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 #pragma once
18
19 #include <iterator>
20 #include <optional>
21 #include <string>
22 #include <string_view>
23
24 #include <dirent.h>
25
26 namespace android::incfs::path {
27
28 namespace details {
29 void appendNextPath(std::string& res, std::string_view c);
30 }
31
32 std::string fromFd(int fd);
33 bool isAbsolute(std::string_view path);
34 std::string normalize(std::string_view path);
35
36 std::string_view relativize(std::string_view parent, std::string_view nested);
relativize(const char * parent,const char * nested)37 inline std::string_view relativize(const char* parent, const char* nested) {
38 return relativize(std::string_view(parent), std::string_view(nested));
39 }
relativize(std::string_view parent,const char * nested)40 inline std::string_view relativize(std::string_view parent, const char* nested) {
41 return relativize(parent, std::string_view(nested));
42 }
relativize(const char * parent,std::string_view nested)43 inline std::string_view relativize(const char* parent, std::string_view nested) {
44 return relativize(std::string_view(parent), nested);
45 }
46
47 std::string_view relativize(std::string&& parent, std::string_view nested) = delete;
48 std::string_view relativize(std::string_view parent, std::string&& nested) = delete;
49
50 // Note: some system headers #define 'dirname' and 'basename' as macros
51
baseName(std::string_view path)52 inline std::string_view baseName(std::string_view path) {
53 using namespace std::literals;
54 if (path.empty()) {
55 return {};
56 }
57 if (path == "/"sv) {
58 return "/"sv;
59 }
60 auto pos = path.rfind('/');
61 while (!path.empty() && pos == path.size() - 1) {
62 path.remove_suffix(1);
63 pos = path.rfind('/');
64 }
65 if (pos == path.npos) {
66 return path.empty() ? "/"sv : path;
67 }
68 return path.substr(pos + 1);
69 }
70
dirName(std::string_view path)71 inline std::string_view dirName(std::string_view path) {
72 using namespace std::literals;
73 if (path.empty()) {
74 return {};
75 }
76 if (path == "/"sv) {
77 return "/"sv;
78 }
79 const auto pos = path.rfind('/');
80 if (pos == 0) {
81 return "/"sv;
82 }
83 if (pos == path.npos) {
84 return "."sv;
85 }
86 return path.substr(0, pos);
87 }
88
89 // Split the |full| path into its directory and basename components.
90 // This modifies the input string to null-terminate the output directory
91 std::pair<std::string_view, std::string_view> splitDirBase(std::string& full);
92
93 int isEmptyDir(std::string_view dir);
94 bool startsWith(std::string_view path, std::string_view prefix);
95 bool endsWith(std::string_view path, std::string_view prefix);
96
openDir(const char * path)97 inline auto openDir(const char* path) {
98 struct closer {
99 void operator()(DIR* d) const { ::closedir(d); }
100 };
101 auto dir = std::unique_ptr<DIR, closer>(::opendir(path));
102 return dir;
103 }
104
105 template <class... Paths>
join(std::string && first,std::string_view second,Paths &&...paths)106 std::string join(std::string&& first, std::string_view second, Paths&&... paths) {
107 std::string& result = first;
108 {
109 using std::size;
110 result.reserve(first.size() + second.size() + 1 + (sizeof...(paths) + ... + size(paths)));
111 }
112 (details::appendNextPath(result, second), ...,
113 details::appendNextPath(result, std::forward<Paths>(paths)));
114 return result;
115 }
116
117 template <class... Paths>
join(std::string_view first,std::string_view second,Paths &&...paths)118 std::string join(std::string_view first, std::string_view second, Paths&&... paths) {
119 return join(std::string(), first, second, std::forward<Paths>(paths)...);
120 }
121 template <class... Paths>
join(const char * first,std::string_view second,Paths &&...paths)122 std::string join(const char* first, std::string_view second, Paths&&... paths) {
123 return path::join(std::string_view(first), second, std::forward<Paths>(paths)...);
124 }
125
126 } // namespace android::incfs::path
127