | Overridden for debug purposes.
    `protected static int` | `transfer​(byte[] from, int offset, int length, java.nio.ByteBuffer to)` |
    `protected static int` | `transfer​(java.nio.ByteBuffer from, java.nio.ByteBuffer to)` |
    `void` | `unRead​(java.nio.ByteBuffer returnedInput)` | Return input that has been read to the input buffer for re-reading by the correct component.
    `protected <A> SocketWrapperBase.CompletionState` | `vectoredOperation​(boolean read, java.nio.ByteBuffer[] buffers, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, java.util.concurrent.TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler)` | Vectored operation.
    `void` | `write​(boolean block, byte[] buf, int off, int len)` | Writes the provided data to the socket write buffer.
    `void` | `write​(boolean block, java.nio.ByteBuffer from)` | Writes the provided data to the socket write buffer.
    `<A> SocketWrapperBase.CompletionState` | `write​(long timeout, java.util.concurrent.TimeUnit unit, A attachment, java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler, java.nio.ByteBuffer... srcs)` | Gather write.
    `<A> SocketWrapperBase.CompletionState` | `write​(java.nio.ByteBuffer[] srcs, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, java.util.concurrent.TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler)` | Gather write.
    `<A> SocketWrapperBase.CompletionState` | `write​(SocketWrapperBase.BlockingMode block, long timeout, java.util.concurrent.TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler, java.nio.ByteBuffer... srcs)` | Gather write.
    `protected void` | `writeBlocking​(byte[] buf, int off, int len)` | Writes the provided data to the socket write buffer.
    `protected void` | `writeBlocking​(java.nio.ByteBuffer from)` | Writes the provided data to the socket write buffer.
    `protected void` | `writeNonBlocking​(byte[] buf, int off, int len)` | Transfers the data to the socket write buffer (writing that data to the socket if the buffer fills up using a non-blocking write) until either all the data has been transferred and space remains in the socket write buffer or a non-blocking write leaves data in the socket write buffer.
    `protected void` | `writeNonBlocking​(java.nio.ByteBuffer from)` | Transfers the data to the socket write buffer (writing that data to the socket if the buffer fills up using a non-blocking write) until either all the data has been transferred and space remains in the socket write buffer or a non-blocking write leaves data in the socket write buffer.
    `protected void` | `writeNonBlockingInternal​(java.nio.ByteBuffer from)` | Separate method so it can be re-used by the socket write buffer to write data to the network

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Field Detail

    - #### sm

          protected static final StringManager sm

    - #### closed

          protected final java.util.concurrent.atomic.AtomicBoolean closed

    - #### previousIOException

          protected volatile java.io.IOException previousIOException

    - #### localAddr

          protected java.lang.String localAddr

    - #### localName

          protected java.lang.String localName

    - #### localPort

          protected int localPort

    - #### remoteAddr

          protected java.lang.String remoteAddr

    - #### remoteHost

          protected java.lang.String remoteHost

    - #### remotePort

          protected int remotePort

    - #### socketBufferHandler

          protected volatile SocketBufferHandler socketBufferHandler

      The buffers used for communicating with the socket.

    - #### bufferedWriteSize

          protected int bufferedWriteSize

      The max size of the individual buffered write buffers

    - #### nonBlockingWriteBuffer

          protected final WriteBuffer nonBlockingWriteBuffer

      Additional buffer used for non-blocking writes. Non-blocking writes need to return immediately even if the data cannot be written immediately but the socket buffer may not be big enough to hold all of the unwritten data. This structure provides an additional buffer to hold the data until it can be written. Not that while the Servlet API only allows one non-blocking write at a time, due to buffering and the possible need to write HTTP headers, this layer may see multiple writes.

    - #### readPending

          protected final java.util.concurrent.Semaphore readPending

    - #### readOperation

          protected volatile SocketWrapperBase.OperationState<?> readOperation

    - #### writePending

          protected final java.util.concurrent.Semaphore writePending

    - #### writeOperation

          protected volatile SocketWrapperBase.OperationState<?> writeOperation

    - #### COMPLETE_WRITE

          public static final SocketWrapperBase.CompletionCheck COMPLETE_WRITE

      This utility CompletionCheck will cause the write to fully write all remaining data. If the operation completes inline, the completion handler will not be called.

