| // 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.bazel.bzlmod; |
| |
| import static com.google.common.collect.ImmutableList.toImmutableList; |
| import static com.google.common.collect.ImmutableMap.toImmutableMap; |
| |
| import com.google.common.collect.ImmutableTable; |
| import com.google.devtools.build.skyframe.SkyFunction; |
| import com.google.devtools.build.skyframe.SkyFunctionException; |
| import com.google.devtools.build.skyframe.SkyKey; |
| import com.google.devtools.build.skyframe.SkyValue; |
| import javax.annotation.Nullable; |
| |
| /** |
| * A simple SkyFunction that takes the information needed by a {@link SingleExtensionEvalFunction} |
| * out of {@link BazelModuleResolutionValue} and stores it in a SkyValue. |
| * |
| * <p>The whole raison d'ĂȘtre of this function is to avoid unnecessary reruns of module extensions. |
| * Whenever any information in the whole dependency graph changes, {@link |
| * BazelModuleResolutionFunction} is rerun, producing a new {@link BazelModuleResolutionValue}. If |
| * {@link SingleExtensionEvalFunction} were to directly depend on {@link |
| * BazelModuleResolutionValue}, any such change would cause ALL module extensions to be rerun. |
| * Instead, by storing the input needed by a single {@link SingleExtensionEvalFunction}, we can rely |
| * on Skyframe's change pruning feature to make sure that we only rerun the module extension whose |
| * input data actually changed. |
| */ |
| public class SingleExtensionUsagesFunction implements SkyFunction { |
| |
| @Override |
| @Nullable |
| public SkyValue compute(SkyKey skyKey, Environment env) |
| throws SkyFunctionException, InterruptedException { |
| BazelDepGraphValue bazelDepGraphValue = |
| (BazelDepGraphValue) env.getValue(BazelDepGraphValue.KEY); |
| if (bazelDepGraphValue == null) { |
| return null; |
| } |
| |
| ModuleExtensionId id = (ModuleExtensionId) skyKey.argument(); |
| ImmutableTable<ModuleExtensionId, ModuleKey, ModuleExtensionUsage> usagesTable = |
| bazelDepGraphValue.getExtensionUsagesTable(); |
| return SingleExtensionUsagesValue.create( |
| usagesTable.row(id), |
| bazelDepGraphValue.getExtensionUniqueNames().get(id), |
| // Filter abridged modules down to only those that actually used this extension. |
| bazelDepGraphValue.getAbridgedModules().stream() |
| .filter(module -> usagesTable.contains(id, module.getKey())) |
| .collect(toImmutableList()), |
| // TODO(wyv): Maybe cache these mappings? |
| usagesTable.row(id).keySet().stream() |
| .collect(toImmutableMap(key -> key, bazelDepGraphValue::getFullRepoMapping))); |
| } |
| } |