private static boolean shouldFollowSymlinksWhenTraversing(Dirents dirents) {
for (Dirent dirent : dirents) {
// This is a specical sentinel file whose existence tells Blaze not to follow symlinks when
// recursively traversing through this directory.
//
// This admittedly ugly feature is used to support workspaces with directories with weird
// symlink structures that aren't intended to be consumed by Blaze.
if (dirent.getName().equals(SENTINEL_FILE_NAME_FOR_NOT_TRAVERSING_SYMLINKS)) {
return false;
}
}
return true;
}
/**
* List the directory and create {@code SkyKey}s to request contents of its children recursively.
*
* <p>The returned keys are of type {@link SkyFunctions#RECURSIVE_FILESYSTEM_TRAVERSAL}.
*/
private static Collection<SkyKey> createRecursiveTraversalKeys(
Environment env, TraversalRequest traversal) throws MissingDepException {
// Use the traversal's path, even if it's a symlink. The contents of the directory, as listed
// in the result, must be relative to it.
DirectoryListingValue dirListing =
(DirectoryListingValue)
getDependentSkyValue(env, DirectoryListingValue.key(traversal.path));
List<SkyKey> result = new ArrayList<>();
for (Dirent dirent : dirListing.getDirents()) {
RootedPath childPath =
RootedPath.toRootedPath(
traversal.path.getRoot(),
traversal.path.getRelativePath().getRelative(dirent.getName()));
TraversalRequest childTraversal = traversal.forChildEntry(childPath);
result.add(RecursiveFilesystemTraversalValue.key(childTraversal));
}
return result;
}
/**
* Looks in the directory specified by {@code recursivePkgKey} for a package, does some work as
* specified by {@link Visitor} if such a package exists, then recursively does work in each
* non-excluded subdirectory as specified by {@link #getSkyKeyForSubdirectory}, and finally
* aggregates the {@link Visitor} value along with values from each subdirectory as specified by
* {@link #aggregateWithSubdirectorySkyValues}, and returns that aggregation.
*
* <p>Returns null if {@code env.valuesMissing()} is true, checked after each call to one of
* {@link RecursiveDirectoryTraversalFunction}'s abstract methods that were given {@code env}.
* (And after each of {@code visitDirectory}'s own uses of {@code env}, of course.)
*/
TReturn visitDirectory(RecursivePkgKey recursivePkgKey, Environment env) {
RootedPath rootedPath = recursivePkgKey.getRootedPath();
ImmutableSet<PathFragment> excludedPaths = recursivePkgKey.getExcludedPaths();
Path root = rootedPath.getRoot();
PathFragment rootRelativePath = rootedPath.getRelativePath();
SkyKey fileKey = FileValue.key(rootedPath);
FileValue fileValue;
try {
fileValue =
(FileValue)
env.getValueOrThrow(
fileKey,
InconsistentFilesystemException.class,
FileSymlinkException.class,
IOException.class);
} catch (InconsistentFilesystemException | FileSymlinkException | IOException e) {
return reportErrorAndReturn(
"Failed to get information about path", e, rootRelativePath, env.getListener());
}
if (fileValue == null) {
return null;
}
if (!fileValue.isDirectory()) {
return getEmptyReturn();
}
PackageIdentifier packageId =
PackageIdentifier.create(recursivePkgKey.getRepository(), rootRelativePath);
if ((packageId.getRepository().isDefault() || packageId.getRepository().isMain())
&& fileValue.isSymlink()
&& fileValue
.getUnresolvedLinkTarget()
.startsWith(directories.getOutputBase().asFragment())) {
// Symlinks back to the output base are not traversed so that we avoid convenience symlinks.
// Note that it's not enough to just check for the convenience symlinks themselves, because
// if the value of --symlink_prefix changes, the old symlinks are left in place. This
// algorithm also covers more creative use cases where people create convenience symlinks
// somewhere in the directory tree manually.
return getEmptyReturn();
}
SkyKey pkgLookupKey = PackageLookupValue.key(packageId);
SkyKey dirListingKey = DirectoryListingValue.key(rootedPath);
Map<
SkyKey,
ValueOrException4<
NoSuchPackageException,
InconsistentFilesystemException,
FileSymlinkException,
IOException>>
pkgLookupAndDirectoryListingDeps =
env.getValuesOrThrow(
ImmutableList.of(pkgLookupKey, dirListingKey),
NoSuchPackageException.class,
InconsistentFilesystemException.class,
FileSymlinkException.class,
IOException.class);
if (env.valuesMissing()) {
return null;
}
PackageLookupValue pkgLookupValue;
try {
pkgLookupValue =
(PackageLookupValue)
Preconditions.checkNotNull(
pkgLookupAndDirectoryListingDeps.get(pkgLookupKey).get(),
"%s %s",
recursivePkgKey,
pkgLookupKey);
} catch (NoSuchPackageException | InconsistentFilesystemException e) {
return reportErrorAndReturn("Failed to load package", e, rootRelativePath, env.getListener());
} catch (IOException | FileSymlinkException e) {
throw new IllegalStateException(e);
}
TVisitor visitor = getInitialVisitor();
DirectoryListingValue dirListingValue;
try {
dirListingValue =
(DirectoryListingValue)
Preconditions.checkNotNull(
pkgLookupAndDirectoryListingDeps.get(dirListingKey).get(),
"%s %s",
recursivePkgKey,
dirListingKey);
} catch (InconsistentFilesystemException | IOException e) {
return reportErrorAndReturn(
"Failed to list directory contents", e, rootRelativePath, env.getListener());
} catch (FileSymlinkException e) {
// DirectoryListingFunction only throws FileSymlinkCycleException when FileFunction throws it,
// but FileFunction was evaluated for rootedPath above, and didn't throw there. It shouldn't
// be able to avoid throwing there but throw here.
