SelectionKeyAttachment.java

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package com.sun.grizzly.util;

import java.nio.channels.SelectionKey;

/**
 * Basic class for all SelectionKey attachments.
 * Custom attachments should be inherited from it.
 *
 * @author Alexey Stashok
 */
public abstract class SelectionKeyAttachment {
    public static final long UNLIMITED_TIMEOUT = Long.MIN_VALUE;
    public static final long DEREGISTERED = Long.MIN_VALUE +1;
    
    protected volatile long timeout = UNLIMITED_TIMEOUT;
    protected volatile long idleTimeoutDelay = UNLIMITED_TIMEOUT;
    protected volatile TimeOutListener timeoutListener;
    protected volatile KeySelectionListener keySelectionListener;

    public static Object getAttachment(SelectionKey key) {
        Object attachment = key.attachment();
        if (attachment instanceof SelectionKeyAttachmentWrapper) {
            return ((SelectionKeyAttachmentWrapper) attachment).getAttachment();
        }

        return attachment;
    }

    /**
     * Returns the idle timeout delay.
     * Default it returns UNLIMITED_TIMEOUT, meaning no idle timeout delay.
     * @return
     */
    public long getIdleTimeoutDelay(){
        return idleTimeoutDelay;
    }

    /**
     * Set the idle timeout delay.
     * Default it returns UNLIMITED_TIMEOUT, meaning no idle timeout delay.
     * @param idleTimeoutDelay
     */
    public void setIdleTimeoutDelay(long idleTimeoutDelay){
        this.idleTimeoutDelay = idleTimeoutDelay;
    }

    /**
     * Get the channel expiration stamp in millis
     * (last time an opeation on the channel was invoked).
     * @return the channel expiration stamp in millis.
     */
    public long getTimeout() {
        return timeout;
    }
    
    /**
     * Set the channel expiration stamp in millis
     * (last time an opeation on the channel was invoked).
     * @param timeout the channel expiration stamp in millis.
     */
    public void setTimeout(long timeout) {
        this.timeout = timeout;
    }

    public TimeOutListener getTimeoutListener() {
        return timeoutListener;
    }

    public void setTimeoutListener(TimeOutListener timeoutListener) {
        this.timeoutListener = timeoutListener;
    }

    public KeySelectionListener getKeySelectionListener() {
        return keySelectionListener;
    }

    public void setKeySelectionListener(KeySelectionListener keySelectionListener) {
        this.keySelectionListener = keySelectionListener;
    }

    /**
     *  called when idle timeout detected.
     *  return true if key should be canceled.
     * @param Key
     * @return
     */
    public boolean timedOut(SelectionKey Key) {
        TimeOutListener listener = this.timeoutListener;
        if (listener != null) {
            return listener.onTimeOut(Key);
        }

        return true;
    }

    /**
     * Used for completely custom selector.select logic.
     *
     * @param selectionKey
     */
    public void handleSelectedKey(SelectionKey selectionKey) {
        final KeySelectionListener listener = keySelectionListener;
        if (listener != null) {
            listener.onKeySelected(selectionKey);
        }
    }

    public void release(SelectionKey selectionKey) {
        idleTimeoutDelay = UNLIMITED_TIMEOUT;
        timeout = UNLIMITED_TIMEOUT;
        timeoutListener = null;
        keySelectionListener = null;
    }

    public interface TimeOutListener {
        boolean onTimeOut(SelectionKey key);
    }

    public interface KeySelectionListener {
        void onKeySelected(SelectionKey selectionKey);
    }
}