fsm contains objects that model files that are stored in a FileSystem with the
filename parametric in time. For example, suppose there is a store of data
in http://cdaweb.gsfc.nasa.gov/istp_public/data/ace/swe/, where the data files are
stored by year and then in each yearly folder, the files contain the date encoded
within the filename. We can then model the storage with the template specification
%Y/ac_k0_swe_%Y%m%d_v01.cdf. A FileStorageModel object can be queried as to what
is available for a time range, and will use the FileSystem object to provide
local copies of the file.
FileStorageModel is the production object providing this functionality. FileStorageModelNew
is an attempt to unify codes by treating filenames as formatted time range strings, which
should reduce code and run more efficiently. This code is not yet proven and should be used
with caution. FileStorageModelAvailabilityDataSetDescriptor provides a DataSetDescriptor
that can be used to get DataSet views describing when data is available.