Package uk.gov.gchq.gaffer.accumulostore.key

Interface RangeFactory

All Known Implementing Classes:

AbstractCoreKeyRangeFactory, ByteEntityRangeFactory, ClassicRangeFactory

public interface RangeFactory

The range factory is designed so that a List of Accumulo Ranges can be created from just a provided ElementId and GraphFilters. The created range list should contain all the ranges (preferably optimised) necessary to retrieve all desired Elements as expressed by the gaffer.accumulostore.operation.

Method Summary

Modifier and Type	Method	Description
List<org.apache.accumulo.core.data.Range>	getRange(ElementId elementId, GraphFilters operation)	Returns a Range representing a query for the given ID
org.apache.accumulo.core.data.Range	getRangeFromPair(Pair<ElementId,ElementId> pairRange, GraphFilters operation)	Operation Returns a Range representing a query for all values between the given ElementIds taken from the minimum comparable byte value of the provided keys and the maximum comparable byte value.

Method Detail

getRange

List<org.apache.accumulo.core.data.Range> getRange(ElementId elementId,
                                                   GraphFilters operation)
                                            throws RangeFactoryException

Returns a Range representing a query for the given ID

Parameters:

elementId - the element id to get the range for

operation - the operation

Returns:

A List of Ranges that are required to return all elements that match the parameters of the query.

Throws:

RangeFactoryException - if a range could not be created

getRangeFromPair

org.apache.accumulo.core.data.Range getRangeFromPair(Pair<ElementId,ElementId> pairRange,
                                                     GraphFilters operation)
                                              throws RangeFactoryException

Operation Returns a Range representing a query for all values between the given ElementIds taken from the minimum comparable byte value of the provided keys and the maximum comparable byte value. Note that depending on the serialisation mechanism used and your key design the results of a range query will differ. The intent here is that values in your gaffer.accumulostore instance should be ordered within the table so that Entities with an Integer Identifier occur in the order 1 2 3

So that a provided pair of 1 and 3 will return entities 1, 2 and 3.

Parameters:

pairRange - the pair of element ids to get the range for

operation - the operation

Returns:

A List of Ranges that are required to return all elements that match the parameters of the query.

Throws:

RangeFactoryException - if a range could not be created