[APPSEC-55936] Remove Reactive::Operation

[Strech]

What does this PR do?

Remove Reactive::Operation class as irresponsible proxy.

Motivation:

After analysis we decide to move forward without existing reactivity and gateway. Decision made based on the fact that implementation is not finished and subpar on complexity and potentially performance compared to benefits it gives us right now.

Change log entry

No.

Additional Notes:

This is a first step in the direction of simplification of the AppSec instrumentation. To gain some speed we need to trim the deadweight.

How to test the change?

CI is enough.

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-12-11 11:59:45

Comparing candidate commit 220c0a1 in PR branch appsec-55936-remove-reactive-operation with baseline commit b985e32 in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 31 metrics, 2 unstable metrics.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 96.98276% with 7 lines in your changes missing coverage. Please review.

Project coverage is 97.76%. Comparing base (b985e32) to head (220c0a1).

Files with missing lines	Patch %	Lines
lib/datadog/appsec/contrib/rack/gateway/watcher.rb	91.89%	3 Missing ⚠️
.../datadog/appsec/contrib/sinatra/gateway/watcher.rb	92.00%	2 Missing ⚠️
...ib/datadog/appsec/contrib/rails/gateway/watcher.rb	90.00%	1 Missing ⚠️
lib/datadog/appsec/monitor/gateway/watcher.rb	92.30%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4138      +/-   ##
==========================================
+ Coverage   97.75%   97.76%   +0.01%     
==========================================
  Files        1357     1355       -2     
  Lines       82130    82040      -90     
  Branches     4174     4171       -3     
==========================================
- Hits        80288    80210      -78     
+ Misses       1842     1830      -12     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[vpellan]

I just have one non-blocking suggestion, other than that LGTM!

[ivoanjo]

Hey @Strech this one looks still relevant to merge in at some point? :)

[Strech]

@ivoanjo Yes, we want to shrink the code, but I'm missing approval of @Datadog/apm-idm-ruby

P.S @marcotc may I ask you for the review?

[datadog-datadog-prod-us1]

Datadog Report

Branch report: appsec-55936-remove-reactive-operation
Commit report: 220c0a1
Test service: dd-trace-rb

✅ 0 Failed, 22063 Passed, 1457 Skipped, 5m 24.89s Total Time