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 <optional>
20 #include <string>
21 #include <string_view>
22 
23 namespace android::incremental::path {
24 
25 namespace details {
26 
27 class CStrWrapper {
28 public:
29     CStrWrapper(std::string_view sv);
30 
31     CStrWrapper(const CStrWrapper&) = delete;
32     void operator=(const CStrWrapper&) = delete;
33     CStrWrapper(CStrWrapper&&) = delete;
34     void operator=(CStrWrapper&&) = delete;
35 
get()36     const char* get() const { return mCstr; }
37     operator const char*() const { return get(); }
38 
39 private:
40     const char* mCstr;
41     std::optional<std::string> mCopy;
42 };
43 
44 void append_next_path(std::string& res, std::string_view c);
45 
46 } // namespace details
47 
48 //
49 // An std::map<> comparator that makes all nested paths to be ordered before the parents.
50 //
51 
52 struct PathCharsLess {
53     bool operator()(char l, char r) const;
54 };
55 
56 struct PathLess {
57     using is_transparent = void;
58     bool operator()(std::string_view l, std::string_view r) const;
59 };
60 
61 //
62 // Returns a zero-terminated version of a passed string view
63 // Only makes a copy if it wasn't zero-terminated already
64 // Useful for passing string view parameters to system functions.
65 //
c_str(std::string_view sv)66 inline details::CStrWrapper c_str(std::string_view sv) {
67     return {sv};
68 }
69 
70 std::string_view relativize(std::string_view parent, std::string_view nested);
relativize(const char * parent,const char * nested)71 inline std::string_view relativize(const char* parent, const char* nested) {
72     return relativize(std::string_view(parent), std::string_view(nested));
73 }
relativize(std::string_view parent,const char * nested)74 inline std::string_view relativize(std::string_view parent, const char* nested) {
75     return relativize(parent, std::string_view(nested));
76 }
relativize(const char * parent,std::string_view nested)77 inline std::string_view relativize(const char* parent, std::string_view nested) {
78     return relativize(std::string_view(parent), nested);
79 }
80 
81 std::string_view relativize(std::string&& parent, std::string_view nested) = delete;
82 std::string_view relativize(std::string_view parent, std::string&& nested) = delete;
83 
84 bool isAbsolute(std::string_view path);
85 std::string normalize(std::string_view path);
86 std::string_view dirname(std::string_view path);
87 std::string_view basename(std::string_view path);
88 std::optional<bool> isEmptyDir(std::string_view dir);
89 bool startsWith(std::string_view path, std::string_view prefix);
90 
91 template <class... Paths>
join(std::string && first,std::string_view second,Paths &&...paths)92 std::string join(std::string&& first, std::string_view second, Paths&&... paths) {
93     std::string& result = first;
94     {
95         using std::size;
96         result.reserve(first.size() + second.size() + 1 + (sizeof...(paths) + ... + size(paths)));
97     }
98     (details::append_next_path(result, second), ...,
99      details::append_next_path(result, std::forward<Paths>(paths)));
100     return std::move(result);
101 }
102 
103 template <class... Paths>
join(std::string_view first,std::string_view second,Paths &&...paths)104 std::string join(std::string_view first, std::string_view second, Paths&&... paths) {
105     return path::join(std::string(), first, second, std::forward<Paths>(paths)...);
106 }
107 
108 template <class... Paths>
join(const char * first,std::string_view second,Paths &&...paths)109 std::string join(const char* first, std::string_view second, Paths&&... paths) {
110     return path::join(std::string_view(first), second, std::forward<Paths>(paths)...);
111 }
112 
113 } // namespace android::incremental::path
114