| // 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.annotations.VisibleForTesting; |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.common.collect.Maps; |
| import com.google.common.collect.Sets; |
| import com.google.common.io.BaseEncoding; |
| import com.google.devtools.build.lib.actions.ActionInput; |
| import com.google.devtools.build.lib.actions.ActionInputHelper; |
| import com.google.devtools.build.lib.actions.ActionInputMap; |
| import com.google.devtools.build.lib.actions.Artifact; |
| import com.google.devtools.build.lib.actions.Artifact.SpecialArtifact; |
| import com.google.devtools.build.lib.actions.Artifact.TreeFileArtifact; |
| import com.google.devtools.build.lib.actions.FileArtifactValue; |
| import com.google.devtools.build.lib.actions.FileStateValue; |
| import com.google.devtools.build.lib.actions.FileValue; |
| import com.google.devtools.build.lib.actions.cache.Md5Digest; |
| import com.google.devtools.build.lib.actions.cache.MetadataHandler; |
| import com.google.devtools.build.lib.util.io.TimestampGranularityMonitor; |
| import com.google.devtools.build.lib.vfs.FileStatus; |
| import com.google.devtools.build.lib.vfs.FileStatusWithDigest; |
| import com.google.devtools.build.lib.vfs.FileStatusWithDigestAdapter; |
| import com.google.devtools.build.lib.vfs.Path; |
| import com.google.devtools.build.lib.vfs.PathFragment; |
| import com.google.devtools.build.lib.vfs.RootedPath; |
| import com.google.devtools.build.lib.vfs.Symlinks; |
| import java.io.FileNotFoundException; |
| import java.io.IOException; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| import javax.annotation.Nullable; |
| |
| /** |
| * Cache provided by an {@link ActionExecutionFunction}, allowing Blaze to obtain data from the |
| * graph and to inject data (e.g. file digests) back into the graph. The cache can be in one of two |
| * modes. After construction it acts as a cache for input and output metadata for the purpose of |
| * checking for an action cache hit. When {@link #discardOutputMetadata} is called, it switches to |
| * a mode where it calls chmod on output files before statting them. This is done here to ensure |
| * that the chmod always comes before the stat in order to ensure that the stat is up to date. |
| * |
| * <p>Data for the action's inputs is injected into this cache on construction, using the Skyframe |
| * graph as the source of truth. |
| * |
| * <p>As well, this cache collects data about the action's output files, which is used in three |
| * ways. First, it is served as requested during action execution, primarily by the {@code |
| * ActionCacheChecker} when determining if the action must be rerun, and then after the action is |
| * run, to gather information about the outputs. Second, it is accessed by {@link ArtifactFunction}s |
| * in order to construct {@link FileArtifactValue}s, and by this class itself to generate {@link |
| * TreeArtifactValue}s. Third, the {@link FilesystemValueChecker} uses it to determine the set of |
| * output files to check for inter-build modifications. Because all these use cases are slightly |
| * different, we must occasionally store two versions of the data for a value. See {@link |
| * #getAdditionalOutputData} for elaboration on the difference between these cases, and see the |
| * javadoc for the various internal maps to see what is stored where. |
| */ |
| @VisibleForTesting |
| public class ActionMetadataHandler implements MetadataHandler { |
| |
| /** |
| * Data for input artifacts. Immutable. |
| * |
| * <p>This should never be read directly. Use {@link #getInputFileArtifactValue} instead. |
| */ |
| private final ActionInputMap inputArtifactData; |
| |
| /** FileValues for each output Artifact. */ |
| private final ConcurrentMap<Artifact, FileValue> outputArtifactData = |
