[Michelprogram]

Fixes ENG-1510

[linear-code]

ENG-1510 Get rid of set_client_data & get_client_data

libsqlite3-sys does not publish a version that contain both client_data.
Using last version from Github involve upgrade version of diesel, sqlxite, diesel_migration

Review in Linear

[Michelprogram]

Thats not really what I was talking about, I was essentially trying to see if we could have one DictCache for all the connections where the inner items would be Arc<EncoderDictionary<'static>> so we can quickly clone them for a compression. We could also basically drop the LRU or make it way bigger.

so i did the shared process-wide dict pool for all connections an i replaced the LRU with a HashMap (cap 64) on overflow we clear. That's simpler than LRU acceptable miss cost for our size and Per-connection state is only current_ids via client data

[Copilot]

Copilot review overview

🟡 Changes recommended

The global cache can reuse dictionaries across unrelated databases, ignore compression levels, and grow beyond its intended limit.

Review effort: Balanced
Findings: 1 · 2

Open (3)

• Global dictionary cache key is not unique across databases · New
• Encoder cache miss bypasses maximum entry limit · New
• Decoder cache miss bypasses maximum entry limit · New

What changed in this PR

Moves prepared Zstandard dictionaries from per-connection LRU caches into a shared process-wide pool.

Changes:

• Adds global encoder and decoder caches.
• Retains only current dictionary IDs per connection.
• Serializes the crate’s tests.

File	Description
.mise/​tasks/​sqlite-compress/​test	Runs tests serially.
sqlite-compress/​src/​cache/​connection.rs	Removes prepared dictionaries from connection state.
sqlite-compress/​src/​cache/​lru.rs	Deletes the per-connection LRU implementation.
sqlite-compress/​src/​cache/​mod.rs	Registers the new pool module.
sqlite-compress/​src/​cache/​pool.rs	Implements global prepared-dictionary storage.
sqlite-compress/​src/​cache/​prepared.rs	Routes dictionary operations through the global pool.
sqlite-compress/​src/​state.rs	Removes formatting whitespace.

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[Sytten]

This clears the whole map at cap, you sure it is what we want?

[Michelprogram]

yep the downside of this is that you need to fill it again with a lot of cache misses but i don't think we'll be doing clear that much. i mean the cost of having an LRU instead is acceptable