InboundHttp2ToHttpAdapter Class — netty Architecture

Source Code

codec-http2/src/main/java/io/netty/handler/codec/http2/InboundHttp2ToHttpAdapter.java lines 40–358

public class InboundHttp2ToHttpAdapter extends Http2EventAdapter {
    private static final ImmediateSendDetector DEFAULT_SEND_DETECTOR = new ImmediateSendDetector() {
        @Override
        public boolean mustSendImmediately(FullHttpMessage msg) {
            if (msg instanceof FullHttpResponse) {
                return ((FullHttpResponse) msg).status().codeClass() == HttpStatusClass.INFORMATIONAL;
            }
            if (msg instanceof FullHttpRequest) {
                return msg.headers().contains(HttpHeaderNames.EXPECT);
            }
            return false;
        }

        @Override
        public FullHttpMessage copyIfNeeded(ByteBufAllocator allocator, FullHttpMessage msg) {
            if (msg instanceof FullHttpRequest) {
                FullHttpRequest copy = ((FullHttpRequest) msg).replace(allocator.buffer(0));
                copy.headers().remove(HttpHeaderNames.EXPECT);
                return copy;
            }
            return null;
        }
    };

    private final int maxContentLength;
    private final ImmediateSendDetector sendDetector;
    private final Http2Connection.PropertyKey messageKey;
    private final boolean propagateSettings;
    protected final Http2Connection connection;
    protected final boolean validateHttpHeaders;

    protected InboundHttp2ToHttpAdapter(Http2Connection connection, int maxContentLength,
                                        boolean validateHttpHeaders, boolean propagateSettings) {
        this.connection = checkNotNull(connection, "connection");
        this.maxContentLength = checkPositive(maxContentLength, "maxContentLength");
        this.validateHttpHeaders = validateHttpHeaders;
        this.propagateSettings = propagateSettings;
        sendDetector = DEFAULT_SEND_DETECTOR;
        messageKey = connection.newKey();
    }

    /**
     * The stream is out of scope for the HTTP message flow and will no longer be tracked
     * @param stream The stream to remove associated state with
     * @param release {@code true} to call release on the value if it is present. {@code false} to not call release.
     */
    protected final void removeMessage(Http2Stream stream, boolean release) {
        FullHttpMessage msg = stream.removeProperty(messageKey);
        if (release && msg != null) {
            msg.release();
        }
    }

    /**
     * Get the {@link FullHttpMessage} associated with {@code stream}.
     * @param stream The stream to get the associated state from
     * @return The {@link FullHttpMessage} associated with {@code stream}.
     */
    protected final FullHttpMessage getMessage(Http2Stream stream) {
        return (FullHttpMessage) stream.getProperty(messageKey);
    }

    /**
     * Make {@code message} be the state associated with {@code stream}.
     * @param stream The stream which {@code message} is associated with.
     * @param message The message which contains the HTTP semantics.
     */
    protected final void putMessage(Http2Stream stream, FullHttpMessage message) {
        FullHttpMessage previous = stream.setProperty(messageKey, message);
        if (previous != message && previous != null) {
            previous.release();
        }
    }

    @Override
    public void onStreamRemoved(Http2Stream stream) {
        removeMessage(stream, true);
    }

    /**
     * Set final headers and fire a channel read event