private boolean hasHashChanged ( Hasher hasher , RegData regDatum ) { String urlExternalForm = regDatum . getURLExternalForm ( ) ; Boolean modified = mUrlExternalForm2Modified . get ( urlExternalForm ) ; if ( modified != null ) { return modified ; } // Check hash String newHash = hasher . hashURL ( urlExternalForm ) ; modified = ! newHash . equals ( regDatum . getHash ( ) ) ; mUrlExternalForm2Modified . put ( urlExternalForm , modified ) ; return modified ; }
Hashes file and compares with the old hash . If hashes are different return true ; false otherwise