Add a reference to the pertinent RunfilesTree to RunfilesArtifactValue.

RELNOTES: None.
PiperOrigin-RevId: 599787221
Change-Id: Id0808314613f8b387fef59f83f76fe0e892fa20f
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ArtifactFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/ArtifactFunction.java
index 71dda42..5250c00 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ArtifactFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ArtifactFunction.java
@@ -32,6 +32,7 @@
 import com.google.devtools.build.lib.actions.FileValue;
 import com.google.devtools.build.lib.actions.FilesetTraversalParams.DirectTraversalRoot;
 import com.google.devtools.build.lib.actions.FilesetTraversalParams.PackageBoundaryMode;
+import com.google.devtools.build.lib.actions.MiddlemanAction;
 import com.google.devtools.build.lib.bugreport.BugReport;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.events.Event;
@@ -148,7 +149,7 @@
             artifactDependencies);
 
     FileArtifactValue individualMetadata = actionValue.getExistingFileArtifactValue(artifact);
-    return createRunfilesArtifactValue(artifact, action, individualMetadata, env);
+    return createRunfilesArtifactValue(artifact, (MiddlemanAction) action, individualMetadata, env);
   }
 
   private static void mkdirForTreeArtifact(
@@ -344,7 +345,7 @@
   @Nullable
   private static RunfilesArtifactValue createRunfilesArtifactValue(
       Artifact artifact,
-      ActionAnalysisMetadata action,
+      MiddlemanAction action,
       FileArtifactValue value,
       SkyFunction.Environment env)
       throws InterruptedException {
@@ -388,7 +389,12 @@
     }
 
     return new RunfilesArtifactValue(
-        value, files.build(), fileValues.build(), trees.build(), treeValues.build());
+        value,
+        action.getRunfilesTree(),
+        files.build(),
+        fileValues.build(),
+        trees.build(),
+        treeValues.build());
   }
 
   @Override
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/BUILD b/src/main/java/com/google/devtools/build/lib/skyframe/BUILD
index 33e40a6..40907eb 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/BUILD
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/BUILD
@@ -598,6 +598,7 @@
         ":tree_artifact_value",
         "//src/main/java/com/google/devtools/build/lib/actions:artifacts",
         "//src/main/java/com/google/devtools/build/lib/actions:file_metadata",
+        "//src/main/java/com/google/devtools/build/lib/actions:runfiles_supplier",
         "//src/main/java/com/google/devtools/build/lib/util:hash_codes",
         "//src/main/java/com/google/devtools/build/skyframe:skyframe-objects",
         "//third_party:guava",
@@ -682,10 +683,8 @@
         "//src/main/java/com/google/devtools/build/lib/actions:action_lookup_key",
         "//src/main/java/com/google/devtools/build/lib/actions:artifacts",
         "//src/main/java/com/google/devtools/build/lib/actions:file_metadata",
-        "//src/main/java/com/google/devtools/build/lib/actions:middleman_type",
         "//src/main/java/com/google/devtools/build/lib/bugreport",
         "//src/main/java/com/google/devtools/build/lib/cmdline",
-        "//src/main/java/com/google/devtools/build/lib/concurrent",
         "//src/main/java/com/google/devtools/build/lib/events",
         "//src/main/java/com/google/devtools/build/lib/util",
         "//src/main/java/com/google/devtools/build/lib/util:detailed_exit_code",
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/RunfilesArtifactValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/RunfilesArtifactValue.java
index ec76bfc..cc8e3f2 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/RunfilesArtifactValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/RunfilesArtifactValue.java
@@ -20,6 +20,7 @@
 import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.actions.FileArtifactValue;
+import com.google.devtools.build.lib.actions.RunfilesSupplier.RunfilesTree;
 import com.google.devtools.build.lib.util.HashCodes;
 import com.google.devtools.build.skyframe.SkyValue;
 
@@ -32,6 +33,7 @@
   }
 
   private final FileArtifactValue metadata;
+  private final RunfilesTree runfilesTree;
 
   // Parallel lists.
   private final ImmutableList<Artifact> files;
@@ -43,11 +45,13 @@
 
   RunfilesArtifactValue(
       FileArtifactValue metadata,
+      RunfilesTree runfilesTree,
       ImmutableList<Artifact> files,
       ImmutableList<FileArtifactValue> fileValues,
       ImmutableList<Artifact> trees,
       ImmutableList<TreeArtifactValue> treeValues) {
     this.metadata = checkNotNull(metadata);
+    this.runfilesTree = checkNotNull(runfilesTree);
     this.files = checkNotNull(files);
     this.fileValues = checkNotNull(fileValues);
     this.trees = checkNotNull(trees);
@@ -63,6 +67,11 @@
     return metadata;
   }
 
+  /** Returns the runfiles tree this value represents. */
+  RunfilesTree getRunfilesTree() {
+    return runfilesTree;
+  }
+
   /** Visits the file artifacts that this runfiles artifact expands to, together with their data. */
   void forEachFile(RunfilesConsumer<FileArtifactValue> consumer) throws InterruptedException {
     for (int i = 0; i < files.size(); i++) {
@@ -79,6 +88,22 @@
 
   @Override
   public boolean equals(Object o) {
+    // This method, seemingly erroneously, does not check whether the runfilesTree of the two
+    // objects is equivalent. This is because it's costly (it involves flattening nested sets and
+    // even if one caches a fingerprint, it's still a fair amount of CPU) and because it's
+    // currently not necessary: RunfilesArtifactValue is only ever created as the SkyValue of
+    // runfiles middlemen and those are special-cased in ActionCacheChecker (see
+    // ActionCacheChecker.checkMiddlemanAction()): the checksum of a middleman artifact is the
+    // function of the checksum of all the artifacts on the inputs of the middleman action, which
+    // includes both the artifacts the runfiles tree links to and the runfiles input manifest,
+    // which in turn encodes the structure of the runfiles tree. The checksum of the middleman
+    // artifact is here as the "metadata" field, which *is* compared here, so the
+    // RunfilesArtifactValues of two runfiles middlemen will be equals iff they represent the same
+    // runfiles tree.
+    //
+    // Eventually, if we ever do away with runfiles input manifests, it will be necessary to change
+    // this (it's weird that one needs to do a round-trip to the file system to determine the
+    // checksum of a runfiles tree), but that's not happening anytime soon.
     if (this == o) {
       return true;
     }