pkgs/jnigen/example/in_app_java/src/android_utils/dartjni.h - native.git - Git at Google

 // Copyright (c) 2022, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 #pragma once

 // Note: include appropriate system jni.h as found by CMake, not third_party/jni.h.
 #include <jni.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>

 #if _WIN32
 #include <windows.h>
 #else
 #include <pthread.h>
 #include <unistd.h>
 #endif

 #if _WIN32
 #define FFI_PLUGIN_EXPORT __declspec(dllexport)
 #else
 #define FFI_PLUGIN_EXPORT
 #endif

 #if defined _WIN32
 #define thread_local __declspec(thread)
 #else
 #define thread_local __thread
 #endif

 #ifdef __ANDROID__
 #include <android/log.h>
 #endif

 #ifdef __ANDROID__
 #define __ENVP_CAST (JNIEnv**)
 #else
 #define __ENVP_CAST (void**)
 #endif

 /// Stores the global state of the JNI.
 typedef struct JniContext {
   JavaVM* jvm;
   jobject classLoader;
   jmethodID loadClassMethod;
   jobject currentActivity;
   jobject appContext;
 } JniContext;

 // jniEnv for this thread, used by inline functions in this header,
 // therefore declared as extern.
 extern thread_local JNIEnv* jniEnv;

 extern JniContext jni;

 /// Types used by JNI API to distinguish between primitive types.
 enum JniType {
   booleanType = 0,
   byteType = 1,
   shortType = 2,
   charType = 3,
   intType = 4,
   longType = 5,
   floatType = 6,
   doubleType = 7,
   objectType = 8,
   voidType = 9,
 };

 /// Result type for use by JNI.
 ///
 /// If [exception] is null, it means the result is valid.
 /// It's assumed that the caller knows the expected type in [result].
 typedef struct JniResult {
   jvalue result;
   jthrowable exception;
 } JniResult;

 /// Similar to [JniResult] but for class lookups.
 typedef struct JniClassLookupResult {
   jclass classRef;
   jthrowable exception;
 } JniClassLookupResult;

 /// Similar to [JniResult] but for method/field ID lookups.
 typedef struct JniPointerResult {
   void* id;
   jthrowable exception;
 } JniPointerResult;

 /// JniExceptionDetails holds 2 jstring objects, one is the result of
 /// calling `toString` on exception object, other is stack trace;
 typedef struct JniExceptionDetails {
   jstring message;
   jstring stacktrace;
 } JniExceptionDetails;

 /// This struct contains functions which wrap method call / field access conveniently along with
 /// exception checking.
 ///
 /// Flutter embedding checks for pending JNI exceptions before an FFI transition, which requires us
 /// to check for and clear the exception before returning to dart code, which requires these functions
 /// to return result types.
 typedef struct JniAccessors {
   JniClassLookupResult (*getClass)(char* internalName);
   JniPointerResult (*getFieldID)(jclass cls, char* fieldName, char* signature);
   JniPointerResult (*getStaticFieldID)(jclass cls,
                                        char* fieldName,
                                        char* signature);
   JniPointerResult (*getMethodID)(jclass cls,
                                   char* methodName,
                                   char* signature);
   JniPointerResult (*getStaticMethodID)(jclass cls,
                                         char* methodName,
                                         char* signature);
   JniResult (*newObject)(jclass cls, jmethodID ctor, jvalue* args);
   JniPointerResult (*newPrimitiveArray)(jsize length, int type);
   JniPointerResult (*newObjectArray)(jsize length,
                                      jclass elementClass,
                                      jobject initialElement);
   JniResult (*getArrayElement)(jarray array, int index, int type);
   JniResult (*callMethod)(jobject obj,
                           jmethodID methodID,
                           int callType,
                           jvalue* args);
   JniResult (*callStaticMethod)(jclass cls,
                                 jmethodID methodID,
                                 int callType,
                                 jvalue* args);
   JniResult (*getField)(jobject obj, jfieldID fieldID, int callType);
   JniResult (*getStaticField)(jclass cls, jfieldID fieldID, int callType);
   JniExceptionDetails (*getExceptionDetails)(jthrowable exception);
 } JniAccessors;

 FFI_PLUGIN_EXPORT JniAccessors* GetAccessors();

 FFI_PLUGIN_EXPORT JavaVM* GetJavaVM(void);

 FFI_PLUGIN_EXPORT JNIEnv* GetJniEnv(void);

 FFI_PLUGIN_EXPORT JNIEnv* SpawnJvm(JavaVMInitArgs* args);

 FFI_PLUGIN_EXPORT jclass LoadClass(const char* name);

 FFI_PLUGIN_EXPORT jobject GetClassLoader(void);

 FFI_PLUGIN_EXPORT jobject GetApplicationContext(void);

 FFI_PLUGIN_EXPORT jobject GetCurrentActivity(void);

 // Migration note: Below inline functions are required by C bindings, but can be moved to dartjni.c
 // once migration to pure dart bindings is complete.

