1 /* 2 * Copyright (C) 2022 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.libraries.pcc.chronicle.api.operation 18 19 /** Representation of the result of an [Operation] as an action to be performed by the caller. */ 20 sealed class Action<B> { 21 /** 22 * An [Operation] which returns [Update] is requesting the caller to use the [newValue] in place 23 * the input to the [Operation]. 24 * 25 * TODO(b/205183415): Consider using an object pool to help reduce the number of allocations 26 * incurred when Update results are used. 27 */ 28 data class Update<B>(val newValue: B) : Action<B>() 29 30 /** 31 * An [Operation] which returns [OmitFromRoot] would like the caller to remove the entity from 32 * within which the [OmitFromRoot] was returned from the highest possible level of nesting. 33 */ 34 object OmitFromRoot : Action<Nothing>() 35 36 /** 37 * An [Operation] which returns [OmitFromParent] would like the caller to remove the entity from 38 * within which the [OmitFromParent] was returned from the nearest collection containing that 39 * entity. 40 */ 41 object OmitFromParent : Action<Nothing>() 42 43 /** 44 * An [Operation] which returns [Throw] would like the caller to throw the [exception] on its 45 * behalf. 46 */ 47 data class Throw(val exception: Throwable) : Action<Nothing>() 48 } 49