Added class and method tags to Timed/Counted interceptors.

[donbeave]

Hi!

I'm using a micrometer heavily, and currently, whenever I need to measure some method usage (timer/counter) I always need to do something like this:

public class UserRepository {

    @Timed(value = "repository.timed", extraTags = {"class", "UserRepository", "method", "findById"})
    public Optional<User> findById(String id) {
        // ...
    }

    // ...
}

But it's very verbose and requires manually adding class names and method name tags for each method. I think it will be better if TimedInterceptor/CountedInterceptor will be able to add this information when it requires. My current implementation is adding these tags for all timers/counters, which I'm not sure is a good solution for everybody, maybe it's better to add an ability to control this behavior inside the annotation, something like this:

public @interface Timed {

    // ...

    /**
     * List of additional tags that will be added to extra tags during intercepting the annotated method.
     */
    ExtraTag[] includeExtraTags() default {};

    // ...

}

public enum ExtraTag {

    SIMPLE_CLASS_NAME,
    CLASS_NAME,
    METHOD_NAME

}

And usage will be:

    @Timed(value = "repository.timed", includeExtraTags = {ExtraTag.CLASS_NAME, ExtraTag.METHOD_NAME})
    public Optional<User> findById(String id) {
        // ...
    }

I like this approach more, but it requires to copy Timed/Counted annotations from the micrometer repository and keeping them here in the micronaut repository as alternatives with this extension.

[CLAassistant]

All committers have signed the CLA.

[graemerocher]

Needs more tests

[donbeave]

Needs more tests

Haven't added tests since I'm not sure which approach is better. Do I need to leave it as is, just add class/method tags for all, or do I need to introduce alternative Micronaut's annotations with extended property includeExtraTags?

[graemerocher]

I think what would make more sense if if we add some strategy interface. Something like:

@Timed(tagStrategy=MyStrategy.class)

Then

class MyStrategy implement TaggingStrategy {
       void customise(ExecutableMethod<?, ?> method, Tagger tagger) {
             tagger.tag("methodName", method.getMethodName());
        }
}

One could then add whatever customisations needed in a meta annotation

[sdelamo]

@donbeave another option would be for you to create your own annotation and then map it to @Timed with the extra tags.

see: https://docs.micronaut.io/4.4.6/api/io/micronaut/inject/annotation/AnnotationMapper.html https://docs.micronaut.io/4.4.6/guide/#_aliasing_mapping_annotations

[hrothwell]

I'm a little late here but I have started something similar that would likely also accomplish this but also not change the underlying tags for everyone who uses this library: #753

[graemerocher]

Resolved by #764