Make key encoder optional and remove default implementation

[bisho]

Remove default key encoder and make key encoding optional

This change removes the default_key_encoder function and makes key encoding optional throughout the codebase. The key_encoder_fn parameter in CacheClient and DefaultExecutor is now Optional[Callable[[Key], bytes]] instead of having a default implementation.

When no key encoder is provided, the executor now passes the raw key string directly to the underlying socket layer, which handles key encoding internally. This simplifies the API by removing the need for a default key encoding strategy at the client level. It also makes the socket api more reliable and easy to use, as it handles large keys, binary, unicode all transparently.

We still prove the ability to use your own encoding for backwards compatibility, if you need to match existing behavior. As long as the key encoder returns small ascii keys, the socket endoder will not change the keys any further.

The change affects:

• Removal of default_key_encoder function and related imports
• Updated method signatures to make key_encoder_fn optional
• Modified executor logic to conditionally apply key encoding
• Updated tests to reflect the new behavior where key encoding happens at the socket level

Performance

Common config: server 127.0.0.1:11211, 10 threads, 1.00M requests (4 runs × 25,000 ops × 10 threads), 200 key space, GC disabled, 160/200 keys populated (95% small 80-250B, 5% large 100KB)                                                                                

  ┌───────────────┬────────┬─────────┬──────────────────────┬──────────────────────┬──────────────────────┐                                                                                                                                                                                       
  │               │        │         │    Socket in Rust    │    meta_* in Rust    │   key-enc in Rust    │
  │   Operation   │        │ BEFORE  ├──────────┬───────────┼──────────┬───────────┼──────────┬───────────┤                                                                                                                                                                                       
  │               │        │         │  Result  │  Speedup  │  Result  │  Speedup  │  Result  │  Speedup  │                                                                                                                                                                                       
  ├───────────────┼────────┼─────────┼──────────┼───────────┼──────────┼───────────┼──────────┼───────────┤                                                                                                                                                                                       
  │               │ RPS    │  46,600 │   76,652 │           │  110,287 │           │  112,054 │           │                                                                                                                                                                                       
  │  SET          ├────────┼─────────┼──────────┤   1.65x   ├──────────┤   2.37x   ├──────────┤   2.40x   │                                                                                                                                                                                       
  │               │ us/req │   21.46 │    13.05 │           │     9.07 │           │     8.92 │           │                                                                                                                                                                                       
  ├───────────────┼────────┼─────────┼──────────┼───────────┼──────────┼───────────┼──────────┼───────────┤                                                                                                                                                                                       
  │               │ RPS    │  46,135 │   81,401 │           │  116,382 │           │  118,682 │           │                                                                                                                                                                                       
  │  GET          ├────────┼─────────┼──────────┤   1.76x   ├──────────┤   2.52x   ├──────────┤   2.57x   │                                                                                                                                                                                       
  │               │ us/req │   21.68 │    12.28 │           │     8.59 │           │     8.43 │           │                                                                                                                                                                                       
  ├───────────────┼────────┼─────────┼──────────┼───────────┼──────────┼───────────┼──────────┼───────────┤                                                                                                                                                                                       
  │               │ RPS    │   2,677 │    3,626 │           │    3,560 │           │    3,567 │           │                                                                                                                                                                                       
  │  MULTI_GET(5) ├────────┼─────────┼──────────┤   1.35x   ├──────────┤   1.33x   ├──────────┤   1.33x   │                                                                                                                                                                                       
  │               │ us/req │  373.52 │   275.81 │           │   280.86 │           │   280.31 │           │                                                                                                                                                                                       
  ├───────────────┼────────┼─────────┼──────────┼───────────┼──────────┼───────────┼──────────┼───────────┤                                                                                                                                                                                       
  │               │ RPS    │  48,080 │   82,886 │           │  123,053 │           │  125,639 │           │                                                                                                                                                                                       
  │  DELETE       ├────────┼─────────┼──────────┤   1.72x   ├──────────┤   2.56x   ├──────────┤   2.61x   │                                                                                                                                                                                       
  │               │ us/req │   20.80 │    12.06 │           │     8.13 │           │     7.96 │           │                                                                                                                                                                                       
  └───────────────┴────────┴─────────┴──────────┴───────────┴──────────┴───────────┴──────────┴───────────┘

[bisho]

• Add batch multi-get execution for improved performance #83
• Make key encoder optional and remove default implementation #82 👈 (View in Graphite)
• Replace command building with direct socket method calls #81
• Migrate MemcacheSocket implementation to Rust #80
• Enhance benchmark with comprehensive SET/GET/DELETE testing #79
• main

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[xmartinez]

LG! Just a nit re: version mismatch.

[bisho]

Merge activity

• Mar 26, 3:31 PM UTC: A user started a stack merge that includes this pull request via Graphite.
• Mar 26, 3:38 PM UTC: Graphite rebased this pull request as part of a merge.
• Mar 26, 3:39 PM UTC: @bisho merged this pull request with Graphite.