//
// ========================================================================
// Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// 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.Flags;
import org.eclipse.jetty.http2.frames.Frame;
import org.eclipse.jetty.http2.frames.FrameType;
import org.eclipse.jetty.http2.frames.PushPromiseFrame;
import org.eclipse.jetty.http2.hpack.HpackEncoder;
import org.eclipse.jetty.io.ByteBufferPool;
import org.eclipse.jetty.util.BufferUtil;
public class PushPromiseGenerator extends FrameGenerator
{
private final HpackEncoder encoder;
public PushPromiseGenerator(HeaderGenerator headerGenerator, HpackEncoder encoder)
{
super(headerGenerator);
this.encoder = encoder;
}
@Override
public void generate(ByteBufferPool.Lease lease, Frame frame)
{
PushPromiseFrame pushPromiseFrame = (PushPromiseFrame)frame;
generatePushPromise(lease, pushPromiseFrame.getStreamId(), pushPromiseFrame.getPromisedStreamId(), pushPromiseFrame.getMetaData());
}
public void generatePushPromise(ByteBufferPool.Lease lease, int streamId, int promisedStreamId, MetaData metaData)
{
if (streamId < 0)
throw new IllegalArgumentException("Invalid stream id: " + streamId);
if (promisedStreamId < 0)
throw new IllegalArgumentException("Invalid promised stream id: " + promisedStreamId);
int maxFrameSize = getMaxFrameSize();
// The promised streamId.
int fixedLength = 4;
maxFrameSize -= fixedLength;
// The lease may already contain other buffers,
// compute the bytes generated by the encoder only.
int leaseSize = lease.getSize();
long leaseLength = lease.getTotalLength();
encoder.encode(metaData, lease, maxFrameSize);
long headersLength = lease.getTotalLength() - leaseLength;
if (headersLength > maxFrameSize)
throw new IllegalArgumentException(String.format("Invalid headers, too big for max frame size: %d > %d", headersLength, maxFrameSize));
// Space for the promised streamId.
headersLength += fixedLength;
int flags = Flags.END_HEADERS;
ByteBuffer header = generateHeader(lease, FrameType.PUSH_PROMISE, (int)headersLength, flags, streamId);
header.putInt(promisedStreamId);
BufferUtil.flipToFlush(header, 0);
lease.insert(leaseSize, header, true);
}
}