    - #### COMPLETE_WRITE_WITH_COMPLETION

          public static final SocketWrapperBase.CompletionCheck COMPLETE_WRITE_WITH_COMPLETION

      This utility CompletionCheck will cause the write to fully write all remaining data. The completion handler will then be called.

    - #### READ_DATA

          public static final SocketWrapperBase.CompletionCheck READ_DATA

      This utility CompletionCheck will cause the completion handler to be called once some data has been read. If the operation completes inline, the completion handler will not be called.

    - #### COMPLETE_READ_WITH_COMPLETION

          public static final SocketWrapperBase.CompletionCheck COMPLETE_READ_WITH_COMPLETION

      This utility CompletionCheck will cause the completion handler to be called once the given buffers are full. The completion handler will then be called.

    - #### COMPLETE_READ

          public static final SocketWrapperBase.CompletionCheck COMPLETE_READ

      This utility CompletionCheck will cause the completion handler to be called once the given buffers are full. If the operation completes inline, the completion handler will not be called.

  - ### Constructor Detail

    - #### SocketWrapperBase

          public SocketWrapperBase​(E socket,
                                   AbstractEndpoint<E,​?> endpoint)

  - ### Method Detail

    - #### getSocket

          public E getSocket()

    - #### reset

          protected void reset​(E closedSocket)

    - #### getEndpoint

          public AbstractEndpoint<E,​?> getEndpoint()

    - #### getCurrentProcessor

          public java.lang.Object getCurrentProcessor()

    - #### setCurrentProcessor

          public void setCurrentProcessor​(java.lang.Object currentProcessor)

    - #### takeCurrentProcessor

          public java.lang.Object takeCurrentProcessor()

    - #### execute

          public void execute​(java.lang.Runnable runnable)

      Transfers processing to a container thread.
      Parameters:
        `runnable` - The actions to process on a container thread
      Throws:
        `java.util.concurrent.RejectedExecutionException` - If the runnable cannot be executed

    - #### getError

          public java.io.IOException getError()

    - #### setError

          public void setError​(java.io.IOException error)

    - #### checkError

          public void checkError()
                          throws java.io.IOException

      Throws:
        `java.io.IOException`

    - #### isUpgraded

          @Deprecated
          public boolean isUpgraded()

      Deprecated.
      Unused. Will be removed in Tomcat 10.
      Returns:
        `true` if the connection has been upgraded.

    - #### setUpgraded

          @Deprecated
          public void setUpgraded​(boolean upgraded)

      Deprecated.
      Unused. Will be removed in Tomcat 10.
      Parameters:
        `upgraded` - `true` if the connection has been upgraded.

    - #### isSecure

          @Deprecated
          public boolean isSecure()

      Deprecated.
      Unused. Will be removed in Tomcat 10.
      Returns:
        `true` if the connection uses TLS

    - #### setSecure

          @Deprecated
          public void setSecure​(boolean secure)

      Deprecated.
      Unused. Will be removed in Tomcat 10.
      Parameters:
        `secure` - `true` if the connection uses TLS

    - #### getNegotiatedProtocol

          public java.lang.String getNegotiatedProtocol()

    - #### setNegotiatedProtocol

          public void setNegotiatedProtocol​(java.lang.String negotiatedProtocol)

    - #### setReadTimeout

          public void setReadTimeout​(long readTimeout)

      Set the timeout for reading. Values of zero or less will be changed to -1.
      Parameters:
        `readTimeout` - The timeout in milliseconds. A value of -1 indicates an infinite timeout.

    - #### getReadTimeout

          public long getReadTimeout()

    - #### setWriteTimeout

          public void setWriteTimeout​(long writeTimeout)

      Set the timeout for writing. Values of zero or less will be changed to -1.
      Parameters:
        `writeTimeout` - The timeout in milliseconds. A value of zero or less indicates an infinite timeout.

