[HUDI-3007] Fix issues in HoodieRepairTool (#4564)

hudi-common/src/main/java/org/apache/hudi/common/fs/FSUtils.java

@@ -721,6 +721,53 @@ public class FSUtils {
     }
   }
 
+  /**
+   * Lists file status at a certain level in the directory hierarchy.
+   * <p>
+   * E.g., given "/tmp/hoodie_table" as the rootPath, and 3 as the expected level,
+   * this method gives back the {@link FileStatus} of all files under
+   * "/tmp/hoodie_table/[*]/[*]/[*]/" folders.
+   *
+   * @param hoodieEngineContext {@link HoodieEngineContext} instance.
+   * @param fs                  {@link FileSystem} instance.
+   * @param rootPath            Root path for the file listing.
+   * @param expectLevel         Expected level of directory hierarchy for files to be added.
+   * @param parallelism         Parallelism for the file listing.
+   * @return A list of file status of files at the level.
+   */
+
+  public static List<FileStatus> getFileStatusAtLevel(
+      HoodieEngineContext hoodieEngineContext, FileSystem fs, Path rootPath,
+      int expectLevel, int parallelism) {
+    List<String> levelPaths = new ArrayList<>();
+    List<FileStatus> result = new ArrayList<>();
+    levelPaths.add(rootPath.toString());
+
+    for (int i = 0; i <= expectLevel; i++) {
+      result = FSUtils.parallelizeFilesProcess(hoodieEngineContext, fs, parallelism,
+          pairOfSubPathAndConf -> {
+            Path path = new Path(pairOfSubPathAndConf.getKey());
+            try {
+              FileSystem fileSystem = path.getFileSystem(pairOfSubPathAndConf.getValue().get());
+              return Arrays.stream(fileSystem.listStatus(path))
+                .collect(Collectors.toList());
+            } catch (IOException e) {
+              throw new HoodieIOException("Failed to list " + path, e);
+            }
+          },
+          levelPaths)
+          .values().stream()
+          .flatMap(list -> list.stream()).collect(Collectors.toList());
+      if (i < expectLevel) {
+        levelPaths = result.stream()
+            .filter(FileStatus::isDirectory)
+            .map(fileStatus -> fileStatus.getPath().toString())
+            .collect(Collectors.toList());
+      }
+    }
+    return result;
+  }
+
   public interface SerializableFunction<T, R> extends Function<T, R>, Serializable {
   }
 }