| /* |
| * Copyright (C) 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef LIBTEXTCLASSIFIER_UTILS_JAVA_JNI_BASE_H_ |
| #define LIBTEXTCLASSIFIER_UTILS_JAVA_JNI_BASE_H_ |
| |
| #include <jni.h> |
| |
| #include <string> |
| |
| #include "utils/base/statusor.h" |
| |
| // When we use a macro as an argument for a macro, an additional level of |
| // indirection is needed, if the macro argument is used with # or ##. |
| #define TC3_ADD_QUOTES_HELPER(TOKEN) #TOKEN |
| #define TC3_ADD_QUOTES(TOKEN) TC3_ADD_QUOTES_HELPER(TOKEN) |
| |
| #ifndef TC3_PACKAGE_NAME |
| #define TC3_PACKAGE_NAME com_google_android_textclassifier |
| #endif |
| |
| #ifndef TC3_PACKAGE_PATH |
| #define TC3_PACKAGE_PATH \ |
| "com/google/android/textclassifier/" |
| #endif |
| |
| #define TC3_JNI_METHOD_NAME_INTERNAL(package_name, class_name, method_name) \ |
| Java_##package_name##_##class_name##_##method_name |
| |
| #define TC3_JNI_METHOD_PRIMITIVE(return_type, package_name, class_name, \ |
| method_name) \ |
| JNIEXPORT return_type JNICALL TC3_JNI_METHOD_NAME_INTERNAL( \ |
| package_name, class_name, method_name) |
| |
| // The indirection is needed to correctly expand the TC3_PACKAGE_NAME macro. |
| // See the explanation near TC3_ADD_QUOTES macro. |
| #define TC3_JNI_METHOD2(return_type, package_name, class_name, method_name) \ |
| TC3_JNI_METHOD_PRIMITIVE(return_type, package_name, class_name, method_name) |
| |
| #define TC3_JNI_METHOD(return_type, class_name, method_name) \ |
| TC3_JNI_METHOD2(return_type, TC3_PACKAGE_NAME, class_name, method_name) |
| |
| #define TC3_JNI_METHOD_NAME2(package_name, class_name, method_name) \ |
| TC3_JNI_METHOD_NAME_INTERNAL(package_name, class_name, method_name) |
| |
| #define TC3_JNI_METHOD_NAME(class_name, method_name) \ |
| TC3_JNI_METHOD_NAME2(TC3_PACKAGE_NAME, class_name, method_name) |
| |
| namespace libtextclassifier3 { |
| |
| // Returns true if the requested capacity is available. |
| bool EnsureLocalCapacity(JNIEnv* env, int capacity); |
| |
| // Returns true if there was an exception. Also it clears the exception. |
| bool JniExceptionCheckAndClear(JNIEnv* env, |
| bool print_exception_on_error = true); |
| |
| // A deleter to be used with std::unique_ptr to delete JNI global references. |
| class GlobalRefDeleter { |
| public: |
| explicit GlobalRefDeleter(JavaVM* jvm) : jvm_(jvm) {} |
| |
| GlobalRefDeleter(const GlobalRefDeleter& orig) = default; |
| |
| // Copy assignment to allow move semantics in ScopedGlobalRef. |
| GlobalRefDeleter& operator=(const GlobalRefDeleter& rhs) { |
| TC3_CHECK_EQ(jvm_, rhs.jvm_); |
| return *this; |
| } |
| |
| // The delete operator. |
| void operator()(jobject object) const { |
| JNIEnv* env; |
| if (object != nullptr && jvm_ != nullptr && |
| JNI_OK == |
| jvm_->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_4)) { |
| env->DeleteGlobalRef(object); |
| } |
| } |
| |
| private: |
| // The jvm_ stashed to use for deletion. |
| JavaVM* const jvm_; |
| }; |
| |
| // A deleter to be used with std::unique_ptr to delete JNI local references. |
| class LocalRefDeleter { |
| public: |
| explicit LocalRefDeleter(JNIEnv* env) |
| : env_(env) {} // NOLINT(runtime/explicit) |
| |
| LocalRefDeleter(const LocalRefDeleter& orig) = default; |
| |
| // Copy assignment to allow move semantics in ScopedLocalRef. |
| LocalRefDeleter& operator=(const LocalRefDeleter& rhs) { |
| env_ = rhs.env_; |
| return *this; |
| } |
| |
| // The delete operator. |
| void operator()(jobject object) const { |
| if (env_) { |
