1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #define LOG_NAMESPACE "StatsLog.tag."
18 #define LOG_TAG "StatsLog_println"
19 
20 #include <jni.h>
21 #include <log/log.h>
22 #include <nativehelper/scoped_local_ref.h>
23 #include "stats_buffer_writer.h"
24 
25 namespace android {
26 
27 static void android_util_StatsLog_write(JNIEnv* env, jobject clazz, jbyteArray buf, jint size,
28         jint atomId) {
29     if (buf == NULL) {
30         return;
31     }
32     jint actualSize = env->GetArrayLength(buf);
33     if (actualSize < size) {
34         return;
35     }
36 
37     jbyte* bufferArray = env->GetByteArrayElements(buf, NULL);
38     if (bufferArray == NULL) {
39         return;
40     }
41 
42     write_buffer_to_statsd((void*) bufferArray, size, atomId);
43 
44     env->ReleaseByteArrayElements(buf, bufferArray, 0);
45 }
46 
47 /*
48  * JNI registration.
49  */
50 static const JNINativeMethod gMethods[] = {
51     /* name, signature, funcPtr */
52     { "writeImpl", "([BII)V", (void*) android_util_StatsLog_write },
53 };
54 
55 int register_android_util_StatsLog(JNIEnv* env)
56 {
57     static const char* kStatsLogClass = "android/util/StatsLog";
58 
59     ScopedLocalRef<jclass> cls(env, env->FindClass(kStatsLogClass));
60     if (cls.get() == nullptr) {
61         ALOGE("jni statsd registration failure, class not found '%s'", kStatsLogClass);
62         return JNI_ERR;
63     }
64 
65     const jint count = sizeof(gMethods) / sizeof(gMethods[0]);
66     int status = env->RegisterNatives(cls.get(), gMethods, count);
67     if (status < 0) {
68         ALOGE("jni statsd registration failure, status: %d", status);
69         return JNI_ERR;
70     }
71     return JNI_VERSION_1_4;
72 }
73 
74 }; // namespace android
75 
76 /*
77  * JNI Initialization
78  */
79 jint JNI_OnLoad(JavaVM* jvm, void* reserved) {
80     JNIEnv* e;
81 
82     ALOGV("statsd : loading JNI\n");
83     // Check JNI version
84     if (jvm->GetEnv((void**)&e, JNI_VERSION_1_4)) {
85         ALOGE("JNI version mismatch error");
86         return JNI_ERR;
87     }
88 
89     return android::register_android_util_StatsLog(e);
90 }
91