| new ConcurrentHashMap<>(); |
| |
| /** |
| * Maps output TreeArtifacts to their contents. These maps are either injected or read |
| * directly from the filesystem. |
| * If the value is null, this means nothing was injected, and the output TreeArtifact |
| * is to have its values read from disk instead. |
| */ |
| private final ConcurrentMap<Artifact, Set<TreeFileArtifact>> outputDirectoryListings = |
| new ConcurrentHashMap<>(); |
| |
| /** Outputs that are to be omitted. */ |
| private final Set<Artifact> omittedOutputs = Sets.newConcurrentHashSet(); |
| |
| /** |
| * Contains RealArtifactValues when those values must be stored separately. |
| * See {@link #getAdditionalOutputData()} for details. |
| */ |
| private final ConcurrentMap<Artifact, FileArtifactValue> additionalOutputData = |
| new ConcurrentHashMap<>(); |
| |
| /** |
| * Data for TreeArtifactValues, constructed from outputArtifactData and |
| * additionalOutputFileData. |
| */ |
| private final ConcurrentMap<Artifact, TreeArtifactValue> outputTreeArtifactData = |
| new ConcurrentHashMap<>(); |
| |
| /** Tracks which Artifacts have had metadata injected. */ |
| private final Set<Artifact> injectedFiles = Sets.newConcurrentHashSet(); |
| |
| private final ImmutableSet<Artifact> outputs; |
| |
| /** |
| * The timestamp granularity monitor for this build. |
| * Use {@link #getTimestampGranularityMonitor(Artifact)} to fetch this member. |
| */ |
| private final TimestampGranularityMonitor tsgm; |
| private final ArtifactPathResolver artifactPathResolver; |
| |
| /** |
| * Whether the action is being executed or not; this flag is set to true in |
| * {@link #discardOutputMetadata}. |
| */ |
| private final AtomicBoolean executionMode = new AtomicBoolean(false); |
| |
| @VisibleForTesting |
| public ActionMetadataHandler( |
| ActionInputMap inputArtifactData, |
| Iterable<Artifact> outputs, |
| TimestampGranularityMonitor tsgm, |
| ArtifactPathResolver artifactPathResolver) { |
| this.inputArtifactData = Preconditions.checkNotNull(inputArtifactData); |
| this.outputs = ImmutableSet.copyOf(outputs); |
| this.tsgm = tsgm; |
| this.artifactPathResolver = artifactPathResolver; |
| } |
| |
| /** |
| * Gets the {@link TimestampGranularityMonitor} to use for a given artifact. |
| * |
| * <p>If the artifact is of type "constant metadata", this returns null so that changes to such |
| * artifacts do not tickle the timestamp granularity monitor, delaying the build for no reason. |
| * |
| * @param artifact the artifact for which to fetch the timestamp granularity monitor |
| * @return the timestamp granularity monitor to use, which may be null |
| */ |
| private TimestampGranularityMonitor getTimestampGranularityMonitor(Artifact artifact) { |
| return artifact.isConstantMetadata() ? null : tsgm; |
| } |
| |
| private static FileArtifactValue metadataFromValue(FileArtifactValue value) |
| throws FileNotFoundException { |
| if (value == FileArtifactValue.MISSING_FILE_MARKER |
| || value == FileArtifactValue.OMITTED_FILE_MARKER) { |
| throw new FileNotFoundException(); |
| } |
| return value; |
| } |
| |
| @Nullable |
| private FileArtifactValue getInputFileArtifactValue(Artifact input) { |
| if (outputs.contains(input)) { |
| return null; |
| } |
| |
| if (input.hasParent() && outputs.contains(input.getParent())) { |
| return null; |
| } |
| |
| return inputArtifactData.getMetadata(input); |
| } |
| |
| @Override |
| public FileArtifactValue getMetadata(Artifact artifact) throws IOException { |
| FileArtifactValue value = getInputFileArtifactValue(artifact); |
| if (value != null) { |
| return metadataFromValue(value); |
| } |
| if (artifact.isSourceArtifact()) { |
| // A discovered input we didn't have data for. |
