Package graphql.execution.instrumentation

Class NoContextChainedInstrumentation

java.lang.Object

graphql.execution.instrumentation.ChainedInstrumentation

graphql.execution.instrumentation.NoContextChainedInstrumentation

All Implemented Interfaces:

Instrumentation

@PublicApi
public class NoContextChainedInstrumentation
extends ChainedInstrumentation

This version of ChainedInstrumentation will call a list of Instrumentations but it will never back on the returned InstrumentationContext objects, hence it is only suitable to certain use cases. Only use this class if you are optimising for memory usage as scale. In most cases the ChainedInstrumentation will do the job required with all the instrumentation features used however some users require the fastest performance and lowest memory usage at scale and this class can be used. At scale, the fact that the graphql engine holds the InstrumentationContext objects in memory for a (relatively) long time (the length of the request or the length of a large field fetch) means that memory pressure can grow and objects move into longer tenure GC pools. Holding these contexts is also not necessary if the instrumentation never needs to know when a certain execution step finishes. The InstrumentationContext is used ot know when an execution step has completed, so instrumentations that do timings say need to use this callback mechanism. Putting such an instrumentation into NoContextChainedInstrumentation would be a mistake because no callback will occur. Therefore, use of this class is reserved for very specific us cases. You are fore-warned. This class never holds onto the returned InstrumentationContext objects and always returns null as itself.

Field Summary

Fields inherited from class graphql.execution.instrumentation.ChainedInstrumentation

instrumentations

Constructor Summary

Constructors

Constructor	Description
NoContextChainedInstrumentation(Instrumentation... instrumentations)
NoContextChainedInstrumentation(List<Instrumentation> instrumentations)

Method Summary

Modifier and Type	Method	Description
@Nullable ExecuteObjectInstrumentationContext	beginExecuteObject(InstrumentationExecutionStrategyParameters parameters, InstrumentationState state)	This is called each time an ExecutionStrategy object resolution is called, which may be multiple times per query as the engine recursively descends over the query.
InstrumentationContext<ExecutionResult>	beginExecuteOperation(InstrumentationExecuteOperationParameters parameters, InstrumentationState state)	This is called just before the execution of the query operation is started.
InstrumentationContext<ExecutionResult>	beginExecution(InstrumentationExecutionParameters parameters, InstrumentationState state)	This is called right at the start of query execution, and it's the first step in the instrumentation chain.
ExecutionStrategyInstrumentationContext	beginExecutionStrategy(InstrumentationExecutionStrategyParameters parameters, InstrumentationState state)	This is called each time an ExecutionStrategy is invoked, which may be multiple times per query as the engine recursively descends over the query.
@Nullable InstrumentationContext<Object>	beginFieldCompletion(InstrumentationFieldCompleteParameters parameters, InstrumentationState state)	This is called just before the complete field is started.
@Nullable InstrumentationContext<Object>	beginFieldExecution(InstrumentationFieldParameters parameters, InstrumentationState state)	This is called just before a field is resolved into a value.
InstrumentationContext<Object>	beginFieldFetch(InstrumentationFieldFetchParameters parameters, InstrumentationState state)	This is called just before a field DataFetcher is invoked.
FieldFetchingInstrumentationContext	beginFieldFetching(InstrumentationFieldFetchParameters parameters, InstrumentationState state)	This is called just before a field DataFetcher is invoked.
@Nullable InstrumentationContext<Object>	beginFieldListCompletion(InstrumentationFieldCompleteParameters parameters, InstrumentationState state)	This is called just before the complete field list is started.
InstrumentationContext<Document>	beginParse(InstrumentationExecutionParameters parameters, InstrumentationState state)	This is called just before a query is parsed.
InstrumentationContext<ExecutionResult>	beginSubscribedFieldEvent(InstrumentationFieldParameters parameters, InstrumentationState state)	This is called each time a subscription field produces a new reactive stream event value and it needs to be mapped over via the graphql field subselection.
InstrumentationContext<List<ValidationError>>	beginValidation(InstrumentationValidationParameters parameters, InstrumentationState state)	This is called just before the parsed query document is validated.

Methods inherited from class graphql.execution.instrumentation.ChainedInstrumentation

beginDeferredField, chainedConsume, chainedMapAndDropNulls, createStateAsync, getInstrumentations, instrumentDataFetcher, instrumentDocumentAndVariables, instrumentExecutionContext, instrumentExecutionInput, instrumentExecutionResult, instrumentSchema

Methods inherited from class java.lang.Object

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

Methods inherited from interface graphql.execution.instrumentation.Instrumentation

createState

Constructor Details

NoContextChainedInstrumentation

public NoContextChainedInstrumentation(List<Instrumentation> instrumentations)

NoContextChainedInstrumentation

public NoContextChainedInstrumentation(Instrumentation... instrumentations)

Method Details

beginExecution

public InstrumentationContext<ExecutionResult> beginExecution(InstrumentationExecutionParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called right at the start of query execution, and it's the first step in the instrumentation chain.

