For review

common/src/main/java/org/apache/arrow/c/CometSchemaImporter.java

@@ -0,0 +1,73 @@
+/*
+ * 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.arrow.c;
+
+import org.apache.arrow.memory.BufferAllocator;
+import org.apache.arrow.vector.FieldVector;
+import org.apache.arrow.vector.types.pojo.Field;
+
+/** This is a simple wrapper around SchemaImporter to make it accessible from Java Arrow. */
+public class CometSchemaImporter {
+  private final BufferAllocator allocator;
+  private final SchemaImporter importer;
+  private final CDataDictionaryProvider provider = new CDataDictionaryProvider();
+
+  public CometSchemaImporter(BufferAllocator allocator) {
+    this.allocator = allocator;
+    this.importer = new SchemaImporter(allocator);
+  }
+
+  public BufferAllocator getAllocator() {
+    return allocator;
+  }
+
+  public CDataDictionaryProvider getProvider() {
+    return provider;
+  }
+
+  public Field importField(ArrowSchema schema) {
+    try {
+      return importer.importField(schema, provider);
+    } finally {
+      schema.release();
+      schema.close();
+    }
+  }
+
+  /**
+   * Imports data from ArrowArray/ArrowSchema into a FieldVector. This is basically the same as Java
+   * Arrow `Data.importVector`. `Data.importVector` initiates `SchemaImporter` internally which is
+   * used to fill dictionary ids for dictionary encoded vectors. Every call to `importVector` will
+   * begin with dictionary ids starting from 0. So, separate calls to `importVector` will overwrite
+   * dictionary ids. To avoid this, we need to use the same `SchemaImporter` instance for all calls
+   * to `importVector`.
+   */
+  public FieldVector importVector(ArrowArray array, ArrowSchema schema) {
+    Field field = importField(schema);
+    FieldVector vector = field.createVector(allocator);
+    Data.importIntoVector(allocator, array, vector, provider);
+
+    return vector;
+  }
+
+  public void close() {
+    provider.close();
+  }
+}

common/src/main/java/org/apache/comet/parquet/BatchReader.java

@@ -108,6 +108,7 @@ public class BatchReader extends RecordReader<Void, ColumnarBatch> implements Cl
   private MessageType requestedSchema;
   private CometVector[] vectors;
   private AbstractColumnReader[] columnReaders;
+  private CometSchemaImporter importer;
   private ColumnarBatch currentBatch;
   private Future<Option<Throwable>> prefetchTask;
   private LinkedBlockingQueue<Pair<PageReadStore, Long>> prefetchQueue;
@@ -519,6 +520,10 @@ public void close() throws IOException {
       fileReader.close();
       fileReader = null;
     }
+    if (importer != null) {
+      importer.close();
+      importer = null;
+    }
   }
 
   @SuppressWarnings("deprecation")
@@ -556,7 +561,8 @@ private boolean loadNextRowGroupIfNecessary() throws Throwable {
       numRowGroupsMetric.add(1);
     }
 
-    CometSchemaImporter importer = new CometSchemaImporter(ALLOCATOR);
+    if (importer != null) importer.close();
+    importer = new CometSchemaImporter(ALLOCATOR);
 
     List<ColumnDescriptor> columns = requestedSchema.getColumns();
     for (int i = 0; i < columns.size(); i++) {

common/src/main/java/org/apache/comet/parquet/ColumnReader.java

@@ -39,7 +39,6 @@
 import org.apache.parquet.column.page.DictionaryPage;
 import org.apache.parquet.column.page.PageReader;
 import org.apache.parquet.schema.LogicalTypeAnnotation;
-import org.apache.spark.sql.comet.util.Utils$;
 import org.apache.spark.sql.types.DataType;
 
 import org.apache.comet.CometConf;
@@ -206,8 +205,7 @@ public CometDecodedVector loadVector() {
 
     try (ArrowArray array = ArrowArray.wrap(addresses[0]);
         ArrowSchema schema = ArrowSchema.wrap(addresses[1])) {
-      FieldVector vector =
-          Utils$.MODULE$.importVector(importer.getAllocator(), importer, array, schema);
+      FieldVector vector = importer.importVector(array, schema);
 
       DictionaryEncoding dictionaryEncoding = vector.getField().getDictionary();
 

common/src/main/scala/org/apache/spark/sql/comet/util/Utils.scala

@@ -25,8 +25,7 @@ import java.nio.channels.Channels
 
 import scala.collection.JavaConverters._
 
-import org.apache.arrow.c.{ArrowArray, ArrowSchema, CDataDictionaryProvider, CometSchemaImporter, Data}
-import org.apache.arrow.memory.BufferAllocator
+import org.apache.arrow.c.CDataDictionaryProvider
 import org.apache.arrow.vector.{BigIntVector, BitVector, DateDayVector, DecimalVector, FieldVector, FixedSizeBinaryVector, Float4Vector, Float8Vector, IntVector, SmallIntVector, TimeStampMicroTZVector, TimeStampMicroVector, TinyIntVector, ValueVector, VarBinaryVector, VarCharVector, VectorSchemaRoot}
 import org.apache.arrow.vector.complex.MapVector
 import org.apache.arrow.vector.dictionary.DictionaryProvider
@@ -39,7 +38,7 @@ import org.apache.spark.sql.types._
 import org.apache.spark.sql.vectorized.ColumnarBatch
 import org.apache.spark.util.io.{ChunkedByteBuffer, ChunkedByteBufferOutputStream}
 
-import org.apache.comet.vector._
+import org.apache.comet.vector.CometVector
 
 object Utils {
   def getConfPath(confFileName: String): String = {
@@ -265,24 +264,4 @@ object Utils {
         throw new SparkException(s"Unsupported Arrow Vector for $reason: ${valueVector.getClass}")
     }
   }
-
-  /**
-   * Imports data from ArrowArray/ArrowSchema into a FieldVector. This is basically the same as
-   * Java Arrow `Data.importVector`. `Data.importVector` initiates `SchemaImporter` internally
-   * which is used to fill dictionary ids for dictionary encoded vectors. Every call to
-   * `importVector` will begin with dictionary ids starting from 0. So, separate calls to
-   * `importVector` will overwrite dictionary ids. To avoid this, we need to use the same
-   * `SchemaImporter` instance for all calls to `importVector`.
-   */
-  def importVector(
-      allocator: BufferAllocator,
-      importer: CometSchemaImporter,
-      array: ArrowArray,
-      schema: ArrowSchema): FieldVector = {
-    val field = importer.importField(schema)
-    val vector = field.createVector(allocator)
-    Data.importIntoVector(allocator, array, vector, importer.getProvider())
-
-    vector
-  }
 }