Optimize import time

[tkf]

#6 makes loading MIMEFileExtensions (v0.1.1) slow:

$ rm ~/.julia/compiled/v1.7/MIMEFileExtensions/*.ji
$ julia -e '@time using MIMEFileExtensions'
  1.088552 seconds (506.06 k allocations: 29.272 MiB, 36.05% compilation time)
$ ls -lh ~/.julia/compiled/v1.7/MIMEFileExtensions
total 208K
-rw-rw-r-- 1 arakaki arakaki 206K Mar 22 21:47 0i4jm_ydM5K.ji
$ julia -e '@time using MIMEFileExtensions'
  0.425975 seconds (478.77 k allocations: 27.534 MiB, 90.62% compilation time)
$ julia -e '@time using MIMEFileExtensions'
  0.425975 seconds (478.77 k allocations: 27.534 MiB, 90.57% compilation time)

It looks like the main reason is that Tuple{Vararg{String}} is not a terrible type to represent variable-length content.

Using Vector{String}:

$ rm ~/.julia/compiled/v1.7/MIMEFileExtensions/*.ji
$ julia -e '@time using MIMEFileExtensions'
  0.443467 seconds (118.20 k allocations: 8.624 MiB, 19.87% compilation time)
$ ls -lh ~/.julia/compiled/v1.7/MIMEFileExtensions
total 208K
-rw-rw-r-- 1 arakaki arakaki 207K Mar 22 21:16 0i4jm_ydM5K.ji
$ julia -e '@time using MIMEFileExtensions'
  0.097309 seconds (90.92 k allocations: 6.949 MiB, 75.95% compilation time)
$ julia -e '@time using MIMEFileExtensions'
  0.097159 seconds (90.91 k allocations: 6.887 MiB, 75.86% compilation time)

Using Vector{Symbol} (this PR):

$ rm ~/.julia/compiled/v1.7/MIMEFileExtensions/*.ji
$ julia -e '@time using MIMEFileExtensions'
  0.438848 seconds (112.58 k allocations: 8.364 MiB, 18.68% compilation time)
$ ls -lh ~/.julia/compiled/v1.7/MIMEFileExtensions
total 196K
-rw-rw-r-- 1 arakaki arakaki 193K Mar 22 21:15 0i4jm_ydM5K.ji
$ julia -e '@time using MIMEFileExtensions'
  0.091745 seconds (85.30 k allocations: 6.627 MiB, 74.87% compilation time)
$ julia -e '@time using MIMEFileExtensions'
  0.091200 seconds (85.30 k allocations: 6.627 MiB, 75.03% compilation time)

Vector{Symbol} is slightly faster and produces a smaller cache.

[codecov]

Codecov Report

Merging #8 (917160f) into main (2a0a4b1) will increase coverage by 1.02%.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##             main       #8      +/-   ##
==========================================
+ Coverage   48.97%   50.00%   +1.02%     
==========================================
  Files           1        1              
  Lines          49       54       +5     
==========================================
+ Hits           24       27       +3     
- Misses         25       27       +2     

Flag	Coverage Δ
Pkg.test	50.00% <66.66%> (+1.02%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/MIMEFileExtensions.jl	50.00% <66.66%> (+1.02%)	⬆️

📣 Codecov can now indicate which changes are the most critical in Pull Requests. Learn more