mpv/misc/jni.h

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2018-03-10 03:25:51 +00:00
/*
* JNI utility functions
*
* Copyright (c) 2015-2016 Matthieu Bouron <matthieu.bouron stupeflix.com>
*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* mpv is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef MP_JNI_H
#define MP_JNI_H
#include <jni.h>
#include "common/msg.h"
/* Convenience macros */
#define MP_JNI_GET_ENV(obj) mp_jni_get_env((obj)->log)
#define MP_JNI_EXCEPTION_CHECK() mp_jni_exception_check(env, 0, NULL)
#define MP_JNI_EXCEPTION_LOG(obj) mp_jni_exception_check(env, 1, (obj)->log)
#define MP_JNI_DO(what, obj, method, ...) (*env)->what(env, obj, method, ##__VA_ARGS__)
#define MP_JNI_NEW(clazz, method, ...) MP_JNI_DO(NewObject, clazz, method, ##__VA_ARGS__)
#define MP_JNI_CALL_INT(obj, method, ...) MP_JNI_DO(CallIntMethod, obj, method, ##__VA_ARGS__)
#define MP_JNI_CALL_BOOL(obj, method, ...) MP_JNI_DO(CallBooleanMethod, obj, method, ##__VA_ARGS__)
#define MP_JNI_CALL_VOID(obj, method, ...) MP_JNI_DO(CallVoidMethod, obj, method, ##__VA_ARGS__)
#define MP_JNI_CALL_STATIC_INT(clazz, method, ...) MP_JNI_DO(CallStaticIntMethod, clazz, method, ##__VA_ARGS__)
#define MP_JNI_CALL_OBJECT(obj, method, ...) MP_JNI_DO(CallObjectMethod, obj, method, ##__VA_ARGS__)
#define MP_JNI_GET_INT(obj, field) MP_JNI_DO(GetIntField, obj, field)
#define MP_JNI_GET_LONG(obj, field) MP_JNI_DO(GetLongField, obj, field)
#define MP_JNI_GET_BOOL(obj, field) MP_JNI_DO(GetBoolField, obj, field)
/*
* Attach permanently a JNI environment to the current thread and retrieve it.
*
* If successfully attached, the JNI environment will automatically be detached
* at thread destruction.
*
* @param attached pointer to an integer that will be set to 1 if the
* environment has been attached to the current thread or 0 if it is
* already attached.
* @param log context used for logging
* @return the JNI environment on success, NULL otherwise
*/
JNIEnv *mp_jni_get_env(struct mp_log *log);
/*
* Convert a jstring to its utf characters equivalent.
*
* @param env JNI environment
* @param string Java string to convert
* @param log context used for logging
* @return a pointer to an array of unicode characters on success, NULL
* otherwise
*/
char *mp_jni_jstring_to_utf_chars(JNIEnv *env, jstring string, struct mp_log *log);
/*
* Convert utf chars to its jstring equivalent.
*
* @param env JNI environment
* @param utf_chars a pointer to an array of unicode characters
* @param log context used for logging
* @return a Java string object on success, NULL otherwise
*/
jstring mp_jni_utf_chars_to_jstring(JNIEnv *env, const char *utf_chars, struct mp_log *log);
/*
* Extract the error summary from a jthrowable in the form of "className: errorMessage"
*
* @param env JNI environment
* @param exception exception to get the summary from
* @param error address pointing to the error, the value is updated if a
* summary can be extracted
* @param log context used for logging
* @return 0 on success, < 0 otherwise
*/
int mp_jni_exception_get_summary(JNIEnv *env, jthrowable exception, char **error, struct mp_log *log);
/*
* Check if an exception has occurred,log it using av_log and clear it.
*
* @param env JNI environment
* @param value used to enable logging if an exception has occurred,
* 0 disables logging, != 0 enables logging
* @param log context used for logging
*/
int mp_jni_exception_check(JNIEnv *env, int logging, struct mp_log *log);
/*
* Jni field type.
*/
enum MPJniFieldType {
MP_JNI_CLASS,
MP_JNI_FIELD,
MP_JNI_STATIC_FIELD,
MP_JNI_STATIC_FIELD_AS_INT,
MP_JNI_METHOD,
MP_JNI_STATIC_METHOD
};
/*
* Jni field describing a class, a field or a method to be retrieved using
* the mp_jni_init_jfields method.
*/
struct MPJniField {
const char *name;
const char *method;
const char *signature;
enum MPJniFieldType type;
int offset;
int mandatory;
};
/*
* Retrieve class references, field ids and method ids to an arbitrary structure.
*
* @param env JNI environment
* @param jfields a pointer to an arbitrary structure where the different
* fields are declared and where the MPJNIField mapping table offsets are
* pointing to
* @param jfields_mapping null terminated array of MPJNIFields describing
* the class/field/method to be retrieved
* @param global make the classes references global. It is the caller
* responsibility to properly release global references.
* @param log_ctx context used for logging, can be NULL
* @return 0 on success, < 0 otherwise
*/
int mp_jni_init_jfields(JNIEnv *env, void *jfields, const struct MPJniField *jfields_mapping, int global, struct mp_log *log);
/*
* Delete class references, field ids and method ids of an arbitrary structure.
*
* @param env JNI environment
* @param jfields a pointer to an arbitrary structure where the different
* fields are declared and where the MPJNIField mapping table offsets are
* pointing to
* @param jfields_mapping null terminated array of MPJNIFields describing
* the class/field/method to be deleted
* @param global treat the classes references as global and delete them
* accordingly
* @param log_ctx context used for logging, can be NULL
* @return 0 on success, < 0 otherwise
*/
int mp_jni_reset_jfields(JNIEnv *env, void *jfields, const struct MPJniField *jfields_mapping, int global, struct mp_log *log);
#endif