| // TODO(bazel-team): Change this to an assertion once Skyframe has native input discovery, so |
| // all inputs will already have metadata known. |
| return null; |
| } else if (artifact.isMiddlemanArtifact()) { |
| // A middleman artifact's data was either already injected from the action cache checker using |
| // #setDigestForVirtualArtifact, or it has the default middleman value. |
| value = additionalOutputData.get(artifact); |
| if (value != null) { |
| return metadataFromValue(value); |
| } |
| value = FileArtifactValue.DEFAULT_MIDDLEMAN; |
| FileArtifactValue oldValue = additionalOutputData.putIfAbsent(artifact, value); |
| checkInconsistentData(artifact, oldValue, value); |
| return metadataFromValue(value); |
| } else if (artifact.isTreeArtifact()) { |
| TreeArtifactValue setValue = getTreeArtifactValue((SpecialArtifact) artifact); |
| if (setValue != null && setValue != TreeArtifactValue.MISSING_TREE_ARTIFACT) { |
| return setValue.getMetadata(); |
| } |
| // We use FileNotFoundExceptions to determine if an Artifact was or wasn't found. |
| // Calling code depends on this particular exception. |
| throw new FileNotFoundException(artifact + " not found"); |
| } |
| // It's an ordinary artifact. |
| FileValue fileValue = outputArtifactData.get(artifact); |
| if (fileValue != null) { |
| // Non-middleman artifacts should only have additionalOutputData if they have |
| // outputArtifactData. We don't assert this because of concurrency possibilities, but at least |
| // we don't check additionalOutputData unless we expect that we might see the artifact there. |
| value = additionalOutputData.get(artifact); |
| // If additional output data is present for this artifact, we use it in preference to the |
| // usual calculation. |
| if (value != null) { |
| return metadataFromValue(value); |
| } |
| if (!fileValue.exists()) { |
| throw new FileNotFoundException(artifact.prettyPrint() + " does not exist"); |
| } |
| return FileArtifactValue.createNormalFile(fileValue); |
| } |
| // We do not cache exceptions besides nonexistence here, because it is unlikely that the file |
| // will be requested from this cache too many times. |
| fileValue = constructFileValue(artifact, /*statNoFollow=*/ null); |
| return maybeStoreAdditionalData(artifact, fileValue, null); |
| } |
| |
| /** |
| * Check that the new {@code data} we just calculated for an {@link Artifact} agrees with the |
| * {@code oldData} (presumably calculated concurrently), if it was present. |
| */ |
| // Not private only because used by SkyframeActionExecutor's metadata handler. |
| static void checkInconsistentData(Artifact artifact, |
| @Nullable Object oldData, Object data) throws IOException { |
| if (oldData != null && !oldData.equals(data)) { |
| // Another thread checked this file since we looked at the map, and got a different answer |
| // than we did. Presumably the user modified the file between reads. |
| throw new IOException("Data for " + artifact.prettyPrint() + " changed to " + data |
| + " after it was calculated as " + oldData); |
| } |
| } |
| |
| /** |
| * See {@link #getAdditionalOutputData} for why we sometimes need to store additional data, even |
| * for normal (non-middleman) artifacts. |
| */ |
| @Nullable |
| private FileArtifactValue maybeStoreAdditionalData( |
| Artifact artifact, FileValue data, @Nullable byte[] injectedDigest) throws IOException { |
| if (!data.exists()) { |
| // Nonexistent files should only occur before executing an action. |
| throw new FileNotFoundException(artifact.prettyPrint() + " does not exist"); |
| } |
| boolean isFile = data.isFile(); |
| if (isFile && !artifact.hasParent() && data.getDigest() != null) { |
| // We do not need to store the FileArtifactValue separately -- the digest is in the file value |
| // and that is all that is needed for this file's metadata. |
