1 files changed, 142 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/TransitiveTargetValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/TransitiveTargetValue.java
new file mode 100644
index 0000000000..69b9638c6f
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+++ b/src/main/java/com/google/devtools/build/lib/skyframe/TransitiveTargetValue.java
@@ -0,0 +1,142 @@
+// 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.devtools.build.lib.collect.nestedset.NestedSet;
+import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
+import com.google.devtools.build.lib.collect.nestedset.Order;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
+import com.google.devtools.build.lib.packages.NoSuchTargetException;
+import com.google.devtools.build.lib.packages.PackageIdentifier;
+import com.google.devtools.build.lib.syntax.Label;
+import com.google.devtools.build.skyframe.SkyKey;
+import com.google.devtools.build.skyframe.SkyValue;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.util.Set;
+
+import javax.annotation.Nullable;
+
+/**
+ * A <i>transitive</i> target reference that, when built in skyframe, loads the entire
+ * transitive closure of a target.
+ *
+ * This will probably be unnecessary once other refactorings occur throughout the codebase
+ * which make loading/analysis interleaving more feasible, or we will migrate "blaze query" to
+ * use this to evaluate its Target graph.
+ */
+@Immutable
+@ThreadSafe
+public class TransitiveTargetValue implements SkyValue {
+
+  // Non-final for serialization purposes.
+  private NestedSet<PackageIdentifier> transitiveSuccessfulPkgs;
+  private NestedSet<PackageIdentifier> transitiveUnsuccessfulPkgs;
+  private NestedSet<Label> transitiveTargets;
+  @Nullable private NestedSet<Label> transitiveRootCauses;
+  @Nullable private NoSuchTargetException errorLoadingTarget;
+
+  private TransitiveTargetValue(NestedSet<PackageIdentifier> transitiveSuccessfulPkgs,
+      NestedSet<PackageIdentifier> transitiveUnsuccessfulPkgs, NestedSet<Label> transitiveTargets,
+      @Nullable NestedSet<Label> transitiveRootCauses,
+      @Nullable NoSuchTargetException errorLoadingTarget) {
+    this.transitiveSuccessfulPkgs = transitiveSuccessfulPkgs;
+    this.transitiveUnsuccessfulPkgs = transitiveUnsuccessfulPkgs;
+    this.transitiveTargets = transitiveTargets;
+    this.transitiveRootCauses = transitiveRootCauses;
+    this.errorLoadingTarget = errorLoadingTarget;
+  }
+
+  private void writeObject(ObjectOutputStream out) throws IOException {
+    // It helps to flatten the transitiveSuccessfulPkgs nested set as it has lots of duplicates.
+    Set<PackageIdentifier> successfulPkgs = transitiveSuccessfulPkgs.toSet();
+    out.writeInt(successfulPkgs.size());
+    for (PackageIdentifier pkg : successfulPkgs) {
+      out.writeObject(pkg);
+    }
+
+    out.writeObject(transitiveUnsuccessfulPkgs);
+    // Deliberately do not write out transitiveTargets. There is a lot of those and they drive
+    // serialization costs through the roof, both in terms of space and of time.
+    // TODO(bazel-team): Deal with this properly once we have efficient serialization of NestedSets.
+    out.writeObject(transitiveRootCauses);
+    out.writeObject(errorLoadingTarget);
+  }
+
+  @SuppressWarnings("unchecked")
+  private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
+    int successfulPkgCount = in.readInt();
+    NestedSetBuilder<PackageIdentifier> pkgs = NestedSetBuilder.stableOrder();
+    for (int i = 0; i < successfulPkgCount; i++) {
+      pkgs.add((PackageIdentifier) in.readObject());
+    }
+    transitiveSuccessfulPkgs = pkgs.build();
+    transitiveUnsuccessfulPkgs = (NestedSet<PackageIdentifier>) in.readObject();
+    // TODO(bazel-team): Deal with transitiveTargets properly.
+    transitiveTargets = NestedSetBuilder.emptySet(Order.STABLE_ORDER);
+    transitiveRootCauses = (NestedSet<Label>) in.readObject();
+    errorLoadingTarget = (NoSuchTargetException) in.readObject();
+  }
+
+  static TransitiveTargetValue unsuccessfulTransitiveLoading(
+      NestedSet<PackageIdentifier> transitiveSuccessfulPkgs,
+      NestedSet<PackageIdentifier> transitiveUnsuccessfulPkgs, NestedSet<Label> transitiveTargets,
+      NestedSet<Label> rootCauses, @Nullable NoSuchTargetException errorLoadingTarget) {
+    return new TransitiveTargetValue(transitiveSuccessfulPkgs, transitiveUnsuccessfulPkgs,
+        transitiveTargets, rootCauses, errorLoadingTarget);
+  }
+
+  static TransitiveTargetValue successfulTransitiveLoading(
+      NestedSet<PackageIdentifier> transitiveSuccessfulPkgs,
+      NestedSet<PackageIdentifier> transitiveUnsuccessfulPkgs,
+      NestedSet<Label> transitiveTargets) {
+    return new TransitiveTargetValue(transitiveSuccessfulPkgs, transitiveUnsuccessfulPkgs,
+        transitiveTargets, null, null);
+  }
+
+  /** Returns the error, if any, from loading the target. */
+  @Nullable
+  public NoSuchTargetException getErrorLoadingTarget() {
+    return errorLoadingTarget;
+  }
+
+  /** Returns the packages that were transitively successfully loaded. */
+  public NestedSet<PackageIdentifier> getTransitiveSuccessfulPackages() {
+    return transitiveSuccessfulPkgs;
+  }
+
+  /** Returns the packages that were transitively successfully loaded. */
+  public NestedSet<PackageIdentifier> getTransitiveUnsuccessfulPackages() {
+    return transitiveUnsuccessfulPkgs;
+  }
+
+  /** Returns the targets that were transitively loaded. */
+  public NestedSet<Label> getTransitiveTargets() {
+    return transitiveTargets;
+  }
+
+  /** Returns the root causes, if any, of why targets weren't loaded. */
+  @Nullable
+  public NestedSet<Label> getTransitiveRootCauses() {
+    return transitiveRootCauses;
+  }
+
+  @ThreadSafe
+  public static SkyKey key(Label label) {
+    return new SkyKey(SkyFunctions.TRANSITIVE_TARGET, label);
+  }
+}