put back arrow/vectorized/BaseBatchReader

arrow/src/main/java/org/apache/iceberg/arrow/vectorized/BaseBatchReader.java

@@ -0,0 +1,82 @@
+/*
+ * 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.iceberg.arrow.vectorized;
+
+import java.util.List;
+import java.util.Map;
+import org.apache.iceberg.parquet.VectorizedReader;
+import org.apache.parquet.column.page.PageReadStore;
+import org.apache.parquet.hadoop.metadata.ColumnChunkMetaData;
+import org.apache.parquet.hadoop.metadata.ColumnPath;
+
+/** A base BatchReader class that contains common functionality */
+@SuppressWarnings("checkstyle:VisibilityModifier")
+public abstract class BaseBatchReader<T> implements VectorizedReader<T> {
+  protected final VectorizedArrowReader[] readers;
+  protected final VectorHolder[] vectorHolders;
+
+  protected BaseBatchReader(List<VectorizedReader<?>> readers) {
+    this.readers =
+        readers.stream()
+            .map(VectorizedArrowReader.class::cast)
+            .toArray(VectorizedArrowReader[]::new);
+    this.vectorHolders = new VectorHolder[readers.size()];
+  }
+
+  @Override
+  public void setRowGroupInfo(
+      PageReadStore pageStore, Map<ColumnPath, ColumnChunkMetaData> metaData, long rowPosition) {
+    for (VectorizedArrowReader reader : readers) {
+      if (reader != null) {
+        reader.setRowGroupInfo(pageStore, metaData, rowPosition);
+      }
+    }
+  }
+
+  protected void closeVectors() {
+    for (int i = 0; i < vectorHolders.length; i++) {
+      if (vectorHolders[i] != null) {
+        // Release any resources used by the vector
+        if (vectorHolders[i].vector() != null) {
+          vectorHolders[i].vector().close();
+        }
+        vectorHolders[i] = null;
+      }
+    }
+  }
+
+  @Override
+  public void close() {
+    for (VectorizedReader<?> reader : readers) {
+      if (reader != null) {
+        reader.close();
+      }
+    }
+    closeVectors();
+  }
+
+  @Override
+  public void setBatchSize(int batchSize) {
+    for (VectorizedArrowReader reader : readers) {
+      if (reader != null) {
+        reader.setBatchSize(batchSize);
+      }
+    }
+  }
+}