misc: add jni helpers

1 files changed, 161 insertions, 0 deletions

diff --git a/misc/jni.h b/misc/jni.h
new file mode 100644
index 0000000000..c9e4c28fe7
--- /dev/null
+++ b/misc/jni.h
@@ -0,0 +1,161 @@
+/*
+ * 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