FromFile loads config from a specified file overriding defaults specified in the def parameter.

FromReader loads config from a reader instance.

* * Get order state from datastore.

* * Get order index.

* * Get order retry timestamp.

* * Get shard state from datastore.

* * Get shard index from data store.

New creates a new Maplock.

* * Save order state in datastore.

* * save order shard state.

* * update order index.

* * update shard index */.

ErrNoSuchLock is returned when the requested lock does not exist.

Maplock provides a locking mechanism based on the passed in reference name.