mondrian.rolap

Class FastBatchingCellReader

java.lang.Object

mondrian.rolap.FastBatchingCellReader

public class FastBatchingCellReader
extends Object

A FastBatchingCellReader doesn't really Read cells: when asked to look up the values of stored measures, it lies, and records the fact that the value was asked for. Later, we can look over the values which are required, fetch them in an efficient way, and re-run the evaluation with a real evaluator.

NOTE: When it doesn't know the answer, it lies by returning an error object. The calling code must be able to deal with that.

This class tries to minimize the amount of storage needed to record the fact that a cell was requested.

Constructor Summary

Constructors

Constructor and Description
FastBatchingCellReader(Execution execution, RolapCube cube, AggregationManager aggMgr) Creates a FastBatchingCellReader.

Method Summary

Modifier and Type	Method and Description
Object	get(RolapEvaluator evaluator) Returns the value of the cell which has the context described by the evaluator.
int	getHitCount()
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.
int	getPendingCount()
boolean	isDirty() Returns whether this reader has told a lie.
void	recordCellRequest(CellRequest request)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FastBatchingCellReader

public FastBatchingCellReader(Execution execution,
                              RolapCube cube,
                              AggregationManager aggMgr)

Creates a FastBatchingCellReader.

Parameters:

execution - Execution that calling statement belongs to. Allows us to check for cancel

cube - Cube that requests belong to

aggMgr - Aggregation manager

Method Detail

get

public 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

public 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.

getHitCount

public int getHitCount()

getPendingCount

public int getPendingCount()

recordCellRequest

public final void recordCellRequest(CellRequest request)

isDirty

public boolean isDirty()

Returns whether this reader has told a lie. This is the case if there are pending batches to load or if setDirty(boolean) has been called.

Returns:

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