public boolean decode(final byte[] bs) {
        if (bs.length < 20) {
            return false;
        }
        this.flushPosition = Bits.getLong(bs, 0);
        this.lastLogIndex = Bits.getLong(bs, 8);
        int len = Bits.getInt(bs, 16);
        this.fileName = AsciiStringUtil.unsafeDecode(bs, 20, len);
        return this.flushPosition >= 0 && this.lastLogIndex >= 0 && !this.fileName.isEmpty();
    }
flushPosition (8 bytes) + lastLogIndex (8 bytes) + path(4 bytes len + string bytes)
jraft-extension/java-log-storage-impl/src/main/java/com/alipay/sofa/jraft/storage/file/assit/FlushStatusCheckpoint.java