It's often unneeded to recheck for an index update at very high frequency, which ends up to be a bottleneck in high-throughput applications
for an unneded guarantee of having latest version of index.
Setting a configurable period, let's say 5 seconds, will make this ReaderProvider reopen an IndexReader once each 5 seconds.

This can be done in background, removing the delay of checks from the call to openReader(); and enabling index warmup in future (Lucene 2.9 feature) in background.
When reopening in background the ratio will be fixed, i.e. the index will be reopened even if there's no request for a new IR.

This impl should manage the timer, but otherwise delegate to another implementation of ReaderProvider (defaulting to current default: SharingBufferReaderProvider) to optionally chain and provide the benefits of the other implementation.