Class ColumnStoreStarTable

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable, StarTable

    public class ColumnStoreStarTable
    extends WrapperStarTable
    StarTable implementation which retrieves its data from ColumnStore objects.
    Since:
    21 Jun 2006
    Author:
    Mark Taylor
    • Constructor Detail

      • ColumnStoreStarTable

        public ColumnStoreStarTable​(StarTable template,
                                    long nrow,
                                    ColumnStore[] colStores)
        Constructor.
        Parameters:
        template - template table supplying metadata
        nrow - number of rows in this table
        colStores - array of ColumnStore objects, one for each column in the table
    • Method Detail

      • getRowCount

        public long getRowCount()
        Description copied from interface: StarTable
        Returns the number of rows in this table, if known. If the number of rows cannot be (easily) determined, a value of -1 will be returned.
        Specified by:
        getRowCount in interface StarTable
        Overrides:
        getRowCount in class WrapperStarTable
        Returns:
        the number of rows, or -1
      • getCell

        public java.lang.Object getCell​(long lrow,
                                        int icol)
                                 throws java.io.IOException
        Description copied from interface: StarTable
        Returns the contents of a given table cell. The class of the returned object should be the same as, or a subclass of, the class returned by getColumnInfo(icol).getContentClass().

        This method is safe for concurrent use from multiple threads, but in general it is recommended to use a RowAccess instead.

        Specified by:
        getCell in interface StarTable
        Overrides:
        getCell in class WrapperStarTable
        Parameters:
        lrow - the index of the cell's row
        icol - the index of the cell's column
        Returns:
        the contents of this cell
        Throws:
        java.io.IOException - if there is an error reading the data
      • getRow

        public java.lang.Object[] getRow​(long lrow)
                                  throws java.io.IOException
        Description copied from interface: StarTable
        Returns the contents of a given table row. The returned value is equivalent to an array formed of all the objects returned by getCell(irow,icol) for all the columns icol in sequence.

        This method is safe for concurrent use from multiple threads, but in general it is recommended to use a RowAccess instead.

        Specified by:
        getRow in interface StarTable
        Overrides:
        getRow in class WrapperStarTable
        Parameters:
        lrow - the index of the row to retrieve
        Returns:
        an array of the objects in each cell in row irow
        Throws:
        java.io.IOException - if there is an error reading the data
      • getRowSequence

        public RowSequence getRowSequence()
                                   throws java.io.IOException
        Description copied from interface: StarTable
        Returns an object which can iterate over all the rows in the table sequentially. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.
        Specified by:
        getRowSequence in interface StarTable
        Overrides:
        getRowSequence in class WrapperStarTable
        Returns:
        new RowSequence
        Throws:
        java.io.IOException - if there is an error providing access
      • getRowSplittable

        public RowSplittable getRowSplittable()
                                       throws java.io.IOException
        Description copied from interface: StarTable
        Returns an object which can iterate over all the rows in the table, but which may also be requested to split recursively for potentially parallel processing.

        The return value must be non-null, and may provide splitting arrangements specially appropriate for the implementation. If this table 'wraps' an upstream table, it is usually best to base the implementation on calls to the the upstream getRowSplittable method, so that upstream policy about how to divide up the table is respected. However, implementations without special requirements may return Tables.getDefaultRowSplittable(this).

        Specified by:
        getRowSplittable in interface StarTable
        Overrides:
        getRowSplittable in class WrapperStarTable
        Returns:
        new RowSplittable
        Throws:
        java.io.IOException
        See Also:
        RowRunner
      • getRowAccess

        public RowAccess getRowAccess()
                               throws java.io.IOException
        Description copied from interface: StarTable
        Returns an object which can provide random access to this table's data, if random access is implemented. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.
        Specified by:
        getRowAccess in interface StarTable
        Overrides:
        getRowAccess in class WrapperStarTable
        Returns:
        new RowAccess
        Throws:
        java.io.IOException - if there is an error setting up access