starknet_patricia_storage: wrap cache of cached storage in Arc

[nimrod-starkware]

Note

Medium Risk
Changes CachedStorage’s internal cache ownership and mutation paths; incorrect Arc::get_mut assumptions could cause panics at runtime if the cache becomes shared.

Overview
Wraps CachedStorage’s LruCache in an Arc, changing the cache field type from LruCache<...> to Arc<LruCache<...>> and updating initialization accordingly.

Updates write/delete cache mutation to go through Arc::get_mut(...).expect(...) before calling put/pop, while read paths continue to use cache peek/contains via the Arc.

^{Written by Cursor Bugbot for commit a72eee1. This will update automatically on new commits. Configure here.}

[reviewable-StarkWare]

This change is 

[nimrod-starkware]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• starknet_patricia_storage: implement clone for cached storage #12128
• starknet_patricia_storage: wrap cache of cached storage in Arc #12252 👈 (View in Graphite)
• starknet_patricia_storage: non mut get in storage trait #12123 : 1 other dependent PR (#12165 )
• starknet_patricia_storage: dont cache reads in cached storage #12251
• starknet_patricia_storage: atomic counters for read stats #12122
• main-v0.14.2

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[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

[cursor]

Arc::get_mut panics if cache is cloned

Medium Severity

The use of Arc::get_mut(&mut self.cache).expect(...) will panic at runtime if the Arc is ever cloned. Since the cache field is pub, external code can call .clone() on it to share the cache. Once cloned, Arc::get_mut() returns None because other references exist, causing the .expect() to panic. This creates a latent panic trap in update_cached_value, set, mset, and delete operations. Using Arc typically implies shared ownership, but this pattern prevents any sharing.

Additional Locations (1)

• crates/starknet_patricia_storage/src/map_storage.rs#L288-L289