// the find
jonhoo/flurry
A port of Java's ConcurrentHashMap to Rust
A Rust port of Java's ConcurrentHashMap, built on crossbeam-epoch for lock-free concurrent reads. Aimed at Rust developers who need a concurrent hash map and want something closer to Java's well-understood semantics. The author explicitly recommends against using it in favor of papaya or dashmap.
The JSR166 Java source is included alongside the Rust code, making it straightforward to audit the translation and understand design intent. Test suite is ported directly from the JDK's own ConcurrentHashMap tests plus the cuckoo stress tests, so correctness coverage is unusually thorough. The live-coding origin means there's hours of video explaining the implementation decisions, which is rare for a concurrent data structure. Dual MIT/Apache licensing matches Rust ecosystem conventions.
The README itself tells you not to use it — documented performance and memory issues under load make this a learning artifact more than a production tool. Development is mostly dormant; a library for a solved problem with known better alternatives has little reason to evolve. The guard-based API (borrowing from crossbeam-epoch) adds cognitive overhead compared to dashmap's more ergonomic interface. No async-aware design, so it doesn't fit naturally into tokio workloads without wrapping.