    - #### getWriteTimeout

          public long getWriteTimeout()

    - #### setKeepAliveLeft

          public void setKeepAliveLeft​(int keepAliveLeft)

    - #### decrementKeepAlive

          public int decrementKeepAlive()

    - #### getRemoteHost

          public java.lang.String getRemoteHost()

    - #### populateRemoteHost

          protected abstract void populateRemoteHost()

    - #### getRemoteAddr

          public java.lang.String getRemoteAddr()

    - #### populateRemoteAddr

          protected abstract void populateRemoteAddr()

    - #### getRemotePort

          public int getRemotePort()

    - #### populateRemotePort

          protected abstract void populateRemotePort()

    - #### getLocalName

          public java.lang.String getLocalName()

    - #### populateLocalName

          protected abstract void populateLocalName()

    - #### getLocalAddr

          public java.lang.String getLocalAddr()

    - #### populateLocalAddr

          protected abstract void populateLocalAddr()

    - #### getLocalPort

          public int getLocalPort()

    - #### populateLocalPort

          protected abstract void populateLocalPort()

    - #### getSocketBufferHandler

          public SocketBufferHandler getSocketBufferHandler()

    - #### hasDataToRead

          public boolean hasDataToRead()

    - #### hasDataToWrite

          public boolean hasDataToWrite()

    - #### isReadyForWrite

          public boolean isReadyForWrite()

      Checks to see if there are any writes pending and if there are calls `registerWriteInterest()` to trigger a callback once the pending writes have completed.

      Note: Once this method has returned `false` it MUST NOT be called again until the pending write has completed and the callback has been fired. TODO: Modify `registerWriteInterest()` so the above restriction is enforced there rather than relying on the caller.

      Returns:
        `true` if no writes are pending and data can be written otherwise `false`

    - #### canWrite

          public boolean canWrite()

    - #### toString

          public java.lang.String toString()

      Overridden for debug purposes. No guarantees are made about the format of this message which may vary significantly between point releases.

      Overrides:
        `toString` in class `java.lang.Object`

    - #### read

          public abstract int read​(boolean block,
                                   byte[] b,
                                   int off,
                                   int len)
                            throws java.io.IOException

      Throws:
        `java.io.IOException`

    - #### read

          public abstract int read​(boolean block,
                                   java.nio.ByteBuffer to)
                            throws java.io.IOException

      Throws:
        `java.io.IOException`

    - #### isReadyForRead

          public abstract boolean isReadyForRead()
                                          throws java.io.IOException

      Throws:
        `java.io.IOException`

    - #### setAppReadBufHandler

          public abstract void setAppReadBufHandler​(ApplicationBufferHandler handler)

    - #### populateReadBuffer

          protected int populateReadBuffer​(byte[] b,
                                           int off,
                                           int len)

    - #### populateReadBuffer

          protected int populateReadBuffer​(java.nio.ByteBuffer to)

    - #### unRead

          public void unRead​(java.nio.ByteBuffer returnedInput)

      Return input that has been read to the input buffer for re-reading by the correct component. There are times when a component may read more data than it needs before it passes control to another component. One example of this is during HTTP upgrade. If an (arguably misbehaving client) sends data associated with the upgraded protocol before the HTTP upgrade completes, the HTTP handler may read it. This method provides a way for that data to be returned so it can be processed by the correct component.
      Parameters:
        `returnedInput` - The input to return to the input buffer.

    - #### close

          public void close()

      Close the socket wrapper.

    - #### doClose

          protected abstract void doClose()

      Perform the actual close. The closed atomic boolean guarantees this will be called only once per wrapper.

    - #### isClosed

          public boolean isClosed()

      Returns:
        true if the wrapper has been closed

    - #### write

          public final void write​(boolean block,
                                  byte[] buf,
                                  int off,
                                  int len)
                           throws java.io.IOException

      Writes the provided data to the socket write buffer. If the socket write buffer fills during the write, the content of the socket write buffer is written to the network and this method starts to fill the socket write buffer again. Depending on the size of the data to write, there may be multiple writes to the network.

      Non-blocking writes must return immediately and the byte array holding the data to be written must be immediately available for re-use. It may not be possible to write sufficient data to the network to allow this to happen. In this case data that cannot be written to the network and cannot be held by the socket buffer is stored in the non-blocking write buffer.

      Note: There is an implementation assumption that, before switching from non-blocking writes to blocking writes, any data remaining in the non-blocking write buffer will have been written to the network.

      Parameters:
        `block` - `true` if a blocking write should be used, otherwise a non-blocking write will be used
        `buf` - The byte array containing the data to be written
        `off` - The offset within the byte array of the data to be written
        `len` - The length of the data to be written
      Throws:
        `java.io.IOException` - If an IO error occurs during the write

    - #### write

          public final void write​(boolean block,
                                  java.nio.ByteBuffer from)
                           throws java.io.IOException

      Writes the provided data to the socket write buffer. If the socket write buffer fills during the write, the content of the socket write buffer is written to the network and this method starts to fill the socket write buffer again. Depending on the size of the data to write, there may be multiple writes to the network.

