update jsoo for testing

[phated]

opening this draft for windows CI testing purposes

[hhugo]

Try with this diff

diff --git a/compiler/test/dune b/compiler/test/dune
index a8b92d0c..111938bc 100644
--- a/compiler/test/dune
+++ b/compiler/test/dune
@@ -22,4 +22,4 @@
  (libraries grain grain-tests.framework grain-tests.suites grain-tests.utils)
  (modules test)
  (js_of_ocaml
-  (flags --no-sourcemap --quiet)))
+  (flags --no-sourcemap --quiet --disable use-js-string)))

[hhugo]

I'm wondering if the slowdown could be due to yojson reading "cmi" pattern

[hhugo]

The current implementation:

• first read the cmi section into some bytes
• convert bytes to string
• Yojson.from_string convert the string back into bytes

An alternative approach can mitigate the perf issue
hhugo@543d5a9

[phated]

Thanks @hhugo! I've cherry-picked that commit into this branch to see it in action. Any idea why this issue is only showing up now (with this upgrade)?

[hhugo]

Thanks @hhugo! I've cherry-picked that commit into this branch to see it in action. Any idea why this issue is only showing up now (with this upgrade)?

js_of_ocaml-compiler.5.1.0 changed the default representation of strings.

[hhugo]

With the commit, you no longer need to disable use-js-string.
I've created a branch with additional changes.
see https://github.com/hhugo/grain/tree/hhugo-jsoo-oom

[phated]

@hhugo the tests have still gone from 3-4 minutes to 16 minutes with the newer JSOO. This seems untenable for us since our compiler binaries are produced via jsoo. Do you have any other ideas why there would be a 400% slowdown between the versions?