| // Copyright 2018 The Bazel Authors. All rights reserved. |
| // |
| // 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.google.devtools.build.skyframe; |
| |
| /** |
| * Hermeticity of a {@link SkyFunction}, meaning whether it accesses external state untracked by |
| * Skyframe during its evaluation. A classic example is a {@link SkyFunction} that consumes a file |
| * on a filesystem: that state is untracked by Skyframe. Skyframe must be more conservative when |
| * using values generated by a non-hermetic function: for instance, a non-hermetic function may need |
| * to be re-run even if all its Skyframe dependencies are unchanged: such a node may be explicitly |
| * dirtied due to outside changes. |
| * |
| * <p>Note that Skyframe does <i>not</i> explicitly re-evaluate non-hermetic functions on every |
| * build: it just relaxes some of its graph-pruning logic to be more conservative with such nodes. |
| */ |
| public enum FunctionHermeticity { |
| HERMETIC, |
| NONHERMETIC |
| } |
