3. Cleanup internal network request handler, fix unused request logging

[teor2345]

Motivation

In PRs #3293 and #3294, we modify Zebra's internal request handling so it is simpler and more reliable.

This PR removes some workarounds and duplicate code that aren't needed any more.

Solution

• Replace sending immediate responses with the new finished response handler code
• Remove special cases and wrapper structs that aren't needed any more
• Fix unused request logging

Review

This PR is ready for review, but it's based on PR #3294, so we should keep it in draft until that PR merges.

@upbqdn can review this PR.

Reviewer Checklist

• Code implements Specs and Designs

I've tested this PR locally, and the regression in the address book metrics stays resolved.

It's hard to test this PR, because we don't have a lot of connection state handling tests. We should have better tests after we implement #1592.

[codecov]

Codecov Report

Merging #3295 (65a07c5) into main (7e63182) will increase coverage by 0.16%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main    #3295      +/-   ##
==========================================
+ Coverage   77.18%   77.34%   +0.16%     
==========================================
  Files         265      265              
  Lines       31462    31415      -47     
==========================================
+ Hits        24283    24298      +15     
+ Misses       7179     7117      -62     

[teor2345]

I made this medium priority, because it could block ticket #3234

[upbqdn]

LGTM, the code is cleaner. 👍 I just wasn't sure about the unused messages.

[upbqdn]

Looks great. The new enum adds more semantics to the code.

[teor2345]

The Google Cloud build failed due to a network error on a server we don't control:

Jan 06 21:07:45.532 INFO {zebrad="65a07c5" net="Main"}: zebrad::commands::download: checking if Zcash Sapling and Sprout parameters have been downloaded
Jan 06 21:07:45.533 INFO {zebrad="65a07c5" net="Main"}: zebra_consensus::primitives::groth16::params: downloading Zcash Sapling parameters
Jan 06 21:08:53.693 INFO {zebrad="65a07c5" net="Main"}: zebra_consensus::primitives::groth16::params: downloading Zcash Sprout parameters
Jan 06 21:19:45.984 INFO {zebrad="65a07c5" net="Main"}: zebra_consensus::primitives::groth16::params: error downloading Zcash Sprout parameters, retrying error=IoError(Custom { kind: Other, error: "sprout-groth16.params failed reading after https://download.z.cash/downloads/sprout-groth16.params.part.1 + https://download.z.cash/downloads/sprout-groth16.params.part.2 bytes, expected 494074384 bytes from 725523612, error: Custom { kind: Other, error: "download response failed: IoError(Os { code: 104, kind: ConnectionReset, message: \"Connection reset by peer\" })" }" })
Jan 06 21:24:04.349 INFO {zebrad="65a07c5" net="Main"}: zebra_consensus::primitives::groth16::params: error downloading Zcash Sprout parameters, retrying error=IoError(Custom { kind: Other, error: "sprout-groth16.params failed reading after https://download.z.cash/downloads/sprout-groth16.params.part.1 + https://download.z.cash/downloads/sprout-groth16.params.part.2 bytes, expected 195836432 bytes from 725523612, error: Custom { kind: Other, error: "download response failed: IoError(Os { code: 104, kind: ConnectionReset, message: \"Connection reset by peer\" })" }" })

So I'll just admin-merge when the rest of CI passes.