Rename compartment-related terminology to use realms instead

[jdm]

This is specifically about components/script/compartments.rs and names like AlreadyInCompartment. Everywhere we use the name compartment, we should use the name realm instead.

[highfive]

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[kunalmohan]

@highfive: assign me

[highfive]

Hey @kunalmohan! Thanks for your interest in working on this issue. It's now assigned to you!

[kunalmohan]

@jdm should

servo/components/config/prefs.rs

Line 380 in d0d3aaa

per_compartment: {

be renamed too?

[jdm]

It turns out that preference can be removed; we don't actually use it anywhere in servo.

[kunalmohan]

Can you explain (or provide a resource) what role preference values play and why don't we need it anymore? Are they, in any way, related to user preferences and how users want servo to operate on their system? I don't have much idea what it means here at this point 😅 . I see that it is being enabled here

servo/resources/prefs.json

Line 65 in 592649b

"js.mem.gc.per_compartment.enabled": true,

And in the above comment, we are talking about removing just the 'per_compartment', right?

[kunalmohan]

Ok, I think I get it. prefs.json sets the values for various limits and functionalities that servo should follow/use by default, right? (I think I have put it in a very vague manner)

[jdm]

There are no uses of pref!(js.mem.gc.per_compartment.enabled) in the rest of the servo code. There is a use of pref!(js.mem.gc.per_zone.enabled), so I think this is just a preference that used to be valid in an older version of spidermonkey, then spidermonkey switch to per-zone garbage collection and we added a new preference for it instead of renaming the existing one.

[jdm]

And yes, the values in prefs.json are read during Servo's startup and used for configurable values in Servo's code.

[kunalmohan]

Ok. I have renamed the variables, functions, structs, etc. in compartments.rs and any other local variables in other files. I have removed the preference and renamed compartments.rs to realms.rs.
I found inCompartment descriptors in codegen/Bindings.conf I guess those are to be renamed too.

[jdm]

Yes please! That will require changing https://github.com/servo/servo/blob/master/components/script/dom/bindings/codegen/CodegenRust.py#L3400-L3401 and

servo/components/script/dom/bindings/codegen/Configuration.py

Line 223 in be40923

self.inCompartmentMethods = [name for name in desc.get('inCompartments', [])]

as well.

[kunalmohan]

Yes I did that. Now the only references remaining are

I don't think anything can be done about the first one (except renaming the imports).
I'm not sure about the others.

[jdm]

Agreed. All of those need to stay.