Add doc + refactor + fix formatting

java/rocksjni/iterator.cc

@@ -14,52 +14,70 @@
 #include "rocksjni/portal.h"
 #include "rocksdb/iterator.h"
 
+/*
+ * Class:     org_rocksdb_Iterator
+ * Method:    isValid0
+ * Signature: (J)Z
+ */
 jboolean Java_org_rocksdb_Iterator_isValid0(
     JNIEnv* env, jobject jobj, jlong handle) {
-  auto st = reinterpret_cast<rocksdb::Iterator*>(handle);
-  assert(st != nullptr);
-  
-  return st->Valid();
+  auto it = rocksdb::IteratorJni::getIterator(handle);
+  return it->Valid();
 }
 
+/*
+ * Class:     org_rocksdb_Iterator
+ * Method:    close0
+ * Signature: (J)V
+ */
 void Java_org_rocksdb_Iterator_seekToFirst0(
     JNIEnv* env, jobject jobj, jlong handle) {
-  auto st = reinterpret_cast<rocksdb::Iterator*>(handle);
-  assert(st != nullptr);
-  
-  st->SeekToFirst();
+  auto it = rocksdb::IteratorJni::getIterator(handle);
+  it->SeekToFirst();
 }
 
+/*
+ * Class:     org_rocksdb_Iterator
+ * Method:    seekToFirst0
+ * Signature: (J)V
+ */
 void Java_org_rocksdb_Iterator_seekToLast0(
     JNIEnv* env, jobject jobj, jlong handle) {
-  auto st = reinterpret_cast<rocksdb::Iterator*>(handle);
-  assert(st != nullptr);
-  
-  st->SeekToLast();
+  auto it = rocksdb::IteratorJni::getIterator(handle);
+  it->SeekToLast();
 }
 
+/*
+ * Class:     org_rocksdb_Iterator
+ * Method:    seekToLast0
+ * Signature: (J)V
+ */
 void Java_org_rocksdb_Iterator_next0(
     JNIEnv* env, jobject jobj, jlong handle) {
-  auto st = reinterpret_cast<rocksdb::Iterator*>(handle);
-  assert(st != nullptr);
-  
-  st->Next();
+  auto it = rocksdb::IteratorJni::getIterator(handle);
+  it->Next();
 }
 
+/*
+ * Class:     org_rocksdb_Iterator
+ * Method:    next0
+ * Signature: (J)V
+ */
 void Java_org_rocksdb_Iterator_prev0(
     JNIEnv* env, jobject jobj, jlong handle) {
-  auto st = reinterpret_cast<rocksdb::Iterator*>(handle);
-  assert(st != nullptr);
-  
-  st->Prev();
+  auto it = rocksdb::IteratorJni::getIterator(handle);
+  it->Prev();
 }
 
+/*
+ * Class:     org_rocksdb_Iterator
+ * Method:    prev0
+ * Signature: (J)V
+ */
 jbyteArray Java_org_rocksdb_Iterator_key0(
     JNIEnv* env, jobject jobj, jlong handle) {
-  auto st = reinterpret_cast<rocksdb::Iterator*>(handle);
-  assert(st != nullptr);
-  
-  rocksdb::Slice key_slice = st->key();
+  auto it = rocksdb::IteratorJni::getIterator(handle);
+  rocksdb::Slice key_slice = it->key();
 
   jbyteArray jkey = env->NewByteArray(key_slice.size());
     env->SetByteArrayRegion(
@@ -68,12 +86,15 @@ jbyteArray Java_org_rocksdb_Iterator_key0(
   return jkey;
 }
 
+/*
+ * Class:     org_rocksdb_Iterator
+ * Method:    key0
+ * Signature: (J)[B
+ */
 jbyteArray Java_org_rocksdb_Iterator_value0(
     JNIEnv* env, jobject jobj, jlong handle) {
-  auto st = reinterpret_cast<rocksdb::Iterator*>(handle);
-  assert(st != nullptr);
-  
-  rocksdb::Slice value_slice = st->value();
+  auto it = rocksdb::IteratorJni::getIterator(handle);
+  rocksdb::Slice value_slice = it->value();
 
   jbyteArray jvalue = env->NewByteArray(value_slice.size());
     env->SetByteArrayRegion(
@@ -82,27 +103,33 @@ jbyteArray Java_org_rocksdb_Iterator_value0(
   return jvalue;
 }
 
+/*
+ * Class:     org_rocksdb_Iterator
+ * Method:    value0
+ * Signature: (J)[B
+ */
 void Java_org_rocksdb_Iterator_seek0(
     JNIEnv* env, jobject jobj, jlong handle,
     jbyteArray jtarget, jint jtarget_len) {
-  auto st = reinterpret_cast<rocksdb::Iterator*>(handle);
-  assert(st != nullptr);
-  
+  auto it = rocksdb::IteratorJni::getIterator(handle);
   jbyte* target = env->GetByteArrayElements(jtarget, 0);
   rocksdb::Slice target_slice(
       reinterpret_cast<char*>(target), jtarget_len);
 
-  st->Seek(target_slice);
+  it->Seek(target_slice);
 
   env->ReleaseByteArrayElements(jtarget, target, JNI_ABORT);
 }
 
+/*
+ * Class:     org_rocksdb_Iterator
+ * Method:    seek0
+ * Signature: (J[BI)V
+ */
 void Java_org_rocksdb_Iterator_status0(
     JNIEnv* env, jobject jobj, jlong handle) {
-  auto st = reinterpret_cast<rocksdb::Iterator*>(handle);
-  assert(st != nullptr);
-  
-  rocksdb::Status s = st->status();
+  auto it = rocksdb::IteratorJni::getIterator(handle);
+  rocksdb::Status s = it->status();
 
   if (s.ok()) {
     return;
@@ -111,12 +138,15 @@ void Java_org_rocksdb_Iterator_status0(
   rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
 }
 
+/*
+ * Class:     org_rocksdb_Iterator
+ * Method:    status0
+ * Signature: (J)V
+ */
 void Java_org_rocksdb_Iterator_close0(
     JNIEnv* env, jobject jobj, jlong handle) {
-  auto st = reinterpret_cast<rocksdb::Iterator*>(handle);
-  assert(st != nullptr);
-  
-  delete st;
+  auto it = rocksdb::IteratorJni::getIterator(handle);
+  delete it;
 
   rocksdb::IteratorJni::setHandle(env, jobj, nullptr);
 }

java/rocksjni/portal.h

@@ -245,6 +245,14 @@ class IteratorJni {
         jobj, getHandleFieldID(env),
         reinterpret_cast<jlong>(op));
   }
+
+  // Cast long to rocksdb::Iterator pointer.
+  static rocksdb::Iterator* getIterator(jlong handle) {
+    auto it = reinterpret_cast<rocksdb::Iterator*>(handle);
+    assert(it != nullptr);
+
+    return it;
+  }
 };
 }  // namespace rocksdb
 #endif  // JAVA_ROCKSJNI_PORTAL_H_