Use fact that the subgraph of ActionLookupValues has the same transitive dependency relations as the full graph to avoid descending into non-ActionLookupValue parts of the graph when collecting ActionLookupValues.

PiperOrigin-RevId: 207472612

1 files changed, 4 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeBuildView.java b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeBuildView.java
index 9b879db1e7..a86d51a58f 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeBuildView.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeBuildView.java
@@ -798,7 +798,10 @@ public final class SkyframeBuildView {
   private static void findActionsRecursively(
       WalkableGraph walkableGraph, SkyKey key, Set<SkyKey> seen, List<ActionLookupValue> result)
       throws InterruptedException {
-    if (!seen.add(key)) {
+    if (!(key instanceof ActionLookupValue.ActionLookupKey) || !seen.add(key)) {
+      // The subgraph of dependencies of ActionLookupValues never has a non-ActionLookupValue
+      // depending on an ActionLookupValue. So we can skip any non-ActionLookupValues in the
+      // traversal as an optimization.
       return;
     }
     SkyValue value = walkableGraph.getValue(key);