1 /*
2 * Copyright (C) 2018 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
17 // Utility class that provides similar calls like JNIEnv, but performs
18 // additional checks on them, so that it's harder to use them incorrectly.
19
20 #ifndef LIBTEXTCLASSIFIER_UTILS_JAVA_JNI_HELPER_H_
21 #define LIBTEXTCLASSIFIER_UTILS_JAVA_JNI_HELPER_H_
22
23 #include <jni.h>
24
25 #include <string>
26
27 #include "utils/base/status.h"
28 #include "utils/base/statusor.h"
29 #include "utils/java/jni-base.h"
30
31 #define TC3_ENSURE_LOCAL_CAPACITY_OR_RETURN \
32 if (!EnsureLocalCapacity(env, 1)) { \
33 TC3_LOG(ERROR) << "EnsureLocalCapacity(1) failed."; \
34 return {Status::UNKNOWN}; \
35 }
36
37 #define TC3_NO_EXCEPTION_OR_RETURN \
38 if (JniExceptionCheckAndClear(env)) { \
39 return {Status::UNKNOWN}; \
40 }
41
42 #define TC3_NOT_NULL_OR_RETURN \
43 if (result == nullptr) { \
44 return {Status::UNKNOWN}; \
45 }
46
47 #define TC3_DEFINE_VARIADIC_SCOPED_LOCAL_REF_ENV_METHOD( \
48 METHOD_NAME, RETURN_TYPE, INPUT_TYPE, POST_CHECK) \
49 template <typename T = RETURN_TYPE> \
50 static StatusOr<ScopedLocalRef<T>> METHOD_NAME( \
51 JNIEnv* env, INPUT_TYPE object, jmethodID method_id, ...) { \
52 TC3_ENSURE_LOCAL_CAPACITY_OR_RETURN; \
53 \
54 va_list args; \
55 va_start(args, method_id); \
56 ScopedLocalRef<T> result( \
57 reinterpret_cast<T>(env->METHOD_NAME##V(object, method_id, args)), \
58 env); \
59 POST_CHECK \
60 va_end(args); \
61 \
62 TC3_NO_EXCEPTION_OR_RETURN; \
63 return result; \
64 }
65
66 #define TC3_JNI_NO_CHECK \
67 {}
68
69 namespace libtextclassifier3 {
70
71 class JniHelper {
72 public:
73 // Misc methods.
74 static StatusOr<ScopedLocalRef<jclass>> FindClass(JNIEnv* env,
75 const char* class_name);
76
77 template <typename T = jobject>
78 static StatusOr<ScopedLocalRef<T>> GetObjectArrayElement(JNIEnv* env,
79 jobjectArray array,
80 jsize index);
81 static StatusOr<jmethodID> GetMethodID(JNIEnv* env, jclass clazz,
82 const char* method_name,
83 const char* return_type);
84
85 static StatusOr<ScopedLocalRef<jobject>> GetStaticObjectField(
86 JNIEnv* env, jclass class_name, jfieldID field_id);
87
88 // New* methods.
89 TC3_DEFINE_VARIADIC_SCOPED_LOCAL_REF_ENV_METHOD(NewObject, jobject, jclass,
90 TC3_NOT_NULL_OR_RETURN);
91 static StatusOr<ScopedLocalRef<jobjectArray>> NewObjectArray(
92 JNIEnv* env, jsize length, jclass element_class,
93 jobject initial_element = nullptr);
94 static StatusOr<ScopedLocalRef<jbyteArray>> NewByteArray(JNIEnv* env,
95 jsize length);
96 static StatusOr<ScopedLocalRef<jintArray>> NewIntArray(JNIEnv* env,
97 jsize length);
98 static StatusOr<ScopedLocalRef<jstring>> NewStringUTF(JNIEnv* env,
99 const char* bytes);
100 static StatusOr<ScopedLocalRef<jfloatArray>> NewFloatArray(JNIEnv* env,
101 jsize length);
102
103 static StatusOr<jsize> GetArrayLength(JNIEnv* env, jarray jinput_fragments);
104
105 static Status SetObjectArrayElement(JNIEnv* env, jobjectArray array,
106 jsize index, jobject val);
107
108 // Call* methods.
109 TC3_DEFINE_VARIADIC_SCOPED_LOCAL_REF_ENV_METHOD(CallObjectMethod, jobject,
110 jobject, TC3_JNI_NO_CHECK);
111 TC3_DEFINE_VARIADIC_SCOPED_LOCAL_REF_ENV_METHOD(CallStaticObjectMethod,
112 jobject, jclass,
113 TC3_JNI_NO_CHECK);
114 static Status CallVoidMethod(JNIEnv* env, jobject object, jmethodID method_id,
115 ...);
116 static StatusOr<bool> CallBooleanMethod(JNIEnv* env, jobject object,
117 jmethodID method_id, ...);
118 static StatusOr<int32> CallIntMethod(JNIEnv* env, jobject object,
119 jmethodID method_id, ...);
120 static StatusOr<int64> CallLongMethod(JNIEnv* env, jobject object,
121 jmethodID method_id, ...);
122 static StatusOr<float> CallFloatMethod(JNIEnv* env, jobject object,
123 jmethodID method_id, ...);
124 static StatusOr<double> CallDoubleMethod(JNIEnv* env, jobject object,
125 jmethodID method_id, ...);
126
127 template <class T>
128 static StatusOr<T> CallStaticIntMethod(JNIEnv* env, jclass clazz,
129 jmethodID method_id, ...);
130 };
131
132 template <typename T>
GetObjectArrayElement(JNIEnv * env,jobjectArray array,jsize index)133 StatusOr<ScopedLocalRef<T>> JniHelper::GetObjectArrayElement(JNIEnv* env,
134 jobjectArray array,
135 jsize index) {
136 TC3_ENSURE_LOCAL_CAPACITY_OR_RETURN;
137 ScopedLocalRef<T> result(
138 reinterpret_cast<T>(env->GetObjectArrayElement(array, index)), env);
139
140 TC3_NO_EXCEPTION_OR_RETURN;
141 return result;
142 }
143
144 template <class T>
CallStaticIntMethod(JNIEnv * env,jclass clazz,jmethodID method_id,...)145 StatusOr<T> JniHelper::CallStaticIntMethod(JNIEnv* env, jclass clazz,
146 jmethodID method_id, ...) {
147 va_list args;
148 va_start(args, method_id);
149 jint result = env->CallStaticIntMethodV(clazz, method_id, args);
150 va_end(args);
151
152 TC3_NO_EXCEPTION_OR_RETURN;
153 return result;
154 }
155
156 } // namespace libtextclassifier3
157
158 #endif // LIBTEXTCLASSIFIER_UTILS_JAVA_JNI_HELPER_H_
159