[incubator-iotdb] branch master updated: Lazy Contruct AliasMap in InternalMNode (#1343)

[qi...@apache.org]

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qiaojialin pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-iotdb.git


The following commit(s) were added to refs/heads/master by this push:
     new 3bad01d  Lazy Contruct AliasMap in InternalMNode (#1343)
3bad01d is described below

commit 3bad01d3b0c6c72734648b9553bab6c10411b047
Author: Jackie Tien <Ja...@foxmail.com>
AuthorDate: Wed Jun 10 17:15:28 2020 +0800

    Lazy Contruct AliasMap in InternalMNode (#1343)
---
 .../iotdb/db/metadata/mnode/InternalMNode.java     | 23 +++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/server/src/main/java/org/apache/iotdb/db/metadata/mnode/InternalMNode.java b/server/src/main/java/org/apache/iotdb/db/metadata/mnode/InternalMNode.java
index c7dbcd5..fa2861f 100644
--- a/server/src/main/java/org/apache/iotdb/db/metadata/mnode/InternalMNode.java
+++ b/server/src/main/java/org/apache/iotdb/db/metadata/mnode/InternalMNode.java
@@ -18,15 +18,14 @@
  */
 package org.apache.iotdb.db.metadata.mnode;
 
-import java.util.LinkedHashMap;
-import org.apache.iotdb.db.exception.metadata.DeleteFailedException;
+import static org.apache.iotdb.db.conf.IoTDBConstant.PATH_SEPARATOR;
 
+import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
-
-import static org.apache.iotdb.db.conf.IoTDBConstant.PATH_SEPARATOR;
+import org.apache.iotdb.db.exception.metadata.DeleteFailedException;
 
 public class InternalMNode extends MNode {
 
@@ -40,12 +39,12 @@ public class InternalMNode extends MNode {
   public InternalMNode(MNode parent, String name) {
     super(parent, name);
     this.children = new LinkedHashMap<>();
-    this.aliasChildren = new LinkedHashMap<>();
   }
 
   @Override
   public boolean hasChild(String name) {
-    return this.children.containsKey(name) || this.aliasChildren.containsKey(name);
+    return this.children.containsKey(name) ||
+        (aliasChildren != null && aliasChildren.containsKey(name));
   }
 
   @Override
@@ -75,11 +74,13 @@ public class InternalMNode extends MNode {
         throw new DeleteFailedException(getFullPath() + PATH_SEPARATOR + name);
       }
     }
-}
+  }
 
   @Override
   public void deleteAliasChild(String alias) throws DeleteFailedException {
-
+    if (aliasChildren == null) {
+      return;
+    }
     if (lock.writeLock().tryLock()) {
       aliasChildren.remove(alias);
       lock.writeLock().unlock();
@@ -90,7 +91,8 @@ public class InternalMNode extends MNode {
 
   @Override
   public MNode getChild(String name) {
-    return children.containsKey(name) ? children.get(name) : aliasChildren.get(name);
+    return children.containsKey(name) ? children.get(name)
+        : (aliasChildren == null ? null : aliasChildren.get(name));
   }
 
   @Override
@@ -104,6 +106,9 @@ public class InternalMNode extends MNode {
 
   @Override
   public void addAlias(String alias, MNode child) {
+    if (aliasChildren == null) {
+      aliasChildren = new LinkedHashMap<>();
+    }
     aliasChildren.put(alias, child);
   }