@Override
    public byte[] readByteArray() throws IOException {
        final int length = readRawVarInt32();
        if (length < 0) {
            throw ProtocolException.negativeSize();
        }

        if (nioBuffer.remaining() < length) {
            throw ProtocolException.misreportedSize();
        }

        final byte[] copy = new byte[length];
        nioBuffer.get(copy);
        return copy;
    }
Read an {@code sint64} field value from the internal buffer.
jraft-rheakv/rheakv-core/src/main/java/com/alipay/sofa/jraft/rhea/serialization/impl/protostuff/io/NioBufInput.java