feat(s3stream): optimize metrics performance

[SCNieh]

• optimize metrics performance by reuse attributes and reduced map indexing cost by using plain object reference

before:

after:

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (d53d0f8) 55.00% compared to head (96943a4) 55.01%.

❗ Current head 96943a4 differs from pull request most recent head a4ea9cb. Consider uploading reports for the commit a4ea9cb to get more accurate results

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #889      +/-   ##
============================================
+ Coverage     55.00%   55.01%   +0.01%     
- Complexity     1246     1247       +1     
============================================
  Files           133      133              
  Lines          8534     8534              
  Branches        789      789              
============================================
+ Hits           4694     4695       +1     
  Misses         3425     3425              
+ Partials        415      414       -1     

Components	Coverage Δ
RocketMQ Broker	∅ <ø> (∅)
RocketMQ Common	5.80% <ø> (ø)
RocketMQ Controller	54.58% <ø> (ø)
RocketMQ Proxy	37.28% <ø> (ø)
RocketMQ Store	73.65% <ø> (+0.04%)	⬆️
RocketMQ Stream	∅ <ø> (∅)
RocketMQ Metadata	35.44% <ø> (ø)

see 1 file with indirect coverage changes