Hi everyone 
I've just published a concurrent hash map implementation which (according to my benchmarks at least) is the fastest one available (faster than both starshard and dashmap). It offers a configurable locking policy (mutex or rwlock) and a configurable hasher (rapidhash is the default). It also supports atomic transactions in both immediate and prepared execution styles.
Would love any feedback on it (good and bad!)
It's called txmap and a link is here https://crates.io/crates/txmap