How to prevent Kindle from downloading word wise and x-ray files?

[xxyzz]

The word wise file created by WordDumb plugin works well until Wi-Fi turned on and Kindle downloads the Kindle Store's file. I have read several hours of nonsense Java variables but still can't find the relevant code, I guess it should be somewhere inside /opt/amazon/ebook/lib/LanguageLayer.jar. Does anyone know how to tell Kindle to stop downloading these files without using an invalid ASIN?

[xxyzz]

I found if the file 'LanguageLayer.Failed' exists in path 'x/updates/ASIN_EBOK.sdr', it will cause `LanguageLayerUpdateHandler.a()` returns `UpdateState.FAILED_PLUGIN_WORDWISE_REJECTED`. Maybe that will prevent Kindle from download word wise file. The mystery path 'x' might be obtained by query '/var/local/dcm.db':

select p_location from DeviceContentEntry where p_cdeKey = 'ASIN' and p_cdeType = 'EBOK'

I can't jailbreak my Kindle since it has the latest firmware, please post the result of the above SQL if you have a rooted Kindle(replace ASIN to the book on your Kindle and has word wise), thanks.

I don't understand the Kindle's Java code in StorageManagerServiceImpl.b(Options) (/opt/amazon/lib/kaf.jar/storage/StorageManagerServiceImpl.class, line 1069):

switch (null.noE[paramOptions.dtH().ordinal()]) {
case 1:
...
case 2:
...
case 3:

shouldn't this code gets null reference? And `paramOptions.dtH()` is enum, shouldn't it start with `case 0`?