shardmap

A simple and efficient thread-safe sharded hashmap for Go. This is an alternative to the standard Go map and sync.Map, and is optimized for when your map needs to perform lots of concurrent reads and writes.

Under the hood shardmap uses robinhood hashmap and wyhash.

Getting Started

Installing

To start using shardmap, install Go and run go get:

$ go get -u github.com/phuslu/shardmap

This will retrieve the library.

Usage

The Map type works similar to a standard Go map, and includes four methods: Set, Get, Delete, Len.

m := shardmap.New[string, string](0)
m.Set("Hello", "Dolly!")
val, _ := m.Get("Hello")
fmt.Printf("%v\n", val)
val, _ = m.Delete("Hello")
fmt.Printf("%v\n", val)
val, _ = m.Get("Hello")
fmt.Printf("%v\n", val)

// Output:
// Dolly!
// Dolly!
// 

Performance

Benchmarking concurrent SET, GET, and DELETE operations for sync.Map, orcaman/concurrent-map, phuslu/shardmap.

go version go1.21.1 linux/amd64 (Intel(R) Xeon(R) Silver 4216 CPU @ 2.10GHz)

     number of cpus: 64
     number of keys: 10000000
            keysize: 16
        random seed: 1695872462865986967

-- sync.Map --
set: 10,000,000 ops over 64 threads in 16141ms, 619,553/sec, 1614 ns/op
get: 10,000,000 ops over 64 threads in 6919ms, 1,445,229/sec, 691 ns/op
del: 10,000,000 ops over 64 threads in 5016ms, 1,993,464/sec, 501 ns/op

-- github.com/orcaman/concurrent-map/v2 --
set: 10,000,000 ops over 64 threads in 1327ms, 7,533,463/sec, 132 ns/op
get: 10,000,000 ops over 64 threads in 252ms, 39,742,423/sec, 25 ns/op
del: 10,000,000 ops over 64 threads in 769ms, 12,995,480/sec, 76 ns/op

-- tailscale.com/syncs --
set: 10,000,000 ops over 64 threads in 473ms, 21,120,763/sec, 47 ns/op
get: 10,000,000 ops over 64 threads in 107ms, 93,572,966/sec, 10 ns/op
del: 10,000,000 ops over 64 threads in 124ms, 80,512,652/sec, 12 ns/op

-- github.com/alphadose/haxmap --
set: 10,000,000 ops over 64 threads in 13285ms, 752,728/sec, 1328 ns/op
get: 10,000,000 ops over 64 threads in 84ms, 119,259,602/sec, 8 ns/op
del: 10,000,000 ops over 64 threads in 1641ms, 6,092,923/sec, 164 ns/op

-- github.com/phuslu/shardmap --
set: 10,000,000 ops over 64 threads in 281ms, 35,588,233/sec, 28 ns/op
get: 10,000,000 ops over 64 threads in 80ms, 125,519,306/sec, 7 ns/op
del: 10,000,000 ops over 64 threads in 121ms, 82,783,512/sec, 12 ns/op

License

shardmap source code is available under the MIT License.