//
//  ========================================================================
//  Copyright (c) 1995-2020 Mort Bay Consulting Pty Ltd and others.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.http2.generator;

import java.nio.ByteBuffer;

import org.eclipse.jetty.http.MetaData;
import org.eclipse.jetty.http2.frames.Frame;
import org.eclipse.jetty.http2.frames.FrameType;
import org.eclipse.jetty.http2.hpack.HpackEncoder;
import org.eclipse.jetty.http2.hpack.HpackException;
import org.eclipse.jetty.io.ByteBufferPool;

public abstract class FrameGenerator
{
    private final HeaderGenerator headerGenerator;

    protected FrameGenerator(HeaderGenerator headerGenerator)
    {
        this.headerGenerator = headerGenerator;
    }

    public abstract int generate(ByteBufferPool.Lease lease, Frame frame) throws HpackException;

    protected ByteBuffer generateHeader(ByteBufferPool.Lease lease, FrameType frameType, int length, int flags, int streamId)
    {
        return headerGenerator.generate(lease, frameType, Frame.HEADER_LENGTH + length, length, flags, streamId);
    }

    public int getMaxFrameSize()
    {
        return headerGenerator.getMaxFrameSize();
    }

    protected ByteBuffer encode(HpackEncoder encoder, ByteBufferPool.Lease lease, MetaData metaData, int maxFrameSize) throws HpackException
    {
        ByteBuffer hpacked = lease.acquire(maxFrameSize, false);
        try
        {
            encoder.encode(hpacked, metaData);
            return hpacked;
        }
        catch (HpackException x)
        {
            lease.release(hpacked);
            throw x;
        }
    }
}
