diff options
Diffstat (limited to 'app/src/main/kotlin/com/pitchedapps/frost/utils/LazyResettable.kt')
-rw-r--r-- | app/src/main/kotlin/com/pitchedapps/frost/utils/LazyResettable.kt | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/utils/LazyResettable.kt b/app/src/main/kotlin/com/pitchedapps/frost/utils/LazyResettable.kt new file mode 100644 index 00000000..c8365f5c --- /dev/null +++ b/app/src/main/kotlin/com/pitchedapps/frost/utils/LazyResettable.kt @@ -0,0 +1,51 @@ +package com.pitchedapps.frost.utils + +import java.io.Serializable +import kotlin.reflect.KProperty + +/** + * Created by Allan Wang on 2017-05-30. + * + * Lazy delegate that can be invalidated if needed + * https://stackoverflow.com/a/37294840/4407321 + */ +private object UNINITIALIZED + +fun <T : Any> lazyResettable(initializer: () -> T): LazyResettable<T> = LazyResettable<T>(initializer) + +class LazyResettable<T : Any>(private val initializer: () -> T, lock: Any? = null) : Lazy<T>, Serializable { + @Volatile private var _value: Any = UNINITIALIZED + private val lock = lock ?: this + + fun invalidate() { + _value = UNINITIALIZED + } + + override val value: T + get() { + val _v1 = _value + if (_v1 !== UNINITIALIZED) + @Suppress("UNCHECKED_CAST") + return _v1 as T + + return synchronized(lock) { + val _v2 = _value + if (_v2 !== UNINITIALIZED) { + @Suppress("UNCHECKED_CAST") + _v2 as T + } else { + val typedValue = initializer() + _value = typedValue + typedValue + } + } + } + + override fun isInitialized(): Boolean = _value !== UNINITIALIZED + + override fun toString(): String = if (isInitialized()) value.toString() else "Lazy value not initialized yet." + + operator fun setValue(any: Any, property: KProperty<*>, t: T) { + _value = t + } +}
\ No newline at end of file |