com.apple.foundationdb.record

Class EvaluationContext

java.lang.Object

com.apple.foundationdb.record.EvaluationContext

@API(value=MAINTAINED)
public class EvaluationContext
extends Object

A context for query evaluation.

The primary state of an evaluation context is a set of parameter Bindings.

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>), RecordQueryPlan.execute(com.apple.foundationdb.record.provider.foundationdb.FDBRecordStoreBase<M>, com.apple.foundationdb.record.EvaluationContext, byte[], com.apple.foundationdb.record.ExecuteProperties)

Field Summary

Fields

Modifier and Type	Field and Description
static EvaluationContext	EMPTY

Method Summary

Modifier and Type	Method and Description
EvaluationContextBuilder	childBuilder() Construct a builder from this context.
static EvaluationContext	empty() Get an empty evaluation context.
static EvaluationContext	forBinding(String bindingName, Object value) Create a new EvaluationContext with a single binding.
static EvaluationContext	forBindings(Bindings bindings) Create a new EvaluationContext around a given set of Bindings from parameter names to values.
Object	getBinding(String name) Get the value bound to a single parameter.
Bindings	getBindings() Retrieve the mapping from parameter names to values associated with this context.
static EvaluationContextBuilder	newBuilder() Construct a new builder from this context.
EvaluationContext	withBinding(String bindingName, Object value) Create a new EvaluationContext with an additional binding.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY

public static final EvaluationContext EMPTY

Method Detail

empty

public static EvaluationContext empty()

Get an empty evaluation context.

Returns:

an evaluation context with no bindings

forBindings

@Nonnull
public static EvaluationContext forBindings(@Nonnull
                                                     Bindings bindings)

Create a new EvaluationContext around a given set of Bindings from parameter names to values.

Parameters:

bindings - a mapping from parameter name to values

Returns:

a new evaluation context with the bindings

forBinding

@Nonnull
public static EvaluationContext forBinding(@Nonnull
                                                    String bindingName,
                                                    @Nullable
                                                    Object value)

Create a new EvaluationContext with a single binding.

Parameters:

bindingName - the binding name to add

value - the value to bind the name to

Returns:

a new EvaluationContext with the new binding

getBindings

@Nonnull
public Bindings getBindings()

Retrieve the mapping from parameter names to values associated with this context.

Returns:

a mapping from parameter names to to values

getBinding

@Nullable
public Object getBinding(@Nonnull
                                   String name)

Get the value bound to a single parameter.

Parameters:

name - the name of the parameter to retrieve the binding of

Returns:

the value bound to the given parameter

See Also:

Bindings.get(String)

childBuilder

@Nonnull
public EvaluationContextBuilder childBuilder()

Construct a builder from this context. This allows the user to create a new EvaluationContext that has all of the same data as the current context except for a few modifications expressed as mutations made to the builder.

Returns:

a builder for this class based on this instance

newBuilder

@Nonnull
public static EvaluationContextBuilder newBuilder()

Construct a new builder from this context.

Returns:

a builder for this class based on this instance

withBinding

@Nonnull
public EvaluationContext withBinding(@Nonnull
                                              String bindingName,
                                              @Nullable
                                              Object value)

Create a new EvaluationContext with an additional binding. The returned context will have all of the same state as the current context included all bindings except that it will bind an additional parameter to an additional value.

Parameters:

bindingName - the binding name to add

value - the value to bind the name to

Returns:

a new EvaluationContext with the new binding