[iotdb] branch rel/1.0 updated: [To rel/1.0][IOTDB-5277] SchemaRegion throws NPE when loading snapshot (#8606)

[zy...@apache.org]

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zyk pushed a commit to branch rel/1.0
in repository https://gitbox.apache.org/repos/asf/iotdb.git


The following commit(s) were added to refs/heads/rel/1.0 by this push:
     new 7520b6c3b4 [To rel/1.0][IOTDB-5277] SchemaRegion throws NPE when loading snapshot (#8606)
7520b6c3b4 is described below

commit 7520b6c3b4bda511480e264ef853173ada0df066
Author: Chen YZ <43...@users.noreply.github.com>
AuthorDate: Mon Dec 26 06:33:05 2022 +0800

    [To rel/1.0][IOTDB-5277] SchemaRegion throws NPE when loading snapshot (#8606)
---
 .../apache/iotdb/db/metadata/MetadataConstant.java |  4 +++
 .../mtree/snapshot/MemMTreeSnapshotUtil.java       |  4 ++-
 .../schemaRegion/SchemaRegionBasicTest.java        | 39 ++++++++++++++++++++++
 3 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/server/src/main/java/org/apache/iotdb/db/metadata/MetadataConstant.java b/server/src/main/java/org/apache/iotdb/db/metadata/MetadataConstant.java
index 4981c9c088..a1f167e24a 100644
--- a/server/src/main/java/org/apache/iotdb/db/metadata/MetadataConstant.java
+++ b/server/src/main/java/org/apache/iotdb/db/metadata/MetadataConstant.java
@@ -85,4 +85,8 @@ public class MetadataConstant {
         throw new RuntimeException("Undefined MNode type " + type);
     }
   }
+
+  public static boolean isStorageGroupType(byte type) {
+    return type == STORAGE_GROUP_MNODE_TYPE || type == STORAGE_GROUP_ENTITY_MNODE_TYPE;
+  }
 }
diff --git a/server/src/main/java/org/apache/iotdb/db/metadata/mtree/snapshot/MemMTreeSnapshotUtil.java b/server/src/main/java/org/apache/iotdb/db/metadata/mtree/snapshot/MemMTreeSnapshotUtil.java
index 3681a975d0..4fda4c0a74 100644
--- a/server/src/main/java/org/apache/iotdb/db/metadata/mtree/snapshot/MemMTreeSnapshotUtil.java
+++ b/server/src/main/java/org/apache/iotdb/db/metadata/mtree/snapshot/MemMTreeSnapshotUtil.java
@@ -57,6 +57,7 @@ import static org.apache.iotdb.db.metadata.MetadataConstant.INTERNAL_MNODE_TYPE;
 import static org.apache.iotdb.db.metadata.MetadataConstant.MEASUREMENT_MNODE_TYPE;
 import static org.apache.iotdb.db.metadata.MetadataConstant.STORAGE_GROUP_ENTITY_MNODE_TYPE;
 import static org.apache.iotdb.db.metadata.MetadataConstant.STORAGE_GROUP_MNODE_TYPE;
+import static org.apache.iotdb.db.metadata.MetadataConstant.isStorageGroupType;
 
 public class MemMTreeSnapshotUtil {
 
@@ -220,7 +221,8 @@ public class MemMTreeSnapshotUtil {
       ancestors.peek().addChild(node);
     }
 
-    if (childrenNum > 0) {
+    //     Storage type means current node is root node, so it must be returned.
+    if (childrenNum > 0 || isStorageGroupType(type)) {
       ancestors.push(node);
       restChildrenNum.push(childrenNum);
     }
diff --git a/server/src/test/java/org/apache/iotdb/db/metadata/schemaRegion/SchemaRegionBasicTest.java b/server/src/test/java/org/apache/iotdb/db/metadata/schemaRegion/SchemaRegionBasicTest.java
index c981009481..c1b13c4c59 100644
--- a/server/src/test/java/org/apache/iotdb/db/metadata/schemaRegion/SchemaRegionBasicTest.java
+++ b/server/src/test/java/org/apache/iotdb/db/metadata/schemaRegion/SchemaRegionBasicTest.java
@@ -185,6 +185,45 @@ public abstract class SchemaRegionBasicTest {
     }
   }
 
+  @Test
+  public void testEmptySnapshot() throws Exception {
+    if (config.getSchemaEngineMode().equals(SchemaEngineMode.Schema_File.name())) {
+      return;
+    }
+    String schemaRegionConsensusProtocolClass = config.getSchemaRegionConsensusProtocolClass();
+    config.setSchemaRegionConsensusProtocolClass(ConsensusFactory.RATIS_CONSENSUS);
+    try {
+      PartialPath storageGroup = new PartialPath("root.sg");
+      SchemaRegionId schemaRegionId = new SchemaRegionId(0);
+      SchemaEngine.getInstance().createSchemaRegion(storageGroup, schemaRegionId);
+      ISchemaRegion schemaRegion = SchemaEngine.getInstance().getSchemaRegion(schemaRegionId);
+
+      File mLogFile =
+          SystemFileFactory.INSTANCE.getFile(
+              schemaRegion.getStorageGroupFullPath()
+                  + File.separator
+                  + schemaRegion.getSchemaRegionId().getId(),
+              MetadataConstant.METADATA_LOG);
+      Assert.assertFalse(mLogFile.exists());
+
+      File snapshotDir = new File(config.getSchemaDir() + File.separator + "snapshot");
+      snapshotDir.mkdir();
+      schemaRegion.createSnapshot(snapshotDir);
+
+      schemaRegion.loadSnapshot(snapshotDir);
+
+      Pair<List<ShowTimeSeriesResult>, Integer> result =
+          schemaRegion.showTimeseries(
+              new ShowTimeSeriesPlan(
+                  new PartialPath("root.sg.**"), false, "tag-key", "tag-value", 0, 0, false),
+              null);
+
+      Assert.assertEquals(0, result.left.size());
+    } finally {
+      config.setSchemaRegionConsensusProtocolClass(schemaRegionConsensusProtocolClass);
+    }
+  }
+
   private Template generateTemplate() throws IllegalPathException {
     Template template =
         new Template(