org.modeshape.jcr.index.local

Interface IndexValues.Converter<T>

Type Parameters:

T - the index's key type

All Known Implementing Classes:

IndexValues.StandardConverter

Enclosing class:

IndexValues

public static interface IndexValues.Converter<T>

Converts between StaticOperand and an index's key type.

Note that IndexDefinition.IndexKind.VALUE indexes may have multiple node keys for a given value, which means that any given value might have a range of keys. Some MapDB-based indexes store such entries using an index key that consists of the actual property value plus a counter. In this way, there are multiple index keys for a given StaticOperand, and the toLowerValue(javax.jcr.query.qom.StaticOperand, java.util.Map<java.lang.String, java.lang.Object>) will return the lowest-possible index key given the StaticOperand, while the toUpperValue(javax.jcr.query.qom.StaticOperand, java.util.Map<java.lang.String, java.lang.Object>) will return the highest-possible index key for the given StaticOperand

IndexDefinition.IndexKind.UNIQUE_VALUE indexes will use the actual property value as the index key, and thus the toLowerValue(javax.jcr.query.qom.StaticOperand, java.util.Map<java.lang.String, java.lang.Object>) and toUpperValue(javax.jcr.query.qom.StaticOperand, java.util.Map<java.lang.String, java.lang.Object>) methods will both return the same index key for the same StaticOperand.

Method Summary

Modifier and Type	Method and Description
T	toLowerValue(StaticOperand operand, Map<String,Object> variables) Create the lowest possible index key for the supplied StaticOperand.
T	toUpperValue(StaticOperand operand, Map<String,Object> variables) Create the highest possible index key for the supplied StaticOperand.

Method Detail

toLowerValue

T toLowerValue(StaticOperand operand,
               Map<String,Object> variables)

Create the lowest possible index key for the supplied StaticOperand.

Parameters:

operand - the static operand; may be null

variables - the bound variables; may not be null but may be empty

Returns:

the lowest/smallest possible index key; or null if the operand is null

toUpperValue

T toUpperValue(StaticOperand operand,
               Map<String,Object> variables)

Create the highest possible index key for the supplied StaticOperand.

Parameters:

operand - the static operand; may be null

variables - the bound variables; may not be null but may be empty

Returns:

the highest/largest possible index key; or null if the operand is null