| // Copyright 2021 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.lib.actionsketch; |
| |
| import static com.google.common.base.Preconditions.checkState; |
| import static java.lang.Math.max; |
| |
| import com.google.auto.value.AutoValue; |
| import com.google.devtools.build.lib.util.BigIntegerFingerprintUtils; |
| import java.math.BigInteger; |
| import javax.annotation.Nullable; |
| |
| /** Container holding a version and a {@link BigInteger} hash that has the version and more. */ |
| @AutoValue |
| public abstract class HashAndVersion { |
| public static final HashAndVersion ZERO = create(BigInteger.ZERO, 0L); |
| |
| public abstract BigInteger hash(); |
| |
| /** |
| * -1 indicates that accurate version information could not be obtained (because all the files in |
| * a symlink chain were not examined, for instance). The hash may only be valid at the currently |
| * evaluating version. |
| */ |
| public abstract long version(); |
| |
| @Nullable |
| public static HashAndVersion create(BigInteger hash, long version) { |
| if (hash == null) { |
| checkState(version == Long.MAX_VALUE, "no hash with valid version %s", version); |
| return null; |
| } |
| return new AutoValue_HashAndVersion(hash, version); |
| } |
| |
| public static HashAndVersion createNoVersion(BigInteger hash) { |
| return create(hash, 0L); |
| } |
| |
| @Nullable |
| public static HashAndVersion composeNullable(HashAndVersion first, HashAndVersion second) { |
| if (first == null || second == null) { |
| return null; |
| } |
| return create( |
| BigIntegerFingerprintUtils.compose(first.hash(), second.hash()), |
| first.version() == -1 || second.version() == -1 |
| ? -1 |
| : max(first.version(), second.version())); |
| } |
| } |