resolve comments

cpp/src/jni/orc/jni_wrapper.cpp

@@ -136,7 +136,7 @@ JNIEXPORT jlong JNICALL Java_org_apache_arrow_adapter_orc_OrcReaderJniWrapper_op
 
   arrow::Status ret;
   if (path.find("hdfs://") == 0) {
-    env->ThrowNew(io_exception_class, "hdfs path not support yet.");
+    env->ThrowNew(io_exception_class, "hdfs path not supported yet.");
   } else {
     ret = arrow::io::ReadableFile::Open(path, &in_file);
   }
@@ -183,6 +183,11 @@ Java_org_apache_arrow_adapter_orc_OrcReaderJniWrapper_nextStripeReader(JNIEnv* e
                                                                        jlong id,
                                                                        jlong batch_size) {
   auto reader = orc_reader_holder_.Lookup(id);
+  if (!reader) {
+    std::string error_message = "invalid reader id " + std::to_string(id);
+    env->ThrowNew(exception_class, error_message.c_str());
+  }
+
   std::shared_ptr<RecordBatchReader> stripe_reader;
   auto status = reader->NextStripeReader(batch_size, &stripe_reader);
 
@@ -202,6 +207,11 @@ Java_org_apache_arrow_adapter_orc_OrcStripeReaderJniWrapper_getSchema(JNIEnv* en
                                                                       jclass this_cls,
                                                                       jlong id) {
   auto stripe_reader = orc_stripe_reader_holder_.Lookup(id);
+  if (!stripe_reader) {
+    std::string error_message = "invalid stripe reader id " + std::to_string(id);
+    env->ThrowNew(exception_class, error_message.c_str());
+  }
+
   auto schema = stripe_reader->schema();
 
   std::shared_ptr<arrow::Buffer> out;
@@ -222,6 +232,11 @@ Java_org_apache_arrow_adapter_orc_OrcStripeReaderJniWrapper_next(JNIEnv* env,
                                                                  jclass this_cls,
                                                                  jlong id) {
   auto stripe_reader = orc_stripe_reader_holder_.Lookup(id);
+  if (!stripe_reader) {
+    std::string error_message = "invalid stripe reader id " + std::to_string(id);
+    env->ThrowNew(exception_class, error_message.c_str());
+  }
+
   std::shared_ptr<arrow::RecordBatch> record_batch;
   auto status = stripe_reader->ReadNext(&record_batch);
   if (!status.ok() || !record_batch) {

java/adapter/orc/src/main/java/org/apache/arrow/adapter/orc/OrcMemoryJniWrapper.java

@@ -22,7 +22,7 @@ package org.apache.arrow.adapter.orc;
  */
 class OrcMemoryJniWrapper implements AutoCloseable {
 
-  private final long id;
+  private final long nativeInstanceId;
 
   private final long memoryAddress;
 
@@ -32,13 +32,13 @@ class OrcMemoryJniWrapper implements AutoCloseable {
 
   /**
    * Construct a new instance.
-   * @param id unique id of the underlying memory.
+   * @param nativeInstanceId unique id of the underlying memory.
    * @param memoryAddress starting memory address of the the underlying memory.
    * @param size size of the valid data.
    * @param capacity allocated memory size.
    */
-  OrcMemoryJniWrapper(long id, long memoryAddress, long size, long capacity) {
-    this.id = id;
+  OrcMemoryJniWrapper(long nativeInstanceId, long memoryAddress, long size, long capacity) {
+    this.nativeInstanceId = nativeInstanceId;
     this.memoryAddress = memoryAddress;
     this.size = size;
     this.capacity = capacity;
@@ -70,7 +70,7 @@ class OrcMemoryJniWrapper implements AutoCloseable {
 
   @Override
   public void close() {
-    release(id);
+    release(nativeInstanceId);
   }
 
   private native void release(long id);

java/adapter/orc/src/main/java/org/apache/arrow/adapter/orc/OrcReader.java

@@ -35,7 +35,7 @@ public class OrcReader implements AutoCloseable {
   /**
    * reference to native reader instance.
    */
-  private final long id;
+  private final long nativeInstanceId;
 
   /**
    * Create an OrcReader that iterate over orc stripes.
@@ -46,7 +46,7 @@ public class OrcReader implements AutoCloseable {
   public OrcReader(String filePath, BufferAllocator allocator) throws IOException {
     this.allocator = allocator;
     this.jniWrapper = OrcReaderJniWrapper.getInstance();
-    this.id = jniWrapper.open(filePath);
+    this.nativeInstanceId = jniWrapper.open(filePath);
   }
 
   /**
@@ -56,7 +56,7 @@ public class OrcReader implements AutoCloseable {
    * @return true if seek operation is succeeded
    */
   public boolean seek(int rowNumber) {
-    return jniWrapper.seek(id, rowNumber);
+    return jniWrapper.seek(nativeInstanceId, rowNumber);
   }
 
