public boolean consume()

in http2/src/main/java/org/apache/mina/http2/impl/Http2HeadersFrameDecoder.java [72:121]
50 lines of code
14 McCabe index (conditional complexity)

    public boolean consume(ByteBuffer buffer) {
        while ((getValue() == null) && buffer.remaining() > 0) {
            switch (state) {
            case PAD_LENGTH:
                padLength = buffer.get();
                if (isFlagSet(FLAGS_PRIORITY)) {
                    decoder = new IntPartialDecoder(4);
                    state = State.STREAM_DEPENDENCY;
                } else {
                    state = State.HEADER;
                    decoder = new BytePartialDecoder(getHeader().getLength() - 1 - padLength);
                }
                break;
            case STREAM_DEPENDENCY:
                if (decoder.consume(buffer)) {
                    builder.streamDependencyID(((IntPartialDecoder)decoder).getValue() & HTTP2_31BITS_MASK);
                    builder.exclusiveMode((((IntPartialDecoder)decoder).getValue() & HTTP2_EXCLUSIVE_MASK) == HTTP2_EXCLUSIVE_MASK);
                    state = State.WEIGHT;
                }
                break;
            case WEIGHT:
                builder.weight((byte) (buffer.get()+1));
                state = State.HEADER;
                int headerLength = getHeader().getLength() - 5;
                if (isFlagSet(FLAGS_PADDING)) {
                    headerLength -= (padLength + 1);
                }
                decoder = new BytePartialDecoder(headerLength);
                break;
            case HEADER:
                if (decoder.consume(buffer)) {
                    builder.headerBlockFragment(((BytePartialDecoder)decoder).getValue());
                    if (isFlagSet(FLAGS_PADDING)) {
                      state = State.PADDING;
                      decoder = new BytePartialDecoder(padLength);
                    } else {
                        setValue(builder.build());
                    }
                }
                break;
            case PADDING:
                if (decoder.consume(buffer)) {
                    builder.padding(((BytePartialDecoder)decoder).getValue());
                    setValue(builder.build());
                }
                break;
            }
        }
        return getValue() != null;
    }