org.jetbrains.kotlin.contracts.description.LazyContractProvider.kt Maven / Gradle / Ivy
/*
* Copyright 2010-2017 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.contracts.description
import org.jetbrains.kotlin.descriptors.CallableDescriptor
import org.jetbrains.kotlin.descriptors.ContractProvider
import org.jetbrains.kotlin.storage.StorageManager
abstract class AbstractContractProvider : ContractProvider {
abstract fun getContractDescription(): ContractDescription?
}
/**
* Essentially, this is a composition of two fields: value of type 'ContractDescription' and
* 'computation', which guarantees to initialize this field.
*
* Such contract providers are present only for source-based declarations, where we need additional
* resolve (force-resolve of the body) to get ContractDescription
*/
class LazyContractProvider(private val storageManager: StorageManager, private val computation: () -> Any?) : AbstractContractProvider() {
@Volatile
private var isComputed: Boolean = false
private var contractDescription: ContractDescription? = null
override fun getContractDescription(): ContractDescription? {
if (!isComputed) {
storageManager.compute(computation)
assert(isComputed) { "Computation of contract hasn't initialized contract properly" }
}
return contractDescription
}
fun setContractDescription(contractDescription: ContractDescription?) {
this.contractDescription = contractDescription
isComputed = true // publish
}
}
/**
* Such contract providers are used where we can be sure about contract presence and don't need
* additional resolve (e.g., for deserialized declarations)
*/
class ContractProviderImpl(private val contractDescription: ContractDescription) : AbstractContractProvider() {
override fun getContractDescription(): ContractDescription = contractDescription
}
// For storing into UserDataMap of FunctionDescriptor
object ContractProviderKey : CallableDescriptor.UserDataKey