@Override
    public int readSInt32() throws IOException {
        checkIfPackedField();
        final int n = readRawVarInt32();
        return (n >>> 1) ^ -(n & 1);
    }
Read an {@code sint32} field value from the internal buffer.
jraft-rheakv/rheakv-core/src/main/java/com/alipay/sofa/jraft/rhea/serialization/impl/protostuff/io/NioBufInput.java