org.jetbrains.kotlin.utils.CachedValueProperty.kt Maven / Gradle / Ivy
/*
* Copyright 2010-2015 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jetbrains.kotlin.utils
import kotlin.properties.ReadOnlyProperty
public class CachedValueProperty(
private val calculator: () -> TValue,
private val timestampCalculator: () -> TTimestamp
) : ReadOnlyProperty {
private var value: TValue? = null
private var timestamp: TTimestamp? = null
public override fun get(thisRef: Any?, desc: PropertyMetadata): TValue {
val currentTimestamp = timestampCalculator()
if (value == null || timestamp != currentTimestamp) {
value = calculator()
timestamp = currentTimestamp
}
return value!!
}
}