DefaultHttp2FrameWriter Class — netty Architecture

Source Code

codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2FrameWriter.java lines 74–643

public class DefaultHttp2FrameWriter implements Http2FrameWriter, Http2FrameSizePolicy, Configuration {
    private static final String STREAM_ID = "Stream ID";
    private static final String STREAM_DEPENDENCY = "Stream Dependency";
    /**
     * This buffer is allocated to the maximum size of the padding field, and filled with zeros.
     * When padding is needed it can be taken as a slice of this buffer. Users should call {@link ByteBuf#retain()}
     * before using their slice.
     */
    private static final ByteBuf ZERO_BUFFER = LeakPresenceDetector.staticInitializer(() ->
            unreleasableBuffer(directBuffer(MAX_UNSIGNED_BYTE).writeZero(MAX_UNSIGNED_BYTE)).asReadOnly());

    private final Http2HeadersEncoder headersEncoder;
    private int maxFrameSize;

    public DefaultHttp2FrameWriter() {
        this(new DefaultHttp2HeadersEncoder());
    }

    public DefaultHttp2FrameWriter(SensitivityDetector headersSensitivityDetector) {
        this(new DefaultHttp2HeadersEncoder(headersSensitivityDetector));
    }

    public DefaultHttp2FrameWriter(SensitivityDetector headersSensitivityDetector, boolean ignoreMaxHeaderListSize) {
        this(new DefaultHttp2HeadersEncoder(headersSensitivityDetector, ignoreMaxHeaderListSize));
    }

    /**
     * @param headersEncoder will be closed if it implements {@link Closeable}
     */
    public DefaultHttp2FrameWriter(Http2HeadersEncoder headersEncoder) {
        this.headersEncoder = headersEncoder;
        maxFrameSize = DEFAULT_MAX_FRAME_SIZE;
    }

    @Override
    public Configuration configuration() {
        return this;
    }

    @Override
    public Http2HeadersEncoder.Configuration headersConfiguration() {
        return headersEncoder.configuration();
    }

    @Override
    public Http2FrameSizePolicy frameSizePolicy() {
        return this;
    }

    @Override
    public void maxFrameSize(int max) throws Http2Exception {
        if (!isMaxFrameSizeValid(max)) {
            throw connectionError(FRAME_SIZE_ERROR, "Invalid MAX_FRAME_SIZE specified in sent settings: %d", max);
        }
        maxFrameSize = max;
    }

    @Override
    public int maxFrameSize() {
        return maxFrameSize;
    }

    @Override
    public void close() {
        if (headersEncoder instanceof Closeable) {
            try {
                ((Closeable) headersEncoder).close();
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    }

    @Override
    public ChannelFuture writeData(ChannelHandlerContext ctx, int streamId, ByteBuf data,
            int padding, boolean endStream, ChannelPromise promise) {
        final SimpleChannelPromiseAggregator promiseAggregator =
                new SimpleChannelPromiseAggregator(promise, ctx.channel(), ctx.executor());
        ByteBuf frameHeader = null;
        try {
            verifyStreamId(streamId, STREAM_ID);