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19 package org.eclipse.jetty.http2.generator;
20
21 import java.nio.ByteBuffer;
22
23 import org.eclipse.jetty.http2.Flags;
24 import org.eclipse.jetty.http2.frames.Frame;
25 import org.eclipse.jetty.http2.frames.FrameType;
26 import org.eclipse.jetty.http2.frames.PriorityFrame;
27 import org.eclipse.jetty.io.ByteBufferPool;
28 import org.eclipse.jetty.util.BufferUtil;
29
30 public class PriorityGenerator extends FrameGenerator
31 {
32 public PriorityGenerator(HeaderGenerator headerGenerator)
33 {
34 super(headerGenerator);
35 }
36
37 @Override
38 public void generate(ByteBufferPool.Lease lease, Frame frame)
39 {
40 PriorityFrame priorityFrame = (PriorityFrame)frame;
41 generatePriority(lease, priorityFrame.getStreamId(), priorityFrame.getParentStreamId(), priorityFrame.getWeight(), priorityFrame.isExclusive());
42 }
43
44 public void generatePriority(ByteBufferPool.Lease lease, int streamId, int parentStreamId, int weight, boolean exclusive)
45 {
46 ByteBuffer header = generateHeader(lease, FrameType.PRIORITY, PriorityFrame.PRIORITY_LENGTH, Flags.NONE, streamId);
47 generatePriorityBody(header, streamId, parentStreamId, weight, exclusive);
48 BufferUtil.flipToFlush(header, 0);
49 lease.append(header, true);
50 }
51
52 public void generatePriorityBody(ByteBuffer header, int streamId, int parentStreamId, int weight, boolean exclusive)
53 {
54 if (streamId < 0)
55 throw new IllegalArgumentException("Invalid stream id: " + streamId);
56 if (parentStreamId < 0)
57 throw new IllegalArgumentException("Invalid parent stream id: " + parentStreamId);
58 if (parentStreamId == streamId)
59 throw new IllegalArgumentException("Stream " + streamId + " cannot depend on stream " + parentStreamId);
60 if (weight < 1 || weight > 256)
61 throw new IllegalArgumentException("Invalid weight: " + weight);
62
63 if (exclusive)
64 parentStreamId |= 0x80_00_00_00;
65 header.putInt(parentStreamId);
66 header.put((byte)(weight - 1));
67 }
68 }