sync-once is similar to sync.Once of the standard library.
It also has struct Once but has two additional methods DoForce() and Reset().
While writing a web application I needed to reload configurations that were calculated using sync.Once.
But sync.Once provide a single method Do() that executes the function only once.
To get around this I wrote this package.
import (
sync "github.com/m-murad/sync-once"
)
func main() {
o := new(sync.Once)
// This will work similar to the Once.Do(f) method of the sync package. The function f is only called once
o.Do(loadConfig())
// To call the function either for the first time or again you need to use the sync.DoForce() method
// This will execute irrespective of weather o.Do() was called earlier or not and mark o (Once) as done.
// Call to o.Do() after o.DoForce() will not execute the function.
o.DoForce(loadConfig())
// To reset o (sync.Once) you need to call the Reset() method.
// This will mark o as not executed but will no call the Do() method. You need to call Do() or DoForce() after this.
// Calls to Do() and DoForce() after this will work as described above.
o.Reset()
}
// load config from a static file or any other operation that is usually performed only once
func loadConfig() {
// Do the work here
}