Slightly sketchy speed-up for /rotation/

[tsutton]

Context: #5471.

Changes: call Flask's builtin url_for once to retrieve a template url and then just use string formatting to build the url for each card.

[TravisBuddy]

Hey @tsutton,
Your changes look good to me!

View build log

TravisBuddy Request Identifier: c7b83080-02b3-11ea-bbb5-2bfb3cbbfe32

[codecov]

Codecov Report

Merging #6773 into master will increase coverage by 0.02%.
The diff coverage is 85%.

@@            Coverage Diff            @@
##           master   #6773      +/-   ##
=========================================
+ Coverage   41.88%   41.9%   +0.02%     
=========================================
  Files         257     257              
  Lines       13314   13329      +15     
  Branches     2020    2023       +3     
=========================================
+ Hits         5577    5586       +9     
- Misses       7491    7492       +1     
- Partials      246     251       +5

Impacted Files	Coverage Δ
decksite/view.py	63.27% <85%> (-0.19%)	⬇️
logsite/api.py	42.85% <0%> (ø)	⬆️
maintenance/elo.py	0% <0%> (ø)	⬆️
magic/multiverse.py	5.45% <0%> (ø)	⬆️
decksite/views/person_achievements.py	35% <0%> (ø)	⬆️
decksite/data/rule.py	23.63% <0%> (ø)	⬆️
logsite/data/match.py	75% <0%> (ø)	⬆️

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[bakert]

What's the total speedup late in full rotation week? About 1s?

What do you think about moving this to shared_web.base_view.BaseView.url_for or (probably more appropriate) decksite.view.View.url_for and doing a little bit of magic based on the input params. Then we could change literally every url_for to use the new function and do this for anything we see more than a few dozen times in a request?

[bakert]

We could even have it store counts of (template + '|' + len(args)) occurrences and flag anything over 50 or something.

[vorpal-buildbot]

Seen on LOGS (created by @tsutton and merged by @vorpal-buildbot 47 seconds ago) Please check your changes!

[vorpal-buildbot]

Seen on PROD (created by @tsutton and merged by @vorpal-buildbot 1 minute and 1 second ago) Please check your changes!