| return FileArtifactValue.createNormalFile(data); |
| } |
| // Unfortunately, the FileValue does not contain enough information for us to calculate the |
| // corresponding FileArtifactValue -- either the metadata must use the modified time, which we |
| // do not expose in the FileValue, or the FileValue didn't store the digest So we store the |
| // metadata separately. |
| // Use the FileValue's digest if no digest was injected, or if the file can't be digested. |
| injectedDigest = injectedDigest != null || !isFile ? injectedDigest : data.getDigest(); |
| FileArtifactValue value = FileArtifactValue.create(artifact, data, injectedDigest); |
| FileArtifactValue oldValue = additionalOutputData.putIfAbsent(artifact, value); |
| checkInconsistentData(artifact, oldValue, value); |
| return metadataFromValue(value); |
| } |
| |
| @Override |
| public void setDigestForVirtualArtifact(Artifact artifact, Md5Digest md5Digest) { |
| Preconditions.checkArgument(artifact.isMiddlemanArtifact(), artifact); |
| Preconditions.checkNotNull(md5Digest, artifact); |
| additionalOutputData.put( |
| artifact, FileArtifactValue.createProxy(md5Digest.getDigestBytesUnsafe())); |
| } |
| |
| private Set<TreeFileArtifact> getTreeArtifactContents(Artifact artifact) { |
| Preconditions.checkArgument(artifact.isTreeArtifact(), artifact); |
| Set<TreeFileArtifact> contents = outputDirectoryListings.get(artifact); |
| if (contents == null) { |
| // Unfortunately, there is no such thing as a ConcurrentHashSet. |
| contents = Collections.newSetFromMap(new ConcurrentHashMap<TreeFileArtifact, Boolean>()); |
| Set<TreeFileArtifact> oldContents = outputDirectoryListings.putIfAbsent(artifact, contents); |
| // Avoid a race condition. |
| if (oldContents != null) { |
| contents = oldContents; |
| } |
| } |
| return contents; |
| } |
| |
| private TreeArtifactValue getTreeArtifactValue(SpecialArtifact artifact) throws IOException { |
| TreeArtifactValue value = outputTreeArtifactData.get(artifact); |
| if (value != null) { |
| return value; |
| } |
| |
| if (executionMode.get()) { |
| // Preserve existing behavior: we don't set non-TreeArtifact directories |
| // read only and executable. However, it's unusual for non-TreeArtifact outputs |
| // to be directories. |
| setTreeReadOnlyAndExecutable(artifact, PathFragment.EMPTY_FRAGMENT); |
| } |
| |
| Set<TreeFileArtifact> registeredContents = outputDirectoryListings.get(artifact); |
| if (registeredContents != null) { |
| // Check that our registered outputs matches on-disk outputs. Only perform this check |
| // when contents were explicitly registered. |
| // TODO(bazel-team): Provide a way for actions to register empty TreeArtifacts. |
| |
| // By the time we're constructing TreeArtifactValues, use of the metadata handler |
| // should be single threaded and there should be no race condition. |
| // The current design of ActionMetadataHandler makes this hard to enforce. |
| Set<PathFragment> paths = null; |
| paths = TreeArtifactValue.explodeDirectory(artifact); |
| Set<TreeFileArtifact> diskFiles = ActionInputHelper.asTreeFileArtifacts(artifact, paths); |
| if (!diskFiles.equals(registeredContents)) { |
| // There might be more than one error here. We first look for missing output files. |
| Set<TreeFileArtifact> missingFiles = Sets.difference(registeredContents, diskFiles); |
| if (!missingFiles.isEmpty()) { |
| // Don't throw IOException--getMetadataMaybe() eats them. |
| // TODO(bazel-team): Report this error in a better way when called by checkOutputs() |
| // Currently it's hard to report this error without refactoring, since checkOutputs() |
| // likes to substitute its own error messages upon catching IOException, and falls |
| // through to unrecoverable error behavior on any other exception. |
