| // Copyright 2014 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.skyframe; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.io.BaseEncoding; |
| import com.google.devtools.build.lib.actions.ActionInput; |
| import com.google.devtools.build.lib.actions.ActionInputFileCache; |
| import com.google.devtools.build.lib.actions.Artifact; |
| import com.google.devtools.build.lib.actions.cache.Metadata; |
| import com.google.devtools.build.lib.vfs.Path; |
| import com.google.protobuf.ByteString; |
| import java.nio.charset.StandardCharsets; |
| import java.util.HashMap; |
| import java.util.Map; |
| import javax.annotation.Nullable; |
| |
| /** |
| * Cache provided by an {@link ActionExecutionFunction}, allowing Blaze to obtain artifact metadata |
| * from the graph. |
| * |
| * <p>Data for the action's inputs is injected into this cache on construction, using the graph as |
| * the source of truth. |
| */ |
| class PerActionFileCache implements ActionInputFileCache { |
| private final Map<Artifact, FileArtifactValue> inputArtifactData; |
| private final boolean missingArtifactsAllowed; |
| // null until first call to getInputFromDigest() |
| private volatile HashMap<ByteString, Artifact> reverseMap; |
| |
| /** |
| * @param inputArtifactData Map from artifact to metadata, used to return metadata upon request. |
| * @param missingArtifactsAllowed whether to tolerate missing artifacts: can happen during input |
| * discovery. |
| */ |
| PerActionFileCache( |
| Map<Artifact, FileArtifactValue> inputArtifactData, boolean missingArtifactsAllowed) { |
| this.inputArtifactData = Preconditions.checkNotNull(inputArtifactData); |
| this.missingArtifactsAllowed = missingArtifactsAllowed; |
| } |
| |
| @Nullable |
| @Override |
| public Metadata getMetadata(ActionInput input) { |
| if (!(input instanceof Artifact)) { |
| return null; |
| } |
| Metadata result = inputArtifactData.get(input); |
| Preconditions.checkState(missingArtifactsAllowed || result != null, "null for %s", input); |
| return result; |
| } |
| |
| @Override |
| public Path getInputPath(ActionInput input) { |
| return ((Artifact) input).getPath(); |
| } |
| |
| @Override |
| public boolean contentsAvailableLocally(ByteString digest) { |
| return getInputFromDigest(digest) != null; |
| } |
| |
| @Nullable |
| @Override |
| public Artifact getInputFromDigest(ByteString digest) { |
| HashMap<ByteString, Artifact> r = reverseMap; // volatile load |
| if (r == null) { |
| r = buildReverseMap(); |
| } |
| return r.get(digest); |
| } |
| |
| private synchronized HashMap<ByteString, Artifact> buildReverseMap() { |
| HashMap<ByteString, Artifact> r = reverseMap; // volatile load |
| if (r != null) { |
| return r; |
| } |
| r = new HashMap<>(inputArtifactData.size()); |
| // It would be nice to have a view of the entries which treats them as a map keyed on digest but |
| // does not require constructing another wrapper object for each entry. Java doesn't come with |
| // any collections which can do this, but cloning RegularImmutableSet and adding the necessary |
| // features wouldn't be too bad. |
| for (Map.Entry<Artifact, FileArtifactValue> e : inputArtifactData.entrySet()) { |
| byte[] bytes = e.getValue().getDigest(); |
| if (bytes != null) { |
| ByteString digest = ByteString.copyFrom(BaseEncoding.base16().lowerCase().encode(bytes) |
| .getBytes(StandardCharsets.US_ASCII)); |
| r.put(digest, e.getKey()); |
| } |
| } |
| reverseMap = r; // volatile store |
| return r; |
| } |
| } |