1 /*
2  * Copyright (C) 2017 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 #include <android_runtime/AndroidRuntime.h>
18 #include <log/log.h>
19 
20 #include <string>
21 
22 // Use reflection to query the default cache dir.
23 // The function is NOT thread-safe. It is expected to be called
24 // at most once per process.
rsQueryCacheDir()25 extern "C" const char* rsQueryCacheDir() {
26     static std::string cacheDir;
27     // First check if we have JavaVM running in this process.
28     if (android::AndroidRuntime::getJavaVM()) {
29         JNIEnv* env = android::AndroidRuntime::getJNIEnv();
30         if (env) {
31             jclass cacheDirClass = env->FindClass("android/renderscript/RenderScriptCacheDir");
32             jfieldID cacheDirID = env->GetStaticFieldID(cacheDirClass, "mCacheDir", "Ljava/io/File;");
33             jobject cache_dir = env->GetStaticObjectField(cacheDirClass, cacheDirID);
34 
35             if (cache_dir) {
36                 jclass fileClass = env->FindClass("java/io/File");
37                 jmethodID getPath = env->GetMethodID(fileClass, "getPath", "()Ljava/lang/String;");
38                 jstring path_string = (jstring)env->CallObjectMethod(cache_dir, getPath);
39                 const char *path_chars = env->GetStringUTFChars(path_string, NULL);
40 
41                 ALOGD("Successfully queried cache dir: %s", path_chars);
42                 cacheDir = std::string(path_chars);
43                 env->ReleaseStringUTFChars(path_string, path_chars);
44             } else {
45                 ALOGD("Cache dir not initialized");
46             }
47         } else {
48             ALOGD("Failed to query the default cache dir.");
49         }
50     }
51 
52     return cacheDir.c_str();
53 }
54 
55