Ripple 1.0 Usergrants Data Migration

[satlead]

Ripple 2.0 has a predecessor which stores data for usergrants in a different path and in a slightly different structure

Good news however is that Usergrants data follows the same structure in both 1.0 and 2.0

Ripple 1.0 stores the usergrants data in the following manner

1. Stores the usergrants in a different path inside a single file user_grants/user_grants.json
2. Also stores policy information to make sure if the policy is updated the grants are cleared based on obsoletion.

In Ripple 2.0 we need the below implementation to support data migration from devices which has the previous version of Ripple

1. During bootstrap look for user_grants.json and create a map of the entries
2. Synchronize with the Cloud data store and gather the latest grants (cloud uses same data structure in both versions)
3. Using latest modified time stamp and checking for policy validity create the new grants entry