SpdyHeaderBlockRawEncoder Class — netty Architecture

Source Code

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyHeaderBlockRawEncoder.java lines 28–89

public class SpdyHeaderBlockRawEncoder extends SpdyHeaderBlockEncoder {

    private final int version;

    public SpdyHeaderBlockRawEncoder(SpdyVersion version) {
        this.version = ObjectUtil.checkNotNull(version, "version").version();
    }

    private static void setLengthField(ByteBuf buffer, int writerIndex, int length) {
        buffer.setInt(writerIndex, length);
    }

    private static void writeLengthField(ByteBuf buffer, int length) {
        buffer.writeInt(length);
    }

    @Override
    public ByteBuf encode(ByteBufAllocator alloc, SpdyHeadersFrame frame) throws Exception {
        Set<CharSequence> names = frame.headers().names();
        int numHeaders = names.size();
        if (numHeaders == 0) {
            return Unpooled.EMPTY_BUFFER;
        }
        if (numHeaders > SPDY_MAX_NV_LENGTH) {
            throw new IllegalArgumentException(
                    "header block contains too many headers");
        }
        ByteBuf headerBlock = alloc.heapBuffer();
        writeLengthField(headerBlock, numHeaders);
        for (CharSequence name: names) {
            writeLengthField(headerBlock, name.length());
            ByteBufUtil.writeAscii(headerBlock, name);
            int savedIndex = headerBlock.writerIndex();
            int valueLength = 0;
            writeLengthField(headerBlock, valueLength);
            for (CharSequence value: frame.headers().getAll(name)) {
                int length = value.length();
                if (length > 0) {
                    ByteBufUtil.writeAscii(headerBlock, value);
                    headerBlock.writeByte(0);
                    valueLength += length + 1;
                }
            }
            if (valueLength != 0) {
                valueLength --;
            }
            if (valueLength > SPDY_MAX_NV_LENGTH) {
                throw new IllegalArgumentException(
                        "header exceeds allowable length: " + name);
            }
            if (valueLength > 0) {
                setLengthField(headerBlock, savedIndex, valueLength);
                headerBlock.writerIndex(headerBlock.writerIndex() - 1);
            }
        }
        return headerBlock;
    }

    @Override
    void end() {
    }
}