throw new IllegalStateException(
"Symlink cycle found after not being found for \"" + rootedPath + "\"");
} catch (NoSuchPackageException e) {
throw new IllegalStateException(e);
}
boolean followSymlinks = shouldFollowSymlinksWhenTraversing(dirListingValue.getDirents());
List<SkyKey> childDeps = new ArrayList<>();
for (Dirent dirent : dirListingValue.getDirents()) {
Type type = dirent.getType();
if (type != Type.DIRECTORY
&& (type != Type.SYMLINK || (type == Type.SYMLINK && !followSymlinks))) {
// Non-directories can never host packages. Symlinks to non-directories are weeded out at
// the next level of recursion when we check if its FileValue is a directory. This is slower
// if there are a lot of symlinks in the tree, but faster if there are only a few, which is
// the case most of the time.
//
// We are not afraid of weird symlink structure here: both cyclical ones and ones that give
// rise to infinite directory trees are diagnosed by FileValue.
continue;
}
String basename = dirent.getName();
if (rootRelativePath.equals(PathFragment.EMPTY_FRAGMENT)
&& PathPackageLocator.DEFAULT_TOP_LEVEL_EXCLUDES.contains(basename)) {
continue;
}
PathFragment subdirectory = rootRelativePath.getRelative(basename);
// If this subdirectory is one of the excluded paths, don't recurse into it.
if (excludedPaths.contains(subdirectory)) {
continue;
}
// If we have an excluded path that isn't below this subdirectory, we shouldn't pass that
// excluded path to our evaluation of the subdirectory, because the exclusion can't
// possibly match anything beneath the subdirectory.
//
// For example, if we're currently evaluating directory "a", are looking at its subdirectory
// "a/b", and we have an excluded path "a/c/d", there's no need to pass the excluded path
// "a/c/d" to our evaluation of "a/b".
//
// This strategy should help to get more skyframe sharing. Consider the example above. A
// subsequent request of "a/b/...", without any excluded paths, will be a cache hit.
//
// TODO(bazel-team): Replace the excludedPaths set with a trie or a SortedSet for better
// efficiency.
ImmutableSet<PathFragment> excludedSubdirectoriesBeneathThisSubdirectory =
PathFragment.filterPathsStartingWith(excludedPaths, subdirectory);
RootedPath subdirectoryRootedPath = RootedPath.toRootedPath(root, subdirectory);
childDeps.add(
getSkyKeyForSubdirectory(
recursivePkgKey.getRepository(),
subdirectoryRootedPath,
excludedSubdirectoriesBeneathThisSubdirectory));
}
Map<SkyKey, SkyValue> subdirectorySkyValues;
if (pkgLookupValue.packageExists() && pkgLookupValue.getRoot().equals(root)) {
SkyKey packageKey = PackageValue.key(packageId);
Map<SkyKey, ValueOrException<NoSuchPackageException>> dependentSkyValues =
env.getValuesOrThrow(
Iterables.concat(childDeps, ImmutableList.of(packageKey)),
NoSuchPackageException.class);
if (env.valuesMissing()) {
return null;
}
Package pkg = null;
try {
PackageValue pkgValue = (PackageValue) dependentSkyValues.get(packageKey).get();
if (pkgValue == null) {
return null;
}
pkg = pkgValue.getPackage();
if (pkg.containsErrors()) {
env.getListener()
.handle(Event.error("package contains errors: " + rootRelativePath.getPathString()));
}
} catch (NoSuchPackageException e) {
// The package had errors, but don't fail-fast as there might be subpackages below the
// current directory.
env.getListener()
.handle(Event.error("package contains errors: " + rootRelativePath.getPathString()));
}
if (pkg != null) {
visitor.visitPackageValue(pkg, env);
if (env.valuesMissing()) {
return null;
}
}
ImmutableMap.Builder<SkyKey, SkyValue> subdirectoryBuilder = ImmutableMap.builder();
for (Map.Entry<SkyKey, ValueOrException<NoSuchPackageException>> entry :
Maps.filterKeys(dependentSkyValues, Predicates.not(Predicates.equalTo(packageKey)))
.entrySet()) {
try {
subdirectoryBuilder.put(entry.getKey(), entry.getValue().get());
} catch (NoSuchPackageException e) {
// ignored.
}
}
subdirectorySkyValues = subdirectoryBuilder.build();
} else {
subdirectorySkyValues = env.getValues(childDeps);
}
if (env.valuesMissing()) {
return null;
}
return aggregateWithSubdirectorySkyValues(visitor, subdirectorySkyValues);
}