| throw new IOException("Output file " + missingFiles.iterator().next() |
| + " was registered, but not present on disk"); |
| } |
| |
| Set<TreeFileArtifact> extraFiles = Sets.difference(diskFiles, registeredContents); |
| // extraFiles cannot be empty |
| throw new IOException( |
| "File " + extraFiles.iterator().next().getParentRelativePath() |
| + ", present in TreeArtifact " + artifact + ", was not registered"); |
| } |
| |
| value = constructTreeArtifactValue(registeredContents); |
| } else { |
| value = constructTreeArtifactValueFromFilesystem(artifact); |
| } |
| |
| TreeArtifactValue oldValue = outputTreeArtifactData.putIfAbsent(artifact, value); |
| checkInconsistentData(artifact, oldValue, value); |
| return value; |
| } |
| |
| private TreeArtifactValue constructTreeArtifactValue(Collection<TreeFileArtifact> contents) |
| throws IOException { |
| Map<TreeFileArtifact, FileArtifactValue> values = |
| Maps.newHashMapWithExpectedSize(contents.size()); |
| |
| for (TreeFileArtifact treeFileArtifact : contents) { |
| FileArtifactValue cachedValue = additionalOutputData.get(treeFileArtifact); |
| if (cachedValue == null) { |
| FileValue fileValue = outputArtifactData.get(treeFileArtifact); |
| // This is similar to what's present in getRealMetadataForArtifact, except |
| // we get back the FileValue, not the metadata. |
| // We do not cache exceptions besides nonexistence here, because it is unlikely that the |
| // file will be requested from this cache too many times. |
| if (fileValue == null) { |
| try { |
| fileValue = constructFileValue(treeFileArtifact, /*statNoFollow=*/ null); |
| } catch (FileNotFoundException e) { |
| String errorMessage = String.format( |
| "Failed to resolve relative path %s inside TreeArtifact %s. " |
| + "The associated file is either missing or is an invalid symlink.", |
| treeFileArtifact.getParentRelativePath(), |
| treeFileArtifact.getParent().getExecPathString()); |
| throw new IOException(errorMessage, e); |
| } |
| } |
| |
| // A minor hack: maybeStoreAdditionalData will force the data to be stored |
| // in additionalOutputData. |
| maybeStoreAdditionalData(treeFileArtifact, fileValue, null); |
| cachedValue = Preconditions.checkNotNull( |
| additionalOutputData.get(treeFileArtifact), treeFileArtifact); |
| } |
| |
| values.put(treeFileArtifact, cachedValue); |
| } |
| |
| return TreeArtifactValue.create(values); |
| } |
| |
| private TreeArtifactValue constructTreeArtifactValueFromFilesystem(SpecialArtifact artifact) |
| throws IOException { |
| Preconditions.checkState(artifact.isTreeArtifact(), artifact); |
| |
| if (!artifactPathResolver.toPath(artifact).isDirectory() |
| || artifactPathResolver.toPath(artifact).isSymbolicLink()) { |
| return TreeArtifactValue.MISSING_TREE_ARTIFACT; |
| } |
| |
| Set<PathFragment> paths = null; |
| paths = TreeArtifactValue.explodeDirectory(artifact); |
| // If you're reading tree artifacts from disk while outputDirectoryListings are being injected, |
| // something has gone terribly wrong. |
| Object previousDirectoryListing = |
| outputDirectoryListings.put(artifact, |
| Collections.newSetFromMap(new ConcurrentHashMap<TreeFileArtifact, Boolean>())); |
| Preconditions.checkState(previousDirectoryListing == null, |
| "Race condition while constructing TreArtifactValue: %s, %s", |
| artifact, previousDirectoryListing); |
| return constructTreeArtifactValue(ActionInputHelper.asTreeFileArtifacts(artifact, paths)); |
| } |
| |
| @Override |
| public void addExpandedTreeOutput(TreeFileArtifact output) { |
| Preconditions.checkState(executionMode.get()); |
| Set<TreeFileArtifact> values = getTreeArtifactContents(output.getParent()); |
| values.add(output); |
| } |
| |
| @Override |
| public Iterable<TreeFileArtifact> getExpandedOutputs(Artifact artifact) { |
