1 files changed, 46 insertions, 0 deletions
diff --git a/build-system/gradle-core/src/main/java/com/android/build/gradle/internal/services/ConfigPhaseFileCreator.kt b/build-system/gradle-core/src/main/java/com/android/build/gradle/internal/services/ConfigPhaseFileCreator.kt
new file mode 100644
index 0000000000..d3d419c147
--- /dev/null
+++ b/build-system/gradle-core/src/main/java/com/android/build/gradle/internal/services/ConfigPhaseFileCreator.kt
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * 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 com.android.build.gradle.internal.services
+
+import org.gradle.api.provider.ValueSource
+import org.gradle.api.provider.ValueSourceParameters
+
+/**
+ * During configuration time, creating a file or directory could lead to configuration cache miss
+ * in the following build because Gradle inspects the return value of some File operations(e.g.
+ * [File.exists]) between builds and treats them as configuration input. For example, if a file is
+ * created in the first run and it already exists before the second run, calling [File.exists] to
+ * that file at configuration time would give us different value which means configuration cache
+ * is not reusable from Gradle point of view.
+ *
+ * There are some cases where we have to create a file or directory during configuration time and
+ * we know whether that file/directory exist or not doesn't affect configuration. In such cases,
+ * this class helps us create a file or directory during configuration time without causing
+ * configuration cache miss.
+ *
+ * To create a file/directory during configuration time: create them in [obtain] function using the
+ * path declared in [Params] instead of computing the path directly. The return value of [obtain]
+ * function needs to be same between different runs unless you want to config cache to be invalided.
+ * It can be a constant like [IGNORE_FILE_CREATION] if you don't need this function to return
+ * anything(Note [Unit] won't work). It can also be a [File] or other types.
+ *
+ */
+interface ConfigPhaseFileCreator<T, P : ConfigPhaseFileCreator.Params> : ValueSource<T, P> {
+
+    interface Params : ValueSourceParameters
+}
+
+const val IGNORE_FILE_CREATION = ""