 // `static inline` because `inline` doesn't work, it may still not
 // inline the function in which case a linker error may be produced.
 //
 // There has to be a better way to do this. Either to force inlining on target
 // platforms, or just leave it as normal function.

 static inline void __load_class_into(jclass* cls, const char* name) {
 #ifdef __ANDROID__
   jstring className = (*jniEnv)->NewStringUTF(jniEnv, name);
   *cls = (*jniEnv)->CallObjectMethod(jniEnv, jni.classLoader,
                                      jni.loadClassMethod, className);
   (*jniEnv)->DeleteLocalRef(jniEnv, className);
 #else
   *cls = (*jniEnv)->FindClass(jniEnv, name);
 #endif
 }

 static inline void load_class(jclass* cls, const char* name) {
   if (*cls == NULL) {
     __load_class_into(cls, name);
   }
 }

 static inline void load_class_gr(jclass* cls, const char* name) {
   if (*cls == NULL) {
     jclass tmp;
     __load_class_into(&tmp, name);
     *cls = (*jniEnv)->NewGlobalRef(jniEnv, tmp);
     (*jniEnv)->DeleteLocalRef(jniEnv, tmp);
   }
 }

 static inline void attach_thread() {
   if (jniEnv == NULL) {
     (*jni.jvm)->AttachCurrentThread(jni.jvm, __ENVP_CAST & jniEnv, NULL);
   }
 }

 static inline void load_method(jclass cls,
                                jmethodID* res,
                                const char* name,
                                const char* sig) {
   if (*res == NULL) {
     *res = (*jniEnv)->GetMethodID(jniEnv, cls, name, sig);
   }
 }

 static inline void load_static_method(jclass cls,
                                       jmethodID* res,
                                       const char* name,
                                       const char* sig) {
   if (*res == NULL) {
     *res = (*jniEnv)->GetStaticMethodID(jniEnv, cls, name, sig);
   }
 }

 static inline void load_field(jclass cls,
                               jfieldID* res,
                               const char* name,
                               const char* sig) {
   if (*res == NULL) {
     *res = (*jniEnv)->GetFieldID(jniEnv, cls, name, sig);
   }
 }

 static inline void load_static_field(jclass cls,
                                      jfieldID* res,
                                      const char* name,
                                      const char* sig) {
   if (*res == NULL) {
     *res = (*jniEnv)->GetStaticFieldID(jniEnv, cls, name, sig);
   }
 }

 static inline jobject to_global_ref(jobject ref) {
   jobject g = (*jniEnv)->NewGlobalRef(jniEnv, ref);
   (*jniEnv)->DeleteLocalRef(jniEnv, ref);
   return g;
 }

 // These functions are useful for C+Dart bindings, and not required for pure dart bindings.

 FFI_PLUGIN_EXPORT JniContext GetJniContext();
 /// For use by jni_gen's generated code
 /// don't use these.

 // these 2 fn ptr vars will be defined by generated code library
 extern JniContext (*context_getter)(void);
 extern JNIEnv* (*env_getter)(void);

 // this function will be exported by generated code library
 // it will set above 2 variables.
 FFI_PLUGIN_EXPORT void setJniGetters(struct JniContext (*cg)(void),
                                      JNIEnv* (*eg)(void));

 static inline void load_env() {
   if (jniEnv == NULL) {
     jni = context_getter();
     jniEnv = env_getter();
   }
 }

 static inline jthrowable check_exception() {
   jthrowable exception = (*jniEnv)->ExceptionOccurred(jniEnv);
   if (exception != NULL) (*jniEnv)->ExceptionClear(jniEnv);
   if (exception == NULL) return NULL;
   return to_global_ref(exception);
 }

 FFI_PLUGIN_EXPORT intptr_t InitDartApiDL(void* data);

 JNIEXPORT void JNICALL
 Java_com_github_dart_1lang_jni_PortContinuation__1resumeWith(JNIEnv* env,
                                                              jobject thiz,
                                                              jlong port,
                                                              jobject result);
 FFI_PLUGIN_EXPORT
 JniResult PortContinuation__ctor(int64_t j);
	// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	#pragma once

