Add FlushChunkMetadataListener

java/tsfile/src/main/java/org/apache/tsfile/write/writer/FlushChunkMetadataListener.java

@@ -0,0 +1,33 @@
+/*
+ * 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
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.tsfile.write.writer;
+
+import org.apache.tsfile.file.metadata.IChunkMetadata;
+import org.apache.tsfile.read.common.Path;
+import org.apache.tsfile.utils.Pair;
+
+import java.util.List;
+
+@FunctionalInterface
+public interface FlushChunkMetadataListener {
+
+  // measurement id -> chunk metadata list
+  void onFlush(List<Pair<Path, List<IChunkMetadata>>> sortedChunkMetadataList);
+}

java/tsfile/src/main/java/org/apache/tsfile/write/writer/TsFileIOWriter.java

@@ -66,6 +66,7 @@
 import java.util.Map.Entry;
 import java.util.Queue;
 import java.util.TreeMap;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 import static org.apache.tsfile.file.metadata.MetadataIndexConstructor.addCurrentIndexNodeToQueue;
 import static org.apache.tsfile.file.metadata.MetadataIndexConstructor.checkAndBuildLevelIndex;
@@ -131,6 +132,8 @@ public class TsFileIOWriter implements AutoCloseable {
 
   protected String encryptKey;
 
+  private final List<FlushChunkMetadataListener> flushListeners = new CopyOnWriteArrayList<>();
+
   /** empty construct function. */
   protected TsFileIOWriter() {
     if (TS_FILE_CONFIG.getEncryptFlag()) {
@@ -210,6 +213,10 @@ public void setEncryptParam(String encryptLevel, String encryptType, String encr
     this.encryptKey = encryptKey;
   }
 
+  public void addFlushListener(FlushChunkMetadataListener listener) {
+    flushListeners.add(listener);
+  }
+
   /**
    * Writes given bytes to output stream. This method is called when total memory size exceeds the
    * chunk group size threshold.
@@ -723,6 +730,12 @@ protected int sortAndFlushChunkMetadata() throws IOException {
       lastSerializePath = seriesPath;
       logger.debug("Flushing {}", seriesPath);
     }
+
+    // notify the listeners
+    for (final FlushChunkMetadataListener listener : flushListeners) {
+      listener.onFlush(sortedChunkMetadataList);
+    }
+
     // clear the cache metadata to release the memory
     chunkGroupMetadataList.clear();
     if (chunkMetadataList != null) {