tree 63dd9a3ee53ea93c07c5cf4de95f503ac693c8a0
parent 9d4e27335fb55833b23e7f9472468fefb1d50955
author Marc Kupietz <kupietz@ids-mannheim.de> 1569920731 +0200
committer Marc Kupietz <kupietz@ids-mannheim.de> 1569942775 +0200

Cache API calls locally

And do this by default. A problem is that the underlying R.cache
package does not provide an expiry mechanism.
To set up an ideal expiry mechanism, the KorAPConnection constructor
should be able to get some short information about API and index
version. This can be handled later, see 
https://github.com/KorAP/Krill/issues/62

Change-Id: Ia7a8d6f0800a67d3ab39f162444751e2818d29bd