add level file metrics

[ucwong]

No description provided.

[codecov]

Codecov Report

Merging #1759 (589e1ea) into master (c8f7769) will increase coverage by 0.01%.
Report is 3 commits behind head on master.
The diff coverage is 0.00%.

❗ Current head 589e1ea differs from pull request most recent head cf0af54. Consider uploading reports for the commit cf0af54 to get more accurate results

@@            Coverage Diff             @@
##           master    #1759      +/-   ##
==========================================
+ Coverage   52.72%   52.73%   +0.01%     
==========================================
  Files         486      486              
  Lines       60472    60476       +4     
==========================================
+ Hits        31881    31890       +9     
+ Misses      26139    26135       -4     
+ Partials     2452     2451       -1     

Files	Coverage Δ
ctxcdb/pebble/pebble.go	37.50% <0.00%> (-0.55%)	⬇️

... and 10 files with indirect coverage changes