slow output, with pauses, with c# source code #677
Description
Something strange is going on. On a 1500-line .cs file, bat takes ~7s to list the file. --pager none, both with and without -p (not much difference with -p). I can see a pause after every1-2 dozen lines are output. --colors never also doesn't make a difference (bench via hyperfine):
| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|---|---|---|---|---|
cmd /c type EntityComponentStore.cs |
86.1 ± 7.3 | 75.9 | 101.1 | 1.0 |
bat --pager none EntityComponentStore.cs |
7734.8 ± 586.6 | 6857.4 | 8700.1 | 89.9 |
bat --pager none -p EntityComponentStore.cs |
6982.9 ± 464.3 | 6290.5 | 7889.4 | 81.1 |
bat --color never --pager none EntityComponentStore.cs |
7155.5 ± 460.3 | 6586.1 | 7804.1 | 83.1 |
bat --color never --pager none -p EntityComponentStore.cs |
7053.2 ± 492.3 | 6409.1 | 8076.1 | 82.0 |
bat 0.12.1, msvc build on Windows, in a regular cmd.exe console window.
I'd expect some slowdown but it seems like something buggy is happening. If I do the same on a cpp file, also ~1500 lines:
| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|---|---|---|---|---|
cmd /c type ApiDispatchers.cpp |
98.4 ± 10.0 | 83.6 | 115.9 | 1.0 |
bat --pager none ApiDispatchers.cpp |
768.5 ± 88.2 | 677.9 | 995.4 | 7.8 |
bat --pager none -p ApiDispatchers.cpp |
683.8 ± 128.9 | 549.4 | 959.0 | 6.9 |
bat --color never --pager none ApiDispatchers.cpp |
480.1 ± 46.7 | 440.2 | 584.2 | 4.9 |
bat --color never --pager none -p ApiDispatchers.cpp |
447.6 ± 42.5 | 414.6 | 542.0 | 4.5 |
Which is much more in line with what I'd expect. Is there something different about how the syntax highlighting for C# is handled? Is it all regexp or something else expensive based?