	// Note: include appropriate system jni.h as found by CMake, not third_party/jni.h.
	#include <jni.h>
	#include <stdint.h>
	#include <stdio.h>
	#include <stdlib.h>

	#if _WIN32
	#include <windows.h>
	#else
	#include <pthread.h>
	#include <unistd.h>
	#endif

	#if _WIN32
	#define FFI_PLUGIN_EXPORT __declspec(dllexport)
	#else
	#define FFI_PLUGIN_EXPORT
	#endif

	#if defined _WIN32
	#define thread_local __declspec(thread)
	#else
	#define thread_local __thread
	#endif

	#ifdef __ANDROID__
	#include <android/log.h>
	#endif

	#ifdef __ANDROID__
	#define __ENVP_CAST (JNIEnv**)
	#else
	#define __ENVP_CAST (void**)
	#endif

	/// Stores the global state of the JNI.
	typedef struct JniContext {
	JavaVM* jvm;
	jobject classLoader;
	jmethodID loadClassMethod;
	jobject currentActivity;
	jobject appContext;
	} JniContext;

	// jniEnv for this thread, used by inline functions in this header,
	// therefore declared as extern.
	extern thread_local JNIEnv* jniEnv;

	extern JniContext jni;

	/// Types used by JNI API to distinguish between primitive types.
	enum JniType {
	booleanType = 0,
	byteType = 1,
	shortType = 2,
	charType = 3,
	intType = 4,
	longType = 5,
	floatType = 6,
	doubleType = 7,
	objectType = 8,
	voidType = 9,
	};

	/// Result type for use by JNI.
	///
	/// If [exception] is null, it means the result is valid.
	/// It's assumed that the caller knows the expected type in [result].
	typedef struct JniResult {
	jvalue result;
	jthrowable exception;
	} JniResult;

	/// Similar to [JniResult] but for class lookups.
	typedef struct JniClassLookupResult {
	jclass classRef;
	jthrowable exception;
	} JniClassLookupResult;

	/// Similar to [JniResult] but for method/field ID lookups.
	typedef struct JniPointerResult {
	void* id;
	jthrowable exception;
	} JniPointerResult;

	/// JniExceptionDetails holds 2 jstring objects, one is the result of
	/// calling `toString` on exception object, other is stack trace;
	typedef struct JniExceptionDetails {
	jstring message;
	jstring stacktrace;
	} JniExceptionDetails;

	/// This struct contains functions which wrap method call / field access conveniently along with
	/// exception checking.
	///
	/// Flutter embedding checks for pending JNI exceptions before an FFI transition, which requires us
	/// to check for and clear the exception before returning to dart code, which requires these functions
	/// to return result types.
	typedef struct JniAccessors {
	JniClassLookupResult (getClass)(char internalName);
	JniPointerResult (getFieldID)(jclass cls, char fieldName, char* signature);
	JniPointerResult (*getStaticFieldID)(jclass cls,
	char* fieldName,
	char* signature);
	JniPointerResult (*getMethodID)(jclass cls,
	char* methodName,
	char* signature);
	JniPointerResult (*getStaticMethodID)(jclass cls,
	char* methodName,
	char* signature);
	JniResult (newObject)(jclass cls, jmethodID ctor, jvalue args);
	JniPointerResult (*newPrimitiveArray)(jsize length, int type);
	JniPointerResult (*newObjectArray)(jsize length,
	jclass elementClass,
	jobject initialElement);
	JniResult (*getArrayElement)(jarray array, int index, int type);
	JniResult (*callMethod)(jobject obj,
	jmethodID methodID,
	int callType,
	jvalue* args);
	JniResult (*callStaticMethod)(jclass cls,
	jmethodID methodID,
	int callType,
	jvalue* args);
	JniResult (*getField)(jobject obj, jfieldID fieldID, int callType);
	JniResult (*getStaticField)(jclass cls, jfieldID fieldID, int callType);
	JniExceptionDetails (*getExceptionDetails)(jthrowable exception);
	} JniAccessors;

	FFI_PLUGIN_EXPORT JniAccessors* GetAccessors();

	FFI_PLUGIN_EXPORT JavaVM* GetJavaVM(void);

	FFI_PLUGIN_EXPORT JNIEnv* GetJniEnv(void);

	FFI_PLUGIN_EXPORT JNIEnv* SpawnJvm(JavaVMInitArgs* args);

	FFI_PLUGIN_EXPORT jclass LoadClass(const char* name);

	FFI_PLUGIN_EXPORT jobject GetClassLoader(void);

	FFI_PLUGIN_EXPORT jobject GetApplicationContext(void);

	FFI_PLUGIN_EXPORT jobject GetCurrentActivity(void);

	// Migration note: Below inline functions are required by C bindings, but can be moved to dartjni.c
	// once migration to pure dart bindings is complete.

