| /* |
| * Copyright 2012-present Facebook, Inc. |
| * |
| * 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.facebook.buck.util; |
| |
| import com.facebook.buck.io.ProjectFilesystem; |
| import com.facebook.buck.log.Logger; |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.base.Preconditions; |
| import com.google.common.cache.CacheBuilder; |
| import com.google.common.cache.CacheLoader; |
| import com.google.common.cache.LoadingCache; |
| import com.google.common.eventbus.Subscribe; |
| import com.google.common.hash.HashCode; |
| import com.google.common.hash.Hashing; |
| import com.google.common.io.ByteSource; |
| import com.google.common.io.Files; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.nio.file.Path; |
| import java.nio.file.WatchEvent; |
| import java.util.concurrent.ExecutionException; |
| |
| public class DefaultFileHashCache implements FileHashCache { |
| |
| private static final Logger LOG = Logger.get(DefaultFileHashCache.class); |
| |
| private final ProjectFilesystem projectFilesystem; |
| |
| @VisibleForTesting |
| final LoadingCache<Path, HashCode> loadingCache; |
| |
| public DefaultFileHashCache(ProjectFilesystem projectFilesystem) { |
| this.projectFilesystem = projectFilesystem; |
| |
| this.loadingCache = CacheBuilder.newBuilder() |
| .build(new CacheLoader<Path, HashCode>() { |
| @Override |
| public HashCode load(Path path) throws Exception { |
| return getHashCode(path); |
| } |
| }); |
| } |
| |
| private HashCode getHashCode(Path path) throws IOException { |
| // TODO(simons): Should be this.projectFilesystem.computeSha1(path); |
| File file = this.projectFilesystem.resolve(path).toFile(); |
| ByteSource source = Files.asByteSource(file); |
| return source.hash(Hashing.sha1()); |
| } |
| |
| @Override |
| public boolean contains(Path path) { |
| return loadingCache.getIfPresent(path) != null; |
| } |
| |
| /** |
| * @return The {@link com.google.common.hash.HashCode} of the contents of path. |
| */ |
| @Override |
| public HashCode get(Path path) { |
| HashCode sha1; |
| try { |
| // Ignored paths will not generate file change events and so are not invalidated correctly. |
| // Where ignored paths are output files, they are generated by each build and will not |
| // generate cache hits so not caching them is likely a performance win in any case. |
| if (projectFilesystem.isIgnored(path)) { |
| sha1 = getHashCode(path); |
| } else { |
| sha1 = loadingCache.get(path.normalize()); |
| } |
| } catch (ExecutionException | IOException e) { |
| throw new RuntimeException(e); |
| } |
| return Preconditions.checkNotNull(sha1, "Failed to find a HashCode for %s.", path); |
| } |
| |
| /** |
| * Called when file change events are posted to the file change EventBus to invalidate cached |
| * build rules if required. {@link Path}s contained within events must all be relative to the |
| * {@link ProjectFilesystem} root. |
| */ |
| @Subscribe |
| public synchronized void onFileSystemChange(WatchEvent<?> event) throws IOException { |
| if (projectFilesystem.isPathChangeEvent(event)) { |
| // Path event, remove the path from the cache as it has been changed, added or deleted. |
| Path path = ((Path) event.context()).normalize(); |
| LOG.verbose("Invalidating %s", path); |
| loadingCache.invalidate(path); |
| } else { |
| // Non-path change event, likely an overflow due to many change events: invalidate everything. |
| LOG.debug("Invalidating all"); |
| loadingCache.invalidateAll(); |
| } |
| } |
| |
| } |