| return ImmutableSet.copyOf(getTreeArtifactContents(artifact)); |
| } |
| |
| @Override |
| public void injectDigest(ActionInput output, FileStatus statNoFollow, byte[] digest) { |
| Preconditions.checkState(executionMode.get()); |
| // Assumption: any non-Artifact output is 'virtual' and should be ignored here. |
| if (output instanceof Artifact) { |
| final Artifact artifact = (Artifact) output; |
| // We have to add the artifact to injectedFiles before calling constructFileValue to avoid |
| // duplicate chmod calls. |
| Preconditions.checkState(injectedFiles.add(artifact), artifact); |
| FileValue fileValue; |
| try { |
| // This call may do an unnecessary call to Path#getFastDigest to see if the digest is |
| // readily available. We cannot pass the digest in, though, because if it is not available |
| // from the filesystem, this FileValue will not compare equal to another one created for the |
| // same file, because the other one will be missing its digest. |
| fileValue = constructFileValue(artifact, FileStatusWithDigestAdapter.adapt(statNoFollow)); |
| // Ensure the digest supplied matches the actual digest if it exists. |
| byte[] fileDigest = fileValue.getDigest(); |
| if (fileDigest != null && !Arrays.equals(digest, fileDigest)) { |
| BaseEncoding base16 = BaseEncoding.base16(); |
| String digestString = (digest != null) ? base16.encode(digest) : "null"; |
| String fileDigestString = base16.encode(fileDigest); |
| throw new IllegalStateException("Expected digest " + digestString + " for artifact " |
| + artifact + ", but got " + fileDigestString + " (" + fileValue + ")"); |
| } |
| } catch (IOException e) { |
| // Do nothing - we just failed to inject metadata. Real error handling will be done later, |
| // when somebody will try to access that file. |
| return; |
| } |
| // If needed, insert additional data. Note that this can only be true if the file is empty or |
| // the filesystem does not support fast digests. Since we usually only inject digests when |
| // running with a filesystem that supports fast digests, this is fairly unlikely. |
| try { |
| maybeStoreAdditionalData(artifact, fileValue, digest); |
| } catch (IOException e) { |
| if (fileValue.getSize() != 0) { |
| // Empty files currently have their mtimes examined, and so could throw. No other files |
| // should throw, since all filesystem access has already been done. |
| throw new IllegalStateException( |
| "Filesystem should not have been accessed while injecting data for " |
| + artifact.prettyPrint(), e); |
| } |
| // Ignore exceptions for empty files, as above. |
| } |
| } |
| } |
| |
| @Override |
| public void injectRemoteFile(Artifact output, byte[] digest, long size, int locationIndex) { |
| Preconditions.checkState( |
| executionMode.get(), "Tried to inject %s outside of execution.", output); |
| Preconditions.checkArgument( |
| locationIndex != 0 || size == 0, |
| "output = %s, size = %s, locationIndex =%s", |
| output, |
| size, |
| locationIndex); |
| |
| // TODO(shahan): there are a couple of things that could reduce memory usage |
| // 1. We might be able to skip creating an entry in `outputArtifactData` and only create |
| // the `FileArtifactValue`, but there are likely downstream consumers that expect it that |
| // would need to be cleaned up. |
| // 2. Instead of creating an `additionalOutputData` entry, we could add the extra |
| // `locationIndex` to `FileStateValue`. |
| try { |
| injectOutputData( |
| output, new FileArtifactValue.RemoteFileArtifactValue(digest, size, locationIndex)); |
| } catch (IOException e) { |
| throw new IllegalStateException(e); // Should never happen. |
| } |
| } |
| |
| public void injectOutputData(Artifact output, FileArtifactValue artifactValue) |
| throws IOException { |
