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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package jdk.internal.net.http.quic.frames;

import jdk.internal.net.quic.QuicTransportErrors;
import jdk.internal.net.quic.QuicTransportException;

import java.nio.BufferOverflowException;
import java.nio.ByteBuffer;

/**
 * A MAX_STREAM Frame
 *
 * @spec https://www.rfc-editor.org/info/rfc9000
 *      RFC 9000: QUIC: A UDP-Based Multiplexed and Secure Transport
 */
public final class MaxStreamsFrame extends QuicFrame {
    static final long MAX_VALUE = 1L << 60;

    private final long maxStreams;
    private final boolean bidi;

    /**
     * Incoming MAX_STREAMS frame returned by QuicFrame.decode()
     *
     * @param buffer
     * @param type
     * @throws QuicTransportException if the frame was malformed
     */
    MaxStreamsFrame(ByteBuffer buffer, int type) throws QuicTransportException {
        super(MAX_STREAMS);
        bidi = (type == MAX_STREAMS);
        maxStreams = decodeVLField(buffer, "maxStreams");
        if (maxStreams > MAX_VALUE) {
            throw new QuicTransportException("Invalid maximum streams",
                    null, type, QuicTransportErrors.FRAME_ENCODING_ERROR);
        }
    }

    /**
     * Outgoing MAX_STREAMS frame
     */
    public MaxStreamsFrame(boolean bidi, long maxStreams) {
        super(MAX_STREAMS);
        this.bidi = bidi;
        this.maxStreams = requireVLRange(maxStreams, "maxStreams");
    }

    @Override
    public long getTypeField() {
        return MAX_STREAMS + (bidi?0:1);
    }

    @Override
    public void encode(ByteBuffer buffer) {
        if (size() > buffer.remaining()) {
            throw new BufferOverflowException();
        }
        int pos = buffer.position();
        encodeVLField(buffer, getTypeField(), "type");
        encodeVLField(buffer, maxStreams, "maxStreams");
        assert buffer.position() - pos == size();
    }

    /**
     */
    public long maxStreams() {
        return maxStreams;
    }

    public boolean isBidi() {
        return bidi;
    }

    @Override
    public int size() {
        return getVLFieldLengthFor(MAX_STREAMS)
                + getVLFieldLengthFor(maxStreams);
    }

    @Override
    public String toString() {
        return "MaxStreamsFrame(bidi=" + bidi +
                ", maxStreams=" + maxStreams + ')';
    }
}