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

Class NestedField

java.lang.Object

com.apple.foundationdb.record.query.expressions.BaseField

com.apple.foundationdb.record.query.expressions.BaseNestedField

com.apple.foundationdb.record.query.expressions.NestedField

All Implemented Interfaces:

PlanHashable, ComponentWithSingleChild, QueryComponent, QueryHashable

@API(MAINTAINED)
public class NestedField
extends BaseNestedField

A QueryComponent that evaluates a nested component against a Message-valued field.

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

Field Summary

Fields inherited from class com.apple.foundationdb.record.query.expressions.BaseNestedField

childComponent

Constructor Summary

Constructors

Constructor	Description
NestedField(String fieldName, QueryComponent childComponent)

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
<M extends Message> Boolean	evalMessage(FDBRecordStoreBase<M> store, EvaluationContext context, FDBRecord<M> record, Message message)	Return whether or not the given record matches this component.
GraphExpansion	expand(CorrelationIdentifier baseAlias, List<String> fieldNamePrefix)	Expand this query component into a data flow graph.
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()
void	validate(Descriptors.Descriptor descriptor)	Validate that the given descriptor is consistent with this component.
QueryComponent	withOtherChild(QueryComponent newChild)

Methods inherited from class com.apple.foundationdb.record.query.expressions.BaseNestedField

getChild, isAsync

Methods inherited from class com.apple.foundationdb.record.query.expressions.BaseField

basePlanHash, baseQueryHash, findFieldDescriptor, getFieldName, getFieldValue, getName, requireMessageField, requirePrimitiveField, requireScalarField, validateFieldExistence

Methods inherited from class java.lang.Object

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

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

planHash

Methods inherited from interface com.apple.foundationdb.record.query.expressions.QueryComponent

eval, evalAsync, evalMessageAsync, expand

Constructor Detail

NestedField

public NestedField(@Nonnull
                   String fieldName,
                   @Nonnull
                   QueryComponent childComponent)

Method Detail

evalMessage

@Nullable
public <M extends Message> Boolean evalMessage(@Nonnull
                                               FDBRecordStoreBase<M> store,
                                               @Nonnull
                                               EvaluationContext context,
                                               @Nullable
                                               FDBRecord<M> record,
                                               @Nullable
                                               Message message)

Description copied from interface: QueryComponent

Return whether or not the given record matches this component. The message might be the Protobuf form of a record or a piece of that record. If the key expression is meaningful against a subrecord, it should evaluate against the message. Otherwise, it should evaluate against the record and ignore what part of that record is being considered. There should not be any reason to call this method outside of the implementation of another evalMessage. Under ordinary circumstances, if record is null, then message will be null. Otherwise, message will be record.getRecord() or some submessage of that, possibly null if the corresponding field is missing.

Type Parameters:

M - the type of record

Parameters:

store - the record store from which the record came

context - context for bound expressions

record - the record

message - the Protobuf message to evaluate against

Returns:

true/false/null, true if the given record should be included in results, false if it should not, and null if this component cannot determine whether it should be included or not

See Also:

QueryComponent.eval(com.apple.foundationdb.record.provider.foundationdb.FDBRecordStoreBase<M>, com.apple.foundationdb.record.EvaluationContext, com.apple.foundationdb.record.provider.foundationdb.FDBRecord<M>)

validate

public void validate(@Nonnull
                     Descriptors.Descriptor descriptor)

Description copied from interface: QueryComponent

Validate that the given descriptor is consistent with this component. e.g. it has all the fields defined that this component wants to inspect.

Parameters:

descriptor - a record type descriptor, or a submessage descriptor

withOtherChild

public QueryComponent withOtherChild(QueryComponent newChild)

Specified by:

withOtherChild in interface ComponentWithSingleChild

Specified by:

withOtherChild in class BaseNestedField

toString

public String toString()

Overrides:

toString in class Object

expand

public GraphExpansion expand(@Nonnull
                             CorrelationIdentifier baseAlias,
                             @Nonnull
                             List<String> fieldNamePrefix)

Description copied from interface: QueryComponent

Expand this query component into a data flow graph. The returned graph represents an adequate representation of the component as composition of relational expressions and operators.

Parameters:

baseAlias - a an alias that refers to the data flow equivalent of an input to this component

fieldNamePrefix - a list of field names that accumulate a field nesting chain for non-repeated fields

Returns:

a new GraphExpansion representing the query graph equivalent of this query component

See Also:

TODO make this method private in Java 11

equals

public boolean equals(Object o)

Overrides:

equals in class BaseField

hashCode

public int hashCode()

Overrides:

hashCode in class BaseField

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.

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.

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