Datastore wrappers

A datastore is any kind of means of storing and retrieving data that supports a few basic logical operations; the operations are implemented in a script wrapper.

The operations are:

• fetch - copy target data from the datastore to the filesystem (preserves data in datastore)

• store - move target data from filesystem to datastore (destroys data on filesystem)

• test - checks if target data exists

• rm - removes/destroys a piece of target data

• touch - creates an (empty) piece of target data. Useful for status targets, which contain no data but are used as indicators.

Remember, each target can have exactly one item of data associated with it. This is typically the output of running the run/srun command for generating this target. Of course, a target can have more than one output - in this case metatargets are used; eg stderr(Target)

Even if the filesystem is used as the datastore, operating system commands are still used for the above basic operations