1 /*
2  * Copyright 2018 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 package androidx.work
17 
18 /**
19  * An enumeration of the conflict resolution policies available to unique [OneTimeWorkRequest]s in
20  * case of a collision.
21  */
22 enum class ExistingWorkPolicy {
23     /**
24      * If there is existing pending (uncompleted) work with the same unique name, cancel and delete
25      * it. Then, insert the newly-specified work.
26      */
27     REPLACE,
28 
29     /**
30      * If there is existing pending (uncompleted) work with the same unique name, do nothing.
31      * Otherwise, insert the newly-specified work.
32      */
33     KEEP,
34 
35     /**
36      * If there is existing pending (uncompleted) work with the same unique name, append the
37      * newly-specified work as a child of all the leaves of that work sequence. Otherwise, insert
38      * the newly-specified work as the start of a new sequence.
39      *
40      * **Note:** When using APPEND with failed or cancelled prerequisites, newly enqueued work will
41      * also be marked as failed or cancelled respectively. Use
42      * [ExistingWorkPolicy.APPEND_OR_REPLACE] to create a new chain of work.
43      */
44     APPEND,
45 
46     /**
47      * If there is existing pending (uncompleted) work with the same unique name, append the
48      * newly-specified work as the child of all the leaves of that work sequence. Otherwise, insert
49      * the newly-specified work as the start of a new sequence.
50      *
51      * **Note:** If there are failed or cancelled prerequisites, these prerequisites are *dropped*
52      * and the newly-specified work is the start of a new sequence.
53      */
54     APPEND_OR_REPLACE
55 }
56