wisski-cloud-distillery/internal/component/pool.go
2022-11-16 13:07:13 +01:00

64 lines
2 KiB
Go

package component
import (
"sync"
"github.com/FAU-CDI/wisski-distillery/pkg/lazy"
)
// Pool holds a pool of components.
type Pool struct {
pool lazy.Pool[Component, Still]
poolInit sync.Once
}
func (pool *Pool) init() {
pool.poolInit.Do(func() {
pool.pool.Init = Init
})
}
type PoolContext = *lazy.PoolContext[Component]
type AllFunc = func(context PoolContext) []Component
func (pool *Pool) All(core Still, init func(context PoolContext) []Component) []Component {
pool.init()
return pool.pool.All(core, init)
}
// Make creates or returns a cached component of the given Context.
//
// Components are initialized by first calling the init function.
// Then all component-like fields of fields are filled with their appropriate components.
//
// A component-like field has one of the following types:
//
// - A pointer to a struct type that implements component
// - A slice type of an interface type that implements component
//
// These fields are initialized in an undefined order during initialization.
// The init function may not rely on these existing.
// Furthermore, the init function may not cause other components to be initialized.
//
// The init function may be nil, indicating that no additional initialization is required.
func Make[C Component](context PoolContext, core Still, init func(component C)) C {
return lazy.Make(context, init)
}
// ExportAll exports all components that are a C from the pool.
//
// All should be the function of the core that initializes all components.
// All should only make calls to [InitComponent].
func ExportAll[C Component](pool *Pool, core Still, All AllFunc) []C {
pool.init()
return lazy.ExportComponents[Component, Still, C](&pool.pool, core, All)
}
// Export exports the first component that is a C from the pool.
//
// All should be the function of the core that initializes all components.
// All should only make calls to [InitComponent].
func Export[C Component](pool *Pool, core Still, All AllFunc) C {
pool.init()
return lazy.ExportComponent[Component, Still, C](&pool.pool, core, All)
}