1 /*
2 * Copyright 2024 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 @file:JvmMultifileClass
18 @file:JvmName("RelationUtil")
19
20 package androidx.room.util
21
22 import androidx.annotation.RestrictTo
23 import androidx.collection.LongSparseArray
24 import kotlin.jvm.JvmMultifileClass
25 import kotlin.jvm.JvmName
26
27 /**
28 * Utility function used in generated code to recursively fetch relationships when the amount of
29 * keys exceed [MAX_BIND_PARAMETER_CNT].
30 *
31 * @param map - The map containing the relationship keys to fill-in.
32 * @param isRelationCollection - True if [V] is a [Collection] which means it is non null.
33 * @param fetchBlock - A lambda for calling the generated _fetchRelationship function.
34 */
35 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP_PREFIX) // used in generated code
recursiveFetchMapnull36 fun <K : Any, V> recursiveFetchMap(
37 map: MutableMap<K, V>,
38 isRelationCollection: Boolean,
39 fetchBlock: (MutableMap<K, V>) -> Unit
40 ) {
41 val tmpMap = mutableMapOf<K, V>()
42 var count = 0
43 for (key in map.keys) {
44 // Safe because `V` is a nullable type arg when isRelationCollection == false and vice versa
45 @Suppress("UNCHECKED_CAST")
46 if (isRelationCollection) {
47 tmpMap[key] = map[key] as V
48 } else {
49 tmpMap[key] = null as V
50 }
51 count++
52 if (count == MAX_BIND_PARAMETER_CNT) {
53 // recursively load that batch
54 fetchBlock(tmpMap)
55 // for non collection relation, put the loaded batch in the original map,
56 // not needed when dealing with collections since references are passed
57 if (!isRelationCollection) {
58 map.putAll(tmpMap)
59 }
60 tmpMap.clear()
61 count = 0
62 }
63 }
64 if (count > 0) {
65 // load the last batch
66 fetchBlock(tmpMap)
67 // for non collection relation, put the last batch in the original map
68 if (!isRelationCollection) {
69 map.putAll(tmpMap)
70 }
71 }
72 }
73
74 /** Same as [recursiveFetchMap] but for [LongSparseArray]. */
75 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP_PREFIX) // used in generated code
recursiveFetchLongSparseArraynull76 fun <V> recursiveFetchLongSparseArray(
77 map: LongSparseArray<V>,
78 isRelationCollection: Boolean,
79 fetchBlock: (LongSparseArray<V>) -> Unit
80 ) {
81 val tmpMap = LongSparseArray<V>(MAX_BIND_PARAMETER_CNT)
82 var count = 0
83 var mapIndex = 0
84 val limit = map.size()
85 while (mapIndex < limit) {
86 if (isRelationCollection) {
87 tmpMap.put(map.keyAt(mapIndex), map.valueAt(mapIndex))
88 } else {
89 // Safe because `V` is a nullable type arg when isRelationCollection == false
90 @Suppress("UNCHECKED_CAST") tmpMap.put(map.keyAt(mapIndex), null as V)
91 }
92 mapIndex++
93 count++
94 if (count == MAX_BIND_PARAMETER_CNT) {
95 fetchBlock(tmpMap)
96 if (!isRelationCollection) {
97 map.putAll(tmpMap)
98 }
99 tmpMap.clear()
100 count = 0
101 }
102 }
103 if (count > 0) {
104 fetchBlock(tmpMap)
105 if (!isRelationCollection) {
106 map.putAll(tmpMap)
107 }
108 }
109 }
110
111 /** Unfortunately, we cannot read this value so we are only setting it to the SQLite default. */
112 internal const val MAX_BIND_PARAMETER_CNT = 999
113