apollo_propeller: add MessageProcessor scaffolding

[sirandreww-starkware]

Note

Low Risk
Mostly scaffolding and wiring for a new async component; behavior change is limited to emitting timeout/finalization events once the processor is instantiated and run.

Overview
Adds a new message_processor module exposing a MessageProcessor task skeleton for per-message processing, including an engine-facing EventStateManagerToEngine channel protocol.

The processor currently implements timeout handling: after timeout it emits Event::MessageTimeout and a Finalized signal over an unbounded tokio::mpsc sender, then exits; tokio is added as a crate dependency to support this async runtime/timers.

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[reviewable-StarkWare]

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[sirandreww-starkware]

• apollo_propeller: add MessageProcessor scaffolding #12003 : 2 dependent PRs (#12004 , #12780 ) 👈 (View in Graphite)
• apollo_propeller: added shard index utility functions to schedule manager #12002
• apollo_propeller: add sharding module with tests #11944 : 1 other dependent PR (#12001 )
• apollo_propeller: add message padding utilities #11943
• apollo_propeller: add behaviour public API stubs #11942
• apollo_propeller: add minimal config #11196 : 1 other dependent PR (#11197 )
• apollo_propeller: add behaviour skeleton #11195
• apollo_propeller: add Event enum to types #11194
• apollo_propeller: add dial upgrade error handling to handler #11074
• apollo_propeller: add rate-limited queue length warnings #11073
• apollo_propeller: add concurrent streams support to handler #11072
• apollo_propeller: implement outbound substream with message batching #11071
• apollo_propeller: add handler helper methods #11070
• main-v0.14.2

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[ShahakShama]

@ShahakShama resolved 1 discussion.
Reviewable status: 3 of 4 files reviewed, 9 unresolved discussions (waiting on guy-starkware, noamsp-starkware, and sirandreww-starkware).

[ShahakShama]

@ShahakShama resolved 1 discussion.
Reviewable status: 3 of 4 files reviewed, 8 unresolved discussions (waiting on guy-starkware, noamsp-starkware, and sirandreww-starkware).

[ShahakShama]

@ShahakShama resolved 1 discussion.
Reviewable status: 3 of 4 files reviewed, 7 unresolved discussions (waiting on guy-starkware, noamsp-starkware, and sirandreww-starkware).

[sirandreww-starkware]

@sirandreww-starkware made 10 comments and resolved 1 discussion.
Reviewable status: 2 of 4 files reviewed, 6 unresolved discussions (waiting on guy-starkware, noamsp-starkware, and ShahakShama).

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crates/apollo_propeller/src/message_processor.rs line 4 at r1 (raw file):

Previously, ShahakShama wrote…

To make it clear, Andrew please rephrase this at a way that's easier to understand

Removed

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crates/apollo_propeller/src/message_processor.rs line 41 at r1 (raw file):

Previously, ShahakShama wrote…

+1. Also, publisher public key is message identification IIUC
Let's just remove these comments

Done

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crates/apollo_propeller/src/message_processor.rs line 24 at r2 (raw file):

Previously, ShahakShama wrote…

Rename to EventStateManagerToEngine or CommandStateManagerToEngine to make its meaning more clear (and then you can remove the comment above)
If you chose event, rename the Event variant to BehaviourEvent or ExternalEvent

Done

---

crates/apollo_propeller/src/message_processor.rs line 47 at r2 (raw file):

Previously, ShahakShama wrote…

Make these bounded. TODO is fine for now

Added a comment why this needs to be unbounded

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crates/apollo_propeller/src/message_processor.rs line 51 at r2 (raw file):

Previously, ShahakShama wrote…

Rename to describe what this does better

Agreed in meeting not to do this

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crates/apollo_propeller/src/message_processor.rs line 56 at r2 (raw file):

Previously, ShahakShama wrote…

I think this can be debug

Done

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crates/apollo_propeller/src/message_processor.rs line 56 at r2 (raw file):

Previously, ShahakShama wrote…

Add a use statement instead (should've probably wrote this in previous PRs)

Done

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crates/apollo_propeller/src/message_processor.rs line 67 at r2 (raw file):

Previously, ShahakShama wrote…

Explain why you need this, both to me and in the TODO

will be removed in future PRs

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crates/apollo_propeller/src/message_processor.rs line 70 at r3 (raw file):

Previously, ShahakShama wrote…

use tokio::timeout instead

I don't want to restructure the loop, timeout takes a future and runs it with a timeout.
there's also tokio::sleep, but I'm worried that if I give it a duration rather than an instance the duration will reset on the next iteration of the loop

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crates/apollo_propeller/src/message_processor.rs line 70 at r3 (raw file):

Previously, ShahakShama wrote…

Add TODO to run the logic

Not necessary, next PR fixes this

[ShahakShama]

@ShahakShama reviewed 2 files and all commit messages, made 1 comment, and resolved 6 discussions.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on guy-starkware and noamsp-starkware).

[guy-starkware]

@guy-starkware reviewed all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on noamsp-starkware).

[sirandreww-starkware]

@sirandreww-starkware reviewed 4 files and all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on noamsp-starkware).