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Author: fmeum

src/main/java/com/google/devtools/build/lib/remote/AbstractActionInputPrefetcher.java

@@ -110,10 +110,6 @@ private final class DirectoryTracker {
     private final ConcurrentHashMap<Path, DirectoryState> directoryStateMap =
         new ConcurrentHashMap<>();
 
-    public void clear() {
-      directoryStateMap.clear();
-    }
-
     /**
      * Marks a directory as temporarily writable.
      *
@@ -264,6 +260,10 @@ private static boolean shouldDownloadFile(Path path, FileArtifactValue metadata)
 
   protected abstract boolean canDownloadFile(Path path, FileArtifactValue metadata);
 
+  /**
+   * If true, then all previously acquired knowledge of the file system state of this path (e.g. the
+   * existence of tree artifact directories or previously downloaded files) must be discarded.
+   */
   protected abstract boolean forceRefetch(Path path);
 
   /**

src/main/java/com/google/devtools/build/lib/remote/RemoteActionInputFetcher.java

@@ -155,6 +155,11 @@ protected ListenableFuture<Void> doDownloadFile(
   }
 
   public void handleRewoundActionOutputs(Collection<Artifact> outputs) {
+    // SkyframeActionExecutor#prepareForRewinding does *not* call this method because the
+    // RemoteActionFileSystem corresponds to an ActionFileSystemType with inMemoryFileSystem() ==
+    // true. While it is true that resetting outputDirectoryHelper isn't necessary to undo the
+    // caching of output directory creation during action preparation, we still need to reset here
+    // since outputDirectoryHelper is also used by AbstractActionInputPrefetcher.
     outputDirectoryHelper.invalidateTreeArtifactDirectoryCreation(outputs);
     for (Artifact output : outputs) {
       // Action templates have TreeFileArtifacts as outputs, which isn't supported by the trie. We