Specified by:

beginExecution in interface Instrumentation

Overrides:

beginExecution in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable InstrumentationContext object that will be called back when the step ends (assuming it's not null)

beginParse

public InstrumentationContext<Document> beginParse(InstrumentationExecutionParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called just before a query is parsed.

Specified by:

beginParse in interface Instrumentation

Overrides:

beginParse in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable InstrumentationContext object that will be called back when the step ends (assuming it's not null)

beginValidation

public InstrumentationContext<List<ValidationError>> beginValidation(InstrumentationValidationParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called just before the parsed query document is validated.

Specified by:

beginValidation in interface Instrumentation

Overrides:

beginValidation in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable InstrumentationContext object that will be called back when the step ends (assuming it's not null)

beginExecuteOperation

public InstrumentationContext<ExecutionResult> beginExecuteOperation(InstrumentationExecuteOperationParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called just before the execution of the query operation is started.

Specified by:

beginExecuteOperation in interface Instrumentation

Overrides:

beginExecuteOperation in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable InstrumentationContext object that will be called back when the step ends (assuming it's not null)

beginExecutionStrategy

public ExecutionStrategyInstrumentationContext beginExecutionStrategy(InstrumentationExecutionStrategyParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called each time an ExecutionStrategy is invoked, which may be multiple times per query as the engine recursively descends over the query.

Specified by:

beginExecutionStrategy in interface Instrumentation

Overrides:

beginExecutionStrategy in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable ExecutionStrategyInstrumentationContext object that will be called back when the step ends (assuming it's not null)

beginExecuteObject

public @Nullable ExecuteObjectInstrumentationContext beginExecuteObject(InstrumentationExecutionStrategyParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called each time an ExecutionStrategy object resolution is called, which may be multiple times per query as the engine recursively descends over the query.

Specified by:

beginExecuteObject in interface Instrumentation

Overrides:

beginExecuteObject in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable ExecutionStrategyInstrumentationContext object that will be called back when the step ends (assuming it's not null)

beginSubscribedFieldEvent

public InstrumentationContext<ExecutionResult> beginSubscribedFieldEvent(InstrumentationFieldParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called each time a subscription field produces a new reactive stream event value and it needs to be mapped over via the graphql field subselection.

Specified by:

beginSubscribedFieldEvent in interface Instrumentation

Overrides:

beginSubscribedFieldEvent in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable InstrumentationContext object that will be called back when the step ends (assuming it's not null)

beginFieldExecution

public @Nullable InstrumentationContext<Object> beginFieldExecution(InstrumentationFieldParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called just before a field is resolved into a value.

Specified by:

beginFieldExecution in interface Instrumentation

Overrides:

beginFieldExecution in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable InstrumentationContext object that will be called back when the step ends (assuming it's not null)

beginFieldFetch

public InstrumentationContext<Object> beginFieldFetch(InstrumentationFieldFetchParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called just before a field DataFetcher is invoked.

Specified by:

beginFieldFetch in interface Instrumentation

Overrides:

beginFieldFetch in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable InstrumentationContext object that will be called back when the step ends (assuming it's not null)

beginFieldFetching

public FieldFetchingInstrumentationContext beginFieldFetching(InstrumentationFieldFetchParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called just before a field DataFetcher is invoked. The FieldFetchingInstrumentationContext.onFetchedValue(Object) callback will be invoked once a value is returned by a DataFetcher but perhaps before its value is completed if it's a CompletableFuture value.

This method is the replacement method for the now deprecated Instrumentation.beginFieldFetch(InstrumentationFieldFetchParameters, InstrumentationState) method, and it should be implemented in new Instrumentation classes. This default version of this method calls back to the deprecated Instrumentation.beginFieldFetch(InstrumentationFieldFetchParameters, InstrumentationState) method so that older implementations continue to work.

Specified by:

beginFieldFetching in interface Instrumentation

Overrides:

beginFieldFetching in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable InstrumentationContext object that will be called back when the step ends (assuming it's not null)

beginFieldCompletion

public @Nullable InstrumentationContext<Object> beginFieldCompletion(InstrumentationFieldCompleteParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called just before the complete field is started.

Specified by:

beginFieldCompletion in interface Instrumentation

Overrides:

beginFieldCompletion in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable InstrumentationContext object that will be called back when the step ends (assuming it's not null)

beginFieldListCompletion

public @Nullable InstrumentationContext<Object> beginFieldListCompletion(InstrumentationFieldCompleteParameters parameters,
 InstrumentationState state)

Description copied from interface: Instrumentation

This is called just before the complete field list is started.

Specified by:

beginFieldListCompletion in interface Instrumentation

Overrides:

beginFieldListCompletion in class ChainedInstrumentation

Parameters:

parameters - the parameters to this step

state - the state created during the call to Instrumentation.createStateAsync(InstrumentationCreateStateParameters)

Returns:

a nullable InstrumentationContext object that will be called back when the step ends (assuming it's not null)