Fix to memory dealocation when creating a slice from a byte buffer

java/org/rocksdb/Slice.java

@@ -55,7 +55,23 @@ public class Slice extends AbstractSlice<byte[]> {
     createNewSlice1(data);
   }
 
+  /**
+   * Deletes underlying C++ slice pointer
+   * and any buffered data.
+   *
+   * <p/>
+   * Note that this function should be called only after all
+   * RocksDB instances referencing the slice are closed.
+   * Otherwise an undefined behavior will occur.
+   */
+  @Override
+  protected void disposeInternal() {
+    super.disposeInternal();
+    disposeInternalBuf(nativeHandle_);
+  }
+
   @Override protected final native byte[] data0(long handle);
   private native void createNewSlice0(byte[] data, int length);
   private native void createNewSlice1(byte[] data);
+  private native void disposeInternalBuf(long handle);
 }

java/rocksjni/slice.cc

@@ -130,16 +130,19 @@ void Java_org_rocksdb_Slice_createNewSlice0(
 void Java_org_rocksdb_Slice_createNewSlice1(
     JNIEnv * env, jobject jobj, jbyteArray data) {
 
+  const int len = env->GetArrayLength(data);
+
   jboolean isCopy;
   jbyte* ptrData = env->GetByteArrayElements(data, &isCopy);
+  const char* buf = new char[len];
+  memcpy((void*)buf, ptrData, len);
 
-  const rocksdb::Slice* slice = new rocksdb::Slice((const char*)ptrData, env->GetArrayLength(data));
+  const rocksdb::Slice* slice = new rocksdb::Slice(buf, env->GetArrayLength(data));
   rocksdb::AbstractSliceJni::setHandle(env, jobj, slice);
 
-  env->ReleaseByteArrayElements(data, ptrData, JNI_COMMIT);
+  env->ReleaseByteArrayElements(data, ptrData, JNI_ABORT);
 
-  //TODO where do we free ptrData later?
+  //NOTE: buf will be deleted in the org.rocksdb.Slice#dispose method
-  //do we need to call env->ReleaseByteArrayElements(data, ptrData, JNI_ABORT) in the org.rocksdb.Slice#dispose() method?
 }
 
 /*
@@ -156,6 +159,17 @@ jbyteArray Java_org_rocksdb_Slice_data0(
   return data;
 }
 
+/*
+ * Class:     org_rocksdb_Slice
+ * Method:    disposeInternalBuf
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_Slice_disposeInternalBuf(
+    JNIEnv * env, jobject jobj, jlong handle) {
+    const rocksdb::Slice* slice = reinterpret_cast<rocksdb::Slice*>(handle);
+    delete [] slice->data_;
+}
+
 //</editor-fold>
 
 //<editor-fold desc="org.rocksdb.DirectSlice>