      Non-blocking writes must return immediately and the ByteBuffer holding the data to be written must be immediately available for re-use. It may not be possible to write sufficient data to the network to allow this to happen. In this case data that cannot be written to the network and cannot be held by the socket buffer is stored in the non-blocking write buffer.

      Note: There is an implementation assumption that, before switching from non-blocking writes to blocking writes, any data remaining in the non-blocking write buffer will have been written to the network.

      Parameters:
        `block` - `true` if a blocking write should be used, otherwise a non-blocking write will be used
        `from` - The ByteBuffer containing the data to be written
      Throws:
        `java.io.IOException` - If an IO error occurs during the write

    - #### writeBlocking

          protected void writeBlocking​(byte[] buf,
                                       int off,
                                       int len)
                                throws java.io.IOException

      Writes the provided data to the socket write buffer. If the socket write buffer fills during the write, the content of the socket write buffer is written to the network using a blocking write. Once that blocking write is complete, this method starts to fill the socket write buffer again. Depending on the size of the data to write, there may be multiple writes to the network. On completion of this method there will always be space remaining in the socket write buffer.
      Parameters:
        `buf` - The byte array containing the data to be written
        `off` - The offset within the byte array of the data to be written
        `len` - The length of the data to be written
      Throws:
        `java.io.IOException` - If an IO error occurs during the write

    - #### writeBlocking

          protected void writeBlocking​(java.nio.ByteBuffer from)
                                throws java.io.IOException

      Writes the provided data to the socket write buffer. If the socket write buffer fills during the write, the content of the socket write buffer is written to the network using a blocking write. Once that blocking write is complete, this method starts to fill the socket write buffer again. Depending on the size of the data to write, there may be multiple writes to the network. On completion of this method there will always be space remaining in the socket write buffer.
      Parameters:
        `from` - The ByteBuffer containing the data to be written
      Throws:
        `java.io.IOException` - If an IO error occurs during the write

    - #### writeNonBlocking

          protected void writeNonBlocking​(byte[] buf,
                                          int off,
                                          int len)
                                   throws java.io.IOException

      Transfers the data to the socket write buffer (writing that data to the socket if the buffer fills up using a non-blocking write) until either all the data has been transferred and space remains in the socket write buffer or a non-blocking write leaves data in the socket write buffer. After an incomplete write, any data remaining to be transferred to the socket write buffer will be copied to the socket write buffer. If the remaining data is too big for the socket write buffer, the socket write buffer will be filled and the additional data written to the non-blocking write buffer.
      Parameters:
        `buf` - The byte array containing the data to be written
        `off` - The offset within the byte array of the data to be written
        `len` - The length of the data to be written
      Throws:
        `java.io.IOException` - If an IO error occurs during the write

    - #### writeNonBlocking

          protected void writeNonBlocking​(java.nio.ByteBuffer from)
                                   throws java.io.IOException

      Transfers the data to the socket write buffer (writing that data to the socket if the buffer fills up using a non-blocking write) until either all the data has been transferred and space remains in the socket write buffer or a non-blocking write leaves data in the socket write buffer. After an incomplete write, any data remaining to be transferred to the socket write buffer will be copied to the socket write buffer. If the remaining data is too big for the socket write buffer, the socket write buffer will be filled and the additional data written to the non-blocking write buffer.
      Parameters:
        `from` - The ByteBuffer containing the data to be written
      Throws:
        `java.io.IOException` - If an IO error occurs during the write

    - #### writeNonBlockingInternal

          protected void writeNonBlockingInternal​(java.nio.ByteBuffer from)
                                           throws java.io.IOException

      Separate method so it can be re-used by the socket write buffer to write data to the network
      Parameters:
        `from` - The ByteBuffer containing the data to be written
      Throws:
        `java.io.IOException` - If an IO error occurs during the write

    - #### flush

          public boolean flush​(boolean block)
                        throws java.io.IOException

      Writes as much data as possible from any that remains in the buffers.
      Parameters:
        `block` - `true` if a blocking write should be used, otherwise a non-blocking write will be used
      Returns:
        `true` if data remains to be flushed after this method completes, otherwise `false`. In blocking mode therefore, the return value should always be `false`
      Throws:
        `java.io.IOException` - If an IO error occurs during the write

    - #### flushBlocking

          protected void flushBlocking()
                                throws java.io.IOException