   /**
@@ -66,7 +66,7 @@ public class OrcReader implements AutoCloseable {
    * @return ArrowReader that iterate over current stripes
    */
   public ArrowReader nextStripeReader(long batchSize) {
-    long stripeReaderId = jniWrapper.nextStripeReader(id, batchSize);
+    long stripeReaderId = jniWrapper.nextStripeReader(nativeInstanceId, batchSize);
     if (stripeReaderId < 0) {
       return null;
     }
@@ -80,11 +80,11 @@ public class OrcReader implements AutoCloseable {
    * @return number of stripes
    */
   public int getNumberOfStripes() {
-    return jniWrapper.getNumberOfStripes(id);
+    return jniWrapper.getNumberOfStripes(nativeInstanceId);
   }
 
   @Override
   public void close() throws Exception {
-    jniWrapper.close(id);
+    jniWrapper.close(nativeInstanceId);
   }
 }

java/adapter/orc/src/main/java/org/apache/arrow/adapter/orc/OrcReferenceManager.java

@@ -102,18 +102,7 @@ public class OrcReferenceManager implements ReferenceManager {
 
   @Override
   public OwnershipTransferResult transferOwnership(ArrowBuf sourceBuffer, BufferAllocator targetAllocator) {
-    retain();
-    return new OwnershipTransferResult() {
-      @Override
-      public boolean getAllocationFit() {
-        return false;
-      }
-
-      @Override
-      public ArrowBuf getTransferredBuffer() {
-        return sourceBuffer;
-      }
-    };
+    throw new UnsupportedOperationException();
   }
 
   @Override

java/adapter/orc/src/main/java/org/apache/arrow/adapter/orc/OrcStripeReader.java

@@ -43,23 +43,22 @@ public class OrcStripeReader extends ArrowReader {
   /**
    * reference to native stripe reader instance.
    */
-  private final long id;
-  private MessageChannelReader schemaReader;
+  private final long nativeInstanceId;
 
   /**
    * Construct a new instance.
-   * @param id id of the stripe reader instance, obtained by
+   * @param nativeInstanceId nativeInstanceId of the stripe reader instance, obtained by
    *           calling nextStripeReader from OrcReaderJniWrapper
    * @param allocator memory allocator for accounting.
    */
-  OrcStripeReader(long id, BufferAllocator allocator) {
+  OrcStripeReader(long nativeInstanceId, BufferAllocator allocator) {
     super(allocator);
-    this.id = id;
+    this.nativeInstanceId = nativeInstanceId;
   }
 
   @Override
   public boolean loadNextBatch() throws IOException {
-    OrcRecordBatch recordBatch = OrcStripeReaderJniWrapper.next(id);
+    OrcRecordBatch recordBatch = OrcStripeReaderJniWrapper.next(nativeInstanceId);
     if (recordBatch == null) {
       return false;
     }
@@ -91,28 +90,29 @@ public class OrcStripeReader extends ArrowReader {
 
   @Override
   protected void closeReadSource() throws IOException {
-    OrcStripeReaderJniWrapper.close(id);
+    OrcStripeReaderJniWrapper.close(nativeInstanceId);
   }
 
   @Override
   protected Schema readSchema() throws IOException {
-    byte[] schemaBytes = OrcStripeReaderJniWrapper.getSchema(id);
-    schemaReader = new MessageChannelReader(
-                      new ReadChannel(
-                        new ByteArrayReadableSeekableByteChannel(schemaBytes)), allocator);
+    byte[] schemaBytes = OrcStripeReaderJniWrapper.getSchema(nativeInstanceId);
 
-    MessageResult result = schemaReader.readNext();
-    schemaReader.close();
+    try (MessageChannelReader schemaReader =
+           new MessageChannelReader(
+                new ReadChannel(
+                new ByteArrayReadableSeekableByteChannel(schemaBytes)), allocator)) {
 
-    if (result == null) {
-      throw new IOException("Unexpected end of input. Missing schema.");
+      MessageResult result = schemaReader.readNext();
+      if (result == null) {
+        throw new IOException("Unexpected end of input. Missing schema.");
+      }
+
+      if (result.getMessage().headerType() != MessageHeader.Schema) {
+        throw new IOException("Expected schema but header was " + result.getMessage().headerType());
+      }
+
+      return MessageSerializer.deserializeSchema(result.getMessage());
     }
-
-    if (result.getMessage().headerType() != MessageHeader.Schema) {
-      throw new IOException("Expected schema but header was " + result.getMessage().headerType());
-    }
-
-    return MessageSerializer.deserializeSchema(result.getMessage());
   }
 
   @Override