tupshin / hash_cache

The accompanying code largely fulfills the goals of the thread-safe expiring cache that was specified.

Please see the NOTES.md file to see my initial thinking. Note that the approach I outline there is the approach I ended up using.

Design goals: Write a thread safe caching implementation that has good 95th and 99th percentile latencies and also supports expiring keys

Approach:

• Design a trait with the necesaary functions

• Take the stdlib HashMap and wrap it behind an Arc for thread safety.

• Implement the above trait for my custom type

  • Support generic K/V types, as long as they implement the same traits that HashMap requires, such as Eq and Hash.
  • Instead of just storing the Value in the HashMap, store a tuple of (expiration_time, Value), so that values that already expired can be ignored at retrieval time and lazily deleted

see the ISSUES.md file for a description of the limitations of this approach and partial implementation

Running:

To run the tests, use cargo test To run the performance benchmarks, use cargo to install criterion cargo intall cargo-criterion and then run cargo criterion documentation can be access with cargo doc --open