1 files changed, 65 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/skyframe/ErrorInfoManager.java b/src/main/java/com/google/devtools/build/skyframe/ErrorInfoManager.java
new file mode 100644
index 0000000000..01ca34b232
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/skyframe/ErrorInfoManager.java
@@ -0,0 +1,65 @@
+// Copyright 2017 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.skyframe;
+
+import com.google.devtools.build.skyframe.SkyFunctionException.ReifiedSkyFunctionException;
+import java.util.Collection;
+import javax.annotation.Nullable;
+
+/** Used by {@link ParallelEvaluator} to produce and consume {@link ErrorInfo} instances. */
+public interface ErrorInfoManager {
+  ErrorInfo fromException(
+      SkyKey key,
+      ReifiedSkyFunctionException skyFunctionException,
+      boolean isTransitivelyTransient);
+
+  /**
+   * Returns the {@link ErrorInfo} to use when there isn't currently one because
+   * {@link SkyFunction#compute} didn't throw a {@link SkyFunctionException} and there was no cycle.
+   */
+  @Nullable
+  ErrorInfo getErrorInfoToUse(
+      SkyKey skyKey,
+      boolean hasValue,
+      Collection<ErrorInfo> childErrorInfos);
+
+  /**
+   * Trivial {@link ErrorInfoManager} implementation whose {@link #fromException} simply uses
+   * {@link ErrorInfo#fromException} and whose {@link #getErrorInfoToUse} makes an {@link ErrorInfo}
+   * from the given {@code childErrorInfos}.
+   */
+  static class UseChildErrorInfoIfNecessary implements ErrorInfoManager {
+    public static final UseChildErrorInfoIfNecessary INSTANCE = new UseChildErrorInfoIfNecessary();
+
+    private UseChildErrorInfoIfNecessary() {
+    }
+
+    @Override
+    public ErrorInfo fromException(
+        SkyKey key,
+        ReifiedSkyFunctionException skyFunctionException,
+        boolean isTransitivelyTransient) {
+      return ErrorInfo.fromException(skyFunctionException, isTransitivelyTransient);
+    }
+
+    @Override
+    @Nullable
+    public ErrorInfo getErrorInfoToUse(
+        SkyKey skyKey,
+        boolean hasValue,
+        Collection<ErrorInfo> childErrorInfos) {
+      return !childErrorInfos.isEmpty() ? ErrorInfo.fromChildErrors(skyKey, childErrorInfos) : null;
+    }
+  }
+}