gsm

gsm

Enhanced version of Go's sync.Map with generic types and iterators.

Features:

1. Wrapping of all sync.Map methods with methods having generic parameter and return types.
2. Iterator methods Range(), Keys(), and Values()
3. Very fast, on Apple M2 in parallel Load() benchmarks:
   1. Adds 0.1 nanoseconds overhead vs sync.Map
   2. 60x faster than sync.RWMutex.RLock and builtin go map
   3. See benchmarks for raw output
4. Unit tests of every method
5. Documentation including runnable example

Example:

package main

import (
	"fmt"
	"slices"

	"github.com/aaronriekenberg/gsm"
)

func main() {

	type name string

	type person struct {
		title string
		age   int
	}

	nameToPerson := gsm.GenericSyncMap[name, person]{}

	nameToPerson.Store("alice", person{title: "engineer", age: 25})
	nameToPerson.Store("bob", person{title: "manager", age: 35})

	value, ok := nameToPerson.Load("alice")
	fmt.Printf("alice value = %+v ok = %v\n", value, ok)
	fmt.Printf("alice title = %q\n", value.title)

	value, ok = nameToPerson.Load("bob")
	fmt.Printf("bob value = %+v ok = %v\n", value, ok)
	fmt.Printf("bob age = %v\n", value.age)

	swapped := nameToPerson.CompareAndSwap(
		"alice",
		person{title: "engineer", age: 25},
		person{title: "manager", age: 25},
	)
	value, ok = nameToPerson.Load("alice")
	fmt.Printf("swapped = %v value = %+v ok = %v\n", swapped, value, ok)

	keys := slices.Sorted(nameToPerson.Keys())
	fmt.Printf("keys = %v", keys)
}

output:

alice value = {title:engineer age:25} ok = true
alice title = "engineer"
bob value = {title:manager age:35} ok = true
bob age = 35
swapped = true value = {title:manager age:25} ok = true
keys = [alice bob]

Benchmarks:

$ go test -bench=. -benchmem ./...

goos: darwin
goarch: arm64
pkg: github.com/aaronriekenberg/gsm
cpu: Apple M2
BenchmarkSyncMapParallelLoad-8          	769333302	         1.428 ns/op	       0 B/op	       0 allocs/op
BenchmarkGenericSyncMapParallelLoad-8   	758809900	         1.588 ns/op	       0 B/op	       0 allocs/op
BenchmarkRWMutexMapParallelLoad-8       	12766698	        96.07 ns/op	      63 B/op	       1 allocs/op