/*
 * Copyright (c) 2012, 2017 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.grizzly.http2;

import java.io.IOException;
import org.glassfish.grizzly.Buffer;
import org.glassfish.grizzly.CompletionHandler;
import org.glassfish.grizzly.WriteHandler;
import org.glassfish.grizzly.WriteResult;
import org.glassfish.grizzly.asyncqueue.MessageCloner;
import org.glassfish.grizzly.filterchain.FilterChainContext;
import org.glassfish.grizzly.http.HttpPacket;

Interface represents an output sink associated with specific Http2Stream. 
Author:
Alexey Stashok/**
 * Interface represents an output sink associated with specific {@link Http2Stream}. 
 * 
 * @author Alexey Stashok
 */
interface StreamOutputSink {
    boolean canWrite();
    void notifyWritePossible(WriteHandler writeHandler);

    
The method is called by HTTP2 Filter once WINDOW_UPDATE message comes for this Http2Stream. 
Params:
delta – the delta.
Throws:
Http2StreamException – if an error occurs processing the window update./**
     * The method is called by HTTP2 Filter once WINDOW_UPDATE message comes
     * for this {@link Http2Stream}.
     * 
     * @param delta the delta.
     * @throws Http2StreamException if an error occurs processing the window update.
     */
    void onPeerWindowUpdate(int delta) throws Http2StreamException;

    void writeDownStream(HttpPacket httpPacket,
                         FilterChainContext ctx,
                         CompletionHandler<WriteResult> completionHandler,
                         MessageCloner<Buffer> messageCloner)throws IOException;

    
Flush Http2Stream output and notify CompletionHandler once all output data has been flushed. 
Params:
completionHandler – CompletionHandler to be notified/**
     * Flush {@link Http2Stream} output and notify {@link CompletionHandler} once
     * all output data has been flushed.
     * 
     * @param completionHandler {@link CompletionHandler} to be notified
     */
    void flush(CompletionHandler<Http2Stream> completionHandler);
    
    
Returns:
the number of writes (not bytes), that haven't reached network layer/**
     * @return the number of writes (not bytes), that haven't reached network layer
     */
    int getUnflushedWritesCount();
    
    
Closes the output sink by adding last DataFrame with the FIN flag to a queue.
If the output sink is already closed - method does nothing.
/**
     * Closes the output sink by adding last DataFrame with the FIN flag to a queue.
     * If the output sink is already closed - method does nothing.
     */
    void close();

    
Unlike close() this method forces the output sink termination by setting termination flag and canceling all the pending writes. /**
     * Unlike {@link #close()} this method forces the output sink termination
     * by setting termination flag and canceling all the pending writes.
     */
    void terminate(Termination terminationFlag);
    
    boolean isClosed();
}