| // 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.packages; | 
 |  | 
 | import com.google.common.annotations.VisibleForTesting; | 
 | import com.google.common.base.Preconditions; | 
 | import com.google.common.base.Predicate; | 
 | import com.google.common.base.Throwables; | 
 | import com.google.common.collect.ImmutableSet; | 
 | import com.google.common.collect.Lists; | 
 | import com.google.common.util.concurrent.SettableFuture; | 
 | import com.google.devtools.build.lib.cmdline.PackageIdentifier; | 
 | import com.google.devtools.build.lib.concurrent.ThreadSafety; | 
 | import com.google.devtools.build.lib.packages.Globber.BadGlobException; | 
 | import com.google.devtools.build.lib.util.Pair; | 
 | import com.google.devtools.build.lib.vfs.Path; | 
 | import com.google.devtools.build.lib.vfs.PathFragment; | 
 | import com.google.devtools.build.lib.vfs.UnixGlob; | 
 | import java.io.IOException; | 
 | import java.util.ArrayList; | 
 | import java.util.Collection; | 
 | import java.util.HashMap; | 
 | import java.util.HashSet; | 
 | import java.util.List; | 
 | import java.util.Map; | 
 | import java.util.Set; | 
 | import java.util.concurrent.CancellationException; | 
 | import java.util.concurrent.ExecutionException; | 
 | import java.util.concurrent.Executor; | 
 | import java.util.concurrent.Future; | 
 | import java.util.concurrent.atomic.AtomicBoolean; | 
 | import java.util.concurrent.atomic.AtomicReference; | 
 |  | 
 | /** | 
 |  * Caches the results of glob expansion for a package. | 
 |  */ | 
 | @ThreadSafety.ThreadCompatible | 
 | public class GlobCache { | 
 |   /** | 
 |    * A mapping from glob expressions (e.g. "*.java") to the list of files it | 
 |    * matched (in the order returned by VFS) at the time the package was | 
 |    * constructed.  Required for sound dependency analysis. | 
 |    * | 
 |    * We don't use a Multimap because it provides no way to distinguish "key not | 
 |    * present" from (key -> {}). | 
 |    */ | 
 |   private final Map<Pair<String, Boolean>, Future<List<Path>>> globCache = new HashMap<>(); | 
 |  | 
 |   /** | 
 |    * The directory in which our package's BUILD file resides. | 
 |    */ | 
 |   private final Path packageDirectory; | 
 |  | 
 |   /** | 
 |    * The name of the package we belong to. | 
 |    */ | 
 |   private final PackageIdentifier packageId; | 
 |  | 
 |   /** | 
 |    * The package locator-based directory traversal predicate. | 
 |    */ | 
 |   private final Predicate<Path> childDirectoryPredicate; | 
 |  | 
 |   /** | 
 |    * System call caching layer. | 
 |    */ | 
 |   private AtomicReference<? extends UnixGlob.FilesystemCalls> syscalls; | 
 |   private final int maxDirectoriesToEagerlyVisit; | 
 |  | 
 |   /** The thread pool for glob evaluation. */ | 
 |   private final Executor globExecutor; | 
 |  | 
 |   private final AtomicBoolean globalStarted = new AtomicBoolean(false); | 
 |  | 
 |   /** | 
 |    * Create a glob expansion cache. | 
 |    * | 
 |    * @param packageDirectory globs will be expanded relatively to this directory. | 
 |    * @param packageId the name of the package this cache belongs to. | 
 |    * @param locator the package locator. | 
 |    * @param globExecutor thread pool for glob evaluation. | 
 |    * @param maxDirectoriesToEagerlyVisit the number of directories to eagerly traverse on the first | 
 |    *     glob for a given package, in order to warm the filesystem. -1 means do no eager traversal. | 
 |    *     See {@link | 
 |    *     com.google.devtools.build.lib.pkgcache.PackageOptions#maxDirectoriesToEagerlyVisitInGlobbing}. | 
 |    */ | 
 |   public GlobCache( | 
 |       final Path packageDirectory, | 
 |       final PackageIdentifier packageId, | 
 |       final ImmutableSet<PathFragment> ignoredGlobPrefixes, | 
 |       final CachingPackageLocator locator, | 
 |       AtomicReference<? extends UnixGlob.FilesystemCalls> syscalls, | 
 |       Executor globExecutor, | 
 |       int maxDirectoriesToEagerlyVisit) { | 
 |     this.packageDirectory = Preconditions.checkNotNull(packageDirectory); | 
 |     this.packageId = Preconditions.checkNotNull(packageId); | 
 |     this.globExecutor = Preconditions.checkNotNull(globExecutor); | 
 |     this.syscalls = syscalls == null ? new AtomicReference<>(UnixGlob.DEFAULT_SYSCALLS) : syscalls; | 
 |     this.maxDirectoriesToEagerlyVisit = maxDirectoriesToEagerlyVisit; | 
 |  | 
 |     Preconditions.checkNotNull(locator); | 
