Package io.opentelemetry.javaagent.tooling

Class HelperInjector

java.lang.Object

io.opentelemetry.javaagent.tooling.HelperInjector

All Implemented Interfaces:

net.bytebuddy.agent.builder.AgentBuilder.Transformer

public class HelperInjector
extends Object
implements net.bytebuddy.agent.builder.AgentBuilder.Transformer

Injects instrumentation helper classes into the user's classloader.

Care must be taken when using this class. It is used both by the javaagent during its runtime and by gradle muzzle verification plugin during build time. And some code paths in this class require the usage of Instrumentation, which is available for the former, but not for the latter. Unfortunately, these two "modes of operations" and not easily discernible just by reading source code. Be careful.

In a nutshell, an instance of Instrumentation is needed for class injection into bootstrap classloader. This should NOT happen during build-time muzzle verification phase.

Nested Class Summary

Nested classes/interfaces inherited from interface net.bytebuddy.agent.builder.AgentBuilder.Transformer

net.bytebuddy.agent.builder.AgentBuilder.Transformer.ForAdvice, net.bytebuddy.agent.builder.AgentBuilder.Transformer.ForBuildPlugin

Constructor Summary

Constructors

Constructor	Description
HelperInjector(String requestingName, List<String> helperClassNames, List<HelperResource> helperResources, ClassLoader helpersSource, Instrumentation instrumentation)	Construct HelperInjector.

Method Summary

Modifier and Type	Method	Description
static HelperInjector	forDynamicTypes(String requestingName, Collection<net.bytebuddy.dynamic.DynamicType.Unloaded<?>> helpers, Instrumentation instrumentation)
static boolean	isInjectedClass(Class<?> c)
net.bytebuddy.dynamic.DynamicType.Builder<?>	transform(net.bytebuddy.dynamic.DynamicType.Builder<?> builder, net.bytebuddy.description.type.TypeDescription typeDescription, ClassLoader classLoader, net.bytebuddy.utility.JavaModule module)

Methods inherited from class java.lang.Object

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

Constructor Detail

HelperInjector

public HelperInjector(String requestingName,
                      List<String> helperClassNames,
                      List<HelperResource> helperResources,
                      ClassLoader helpersSource,
                      Instrumentation instrumentation)

Construct HelperInjector.

Parameters:

helperClassNames - binary names of the helper classes to inject. These class names must be resolvable by the classloader returned by io.opentelemetry.javaagent.tooling.Utils#getAgentClassLoader(). Classes are injected in the order provided. This is important if there is interdependency between helper classes that requires them to be injected in a specific order. And be careful, the class's package in library will be renamed like 'io.opentelemetry.instrumentation' to 'io.opentelemetry.javaagent.shaded.instrumentation'

Method Detail

forDynamicTypes

public static HelperInjector forDynamicTypes(String requestingName,
                                             Collection<net.bytebuddy.dynamic.DynamicType.Unloaded<?>> helpers,
                                             Instrumentation instrumentation)

transform

public net.bytebuddy.dynamic.DynamicType.Builder<?> transform(net.bytebuddy.dynamic.DynamicType.Builder<?> builder,
                                                              net.bytebuddy.description.type.TypeDescription typeDescription,
                                                              ClassLoader classLoader,
                                                              net.bytebuddy.utility.JavaModule module)

Specified by:

transform in interface net.bytebuddy.agent.builder.AgentBuilder.Transformer

isInjectedClass

public static boolean isInjectedClass(Class<?> c)