1 /*
2 * Copyright (C) 2023 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-base/file.h>
18 #include <android-base/logging.h>
19
20 #include <fstream>
21
22 #include "storage.h"
23 #include "util.h"
24
ConnectedDevicesStorage()25 ConnectedDevicesStorage::ConnectedDevicesStorage() {
26 const std::string home_path = GetHomeDirPath();
27 if (home_path.empty()) {
28 return;
29 }
30
31 const std::string home_fastboot_path = home_path + kPathSeparator + ".fastboot";
32
33 if (!EnsureDirectoryExists(home_fastboot_path)) {
34 LOG(FATAL) << "Cannot create directory: " << home_fastboot_path;
35 }
36
37 // We're using a separate file for locking because the Windows LockFileEx does not
38 // permit opening a file stream for the locked file, even within the same process. So,
39 // we have to use fd or handle API to manipulate the storage files, which makes it
40 // nearly impossible to fully rewrite a file content without having to recreate it.
41 // Unfortunately, this is not an option during holding a lock.
42 devices_path_ = home_fastboot_path + kPathSeparator + "devices";
43 devices_lock_path_ = home_fastboot_path + kPathSeparator + "devices.lock";
44 }
45
WriteDevices(const FileLock &,const std::set<std::string> & devices)46 void ConnectedDevicesStorage::WriteDevices(const FileLock&, const std::set<std::string>& devices) {
47 std::ofstream devices_stream(devices_path_);
48 std::copy(devices.begin(), devices.end(),
49 std::ostream_iterator<std::string>(devices_stream, "\n"));
50 }
51
ReadDevices(const FileLock &)52 std::set<std::string> ConnectedDevicesStorage::ReadDevices(const FileLock&) {
53 std::ifstream devices_stream(devices_path_);
54 std::istream_iterator<std::string> start(devices_stream), end;
55 std::set<std::string> devices(start, end);
56 return devices;
57 }
58
Clear(const FileLock &)59 void ConnectedDevicesStorage::Clear(const FileLock&) {
60 if (!android::base::RemoveFileIfExists(devices_path_)) {
61 LOG(FATAL) << "Failed to clear connected device list: " << devices_path_;
62 }
63 }
64
Lock() const65 FileLock ConnectedDevicesStorage::Lock() const {
66 return FileLock(devices_lock_path_);
67 }