ceph/src/rocksdb/java/rocksjni/table_filter_jnicallback.cc

   1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under both the GPLv2 (found in the
   3 //  COPYING file in the root directory) and Apache 2.0 License
   4 //  (found in the LICENSE.Apache file in the root directory).
   5 //
   6 // This file implements the callback "bridge" between Java and C++ for
   7 // ROCKSDB_NAMESPACE::TableFilter.
   8
   9 #include "rocksjni/table_filter_jnicallback.h"
  10 #include "rocksjni/portal.h"
  11
  12 namespace ROCKSDB_NAMESPACE {
  13 TableFilterJniCallback::TableFilterJniCallback(
  14     JNIEnv* env, jobject jtable_filter)
  15     : JniCallback(env, jtable_filter) {
  16   m_jfilter_methodid =
  17       AbstractTableFilterJni::getFilterMethod(env);
  18   if(m_jfilter_methodid == nullptr) {
  19     // exception thrown: NoSuchMethodException or OutOfMemoryError
  20     return;
  21   }
  22
  23   // create the function reference
  24   /*
  25   Note the JNI ENV must be obtained/release
  26   on each call to the function itself as
  27   it may be called from multiple threads
  28   */
  29   m_table_filter_function =
  30       [this](const ROCKSDB_NAMESPACE::TableProperties& table_properties) {
  31         jboolean attached_thread = JNI_FALSE;
  32         JNIEnv* thread_env = getJniEnv(&attached_thread);
  33         assert(thread_env != nullptr);
  34
  35         // create a Java TableProperties object
  36         jobject jtable_properties = TablePropertiesJni::fromCppTableProperties(
  37             thread_env, table_properties);
  38         if (jtable_properties == nullptr) {
  39           // exception thrown from fromCppTableProperties
  40           thread_env->ExceptionDescribe();  // print out exception to stderr
  41           releaseJniEnv(attached_thread);
  42           return false;
  43         }
  44
  45         jboolean result = thread_env->CallBooleanMethod(
  46             m_jcallback_obj, m_jfilter_methodid, jtable_properties);
  47         if (thread_env->ExceptionCheck()) {
  48           // exception thrown from CallBooleanMethod
  49           thread_env->DeleteLocalRef(jtable_properties);
  50           thread_env->ExceptionDescribe();  // print out exception to stderr
  51           releaseJniEnv(attached_thread);
  52           return false;
  53         }
  54
  55         // ok... cleanup and then return
  56         releaseJniEnv(attached_thread);
  57         return static_cast<bool>(result);
  58       };
  59 }
  60
  61 std::function<bool(const ROCKSDB_NAMESPACE::TableProperties&)>
  62 TableFilterJniCallback::GetTableFilterFunction() {
  63   return m_table_filter_function;
  64 }
  65
  66 }  // namespace ROCKSDB_NAMESPACE