ffjni.h (4931B)
1 /* 2 * JNI utility functions 3 * 4 * Copyright (c) 2015-2016 Matthieu Bouron <matthieu.bouron stupeflix.com> 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23 #ifndef AVCODEC_FFJNI_H 24 #define AVCODEC_FFJNI_H 25 26 #include "jni.h" 27 #include <stddef.h> 28 29 /* 30 * Attach permanently a JNI environment to the current thread and retrieve it. 31 * 32 * If successfully attached, the JNI environment will automatically be detached 33 * at thread destruction. 34 * 35 * @param attached pointer to an integer that will be set to 1 if the 36 * environment has been attached to the current thread or 0 if it is 37 * already attached. 38 * @param log_ctx context used for logging, can be NULL 39 * @return the JNI environment on success, NULL otherwise 40 */ 41 JNIEnv *ff_jni_get_env(void *log_ctx); 42 43 /* 44 * Convert a jstring to its utf characters equivalent. 45 * 46 * @param env JNI environment 47 * @param string Java string to convert 48 * @param log_ctx context used for logging, can be NULL 49 * @return a pointer to an array of unicode characters on success, NULL 50 * otherwise 51 */ 52 char *ff_jni_jstring_to_utf_chars(JNIEnv *env, jstring string, void *log_ctx); 53 54 /* 55 * Convert utf chars to its jstring equivalent. 56 * 57 * @param env JNI environment 58 * @param utf_chars a pointer to an array of unicode characters 59 * @param log_ctx context used for logging, can be NULL 60 * @return a Java string object on success, NULL otherwise 61 */ 62 jstring ff_jni_utf_chars_to_jstring(JNIEnv *env, const char *utf_chars, void *log_ctx); 63 64 /* 65 * Extract the error summary from a jthrowable in the form of "className: errorMessage" 66 * 67 * @param env JNI environment 68 * @param exception exception to get the summary from 69 * @param error address pointing to the error, the value is updated if a 70 * summary can be extracted 71 * @param log_ctx context used for logging, can be NULL 72 * @return 0 on success, < 0 otherwise 73 */ 74 int ff_jni_exception_get_summary(JNIEnv *env, jthrowable exception, char **error, void *log_ctx); 75 76 /* 77 * Check if an exception has occurred,log it using av_log and clear it. 78 * 79 * @param env JNI environment 80 * @param log value used to enable logging if an exception has occurred, 81 * 0 disables logging, != 0 enables logging 82 * @param log_ctx context used for logging, can be NULL 83 */ 84 int ff_jni_exception_check(JNIEnv *env, int log, void *log_ctx); 85 86 /* 87 * Jni field type. 88 */ 89 enum FFJniFieldType { 90 91 FF_JNI_CLASS, 92 FF_JNI_FIELD, 93 FF_JNI_STATIC_FIELD, 94 FF_JNI_METHOD, 95 FF_JNI_STATIC_METHOD 96 97 }; 98 99 /* 100 * Jni field describing a class, a field or a method to be retrieved using 101 * the ff_jni_init_jfields method. 102 */ 103 struct FFJniField { 104 105 const char *name; 106 const char *method; 107 const char *signature; 108 enum FFJniFieldType type; 109 size_t offset; 110 int mandatory; 111 112 }; 113 114 /* 115 * Retrieve class references, field ids and method ids to an arbitrary structure. 116 * 117 * @param env JNI environment 118 * @param jfields a pointer to an arbitrary structure where the different 119 * fields are declared and where the FFJNIField mapping table offsets are 120 * pointing to 121 * @param jfields_mapping null terminated array of FFJNIFields describing 122 * the class/field/method to be retrieved 123 * @param global make the classes references global. It is the caller 124 * responsibility to properly release global references. 125 * @param log_ctx context used for logging, can be NULL 126 * @return 0 on success, < 0 otherwise 127 */ 128 int ff_jni_init_jfields(JNIEnv *env, void *jfields, const struct FFJniField *jfields_mapping, int global, void *log_ctx); 129 130 /* 131 * Delete class references, field ids and method ids of an arbitrary structure. 132 * 133 * @param env JNI environment 134 * @param jfields a pointer to an arbitrary structure where the different 135 * fields are declared and where the FFJNIField mapping table offsets are 136 * pointing to 137 * @param jfields_mapping null terminated array of FFJNIFields describing 138 * the class/field/method to be deleted 139 * @param global threat the classes references as global and delete them 140 * accordingly 141 * @param log_ctx context used for logging, can be NULL 142 * @return 0 on success, < 0 otherwise 143 */ 144 int ff_jni_reset_jfields(JNIEnv *env, void *jfields, const struct FFJniField *jfields_mapping, int global, void *log_ctx); 145 146 #endif /* AVCODEC_FFJNI_H */