SpdyFrameEncoder Class — netty Architecture

Source Code

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyFrameEncoder.java lines 30–171

public class SpdyFrameEncoder {

    private final int version;

    /**
     * Creates a new instance with the specified {@code spdyVersion}.
     */
    public SpdyFrameEncoder(SpdyVersion spdyVersion) {
        version = ObjectUtil.checkNotNull(spdyVersion, "spdyVersion").version();
    }

    protected void writeControlFrameHeader(ByteBuf buffer, int type, byte flags, int length) {
        buffer.writeShort(version | 0x8000);
        buffer.writeShort(type);
        buffer.writeByte(flags);
        buffer.writeMedium(length);
    }

    public ByteBuf encodeDataFrame(ByteBufAllocator allocator, int streamId, boolean last, ByteBuf data) {
        byte flags = last ? SPDY_DATA_FLAG_FIN : 0;
        int length = data.readableBytes();
        ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN);
        frame.writeInt(streamId & 0x7FFFFFFF);
        frame.writeByte(flags);
        frame.writeMedium(length);
        frame.writeBytes(data, data.readerIndex(), length);
        return frame;
    }

    public ByteBuf encodeSynStreamFrame(ByteBufAllocator allocator,  int streamId, int associatedToStreamId,
            byte priority, boolean last, boolean unidirectional, ByteBuf headerBlock) {
        int headerBlockLength = headerBlock.readableBytes();
        byte flags = last ? SPDY_FLAG_FIN : 0;
        if (unidirectional) {
            flags |= SPDY_FLAG_UNIDIRECTIONAL;
        }
        int length = 10 + headerBlockLength;
        ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN);
        writeControlFrameHeader(frame, SPDY_SYN_STREAM_FRAME, flags, length);
        frame.writeInt(streamId);
        frame.writeInt(associatedToStreamId);
        frame.writeShort((priority & 0xFF) << 13);
        frame.writeBytes(headerBlock, headerBlock.readerIndex(), headerBlockLength);
        return frame;
    }

    public ByteBuf encodeSynReplyFrame(ByteBufAllocator allocator, int streamId, boolean last, ByteBuf headerBlock) {
        int headerBlockLength = headerBlock.readableBytes();
        byte flags = last ? SPDY_FLAG_FIN : 0;
        int length = 4 + headerBlockLength;
        ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN);
        writeControlFrameHeader(frame, SPDY_SYN_REPLY_FRAME, flags, length);
        frame.writeInt(streamId);
        frame.writeBytes(headerBlock, headerBlock.readerIndex(), headerBlockLength);
        return frame;
    }

    public ByteBuf encodeRstStreamFrame(ByteBufAllocator allocator, int streamId, int statusCode) {
        byte flags = 0;
        int length = 8;
        ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN);
        writeControlFrameHeader(frame, SPDY_RST_STREAM_FRAME, flags, length);
        frame.writeInt(streamId);
        frame.writeInt(statusCode);
        return frame;
    }

    public ByteBuf encodeSettingsFrame(ByteBufAllocator allocator, SpdySettingsFrame spdySettingsFrame) {
        Set<Integer> ids = spdySettingsFrame.ids();
        int numSettings = ids.size();

        byte flags = spdySettingsFrame.clearPreviouslyPersistedSettings() ?
                SPDY_SETTINGS_CLEAR : 0;
        int length = 4 + 8 * numSettings;
        ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN);
        writeControlFrameHeader(frame, SPDY_SETTINGS_FRAME, flags, length);
        frame.writeInt(numSettings);
        for (Integer id : ids) {
            flags = 0;
            if (spdySettingsFrame.isPersistValue(id)) {
                flags |= SPDY_SETTINGS_PERSIST_VALUE;