FieldBackedProvider (javaagent-tooling 0.14.0 API)

java.lang.Object
- io.opentelemetry.javaagent.tooling.context.FieldBackedProvider

All Implemented Interfaces:

InstrumentationContextProvider
```
public class FieldBackedProvider
extends Object
implements InstrumentationContextProvider
```
InstrumentationContextProvider which stores context in a field that is injected into a class and falls back to global map if field was not injected.
This is accomplished by
1. Injecting a Dynamic Interface that provides getter and setter for context field
2. Applying Dynamic Interface to a type needing context, implementing interface methods and adding context storage field
3. Injecting a Dynamic Class created from FieldBackedProvider.ContextStoreImplementationTemplate to use injected field or fall back to a static map
4. Rewriting calls to the context-store to access the specific dynamic FieldBackedProvider.ContextStoreImplementationTemplate
Example:
InstrumentationContext.get(Runnable.class, RunnableState.class)")
is rewritten to:
FieldBackedProvider$ContextStore$Runnable$RunnableState12345.getContextStore(runnableRunnable.class, RunnableState.class)

Constructor Summary

Constructors
Constructor Description

FieldBackedProvider(Class<?> instrumenterClass, Map<String,String> contextStore)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`net.bytebuddy.agent.builder.AgentBuilder.Identified.Extendable`	`additionalInstrumentation(net.bytebuddy.agent.builder.AgentBuilder.Identified.Extendable builder)`	Hook to define additional instrumentation.
`net.bytebuddy.agent.builder.AgentBuilder.Identified.Extendable`	`instrumentationTransformer(net.bytebuddy.agent.builder.AgentBuilder.Identified.Extendable builder)`	Hook to provide an agent builder after advice is applied to target class.
`static void`	`resetContextMatchers()`	Clear set that prevents multiple matchers for same context class.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - FieldBackedProvider
```
public FieldBackedProvider(Class<?> instrumenterClass,
                           Map<String,String> contextStore)
```
- Method Detail
  - instrumentationTransformer
```
public net.bytebuddy.agent.builder.AgentBuilder.Identified.Extendable instrumentationTransformer(net.bytebuddy.agent.builder.AgentBuilder.Identified.Extendable builder)
```
    Description copied from interface: InstrumentationContextProvider
    
    Hook to provide an agent builder after advice is applied to target class. Used to implement context-store lookup.
    
    Specified by:
    
    instrumentationTransformer in interface InstrumentationContextProvider
  - resetContextMatchers
```
public static void resetContextMatchers()
```
    Clear set that prevents multiple matchers for same context class.
  - additionalInstrumentation
```
public net.bytebuddy.agent.builder.AgentBuilder.Identified.Extendable additionalInstrumentation(net.bytebuddy.agent.builder.AgentBuilder.Identified.Extendable builder)
```
    Description copied from interface: InstrumentationContextProvider
    
    Hook to define additional instrumentation. Run at instrumentation advice is hooked up.
    
    Specified by:
    
    additionalInstrumentation in interface InstrumentationContextProvider