1 /*
2  * Copyright (C) 2016 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 #ifndef ANDROID_HIDL_TRANSPORT_UTILS_H
18 #define ANDROID_HIDL_TRANSPORT_UTILS_H
19 
20 #include <android/hidl/base/1.0/IBase.h>
21 
22 namespace android {
23 namespace hardware {
24 namespace details {
25 
26 /*
27  * Verifies the interface chain of 'interface' contains 'castTo'
28  * @param emitError if emitError is false, return Return<bool>{false} on error; if emitError
29  * is true, the Return<bool> object contains the actual error.
30  */
31 inline Return<bool> canCastInterface(::android::hidl::base::V1_0::IBase* interface,
32         const char* castTo, bool emitError = false) {
33     if (interface == nullptr) {
34         return false;
35     }
36 
37     bool canCast = false;
38     auto chainRet = interface->interfaceChain([&](const hidl_vec<hidl_string> &types) {
39         for (size_t i = 0; i < types.size(); i++) {
40             if (types[i] == castTo) {
41                 canCast = true;
42                 break;
43             }
44         }
45     });
46 
47     if (!chainRet.isOk()) {
48         // call fails, propagate the error if emitError
49         return emitError
50                 ? details::StatusOf<void, bool>(chainRet)
51                 : Return<bool>(false);
52     }
53 
54     return canCast;
55 }
56 
getDescriptor(::android::hidl::base::V1_0::IBase * interface)57 inline std::string getDescriptor(::android::hidl::base::V1_0::IBase* interface) {
58     std::string myDescriptor{};
59     auto ret = interface->interfaceDescriptor([&](const hidl_string &types) {
60         myDescriptor = types.c_str();
61     });
62     ret.isOk(); // ignored, return empty string if not isOk()
63     return myDescriptor;
64 }
65 
66 }   // namespace details
67 }   // namespace hardware
68 }   // namespace android
69 
70 #endif //ANDROID_HIDL_TRANSPORT_UTILS_H
71