 |     childDirectoryPredicate = | 
 |         directory -> { | 
 |           if (directory.equals(packageDirectory)) { | 
 |             return true; | 
 |           } | 
 |  | 
 |           PathFragment subPackagePath = | 
 |               packageId.getPackageFragment().getRelative(directory.relativeTo(packageDirectory)); | 
 |  | 
 |           for (PathFragment ignoredPrefix : ignoredGlobPrefixes) { | 
 |             if (subPackagePath.startsWith(ignoredPrefix)) { | 
 |               return false; | 
 |             } | 
 |           } | 
 |  | 
 |           PackageIdentifier subPackageId = | 
 |               PackageIdentifier.create(packageId.getRepository(), subPackagePath); | 
 |           return locator.getBuildFileForPackage(subPackageId) == null; | 
 |         }; | 
 |   } | 
 |  | 
 |   /** | 
 |    * Returns the future result of evaluating glob "pattern" against this | 
 |    * package's directory, using the package's cache of previously-started | 
 |    * globs if possible. | 
 |    * | 
 |    * @return the list of paths matching the pattern, relative to the package's | 
 |    *   directory. | 
 |    * @throws BadGlobException if the glob was syntactically invalid, or | 
 |    *  contained uplevel references. | 
 |    */ | 
 |   Future<List<Path>> getGlobUnsortedAsync(String pattern, boolean excludeDirs) | 
 |       throws BadGlobException { | 
 |     Future<List<Path>> cached = globCache.get(Pair.of(pattern, excludeDirs)); | 
 |     if (cached == null) { | 
 |       if (maxDirectoriesToEagerlyVisit > -1 | 
 |           && !globalStarted.getAndSet(true)) { | 
 |         packageDirectory.prefetchPackageAsync(maxDirectoriesToEagerlyVisit); | 
 |       } | 
 |       cached = safeGlobUnsorted(pattern, excludeDirs); | 
 |       setGlobPaths(pattern, excludeDirs, cached); | 
 |     } | 
 |     return cached; | 
 |   } | 
 |  | 
 |   @VisibleForTesting | 
 |   List<String> getGlobUnsorted(String pattern) | 
 |       throws IOException, BadGlobException, InterruptedException { | 
 |     return getGlobUnsorted(pattern, false); | 
 |   } | 
 |  | 
 |   @VisibleForTesting | 
 |   protected List<String> getGlobUnsorted(String pattern, boolean excludeDirs) | 
 |       throws IOException, BadGlobException, InterruptedException { | 
 |     Future<List<Path>> futureResult = getGlobUnsortedAsync(pattern, excludeDirs); | 
 |     List<Path> globPaths = fromFuture(futureResult); | 
 |     // Replace the UnixGlob.GlobFuture with a completed future object, to allow | 
 |     // garbage collection of the GlobFuture and GlobVisitor objects. | 
 |     if (!(futureResult instanceof SettableFuture<?>)) { | 
 |       SettableFuture<List<Path>> completedFuture = SettableFuture.create(); | 
 |       completedFuture.set(globPaths); | 
 |       globCache.put(Pair.of(pattern, excludeDirs), completedFuture); | 
 |     } | 
 |  | 
 |     List<String> result = Lists.newArrayListWithCapacity(globPaths.size()); | 
 |     for (Path path : globPaths) { | 
 |       String relative = path.relativeTo(packageDirectory).getPathString(); | 
 |       // Don't permit "" (meaning ".") in the glob expansion, since it's | 
 |       // invalid as a label, plus users should say explicitly if they | 
 |       // really want to name the package directory. | 
 |       if (!relative.isEmpty()) { | 
 |         result.add(relative); | 
 |       } | 
 |     } | 
 |     return result; | 
 |   } | 
 |  | 
 |   /** Adds glob entries to the cache. */ | 
 |   private void setGlobPaths(String pattern, boolean excludeDirectories, Future<List<Path>> result) { | 
 |     globCache.put(Pair.of(pattern, excludeDirectories), result); | 
 |   } | 
 |  | 
 |   /** | 
 |    * Actually execute a glob against the filesystem.  Otherwise similar to | 
 |    * getGlob(). | 
 |    */ | 
 |   @VisibleForTesting | 
 |   Future<List<Path>> safeGlobUnsorted(String pattern, boolean excludeDirs) throws BadGlobException { | 
 |     // Forbidden patterns: | 
 |     if (pattern.indexOf('?') != -1) { | 
 |       throw new BadGlobException("glob pattern '" + pattern + "' contains forbidden '?' wildcard"); | 
 |     } | 
 |     // Patterns forbidden by UnixGlob library: | 
 |     String error = UnixGlob.checkPatternForError(pattern); | 
 |     if (error != null) { | 
 |       throw new BadGlobException(error + " (in glob pattern '" + pattern + "')"); | 
 |     } | 
 |     try { | 
 |       return UnixGlob.forPath(packageDirectory) | 
 |           .addPattern(pattern) | 
 |           .setExcludeDirectories(excludeDirs) | 