| Preconditions.checkState(injectedFiles.add(output), output); |
| // While `artifactValue` carries the important information, the control flow of `getMetadata` |
| // requires an entry in `outputArtifactData` to access `additionalOutputData`, so a |
| // `PLACEHOLDER` is added to `outputArtifactData`. |
| FileValue oldFileValue = outputArtifactData.putIfAbsent(output, FileValue.PLACEHOLDER); |
| checkInconsistentData(output, oldFileValue, FileValue.PLACEHOLDER); |
| FileArtifactValue oldArtifactValue = additionalOutputData.putIfAbsent(output, artifactValue); |
| checkInconsistentData(output, oldArtifactValue, artifactValue); |
| } |
| |
| @Override |
| public void markOmitted(ActionInput output) { |
| Preconditions.checkState(executionMode.get()); |
| if (output instanceof Artifact) { |
| Artifact artifact = (Artifact) output; |
| Preconditions.checkState(omittedOutputs.add(artifact), artifact); |
| additionalOutputData.put(artifact, FileArtifactValue.OMITTED_FILE_MARKER); |
| } |
| } |
| |
| @Override |
| public boolean artifactOmitted(Artifact artifact) { |
| // TODO(ulfjack): this is currently unreliable, see the documentation on MetadataHandler. |
| return omittedOutputs.contains(artifact); |
| } |
| |
| @Override |
| public void discardOutputMetadata() { |
| boolean wasExecutionMode = executionMode.getAndSet(true); |
| Preconditions.checkState(!wasExecutionMode); |
| Preconditions.checkState(injectedFiles.isEmpty(), |
| "Files cannot be injected before action execution: %s", injectedFiles); |
| Preconditions.checkState(omittedOutputs.isEmpty(), |
| "Artifacts cannot be marked omitted before action execution: %s", omittedOutputs); |
| outputArtifactData.clear(); |
| outputDirectoryListings.clear(); |
| outputTreeArtifactData.clear(); |
| additionalOutputData.clear(); |
| } |
| |
| /** @return data for output files that was computed during execution. */ |
| Map<Artifact, FileValue> getOutputArtifactData() { |
| return outputArtifactData; |
| } |
| |
| /** |
| * @return data for TreeArtifacts that was computed during execution. May contain copies of |
| * {@link TreeArtifactValue#MISSING_TREE_ARTIFACT}. |
| */ |
| Map<Artifact, TreeArtifactValue> getOutputTreeArtifactData() { |
| return outputTreeArtifactData; |
| } |
| |
| /** |
| * Returns data for any output files whose metadata was not computable from the corresponding |
| * entry in {@link #getOutputArtifactData}. |
| * |
| * <p>There are three reasons why we might not be able to compute metadata for an artifact from |
| * the FileValue. First, middleman artifacts have no corresponding FileValues. Second, if |
| * computing a file's digest is not fast, the FileValue does not do so, so a file on a filesystem |
| * without fast digests has to have its metadata stored separately. Third, some files' metadata |
| * (directories, empty files) contain their mtimes, which the FileValue does not expose, so that |
| * has to be stored separately. |
| * |
| * <p>Note that for files that need digests, we can't easily inject the digest in the FileValue |
| * because it would complicate equality-checking on subsequent builds -- if our filesystem doesn't |
| * do fast digests, the comparison value would not have a digest. |
| */ |
| Map<Artifact, FileArtifactValue> getAdditionalOutputData() { |
| return additionalOutputData; |
| } |
| |
| /** |
| * Constructs a new FileValue, saves it, and checks inconsistent data. This calls chmod on the |
| * file if we're in executionMode. |
| */ |
| private FileValue constructFileValue( |
| Artifact artifact, @Nullable FileStatusWithDigest statNoFollow) |
| throws IOException { |
| // We first chmod the output files before we construct the FileContentsProxy. The proxy may use |
| // ctime, which is affected by chmod. |
