Minor refactor

Convert OrcReaderJniWrapper to singleton model to allow client handle library loading exception

cpp/src/jni/orc/jni_wrapper.cpp

@@ -133,7 +133,7 @@ extern "C" {
 #endif
 
 JNIEXPORT jlong JNICALL Java_org_apache_arrow_adapter_orc_OrcReaderJniWrapper_open(
-    JNIEnv* env, jclass this_cls, jstring file_path) {
+    JNIEnv* env, jobject this_obj, jstring file_path) {
   std::shared_ptr<arrow::io::ReadableFile> in_file;
 
   std::string path = JStringToCString(env, file_path);
@@ -164,19 +164,19 @@ JNIEXPORT jlong JNICALL Java_org_apache_arrow_adapter_orc_OrcReaderJniWrapper_op
 }
 
 JNIEXPORT void JNICALL Java_org_apache_arrow_adapter_orc_OrcReaderJniWrapper_close(
-    JNIEnv* env, jclass this_cls, jlong id) {
+    JNIEnv* env, jobject this_obj, jlong id) {
   orc_reader_holder_.Erase(id);
 }
 
 JNIEXPORT jboolean JNICALL Java_org_apache_arrow_adapter_orc_OrcReaderJniWrapper_seek(
-    JNIEnv* env, jclass this_cls, jlong id, jint row_number) {
+    JNIEnv* env, jobject this_obj, jlong id, jint row_number) {
   auto reader = orc_reader_holder_.Lookup(id);
   return reader->Seek(row_number).ok();
 }
 
 JNIEXPORT jint JNICALL
 Java_org_apache_arrow_adapter_orc_OrcReaderJniWrapper_getNumberOfStripes(JNIEnv* env,
-                                                                         jclass this_cls,
+                                                                         jobject this_obj,
                                                                          jlong id) {
   auto reader = orc_reader_holder_.Lookup(id);
   return reader->NumberOfStripes();
@@ -184,7 +184,7 @@ Java_org_apache_arrow_adapter_orc_OrcReaderJniWrapper_getNumberOfStripes(JNIEnv*
 
 JNIEXPORT jlong JNICALL
 Java_org_apache_arrow_adapter_orc_OrcReaderJniWrapper_nextStripeReader(JNIEnv* env,
-                                                                       jclass this_cls,
+                                                                       jobject this_obj,
                                                                        jlong id,
                                                                        jlong batch_size) {
   auto reader = GetNativeReader(id);

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

@@ -17,12 +17,11 @@
 
 package org.apache.arrow.adapter.orc;
 
-import java.io.IOException;
-
 /**
  * Wrapper for orc memory allocated by native code.
  */
 class OrcMemoryJniWrapper implements AutoCloseable {
+
   private final long id;
 
   private final long memoryAddress;
@@ -31,14 +30,6 @@ class OrcMemoryJniWrapper implements AutoCloseable {
 
   private final long capacity;
 
-  static {
-    try {
-      OrcJniUtils.loadOrcAdapterLibraryFromJar();
-    } catch (IOException e) {
-      throw new ExceptionInInitializerError(e);
-    }
-  }
-
   /**
    * Construct a new instance.
    * @param id unique id of the underlying memory.

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

@@ -29,6 +29,7 @@ import org.apache.arrow.vector.ipc.ArrowReader;
  *  ArrowReader.
  */
 public class OrcReader implements AutoCloseable {
+  private final OrcReaderJniWrapper jniWrapper;
   private BufferAllocator allocator;
 
   private final long id;
@@ -41,7 +42,8 @@ public class OrcReader implements AutoCloseable {
    */
   public OrcReader(String filePath, BufferAllocator allocator) throws IOException {
     this.allocator = allocator;
-    id = OrcReaderJniWrapper.open(filePath);
+    this.jniWrapper = OrcReaderJniWrapper.getInstance();
+    this.id = jniWrapper.open(filePath);
   }
 
   /**
@@ -51,7 +53,7 @@ public class OrcReader implements AutoCloseable {
    * @return true if seek operation is succeeded
    */
   public boolean seek(int rowNumber) {
-    return OrcReaderJniWrapper.seek(id, rowNumber);
+    return jniWrapper.seek(id, rowNumber);
   }
 
