fuookami.ospf.kotlin.utils.meta_programming.LazyDelegate.kt Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of ospf-kotlin-utils Show documentation

There is a newer version: 1.0.29

package fuookami.ospf.kotlin.utils.meta_programming

import java.util.concurrent.atomic.*
import kotlin.reflect.*
import kotlinx.coroutines.*

fun  lazyDelegate(lazyFunc: () -> U): LazyDelegate {
    return LazyDelegate(lazyFunc)
}

@JvmName("selfLazyDelegate")
fun  lazyDelegate(lazyFunc: (T) -> U): SelfLazyDelegate {
    return SelfLazyDelegate(lazyFunc)
}

fun  lazyDelegate(lazyKProperty: KProperty1): SelfLazyDelegate {
    return SelfLazyDelegate { lazyKProperty(it) }
}

fun  suspendLazy(lazyFunc: suspend () -> T): SuspendLazy {
    return SuspendLazy(lazyFunc)
}

class LazyDelegate(
    private val lazyFunc: () -> U
) {
    lateinit var range: U

    operator fun getValue(self: T, property: KProperty<*>): U {
        if (!::range.isInitialized) {
            range = lazyFunc()
        }
        return range
    }

    operator fun setValue(self: T, property: KProperty<*>, value: U) {
        if (!::range.isInitialized) {
            range = lazyFunc()
        }
        range = value
    }
}

class SelfLazyDelegate(
    private val lazyFunc: (T) -> U
) {
    lateinit var range: U

    operator fun getValue(self: T, property: KProperty<*>): U {
        if (!::range.isInitialized) {
            range = lazyFunc(self)
        }
        return range
    }

    operator fun setValue(self: T, property: KProperty<*>, value: U) {
        if (!::range.isInitialized) {
            range = lazyFunc(self)
        }
        range = value
    }
}

class SuspendLazy(
    private val lazyFunc: suspend () -> T,
) {
    private val value = AtomicReference>()

    suspend operator fun invoke(): T = (
            value.get()
                ?: coroutineScope {
                    value.updateAndGet { actual ->
                        actual ?: async { lazyFunc() }
                    }
                }
            ).await()
}