| if (executionMode.get()) { |
| Preconditions.checkState(!artifact.isTreeArtifact()); |
| setPathReadOnlyAndExecutable(artifact); |
| } |
| |
| FileValue value = fileValueFromArtifact(artifact, artifactPathResolver, statNoFollow, |
| getTimestampGranularityMonitor(artifact)); |
| FileValue oldFsValue = outputArtifactData.putIfAbsent(artifact, value); |
| checkInconsistentData(artifact, oldFsValue, value); |
| return value; |
| } |
| |
| @VisibleForTesting |
| static FileValue fileValueFromArtifact(Artifact artifact, |
| @Nullable FileStatusWithDigest statNoFollow, @Nullable TimestampGranularityMonitor tsgm) |
| throws IOException { |
| return fileValueFromArtifact(artifact, ArtifactPathResolver.IDENTITY, statNoFollow, tsgm); |
| } |
| |
| private static FileValue fileValueFromArtifact(Artifact artifact, |
| ArtifactPathResolver artifactPathResolver, |
| @Nullable FileStatusWithDigest statNoFollow, @Nullable TimestampGranularityMonitor tsgm) |
| throws IOException { |
| Path path = artifactPathResolver.toPath(artifact); |
| RootedPath rootedPath = |
| RootedPath.toRootedPath( |
| artifactPathResolver.transformRoot(artifact.getRoot().getRoot()), |
| artifact.getRootRelativePath()); |
| if (statNoFollow == null) { |
| statNoFollow = FileStatusWithDigestAdapter.adapt(path.statIfFound(Symlinks.NOFOLLOW)); |
| if (statNoFollow == null) { |
| return FileValue.value(rootedPath, FileStateValue.NONEXISTENT_FILE_STATE_NODE, |
| rootedPath, FileStateValue.NONEXISTENT_FILE_STATE_NODE); |
| } |
| } |
| Path realPath = path; |
| // We use FileStatus#isSymbolicLink over Path#isSymbolicLink to avoid the unnecessary stat |
| // done by the latter. |
| if (statNoFollow.isSymbolicLink()) { |
| realPath = path.resolveSymbolicLinks(); |
| // We need to protect against symlink cycles since FileValue#value assumes it's dealing with a |
| // file that's not in a symlink cycle. |
| if (realPath.equals(path)) { |
| throw new IOException("symlink cycle"); |
| } |
| } |
| RootedPath realRootedPath = |
| RootedPath.toRootedPathMaybeUnderRoot( |
| realPath, |
| ImmutableList.of(artifactPathResolver.transformRoot(artifact.getRoot().getRoot()))); |
| FileStateValue fileStateValue = |
| FileStateValue.createWithStatNoFollow(rootedPath, statNoFollow, tsgm); |
| // TODO(bazel-team): consider avoiding a 'stat' here when the symlink target hasn't changed |
| // and is a source file (since changes to those are checked separately). |
| FileStateValue realFileStateValue = realPath.equals(path) |
| ? fileStateValue |
| : FileStateValue.create(realRootedPath, tsgm); |
| return FileValue.value(rootedPath, fileStateValue, realRootedPath, realFileStateValue); |
| } |
| |
| private void setPathReadOnlyAndExecutable(Artifact artifact) throws IOException { |
| // If the metadata was injected, we assume the mode is set correct and bail out early to avoid |
| // the additional overhead of resetting it. |
| if (injectedFiles.contains(artifact)) { |
| return; |
| } |
| Path path = artifactPathResolver.toPath(artifact); |
| if (path.isFile(Symlinks.NOFOLLOW)) { // i.e. regular files only. |
| // We trust the files created by the execution engine to be non symlinks with expected |
| // chmod() settings already applied. |
| path.chmod(0555); // Sets the file read-only and executable. |
| } |
| } |
| |
| private void setTreeReadOnlyAndExecutable(SpecialArtifact parent, PathFragment subpath) |
| throws IOException { |
| Path path = artifactPathResolver.toPath(parent).getRelative(subpath); |
| if (path.isDirectory()) { |
| path.chmod(0555); |
| for (Path child : path.getDirectoryEntries()) { |
| setTreeReadOnlyAndExecutable(parent, subpath.getChild(child.getBaseName())); |
| } |
| } else { |
| setPathReadOnlyAndExecutable(ActionInputHelper.treeFileArtifact(parent, subpath)); |
| } |
| } |
| } |