	// `static inline` because `inline` doesn't work, it may still not
	// inline the function in which case a linker error may be produced.
	//
	// There has to be a better way to do this. Either to force inlining on target
	// platforms, or just leave it as normal function.

	static inline void __load_class_into(jclass* cls, const char* name) {
	#ifdef __ANDROID__
	jstring className = (*jniEnv)->NewStringUTF(jniEnv, name);
	cls = (jniEnv)->CallObjectMethod(jniEnv, jni.classLoader,
	jni.loadClassMethod, className);
	(*jniEnv)->DeleteLocalRef(jniEnv, className);
	#else
	cls = (jniEnv)->FindClass(jniEnv, name);
	#endif
	}

	static inline void load_class(jclass* cls, const char* name) {
	if (*cls == NULL) {
	__load_class_into(cls, name);
	}
	}

	static inline void load_class_gr(jclass* cls, const char* name) {
	if (*cls == NULL) {
	jclass tmp;
	__load_class_into(&tmp, name);
	cls = (jniEnv)->NewGlobalRef(jniEnv, tmp);
	(*jniEnv)->DeleteLocalRef(jniEnv, tmp);
	}
	}

	static inline void attach_thread() {
	if (jniEnv == NULL) {
	(*jni.jvm)->AttachCurrentThread(jni.jvm, __ENVP_CAST & jniEnv, NULL);
	}
	}

	static inline void load_method(jclass cls,
	jmethodID* res,
	const char* name,
	const char* sig) {
	if (*res == NULL) {
	res = (jniEnv)->GetMethodID(jniEnv, cls, name, sig);
	}
	}

	static inline void load_static_method(jclass cls,
	jmethodID* res,
	const char* name,
	const char* sig) {
	if (*res == NULL) {
	res = (jniEnv)->GetStaticMethodID(jniEnv, cls, name, sig);
	}
	}

	static inline void load_field(jclass cls,
	jfieldID* res,
	const char* name,
	const char* sig) {
	if (*res == NULL) {
	res = (jniEnv)->GetFieldID(jniEnv, cls, name, sig);
	}
	}

	static inline void load_static_field(jclass cls,
	jfieldID* res,
	const char* name,
	const char* sig) {
	if (*res == NULL) {
	res = (jniEnv)->GetStaticFieldID(jniEnv, cls, name, sig);
	}
	}

	static inline jobject to_global_ref(jobject ref) {
	jobject g = (*jniEnv)->NewGlobalRef(jniEnv, ref);
	(*jniEnv)->DeleteLocalRef(jniEnv, ref);
	return g;
	}

	// These functions are useful for C+Dart bindings, and not required for pure dart bindings.

	FFI_PLUGIN_EXPORT JniContext GetJniContext();
	/// For use by jni_gen's generated code
	/// don't use these.

	// these 2 fn ptr vars will be defined by generated code library
	extern JniContext (*context_getter)(void);
	extern JNIEnv* (*env_getter)(void);

	// this function will be exported by generated code library
	// it will set above 2 variables.
	FFI_PLUGIN_EXPORT void setJniGetters(struct JniContext (*cg)(void),
	JNIEnv* (*eg)(void));

	static inline void load_env() {
	if (jniEnv == NULL) {
	jni = context_getter();
	jniEnv = env_getter();
	}
	}

	static inline jthrowable check_exception() {
	jthrowable exception = (*jniEnv)->ExceptionOccurred(jniEnv);
	if (exception != NULL) (*jniEnv)->ExceptionClear(jniEnv);
	if (exception == NULL) return NULL;
	return to_global_ref(exception);
	}

	FFI_PLUGIN_EXPORT intptr_t InitDartApiDL(void* data);

	JNIEXPORT void JNICALL
	Java_com_github_dart_1lang_jni_PortContinuation__1resumeWith(JNIEnv* env,
	jobject thiz,
	jlong port,
	jobject result);
	FFI_PLUGIN_EXPORT
	JniResult PortContinuation__ctor(int64_t j);