      Writes all remaining data from the buffers and blocks until the write is complete.
      Throws:
        `java.io.IOException` - If an IO error occurs during the write

    - #### flushNonBlocking

          protected abstract boolean flushNonBlocking()
                                               throws java.io.IOException

      Writes as much data as possible from any that remains in the buffers.
      Returns:
        `true` if data remains to be flushed after this method completes, otherwise `false`.
      Throws:
        `java.io.IOException` - If an IO error occurs during the write

    - #### doWrite

          protected void doWrite​(boolean block)
                          throws java.io.IOException

      Write the contents of the socketWriteBuffer to the socket. For blocking writes either then entire contents of the buffer will be written or an IOException will be thrown. Partial blocking writes will not occur.
      Parameters:
        `block` - Should the write be blocking or not?
      Throws:
        `java.io.IOException` - If an I/O error such as a timeout occurs during the write

    - #### doWrite

          protected abstract void doWrite​(boolean block,
                                          java.nio.ByteBuffer from)
                                   throws java.io.IOException

      Write the contents of the ByteBuffer to the socket. For blocking writes either then entire contents of the buffer will be written or an IOException will be thrown. Partial blocking writes will not occur.
      Parameters:
        `block` - Should the write be blocking or not?
        `from` - the ByteBuffer containing the data to be written
      Throws:
        `java.io.IOException` - If an I/O error such as a timeout occurs during the write

    - #### processSocket

          public void processSocket​(SocketEvent socketStatus,
                                    boolean dispatch)

    - #### registerReadInterest

          public abstract void registerReadInterest()

    - #### registerWriteInterest

          public abstract void registerWriteInterest()

    - #### createSendfileData

          public abstract SendfileDataBase createSendfileData​(java.lang.String filename,
                                                              long pos,
                                                              long length)

    - #### processSendfile

          public abstract SendfileState processSendfile​(SendfileDataBase sendfileData)

      Starts the sendfile process. It is expected that if the sendfile process does not complete during this call and does not report an error, that the caller will not add the socket to the poller (or equivalent). That is the responsibility of this method.
      Parameters:
        `sendfileData` - Data representing the file to send
      Returns:
        The state of the sendfile process after the first write.

    - #### doClientAuth

          public abstract void doClientAuth​(SSLSupport sslSupport)
                                     throws java.io.IOException

      Require the client to perform CLIENT-CERT authentication if it hasn't already done so.
      Parameters:
        `sslSupport` - The SSL/TLS support instance currently being used by the connection that may need updating after the client authentication
      Throws:
        `java.io.IOException` - If authentication is required then there will be I/O with the client and this exception will be thrown if that goes wrong

    - #### getSslSupport

          public abstract SSLSupport getSslSupport​(java.lang.String clientCertProvider)

    - #### hasAsyncIO

          public boolean hasAsyncIO()

      Allows using NIO2 style read/write.
      Returns:
        `true` if the connector has the capability enabled

    - #### needSemaphores

          public boolean needSemaphores()

      Allows indicating if the connector needs semaphores.
      Returns:
        This default implementation always returns `false`

    - #### hasPerOperationTimeout

          public boolean hasPerOperationTimeout()

      Allows indicating if the connector supports per operation timeout.
      Returns:
        This default implementation always returns `false`

    - #### isReadPending

          public boolean isReadPending()

      Allows checking if an asynchronous read operation is currently pending.
      Returns:
        `true` if the endpoint supports asynchronous IO and a read operation is being processed asynchronously

    - #### isWritePending

          public boolean isWritePending()

      Allows checking if an asynchronous write operation is currently pending.
      Returns:
        `true` if the endpoint supports asynchronous IO and a write operation is being processed asynchronously

    - #### awaitReadComplete

          @Deprecated
          public boolean awaitReadComplete​(long timeout,
                                           java.util.concurrent.TimeUnit unit)

      Deprecated.
      If an asynchronous read operation is pending, this method will block until the operation completes, or the specified amount of time has passed.
      Parameters:
        `timeout` - The maximum amount of time to wait
        `unit` - The unit for the timeout
      Returns:
        `true` if the read operation is complete, `false` if the operation is still pending and the specified timeout has passed

    - #### awaitWriteComplete

          @Deprecated
          public boolean awaitWriteComplete​(long timeout,
                                            java.util.concurrent.TimeUnit unit)