   /**
@@ -61,7 +63,7 @@ public class OrcReader implements AutoCloseable {
    * @return ArrowReader that iterate over current stripes
    */
   public ArrowReader nextStripeReader(long batchSize) {
-    long stripeReaderId = OrcReaderJniWrapper.nextStripeReader(id, batchSize);
+    long stripeReaderId = jniWrapper.nextStripeReader(id, batchSize);
     if (stripeReaderId < 0) {
       return null;
     }
@@ -75,11 +77,11 @@ public class OrcReader implements AutoCloseable {
    * @return number of stripes
    */
   public int getNumberOfStripes() {
-    return OrcReaderJniWrapper.getNumberOfStripes(id);
+    return jniWrapper.getNumberOfStripes(id);
   }
 
   @Override
   public void close() throws Exception {
-    OrcReaderJniWrapper.close(id);
+    jniWrapper.close(id);
   }
 }

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

@@ -23,12 +23,20 @@ import java.io.IOException;
  * JNI wrapper for Orc reader.
  */
 class OrcReaderJniWrapper {
-  static {
-    try {
-      OrcJniUtils.loadOrcAdapterLibraryFromJar();
-    } catch (IOException e) {
-      throw new ExceptionInInitializerError(e);
+
+  private static volatile OrcReaderJniWrapper INSTANCE;
+
+  static OrcReaderJniWrapper getInstance() throws IOException {
+    if (INSTANCE == null) {
+      synchronized (OrcReaderJniWrapper.class) {
+        if (INSTANCE == null) {
+          OrcJniUtils.loadOrcAdapterLibraryFromJar();
+          INSTANCE = new OrcReaderJniWrapper();
+        }
+      }
     }
+
+    return INSTANCE;
   }
 
   /**
@@ -37,13 +45,13 @@ class OrcReaderJniWrapper {
    * @return id of the orc reader instance if file opened successfully,
    *     otherwise return error code * -1.
    */
-  static native long open(String fileName);
+  native long open(String fileName);
 
   /**
-   * Close the underlying reader and release related resources.
+   * Release resources associated with designated reader instance.
    * @param readerId id of the reader instance.
    */
-  static native void close(long readerId);
+  native void close(long readerId);
 
   /**
    *  Seek to designated row. Invoke nextStripeReader() after seek
@@ -52,14 +60,14 @@ class OrcReaderJniWrapper {
    * @param rowNumber the rows number to seek
    * @return true if seek operation is succeeded
    */
-  static native boolean seek(long readerId, int rowNumber);
+  native boolean seek(long readerId, int rowNumber);
 
   /**
    * The number of stripes in the file.
    * @param readerId id of the reader instance
    * @return number of stripes
    */
-  static native int getNumberOfStripes(long readerId);
+  native int getNumberOfStripes(long readerId);
 
   /**
    * Get a stripe level ArrowReader with specified batchSize in each record batch.
@@ -67,5 +75,5 @@ class OrcReaderJniWrapper {
    * @param batchSize the number of rows loaded on each iteration
    * @return id of the stripe reader instance.
    */
-  static native long nextStripeReader(long readerId, long batchSize);
+  native long nextStripeReader(long readerId, long batchSize);
 }

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

@@ -45,7 +45,8 @@ public class OrcStripeReader extends ArrowReader {
 
   /**
    * Construct a new instance.
-   * @param id id of the stripe reader instance
+   * @param id id of the stripe reader instance, obtained by
+   *           calling nextStripeReader from OrcReaderJniWrapper
    * @param allocator memory allocator for accounting.
    */
   OrcStripeReader(long id, BufferAllocator allocator) {

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

@@ -17,21 +17,11 @@
 
 package org.apache.arrow.adapter.orc;
 
-import java.io.IOException;
-
 /**
  * JNI wrapper for orc stripe reader.
  */
 class OrcStripeReaderJniWrapper {
 
-  static {
-    try {
-      OrcJniUtils.loadOrcAdapterLibraryFromJar();
-    } catch (IOException e) {
-      throw new ExceptionInInitializerError(e);
-    }
-  }
-
   /**
    * Get the schema of current stripe.
    * @param readerId id of the stripe reader instance.