Write more on progress

rust-lang · MarcusGrass · Feb 23, 2024 · Feb 23, 2024 · Feb 25, 2024 · Feb 25, 2024
commit bdf8291d157cf19aa53f6a23f6bceb3771b47a73
diff --git a/Progress.md b/Progress.md
@@ -8,11 +8,10 @@ This is non-trivial when internals can run threaded, eagerly printing cannot hap
 to be passed back through buffers. Even that would be non-trivial if there wasn't color-term writing happening
 making things complicated.
 
-## Rustc termcolor vendoring
-
-A big problem is the way that `rustc` vendors termcolor. It vendors some types but no printing facilities, 
-and the vendored code isn't interoperable with the published `termcolor` library, which means that 
-either the printing facilities need to be reinvented (no), or some compatibility-code needs to be introduced (yes).
+The change became pretty big, even though the only substantive change 
+is in `print.rs` and `bin/main.rs`, because the printer has to be propagated 
+deep into the library, about half of the changes are adding a function argument, and reformatting 
+caused by those lines becoming too long.
 
 ## Changes
 
@@ -26,3 +25,42 @@ In practice there are four printing facilities used:
 4. Term stderr, this is done by `rustc_error` and the most complex to integrate.
 
 Additionally, these four facilities can't be separated, since they have to preserve order between each other.
+
+### Rename StdoutEmitter
+
+Confusing naming, it doesn't output into `stdout`, but into the 
+provided buffer.
+
+## Pros
+
+This change brings a substantial speedup, especially for large projects, the speedup
+becoming less and less but not none or negative for smaller projects.  
+
+If instant measures as the average reaction time of 250ms, this brings 
+down tokio from the not-instant 271ms, to the instant 86ms. 
+
+Giving space for projects almost 3x tokio's size to have an "instant" formatting experience.
+
+## Drawbacks
+
+There are some drawbacks to consider
+
+### Late printing memory increase
+
+All messages that would have gone into `stdout` or `stderr` now go
+into an in-mem buffer. This causes a memory-overhead which scales with project size
+(number of files). For a large project, this is a difference of
+`117M` on the master version, and `170M` on this version.
+
+### Rustc termcolor vendoring
+
+A problem is the way that `rustc` vendors termcolor. It vendors some types but no printing facilities,
+and the vendored code isn't interoperable with the published `termcolor` library, which means that
+either the printing facilities need to be reinvented (no), or some compatibility-code needs to be introduced (yes).
+Hopefully there's some better solution to this, but it's liveable at the moment.
+
+### Accidentally messing with outputs will cause an output jumble
+
+This change would make any direct interaction with `stdout` and `stderr` in the 
+formatting codepath a bug. Generally, printing deep inside a library is considered bad for 
+imo, but now that would be upgraded to a bug.