      Deprecated.
      If an asynchronous write operation is pending, this method will block until the operation completes, or the specified amount of time has passed.
      Parameters:
        `timeout` - The maximum amount of time to wait
        `unit` - The unit for the timeout
      Returns:
        `true` if the read operation is complete, `false` if the operation is still pending and the specified timeout has passed

    - #### read

          public final <A> SocketWrapperBase.CompletionState read​(long timeout,
                                                                  java.util.concurrent.TimeUnit unit,
                                                                  A attachment,
                                                                  java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler,
                                                                  java.nio.ByteBuffer... dsts)

      Scatter read. The completion handler will be called once some data has been read or an error occurred. The default NIO2 behavior is used: the completion handler will be called as soon as some data has been read, even if the read has completed inline.
      Type Parameters:
        `A` - The attachment type
      Parameters:
        `timeout` - timeout duration for the read
        `unit` - units for the timeout duration
        `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
        `handler` - to call when the IO is complete
        `dsts` - buffers
      Returns:
        the completion state (done, done inline, or still pending)

    - #### read

          public final <A> SocketWrapperBase.CompletionState read​(SocketWrapperBase.BlockingMode block,
                                                                  long timeout,
                                                                  java.util.concurrent.TimeUnit unit,
                                                                  A attachment,
                                                                  SocketWrapperBase.CompletionCheck check,
                                                                  java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler,
                                                                  java.nio.ByteBuffer... dsts)

      Scatter read. The completion handler will be called once some data has been read or an error occurred. If a CompletionCheck object has been provided, the completion handler will only be called if the callHandler method returned true. If no CompletionCheck object has been provided, the default NIO2 behavior is used: the completion handler will be called as soon as some data has been read, even if the read has completed inline.
      Type Parameters:
        `A` - The attachment type
      Parameters:
        `block` - is the blocking mode that will be used for this operation
        `timeout` - timeout duration for the read
        `unit` - units for the timeout duration
        `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
        `check` - for the IO operation completion
        `handler` - to call when the IO is complete
        `dsts` - buffers
      Returns:
        the completion state (done, done inline, or still pending)

    - #### read

          public final <A> SocketWrapperBase.CompletionState read​(java.nio.ByteBuffer[] dsts,
                                                                  int offset,
                                                                  int length,
                                                                  SocketWrapperBase.BlockingMode block,
                                                                  long timeout,
                                                                  java.util.concurrent.TimeUnit unit,
                                                                  A attachment,
                                                                  SocketWrapperBase.CompletionCheck check,
                                                                  java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler)

      Scatter read. The completion handler will be called once some data has been read or an error occurred. If a CompletionCheck object has been provided, the completion handler will only be called if the callHandler method returned true. If no CompletionCheck object has been provided, the default NIO2 behavior is used: the completion handler will be called as soon as some data has been read, even if the read has completed inline.
      Type Parameters:
        `A` - The attachment type
      Parameters:
        `dsts` - buffers
        `offset` - in the buffer array
        `length` - in the buffer array
        `block` - is the blocking mode that will be used for this operation
        `timeout` - timeout duration for the read
        `unit` - units for the timeout duration
        `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
        `check` - for the IO operation completion
        `handler` - to call when the IO is complete
      Returns:
        the completion state (done, done inline, or still pending)

    - #### write

          public final <A> SocketWrapperBase.CompletionState write​(long timeout,
                                                                   java.util.concurrent.TimeUnit unit,
                                                                   A attachment,
                                                                   java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler,
                                                                   java.nio.ByteBuffer... srcs)

      Gather write. The completion handler will be called once some data has been written or an error occurred. The default NIO2 behavior is used: the completion handler will be called, even if the write is incomplete and data remains in the buffers, or if the write completed inline.
      Type Parameters:
        `A` - The attachment type
      Parameters:
        `timeout` - timeout duration for the write
        `unit` - units for the timeout duration
        `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
        `handler` - to call when the IO is complete
        `srcs` - buffers
      Returns:
        the completion state (done, done inline, or still pending)

    - #### write

          public final <A> SocketWrapperBase.CompletionState write​(SocketWrapperBase.BlockingMode block,
                                                                   long timeout,
                                                                   java.util.concurrent.TimeUnit unit,
                                                                   A attachment,
                                                                   SocketWrapperBase.CompletionCheck check,
                                                                   java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler,
                                                                   java.nio.ByteBuffer... srcs)

