mirror of
https://github.com/ergochat/ergo.git
synced 2024-11-25 05:19:25 +01:00
34 lines
936 B
Go
34 lines
936 B
Go
// Copyright (c) 2022 Shivaram Lingamneni
|
|
// released under the MIT license
|
|
|
|
package utils
|
|
|
|
import (
|
|
"sync/atomic"
|
|
"unsafe"
|
|
)
|
|
|
|
/*
|
|
This can be used to implement the following pattern:
|
|
|
|
1. Prepare a config object (this can be arbitrarily expensive)
|
|
2. Take a pointer to the config object and use Set() to install it
|
|
3. Use Get() to access the config from any goroutine
|
|
4. To update the config, call Set() again with a new prepared config object
|
|
5. As long as any individual config object is not modified (by any goroutine)
|
|
after it is installed with Set(), this is free of data races, and Get()
|
|
is extremely cheap (on amd64 it compiles down to plain MOV instructions).
|
|
*/
|
|
|
|
type ConfigStore[Config any] struct {
|
|
ptr unsafe.Pointer
|
|
}
|
|
|
|
func (c *ConfigStore[Config]) Get() *Config {
|
|
return (*Config)(atomic.LoadPointer(&c.ptr))
|
|
}
|
|
|
|
func (c *ConfigStore[Config]) Set(ptr *Config) {
|
|
atomic.StorePointer(&c.ptr, unsafe.Pointer(ptr))
|
|
}
|