mondrian.rolap
Interface CellReader

All Known Implementing Classes:

FastBatchingCellReader

interface CellReader

A CellReader finds the cell value for the current context held by evaluator.

It returns:

• null if the source is unable to evaluate the cell (for example, AggregatingCellReader does not have the cell in its cache). This value should only be returned if the caller is expecting it.
• Util.nullValue if the cell evaluates to null
• Util.ErrorCellValue if the cell evaluates to an error
• an Object representing a value (often a Double or a BigDecimal), otherwise

Since:

10 August, 2001

Author:

jhyde

Method Summary

Object	get(RolapEvaluator evaluator) Returns the value of the cell which has the context described by the evaluator.
int	getMissCount() Returns the number of times this cell reader has told a lie (since creation), because the required cell value is not in the cache.
boolean	isDirty()

Method Detail

get

Object get(RolapEvaluator evaluator)

Returns the value of the cell which has the context described by the evaluator. A cell could have optional compound member coordinates usually specified using the Aggregate function. These compound members are contained in the evaluator.

If no aggregation contains the required cell, returns null.

If the value is null, returns Util.nullValue.

Returns:

Cell value, or null if not found, or Util.nullValue if the value is null

getMissCount

int getMissCount()

Returns the number of times this cell reader has told a lie (since creation), because the required cell value is not in the cache.

isDirty

boolean isDirty()

Returns:

whether thus cell reader has any pending cell requests that are not loaded yet.