| env_->DeleteLocalRef(object); |
| } |
| } |
| |
| private: |
| // The env_ stashed to use for deletion. Thread-local, don't share! |
| JNIEnv* env_; |
| }; |
| |
| // A smart pointer that deletes a reference when it goes out of scope. |
| // |
| // Note that this class is not thread-safe since it caches JNIEnv in |
| // the deleter. Do not use the same jobject across different threads. |
| template <typename T, typename Env, typename Deleter> |
| class ScopedRef { |
| public: |
| ScopedRef() : ptr_(nullptr, Deleter(nullptr)) {} |
| ScopedRef(T value, Env* env) : ptr_(value, Deleter(env)) {} |
| |
| T get() const { return ptr_.get(); } |
| |
| T release() { return ptr_.release(); } |
| |
| bool operator!() const { return !ptr_; } |
| |
| bool operator==(void* value) const { return ptr_.get() == value; } |
| |
| explicit operator bool() const { return ptr_ != nullptr; } |
| |
| void reset(T value, Env* env) { |
| ptr_.reset(value); |
| ptr_.get_deleter() = Deleter(env); |
| } |
| |
| private: |
| std::unique_ptr<typename std::remove_pointer<T>::type, Deleter> ptr_; |
| }; |
| |
| template <typename T, typename U, typename Env, typename Deleter> |
| inline bool operator==(const ScopedRef<T, Env, Deleter>& x, |
| const ScopedRef<U, Env, Deleter>& y) { |
| return x.get() == y.get(); |
| } |
| |
| template <typename T, typename Env, typename Deleter> |
| inline bool operator==(const ScopedRef<T, Env, Deleter>& x, std::nullptr_t) { |
| return x.get() == nullptr; |
| } |
| |
| template <typename T, typename Env, typename Deleter> |
| inline bool operator==(std::nullptr_t, const ScopedRef<T, Env, Deleter>& x) { |
| return nullptr == x.get(); |
| } |
| |
| template <typename T, typename U, typename Env, typename Deleter> |
| inline bool operator!=(const ScopedRef<T, Env, Deleter>& x, |
| const ScopedRef<U, Env, Deleter>& y) { |
| return x.get() != y.get(); |
| } |
| |
| template <typename T, typename Env, typename Deleter> |
| inline bool operator!=(const ScopedRef<T, Env, Deleter>& x, std::nullptr_t) { |
| return x.get() != nullptr; |
| } |
| |
| template <typename T, typename Env, typename Deleter> |
| inline bool operator!=(std::nullptr_t, const ScopedRef<T, Env, Deleter>& x) { |
| return nullptr != x.get(); |
| } |
| |
| template <typename T, typename U, typename Env, typename Deleter> |
| inline bool operator<(const ScopedRef<T, Env, Deleter>& x, |
| const ScopedRef<U, Env, Deleter>& y) { |
| return x.get() < y.get(); |
| } |
| |
| template <typename T, typename U, typename Env, typename Deleter> |
| inline bool operator>(const ScopedRef<T, Env, Deleter>& x, |
| const ScopedRef<U, Env, Deleter>& y) { |
| return x.get() > y.get(); |
| } |
| |
| // A smart pointer that deletes a JNI global reference when it goes out |
| // of scope. Usage is: |
| // ScopedGlobalRef<jobject> scoped_global(env->JniFunction(), jvm); |
| template <typename T> |
| using ScopedGlobalRef = ScopedRef<T, JavaVM, GlobalRefDeleter>; |
| |
| // Ditto, but usage is: |
| // ScopedLocalRef<jobject> scoped_local(env->JniFunction(), env); |
| template <typename T> |
| using ScopedLocalRef = ScopedRef<T, JNIEnv, LocalRefDeleter>; |
| |
| // A helper to create global references. |
| template <typename T> |
| ScopedGlobalRef<T> MakeGlobalRef(T object, JNIEnv* env, JavaVM* jvm) { |
| const jobject global_object = env->NewGlobalRef(object); |
| return ScopedGlobalRef<T>(reinterpret_cast<T>(global_object), jvm); |
| } |
| |
| } // namespace libtextclassifier3 |
| |
| #endif // LIBTEXTCLASSIFIER_UTILS_JAVA_JNI_BASE_H_ |