for unittest

after the call, tValue hold the resp to delete [] the buffer memory

after update: Get() >= prop_num

Return the crc32c of data[0,n-1]

For test.

help function for mem visitor

1. load write file : from new to old; push record to worker in the opposite of [0, max_filesize] order; 2. load merge file : from new to old; push rec

the most recent write file => read from old to new; start offset to max_filesize per file;

Return a masked representation of crc. Motivation: it is problematic to compute the CRC of a string that contains embedded CRCs. Therefore we recomm