 |           .setDirectoryFilter(childDirectoryPredicate) | 
 |           .setExecutor(globExecutor) | 
 |           .setFilesystemCalls(syscalls) | 
 |           .globAsync(); | 
 |     } catch (UnixGlob.BadPattern ex) { | 
 |       throw new BadGlobException(ex.getMessage()); | 
 |     } | 
 |   } | 
 |  | 
 |   /** | 
 |    * Sanitize the future exceptions - the only expected checked exception | 
 |    * is IOException. | 
 |    */ | 
 |   private static List<Path> fromFuture(Future<List<Path>> future) | 
 |       throws IOException, InterruptedException { | 
 |     try { | 
 |       return future.get(); | 
 |     } catch (ExecutionException e) { | 
 |       Throwable cause = e.getCause(); | 
 |       Throwables.propagateIfPossible(cause, | 
 |           IOException.class, InterruptedException.class); | 
 |       throw new RuntimeException(e); | 
 |     } | 
 |   } | 
 |  | 
 |   /** | 
 |    * Helper for evaluating the build language expression "glob(includes, excludes)" in the context | 
 |    * of this package. | 
 |    * | 
 |    * <p>Called by PackageFactory via Package. | 
 |    */ | 
 |   public List<String> globUnsorted( | 
 |       List<String> includes, List<String> excludes, boolean excludeDirs, boolean allowEmpty) | 
 |       throws IOException, BadGlobException, InterruptedException { | 
 |     // Start globbing all patterns in parallel. The getGlob() calls below will | 
 |     // block on an individual pattern's results, but the other globs can | 
 |     // continue in the background. | 
 |     for (String pattern : includes) { | 
 |       @SuppressWarnings("unused") | 
 |       Future<?> possiblyIgnoredError = getGlobUnsortedAsync(pattern, excludeDirs); | 
 |     } | 
 |  | 
 |     HashSet<String> results = new HashSet<>(); | 
 |     for (String pattern : includes) { | 
 |       List<String> items = getGlobUnsorted(pattern, excludeDirs); | 
 |       if (!allowEmpty && items.isEmpty()) { | 
 |         throw new BadGlobException( | 
 |             "glob pattern '" | 
 |                 + pattern | 
 |                 + "' didn't match anything, but allow_empty is set to False " | 
 |                 + "(the default value of allow_empty can be set with " | 
 |                 + "--incompatible_disallow_empty_glob)."); | 
 |       } | 
 |       results.addAll(items); | 
 |     } | 
 |     try { | 
 |       UnixGlob.removeExcludes(results, excludes); | 
 |     } catch (UnixGlob.BadPattern ex) { | 
 |       throw new BadGlobException(ex.getMessage()); | 
 |     } | 
 |     if (!allowEmpty && results.isEmpty()) { | 
 |       throw new BadGlobException( | 
 |           "all files in the glob have been excluded, but allow_empty is set to False " | 
 |               + "(the default value of allow_empty can be set with " | 
 |               + "--incompatible_disallow_empty_glob)."); | 
 |     } | 
 |     return new ArrayList<>(results); | 
 |   } | 
 |  | 
 |   public Set<Pair<String, Boolean>> getKeySet() { | 
 |     return globCache.keySet(); | 
 |   } | 
 |  | 
 |   /** | 
 |    * Block on the completion of all potentially-abandoned background tasks. | 
 |    */ | 
 |   public void finishBackgroundTasks() { | 
 |     finishBackgroundTasks(globCache.values()); | 
 |   } | 
 |  | 
 |   public void cancelBackgroundTasks() { | 
 |     cancelBackgroundTasks(globCache.values()); | 
 |   } | 
 |  | 
 |   private static void finishBackgroundTasks(Collection<Future<List<Path>>> tasks) { | 
 |     for (Future<List<Path>> task : tasks) { | 
 |       try { | 
 |         fromFuture(task); | 
 |       } catch (CancellationException | IOException | InterruptedException e) { | 
 |         // Ignore: If this was still going on in the background, some other | 
 |         // failure already occurred. | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   private static void cancelBackgroundTasks(Collection<Future<List<Path>>> tasks) { | 
 |     for (Future<List<Path>> task : tasks) { | 
 |       task.cancel(true); | 
 |     } | 
 |  | 
 |     for (Future<List<Path>> task : tasks) { | 
 |       try { | 
 |         task.get(); | 
 |       } catch (CancellationException | ExecutionException | InterruptedException e) { | 
 |         // We don't care. Point is, the task does not bother us anymore. | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   @Override | 
 |   public String toString() { | 
 |     return "GlobCache for " + packageId + " in " + packageDirectory; | 
 |   } | 
 | } |