A lightning fast concurrent hashmap
The hashing algorithm used was xxHash and the hashmap's buckets were implemented using Harris lock-free list
You need Golang 1.18.x or above
$ go get github.com/alphadose/haxmappackage main
import (
"fmt"
"github.com/alphadose/haxmap"
)
func main() {
// initialize map with key type `int` and value type `string`
mep := haxmap.New[int, string]()
// set a value (overwrites existing value if present)
mep.Set(1, "one")
// get the value and print it
val, ok := mep.Get(1)
if ok {
println(val)
}
mep.Set(2, "two")
mep.Set(3, "three")
mep.Set(4, "four")
// ForEach loop to iterate over all key-value pairs and execute the given lambda
mep.ForEach(func(key int, value string) bool {
fmt.Printf("Key -> %d | Value -> %s\n", key, value)
return true // return `true` to continue iteration and `false` to break iteration
})
mep.Del(1) // delete a value
mep.Del(0) // delete is safe even if a key doesn't exists
// bulk deletion is supported too in the same API call
// has better performance than deleting keys one by one
mep.Del(2, 3, 4)
if mep.Len() == 0 {
println("cleanup complete")
}
}Benchmarks were performed against golang sync.Map and the latest cornelk-hashmap
All results were computed from benchstat of 20 runs (code available here)
- Concurrent Reads Only
name time/op
HaxMapReadsOnly-8 6.94µs ± 4%
GoSyncMapReadsOnly-8 21.5µs ± 3%
CornelkMapReadsOnly-8 8.39µs ± 8%
- Concurrent Reads with Writes
name time/op
HaxMapReadsWithWrites-8 8.23µs ± 3%
GoSyncMapReadsWithWrites-8 25.0µs ± 2%
CornelkMapReadsWithWrites-8 8.83µs ±20%
name alloc/op
HaxMapReadsWithWrites-8 1.25kB ± 5%
GoSyncMapReadsWithWrites-8 6.20kB ± 7%
CornelkMapReadsWithWrites-8 1.53kB ± 9%
name allocs/op
HaxMapReadsWithWrites-8 156 ± 5%
GoSyncMapReadsWithWrites-8 574 ± 7%
CornelkMapReadsWithWrites-8 191 ± 9%
From the above results it is evident that haxmap takes the least time, memory and allocations in all cases making it the best golang concurrent hashmap in this period of time
- HaxMap by default uses xxHash algorithm, but you can override this and plug-in your own custom hash function. Beneath lies an example for the same.
package main
import (
"github.com/alphadose/haxmap"
)
// your custom hash function
// the hash function signature must adhere to `func(keyType) uintptr`
func customStringHasher(s string) uintptr {
return uintptr(len(s))
}
func main() {
m := haxmap.New[string, string]() // initialize a string-string map
m.SetHasher(customStringHasher) // this overrides the default xxHash algorithm
m.Set("one", "1")
val, ok := m.Get("one")
if ok {
println(val)
}
}- You can pre-allocate the size of the map which will improve performance in some cases.
package main
import (
"github.com/alphadose/haxmap"
)
func main() {
const initialSize = 1 << 10
// pre-allocating the size of the map will prevent all grow operations
// until that limit is hit thereby improving performance
m := haxmap.New[int, string](initialSize)
m.Set(1, "1")
val, ok := m.Get(1)
if ok {
println(val)
}
}
