Package mondrian.rolap

Interface CellKey

All Superinterfaces:
Serializable
All Known Implementing Classes:
CellKey.Four, CellKey.Many, CellKey.One, CellKey.Three, CellKey.Two, CellKey.Zero
public interface CellKey extends Serializable
A CellKey is used as a key in maps which access cells by their position.

CellKey is also used within SparseSegmentDataset to store values within aggregations.

It is important that CellKey is memory-efficient, and that the Object.hashCode() and Object.equals(java.lang.Object) methods are extremely efficient. There are particular implementations for the most likely cases where the number of axes is 1, 2, 3 and 4 as well as a general implementation.

To create a key, call the CellKey.Generator.newCellKey(int[]) method.

Since:
10 August, 2001
Author:
jhyde

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static class 
    CellKey.Four
     
    static class 
    CellKey.Generator
     
    static class 
    CellKey.Many
     
    static class 
    CellKey.One
     
    static class 
    CellKey.Three
     
    static class 
    CellKey.Two
     
    static class 
    CellKey.Zero
     

  • Method Summary

    Modifier and Type
    Method
    Description
    CellKey
    copy()
    Returns a mutable copy of this CellKey.
    int
    getAxis(int axis)
    Returns the axisth axis value.
    int
    getOffset(int[] axisMultipliers)
    Returns the offset of the cell in a raster-scan order.
    int[]
    getOrdinals()
    Returns the axis keys as an array.
    void
    setAxis(int axis, int value)
    Sets a given axis.
    void
    setOrdinals(int[] pos)
    This method make a copy of the int array parameter.
    int
    size()
    Returns the number of axes.

  • Method Details

    • size

      int size()
      Returns the number of axes.
      Returns:
      number of axes

    • getOrdinals

      int[] getOrdinals()
      Returns the axis keys as an array.

      Note: caller should treat the array as immutable. If the contents of the array are modified, behavior is unspecified.

      Returns:
      Array of axis keys

    • setOrdinals

      void setOrdinals(int[] pos)
      This method make a copy of the int array parameter. Throws a RuntimeException if the int array size is not the size of the CellKey.
      Parameters:
      pos - Array of axis keys

    • getAxis

      int getAxis(int axis)
      Returns the axisth axis value.
      Parameters:
      axis - Axis ordinal
      Returns:
      Value of the axisth axis
      Throws:
      ArrayIndexOutOfBoundsException - if axis is out of range

    • setAxis

      void setAxis(int axis, int value)
      Sets a given axis.
      Parameters:
      axis - Axis ordinal
      value - Value
      Throws:
      RuntimeException - if axis parameter is larger than size()

    • copy

      CellKey copy()
      Returns a mutable copy of this CellKey.
      Returns:
      Mutable copy

    • getOffset

      int getOffset(int[] axisMultipliers)
      Returns the offset of the cell in a raster-scan order.

      For example, if the axes have lengths {2, 5, 10} then cell (2, 3, 4) has offset

      (2 * mulitiplers[0]) + (3 * multipliers[1]) + (4 * multipliers[2])
      = (2 * 50) + (3 * 10) + (4 * 1)
      = 134

      The multipliers are the product of the lengths of all later axes, in this case (50, 10, 1).

      Parameters:
      axisMultipliers - For each axis, the product of the lengths of later axes
      Returns:
      The raster-scan ordinal of this cell