Package uk.ac.starlink.ttools.plot2.data

Interface DataStore

  • All Known Implementing Classes:
    SimpleDataStoreFactory, StepDataStore
    public interface DataStore
    Contains all the actual data required for a plot. To extract usable data for a plot, a suitable DataSpec object is also required.

    Because instances of this class manage the data, by keeping track of the DataStores in an application you can control where the memory is used. All the other objects connected with a plot, for instance the PlotLayers and DataSpecs, are cheap to produce and have small memory footprints, so can be created and destroyed as required. As a rule therefore, DataStore objects should be managed by a single class, and references not kept to them by any other potentially long-lived objects.

    Obtain an instance of this class from a DataStoreFactory.

    Since:
    6 Feb 2013
    Author:
    Mark Taylor

    • Method Detail

      • hasData

        boolean hasData​(DataSpec spec)
        Indicates whether this store has the data described by a given DataSpec.
        Parameters:
        spec - plot data specification object

      • getTupleSequence

        TupleSequence getTupleSequence​(DataSpec spec)
        Returns the data described by a given DataSpec as a sequence of tuples. Must only be called if hasData(uk.ac.starlink.ttools.plot2.data.DataSpec) returns true for the given DataSpec; if not, behaviour is undefined.
        Parameters:
        spec - plot data specification object
        Returns:
        sequence of values which can be used to perform a plot