1 /*
2  * Copyright (C) 2023 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 #pragma once
17 
18 #include <android-base/thread_annotations.h>
19 #include <jni.h>
20 
21 #include <optional>
22 #include <string>
23 
24 #include "absl/status/statusor.h"
25 #include "fcp/client/flags.h"
26 #include "fcp/client/log_manager.h"
27 #include "fcp/client/simple_task_environment.h"
28 
29 namespace fcp {
30 namespace client {
31 namespace engine {
32 namespace jni {
33 
34 // A wrapper around the Java example iterator class. Object is only valid for
35 // the time of a JNI call and must not be kept around for any longer. Can be
36 // created on an arbitrary thread.
37 class ExampleIteratorWrapperImpl : public ExampleIterator {
38  public:
39   ExampleIteratorWrapperImpl(JavaVM *jvm, jobject example_iterator);
40 
41   ~ExampleIteratorWrapperImpl() override;
42 
43   absl::StatusOr<std::string> Next() override;
44 
45   void Close() override final;
46 
47  private:
48   jmethodID next_id_;
49   jmethodID close_id_;
50   std::mutex close_mu_;
51   bool closed_ GUARDED_BY(close_mu_);
52   JavaVM *const jvm_;
53   jobject jthis_;
54 };
55 
56 }  // namespace jni
57 }  // namespace engine
58 }  // namespace client
59 }  // namespace fcp
60