1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
/*
* Copyright (C) 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_INSTALLD_UNIQUE_FILE_H
#define ANDROID_INSTALLD_UNIQUE_FILE_H
#include <functional>
#include <string>
namespace android {
namespace installd {
// A file management helper that serves two purposes:
//
// 1. Closes the file description on destruction, similar unique_fd.
// 2. Runs a cleanup function on after close, if not cancelled.
//
// The class does not assume the relationship between the given fd and file path.
//
// Example:
//
// UniqueFile file(open(...),
// filepath,
// [](const std::string& path) {
// unlink(path.c_str());
// });
// if (file.fd() == -1) {
// // Error opening...
// }
//
// ...
// if (error) {
// // At this point, when the UniqueFile is destructed, the cleanup function will run
// // (e.g. to delete the file) after the fd is closed.
// return -1;
// }
//
// (Success case)
// file.DisableCleanup();
// // At this point, when the UniqueFile is destructed, the cleanup function will not run
// // (e.g. leaving the file around) after the fd is closed.
//
class UniqueFile {
private:
using CleanUpFunction = std::function<void (const std::string&)>;
public:
UniqueFile();
UniqueFile(int value, std::string path);
UniqueFile(int value, std::string path, CleanUpFunction cleanup);
UniqueFile(UniqueFile&& other);
~UniqueFile();
UniqueFile& operator=(UniqueFile&& other);
int fd() const {
return value_;
}
const std::string& path() const {
return path_;
}
void DisableAutoClose() {
auto_close_ = false;
}
void DisableCleanup() {
do_cleanup_ = false;
}
void reset();
void reset(int new_value, std::string path, CleanUpFunction new_cleanup = nullptr);
private:
void release();
int value_;
std::string path_;
CleanUpFunction cleanup_;
bool do_cleanup_;
bool auto_close_;
};
} // namespace installd
} // namespace android
#endif // ANDROID_INSTALLD_UNIQUE_FILE_H
|
