IGNORE: chore: Merge comet-parquet-exec into (just to see diff)

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

@@ -23,6 +23,7 @@
 import org.slf4j.LoggerFactory;
 
 import org.apache.parquet.column.ColumnDescriptor;
+import org.apache.parquet.schema.Type;
 import org.apache.spark.sql.types.DataType;
 import org.apache.spark.sql.types.TimestampNTZType$;
 
@@ -36,6 +37,9 @@ public abstract class AbstractColumnReader implements AutoCloseable {
   /** The Spark data type. */
   protected final DataType type;
 
+  /** The Spark data type. */
+  protected final Type fieldType;
+
   /** Parquet column descriptor. */
   protected final ColumnDescriptor descriptor;
 
@@ -61,13 +65,23 @@ public abstract class AbstractColumnReader implements AutoCloseable {
 
   public AbstractColumnReader(
       DataType type,
+      Type fieldType,
       ColumnDescriptor descriptor,
       boolean useDecimal128,
       boolean useLegacyDateTimestamp) {
     this.type = type;
+    this.fieldType = fieldType;
     this.descriptor = descriptor;
     this.useDecimal128 = useDecimal128;
     this.useLegacyDateTimestamp = useLegacyDateTimestamp;
+  }
+
+  public AbstractColumnReader(
+      DataType type,
+      ColumnDescriptor descriptor,
+      boolean useDecimal128,
+      boolean useLegacyDateTimestamp) {
+    this(type, null, descriptor, useDecimal128, useLegacyDateTimestamp);
     TypeUtil.checkParquetType(descriptor, type);
   }
 

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

@@ -272,7 +272,7 @@ public void init() throws URISyntaxException, IOException {
       requestedSchema =
           CometParquetReadSupport.clipParquetSchema(
               requestedSchema, sparkSchema, isCaseSensitive, useFieldId, ignoreMissingIds);
-      if (requestedSchema.getColumns().size() != sparkSchema.size()) {
+      if (requestedSchema.getFieldCount() != sparkSchema.size()) {
         throw new IllegalArgumentException(
             String.format(
                 "Spark schema has %d columns while " + "Parquet schema has %d columns",

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

@@ -234,4 +234,56 @@ public static native void setPageV2(
    * @param handle the handle to the native Parquet column reader
    */
   public static native void closeColumnReader(long handle);
+
+  ///////////// Arrow Native Parquet Reader APIs
+  // TODO: Add partitionValues(?), improve requiredColumns to use a projection mask that corresponds
+  // to arrow.
+  //      Add batch size, datetimeRebaseModeSpec, metrics(how?)...
+
+  /**
+   * Initialize a record batch reader for a PartitionedFile
+   *
+   * @param filePath
+   * @param start
+   * @param length
+   * @return a handle to the record batch reader, used in subsequent calls.
+   */
+  public static native long initRecordBatchReader(
+      String filePath,
+      long fileSize,
+      long start,
+      long length,
+      byte[] requiredSchema,
+      String sessionTimezone);
+
+  // arrow native version of read batch
+  /**
+   * Read the next batch of data into memory on native side
+   *
+   * @param handle
+   * @return the number of rows read
+   */
+  public static native int readNextRecordBatch(long handle);
+
+  // arrow native equivalent of currentBatch. 'columnNum' is number of the column in the record
+  // batch
+  /**
+   * Load the column corresponding to columnNum in the currently loaded record batch into JVM
+   *
+   * @param handle
+   * @param columnNum
+   * @param arrayAddr
+   * @param schemaAddr
+   */
+  public static native void currentColumnBatch(
+      long handle, int columnNum, long arrayAddr, long schemaAddr);
+
+  // arrow native version to close record batch reader
+
+  /**
+   * Close the record batch reader. Free the resources
+   *
+   * @param handle
+   */
+  public static native void closeRecordBatchReader(long handle);
 }