chore: remove udb as a dependency of envoy-client

[NathanFlurry]

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[NathanFlurry]

• DO NOT MERGE: sandbox benches #4597 : 2 dependent PRs (#4599 , #4600 )
• fix(envoy-client): add tls #4595
• chore: fix driver test suite #4591
• chore: tunnel auth #4588
• chore: remove udb as a dependency of envoy-client #4587 👈 (View in Graphite)
• chore: revert actor v2 hack #4586
• fix: fix pool metadata protocol version refresh, rivetkit native ws #4585
• feat: US-001 - Define SqliteKv trait in rivetkit-sqlite-native #4584
• feat(rust/engine-runner): minimal rust engine runner #4289
• chore: delete kv channel #4583
• feat(engine): rust runner #4582
• chore: remove non-engine drivers #4574 : 1 other dependent PR (#4581 )
• feat: dynamic actors #4397
• fix: driver test suite & sqlite reliability #4559
• fix: remove serverless token #4572
• fix: misc token fixes #4569
• fix(pb): clean up actor stop decision handling #4566
• fix(envoy): use global instance, add signal handlers #4565
• chore: misc fixes, add pb snapshot test #4561
• fix(cache): make in memory cache global #4560
• main

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[MasterPtato]

This is unnecessary, rivet-util is not a heavy dep.

[claude]

PR Review: chore: remove udb as a dependency of envoy-client

Summary: This PR extracts serde utilities from rivet-util into a new rivet-util-serde crate to reduce the dependency footprint of envoy-client and envoy-protocol.

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Motivation Clarity

MasterPtato's review (now dismissed) questioned whether this is necessary. The PR description does not include evidence for why this is needed. A cargo tree snippet showing which heavy transitive deps rivet-util pulls into envoy-client that would not otherwise be there would clarify the value.

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build.rs Post-Processing Hack

The most significant concern is the post_process_generated_rust function in engine/sdks/rust/envoy-protocol/build.rs. This function does a string-replacement on generated _generated.rs files to rewrite rivet_util::serde::HashableMap to rivet_util_serde::HashableMap because the upstream code generator (vbare_compiler) hard-codes the old path.

Issues with this approach:

1. Fragile — if vbare_compiler changes its output format, the replacement silently does nothing and compilation breaks without a clear cause.
2. Wrong layer — the fix belongs in vbare_compiler::Config::with_hashable_map() as a configurable type path, not as a post-processing step in a consuming crate's build script.
3. Incremental build risk — Cargo determines whether to re-run build scripts based on declared inputs. Patching generated files in OUT_DIR can have subtle interactions with incremental builds where the patch may or may not re-apply.

Recommendation: Update vbare_compiler to accept a custom path for the hashable map type (e.g. Config::with_hashable_map_path("rivet_util_serde::HashableMap")) rather than patching generated output after the fact.

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Minor: Unnecessary Trait Bounds on FakeMap::From<Vec>

(Pre-existing code now prominently in the new crate.)

The From<Vec<(K, V)>> impl has an unnecessary K: Eq + Hash bound. FakeMap is a Vec-backed structure and does not need hashing for this conversion. This unnecessarily restricts use with non-hashable key types that FakeMap would otherwise support.

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Code Quality

The refactoring itself is clean:

• The new crate's Cargo.toml properly uses workspace dependencies.
• engine/packages/util/src/serde.rs is cleanly reduced to pub use rivet_util_serde::*;, maintaining backward compatibility for existing callers.
• Import paths in envoy-client and envoy-protocol are updated consistently.

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Summary

Area	Note
Motivation	A cargo tree diff would justify why this extraction is worth the new crate
Blocking	build.rs string-replacement workaround should be replaced with a vbare_compiler config option
Minor	Unnecessary Eq + Hash bound on FakeMap::From<Vec>

The refactoring structure is sound. The build.rs post-processing hack is the main thing worth addressing before merging.

wrong

[MasterPtato]

Merge activity

• Apr 8, 8:52 PM UTC: A user started a stack merge that includes this pull request via Graphite.
• Apr 8, 9:30 PM UTC: Graphite rebased this pull request as part of a merge.
• Apr 8, 9:31 PM UTC: @MasterPtato merged this pull request with Graphite.