      Gather write. The completion handler will be called once some data has been written or an error occurred. If a CompletionCheck object has been provided, the completion handler will only be called if the callHandler method returned true. If no CompletionCheck object has been provided, the default NIO2 behavior is used: the completion handler will be called, even if the write is incomplete and data remains in the buffers, or if the write completed inline.
      Type Parameters:
        `A` - The attachment type
      Parameters:
        `block` - is the blocking mode that will be used for this operation
        `timeout` - timeout duration for the write
        `unit` - units for the timeout duration
        `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
        `check` - for the IO operation completion
        `handler` - to call when the IO is complete
        `srcs` - buffers
      Returns:
        the completion state (done, done inline, or still pending)

    - #### write

          public final <A> SocketWrapperBase.CompletionState write​(java.nio.ByteBuffer[] srcs,
                                                                   int offset,
                                                                   int length,
                                                                   SocketWrapperBase.BlockingMode block,
                                                                   long timeout,
                                                                   java.util.concurrent.TimeUnit unit,
                                                                   A attachment,
                                                                   SocketWrapperBase.CompletionCheck check,
                                                                   java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler)

      Gather write. The completion handler will be called once some data has been written or an error occurred. If a CompletionCheck object has been provided, the completion handler will only be called if the callHandler method returned true. If no CompletionCheck object has been provided, the default NIO2 behavior is used: the completion handler will be called, even if the write is incomplete and data remains in the buffers, or if the write completed inline.
      Type Parameters:
        `A` - The attachment type
      Parameters:
        `srcs` - buffers
        `offset` - in the buffer array
        `length` - in the buffer array
        `block` - is the blocking mode that will be used for this operation
        `timeout` - timeout duration for the write
        `unit` - units for the timeout duration
        `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
        `check` - for the IO operation completion
        `handler` - to call when the IO is complete
      Returns:
        the completion state (done, done inline, or still pending)

    - #### vectoredOperation

          protected final <A> SocketWrapperBase.CompletionState vectoredOperation​(boolean read,
                                                                                  java.nio.ByteBuffer[] buffers,
                                                                                  int offset,
                                                                                  int length,
                                                                                  SocketWrapperBase.BlockingMode block,
                                                                                  long timeout,
                                                                                  java.util.concurrent.TimeUnit unit,
                                                                                  A attachment,
                                                                                  SocketWrapperBase.CompletionCheck check,
                                                                                  java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler)

      Vectored operation. The completion handler will be called once the operation is complete or an error occurred. If a CompletionCheck object has been provided, the completion handler will only be called if the callHandler method returned true. If no CompletionCheck object has been provided, the default NIO2 behavior is used: the completion handler will be called, even if the operation is incomplete, or if the operation completed inline.
      Type Parameters:
        `A` - The attachment type
      Parameters:
        `read` - true if the operation is a read, false if it is a write
        `buffers` - buffers
        `offset` - in the buffer array
        `length` - in the buffer array
        `block` - is the blocking mode that will be used for this operation
        `timeout` - timeout duration for the write
        `unit` - units for the timeout duration
        `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
        `check` - for the IO operation completion
        `handler` - to call when the IO is complete
      Returns:
        the completion state (done, done inline, or still pending)

    - #### newOperationState

          protected abstract <A> SocketWrapperBase.OperationState<A> newOperationState​(boolean read,
                                                                                       java.nio.ByteBuffer[] buffers,
                                                                                       int offset,
                                                                                       int length,
                                                                                       SocketWrapperBase.BlockingMode block,
                                                                                       long timeout,
                                                                                       java.util.concurrent.TimeUnit unit,
                                                                                       A attachment,
                                                                                       SocketWrapperBase.CompletionCheck check,
                                                                                       java.nio.channels.CompletionHandler<java.lang.Long,​? super A> handler,
                                                                                       java.util.concurrent.Semaphore semaphore,
                                                                                       SocketWrapperBase.VectoredIOCompletionHandler<A> completion)

    - #### transfer

          protected static int transfer​(byte[] from,
                                        int offset,
                                        int length,
                                        java.nio.ByteBuffer to)

    - #### transfer

          protected static int transfer​(java.nio.ByteBuffer from,
                                        java.nio.ByteBuffer to)

    - #### buffersArrayHasRemaining

          protected static boolean buffersArrayHasRemaining​(java.nio.ByteBuffer[] buffers,
                                                            int offset,
                                                            int length)