public class NginxClojureAsynChannel {

    public static interface CompletionListener<T> {
        /**
         * 
         * @param status
         *        read/written number of bytes 
         * @param attachment
         *        the attachment object which was as the last read/write method input argument before CompletionListener argument.
         *        e.g. <code>write(buf, off, size, attachement,listener)</code>
         */
        public void onDone(long status, T attachment);

        /**
         * 
         * @param code
         *        if code = 0, eof for read/write , always > 0
         *        if code < 0, code is error code which range from 
         *        NginxClojureAsynSocket.NGX_HTTP_CLOJURE_SOCKET_ERR to NGX_HTTP_CLOJURE_SOCKET_ERR_OUTOFMEMORY
         *        We can get the error string by invoking buildError(code)
         * @param attachment
         *        the attachment object which was as the last read/write method input argument before CompletionListener argument.
         *        e.g. <code>write(buf, off, size, attachement, listener)</code>
         */
        public void onError(long code, T attachment);
    }

/**
     * if timeout is negative, it will be ignored. if timeout is 0, this means no timeout.
     */
    public void setTimeout(long connectTimeout, long readTimeout, long writeTimeout);
    /**
     * connect to remote server, unix domain socket also supported
     * @param url 
     *        e.g. "192.168.2.34:80" , "www.bing.com:80", or unix domain socket "unix:/var/mytest/server.sock"
     * @param listener 
     *        completion listener
     * @param attachement 
     *        when action is done or meets error this attachment will be passed to the method of the completion listener
     */
    public <T> void connect(String url, T attachement, CompletionListener<T> listener);

    public <T> void write(byte[] buf, long off, long size, T attachement, CompletionListener<T> listener);

    public <T> void write(ByteBuffer buf, T attachement, CompletionListener<T> listener) ;

    public <T> void read(byte[] buf, long off, long size, T attachement, CompletionListener<T> listener);

    public <T> void read(ByteBuffer buf, T attachement, CompletionListener<T> listener);

    public boolean isClosed();

    public void setListener(ChannelListener<NginxClojureAsynChannel> listener) ;