Update from Google.

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MOE_MIGRATED_REVID=85702957

1 files changed, 148 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/FileArtifactValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/FileArtifactValue.java
new file mode 100644
index 0000000000..7acc38c994
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/FileArtifactValue.java
@@ -0,0 +1,148 @@
+// Copyright 2014 Google Inc. 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.Objects;
+import com.google.common.base.Preconditions;
+import com.google.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.actions.cache.DigestUtils;
+import com.google.devtools.build.lib.vfs.FileStatus;
+import com.google.devtools.build.lib.vfs.Path;
+
+import java.io.IOException;
+import java.util.Arrays;
+
+import javax.annotation.Nullable;
+
+/**
+ * Stores the data of an artifact corresponding to a file. This file may be an ordinary file, in
+ * which case we would expect to see a digest and size; a directory, in which case we would expect
+ * to see an mtime; or an empty file, where we would expect to see a size (=0), mtime, and digest
+ */
+public class FileArtifactValue extends ArtifactValue {
+  /** Data for Middleman artifacts that did not have data specified. */
+  static final FileArtifactValue DEFAULT_MIDDLEMAN = new FileArtifactValue(null, 0, 0);
+  /** Data that marks that a file is not present on the filesystem. */
+  static final FileArtifactValue MISSING_FILE_MARKER = new FileArtifactValue(null, 1, 0);
+
+  @Nullable private final byte[] digest;
+  private final long mtime;
+  private final long size;
+
+  private FileArtifactValue(byte[] digest, long size) {
+    Preconditions.checkState(size >= 0, "size must be non-negative: %s %s", digest, size);
+    this.digest = Preconditions.checkNotNull(digest, size);
+    this.size = size;
+    this.mtime = -1;
+  }
+
+  // Only used by empty files (non-null digest) and directories (null digest).
+  private FileArtifactValue(byte[] digest, long mtime, long size) {
+    Preconditions.checkState(mtime >= 0, "mtime must be non-negative: %s %s", mtime, size);
+    Preconditions.checkState(size == 0, "size must be zero: %s %s", mtime, size);
+    this.digest = digest;
+    this.size = size;
+    this.mtime = mtime;
+  }
+
+  static FileArtifactValue create(Artifact artifact) throws IOException {
+    Path path = artifact.getPath();
+    FileStatus stat = path.stat();
+    boolean isFile = stat.isFile();
+    return create(artifact, isFile, isFile ? stat.getSize() : 0, null);
+  }
+
+  static FileArtifactValue create(Artifact artifact, FileValue fileValue) throws IOException {
+    boolean isFile = fileValue.isFile();
+    return create(artifact, isFile, isFile ? fileValue.getSize() : 0,
+        isFile ? fileValue.getDigest() : null);
+  }
+
+  static FileArtifactValue create(Artifact artifact, boolean isFile, long size,
+      @Nullable byte[] digest) throws IOException {
+    if (isFile && digest == null) {
+      digest = DigestUtils.getDigestOrFail(artifact.getPath(), size);
+    }
+    if (!DigestUtils.useFileDigest(artifact, isFile, size)) {
+      // In this case, we need to store the mtime because the action cache uses mtime to determine
+      // if this artifact has changed. This is currently true for empty files and directories. We
+      // do not optimize for this code path (by storing the mtime in a FileValue) because we do not
+      // like it and may remove this special-casing for empty files in the future. We want this code
+      // path to go away somehow too for directories (maybe by implementing FileSet
+      // in Skyframe)
+      return new FileArtifactValue(digest, artifact.getPath().getLastModifiedTime(), size);
+    }
+    Preconditions.checkState(digest != null, artifact);
+    return new FileArtifactValue(digest, size);
+  }
+
+  static FileArtifactValue createMiddleman(byte[] digest) {
+    Preconditions.checkNotNull(digest);
+    // The Middleman artifact values have size 1 because we want their digests to be used. This hack
+    // can be removed once empty files are digested.
+    return new FileArtifactValue(digest, /*size=*/1);
+  }
+
+  @Nullable
+  byte[] getDigest() {
+    return digest;
+  }
+
+  /** Gets the size of the file. Directories have size 0. */
+  long getSize() {
+    return size;
+  }
+
+  /**
+   * Gets last modified time of file. Should only be called if {@link DigestUtils#useFileDigest} was
+   * false for this artifact -- namely, either it is a directory or an empty file. Note that since
+   * we store directory sizes as 0, all files for which this method can be called have size 0.
+   */
+  long getModifiedTime() {
+    Preconditions.checkState(size == 0, "%s %s %s", digest, mtime, size);
+    return mtime;
+  }
+
+  @Override
+  public int hashCode() {
+    // Hash digest by content, not reference. Note that digest is the only array in this array.
+    return Arrays.deepHashCode(new Object[] {size, mtime, digest});
+  }
+
+  /**
+   * Two FileArtifactValues will only compare equal if they have the same content. This differs
+   * from the {@code Metadata#equivalence} method, which allows for comparison using mtime if
+   * one object does not have a digest available.
+   */
+  @Override
+  public boolean equals(Object other) {
+    if (this == other) {
+      return true;
+    }
+    if (!(other instanceof FileArtifactValue)) {
+      return false;
+    }
+    FileArtifactValue that = (FileArtifactValue) other;
+    return this.mtime == that.mtime && this.size == that.size
+        && Arrays.equals(this.digest, that.digest);
+  }
+
+  @Override
+  public String toString() {
+    return Objects.toStringHelper(FileArtifactValue.class)
+        .add("digest", digest)
+        .add("mtime", mtime)
+        .add("size", size).toString();
+  }
+}