# xacrimon/dashmap

Blazing fast concurrent HashMap for Rust.

Repository: https://github.com/xacrimon/dashmap
Canonical: https://ross.abutalabs.com/products/dashmap
Language: Rust
License: MIT
License Family: permissive
Topics: hashmap, hashtable, concurrent-programming, concurrent, concurrent-data-structure, concurrent-map, data-structures
Last push: 2026-05-17T21:25:40+00:00

## Health v2 (maintenance only)
Score: 75/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 82, release rhythm 52, longevity 100
- inputs: {"age_days": 2462, "days_push": 108, "days_rel": 108, "gap_med": 619, "n_releases_24m": 2}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4106, forks 191 (observed 2026-08-28T04:08:35.635178+00:00)

## What it is
DashMap is a blazingly fast concurrent HashMap implementation for Rust with an API similar to std::collections::HashMap. It serves as a direct replacement for RwLock<HashMap<K, V>>, allowing shared mutable access across threads via Arc.

## Use cases
- share a mutable hashmap across threads without manual locking
- replace RwLock<HashMap<K, V>> with a faster concurrent map
- build a thread-safe in-memory cache in Rust
- store shared state in a multi-threaded web server
- implement concurrent counters or key-value lookups

## When to choose
- you need concurrent read/write access to a key-value map from multiple threads
- you want a drop-in API similar to std HashMap with interior mutability
- performance of lock-protected std HashMap is a bottleneck in your Rust application

## When to avoid
- your map is only accessed from a single thread (use std::collections::HashMap)
- you need ordered maps or sorted iteration (use BTreeMap or an ordered concurrent structure)
- you need persistence or a networked key-value store (use a database instead)

## Facets
- artifact type: library
- maturity: stable
- function: concurrency, caching, developer-tools
- domain: developer-tools, performance
- platform: rust, cross-platform
- tags: concurrent-hashmap, sharded-map, thread-safe, data-structures, lock-free, algorithms

## Member repositories
- xacrimon/dashmap (main) score 75

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:35.635178+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:23:14.060626+00:00, confidence not recorded.
  - readme: https://github.com/xacrimon/dashmap (fetched 2026-08-28T04:08:35.635178+00:00, sha 4ca52f422b55)
  - registry_crates: https://crates.io/api/v1/crates/dashmap (fetched 2026-08-29T09:14:42.802622+00:00, sha 677d293fc760)
- Data as of 2026-08-30T08:39:29.467469+00:00.