@Override
    public int readInt32() throws IOException {
        checkIfPackedField();
        return readRawVarInt32();
    }
Read an {@code int32} field value from the internal buffer.
jraft-rheakv/rheakv-core/src/main/java/com/alipay/sofa/jraft/rhea/serialization/impl/protostuff/io/UnsafeNioBufInput.java