HDDS-8739. Snapdiff should return complete absolute path in Diff Entry

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/snapshot/FSODirectoryPathResolver.java

@@ -0,0 +1,115 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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 org.apache.hadoop.ozone.om.snapshot;
+
+import org.apache.hadoop.hdds.utils.db.Table;
+import org.apache.hadoop.hdds.utils.db.TableIterator;
+import org.apache.hadoop.ozone.om.helpers.OmDirectoryInfo;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Queue;
+import java.util.Set;
+
+import static org.apache.hadoop.ozone.OzoneConsts.OM_KEY_PREFIX;
+
+public class FSODirectoryPathResolver implements ObjectPathResolver {
+
+  private String prefix;
+  private long bucketId;
+  private Table<String, OmDirectoryInfo> dirInfoTable;
+
+  public FSODirectoryPathResolver(String prefix, long bucketId,
+      Table<String, OmDirectoryInfo> dirInfoTable) {
+    this.prefix = prefix;
+    this.dirInfoTable = dirInfoTable;
+    this.bucketId = bucketId;
+  }
+
+  private void addToPathMap(ObjectIDPathVal objectIDPathVal,
+                            Set<Long> dirObjIds, Map<Long, Path> pathMap) {
+    if (dirObjIds.contains(objectIDPathVal.getObjectId())) {
+      pathMap.put(objectIDPathVal.getObjectId(), objectIDPathVal.getPath());
+      dirObjIds.remove(objectIDPathVal.getObjectId());
+    }
+  }
+
+  /**
+   * Assuming all dirObjIds belong to a bucket this function resolves absolute
+   * path for a given FSO bucket.
+   * @param dirObjIds
+   * @return Map of Path corresponding to provided directory object IDs
+   */
+  @Override
+  public Map<Long, Path> getAbsolutePathForObjectIDs(Set<Long> dirObjIds)
+      throws IOException {
+    // Root of a bucket would always have the key as /volumeId/bucketId/bucketId/
+    if (dirObjIds.isEmpty()) {
+      return Collections.emptyMap();
+    }
+
+    Map<Long, Path> pathMap = new HashMap<>();
+    Queue<ObjectIDPathVal> objectIdPathVals = new LinkedList<>();
+    ObjectIDPathVal root = new ObjectIDPathVal(bucketId, Paths.get("/"));
+    objectIdPathVals.add(root);
+    addToPathMap(root, dirObjIds, pathMap);
+
+    while (!objectIdPathVals.isEmpty() && dirObjIds.size() > 0) {
+      ObjectIDPathVal parent = objectIdPathVals.poll();
+      try(TableIterator<String, ? extends Table.KeyValue<String, OmDirectoryInfo>>
+              subDirIter = dirInfoTable.iterator(
+                  prefix + parent.getObjectId())) {
+        while (dirObjIds.size() > 0 && subDirIter.hasNext()) {
+          OmDirectoryInfo dir = subDirIter.next().getValue();
+          ObjectIDPathVal pathVal = new ObjectIDPathVal(dir.getObjectID(),
+              parent.getPath().resolve(dir.getName()));
+          addToPathMap(pathVal, dirObjIds, pathMap);
+        }
+      }
+    }
+
+    if (dirObjIds.size() > 0) {
+      throw new IllegalArgumentException(
+          "Dir object Ids required but not found in bucket: " + dirObjIds);
+    }
+    return pathMap;
+  }
+
+  private static class ObjectIDPathVal {
+    private long objectId;
+    private Path path;
+
+    public ObjectIDPathVal(long objectId, Path path) {
+      this.objectId = objectId;
+      this.path = path;
+    }
+
+    public long getObjectId() {
+      return objectId;
+    }
+
+    public Path getPath() {
+      return path;
+    }
+  }
+}

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/snapshot/ObjectPathResolver.java

@@ -0,0 +1,12 @@
+package org.apache.hadoop.ozone.om.snapshot;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.Map;
+import java.util.Set;
+
+public interface ObjectPathResolver {
+
+  public Map<Long, Path> getAbsolutePathForObjectIDs(Set<Long> objIds)
+      throws IOException;
+}