Package com.apple.foundationdb.record.query.expressions

Class Comparisons.NullComparison

java.lang.Object

com.apple.foundationdb.record.query.expressions.Comparisons.NullComparison

All Implemented Interfaces:

PlanHashable, Comparisons.Comparison, QueryHashable

Enclosing class:

Comparisons

public static class Comparisons.NullComparison
extends Object
implements Comparisons.Comparison

A unary predicate for special nullity checks, such as NULL and NOT NULL.

Nested Class Summary

Nested classes/interfaces inherited from interface com.apple.foundationdb.record.PlanHashable

PlanHashable.PlanHashKind

Nested classes/interfaces inherited from interface com.apple.foundationdb.record.QueryHashable

QueryHashable.QueryHashKind

Constructor Summary

Constructors

Constructor	Description
NullComparison(Comparisons.Type type)

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
Boolean	eval(FDBRecordStoreBase<?> store, EvaluationContext context, Object value)	Evaluate this comparison for the value taken from the target record.
Object	getComparand(FDBRecordStoreBase<?> store, EvaluationContext context)	Get the comparison value from the evaluation context.
Comparisons.Type	getType()	Get the comparison type.
int	hashCode()
int	planHash(PlanHashable.PlanHashKind hashKind)	Return a hash similar to hashCode, but with the additional guarantee that is is stable across JVMs.
int	queryHash(QueryHashable.QueryHashKind hashKind)	Return a hash similar to hashCode, but with the additional guarantee that is is stable across JVMs.
String	toString()
String	typelessString()	Get the printed representation of the comparison less the comparison operator itself.
void	validate(Descriptors.FieldDescriptor descriptor, boolean fannedOut)	Validate that this comparison is compatible with a given record field.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.apple.foundationdb.record.query.expressions.Comparisons.Comparison

getComparand, hasMultiColumnComparand

Methods inherited from interface com.apple.foundationdb.record.PlanHashable

planHash

Constructor Detail

NullComparison

public NullComparison(@Nonnull
                      Comparisons.Type type)

Method Detail

eval

@Nullable
public Boolean eval(@Nonnull
                    FDBRecordStoreBase<?> store,
                    @Nonnull
                    EvaluationContext context,
                    @Nullable
                    Object value)

Description copied from interface: Comparisons.Comparison

Evaluate this comparison for the value taken from the target record.

Specified by:

eval in interface Comparisons.Comparison

Parameters:

store - the record store for the query

context - the evaluation context for getting the other comparison value

value - the value taken from the record

Returns:

the tri-valued logic result of the comparison

validate

public void validate(@Nonnull
                     Descriptors.FieldDescriptor descriptor,
                     boolean fannedOut)

Description copied from interface: Comparisons.Comparison

Validate that this comparison is compatible with a given record field.

Specified by:

validate in interface Comparisons.Comparison

Parameters:

descriptor - the Protobuf descriptor for the proposed comparison field

fannedOut - whether a repeated field fans out into multiple comparisons or is treated as a single list value

getType

@Nonnull
public Comparisons.Type getType()

Description copied from interface: Comparisons.Comparison

Get the comparison type.

Specified by:

getType in interface Comparisons.Comparison

Returns:

the comparison type

getComparand

@Nullable
public Object getComparand(@Nullable
                           FDBRecordStoreBase<?> store,
                           @Nullable
                           EvaluationContext context)

Description copied from interface: Comparisons.Comparison

Get the comparison value from the evaluation context.

Specified by:

getComparand in interface Comparisons.Comparison

Parameters:

store - the record store for the query

context - the context for query evaluation

Returns:

the value to be compared

typelessString

@Nonnull
public String typelessString()

Description copied from interface: Comparisons.Comparison

Get the printed representation of the comparison less the comparison operator itself.

Specified by:

typelessString in interface Comparisons.Comparison

Returns:

the typeless string

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

planHash

public int planHash(@Nonnull
                    PlanHashable.PlanHashKind hashKind)

Description copied from interface: PlanHashable

Return a hash similar to hashCode, but with the additional guarantee that is is stable across JVMs.

Specified by:

planHash in interface PlanHashable

Parameters:

hashKind - the "kind" of hash to calculate. Each kind of hash has a particular logic with regards to included and excluded items.

Returns:

a stable hash code

queryHash

public int queryHash(@Nonnull
                     QueryHashable.QueryHashKind hashKind)

Description copied from interface: QueryHashable

Return a hash similar to hashCode, but with the additional guarantee that is is stable across JVMs.

Specified by:

queryHash in interface QueryHashable

Parameters:

hashKind - the "kind" of hash to calculate. Each kind of hash has a particular logic with regards to included and excluded items.

Returns:

a stable hash code