Songchun Fan | 3c82a30 | 2019-11-29 14:23:45 -0800 | [diff] [blame] | 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 | #include "path.h" |
| 18 | |
| 19 | #include <android-base/strings.h> |
| 20 | #include <android-base/logging.h> |
| 21 | |
| 22 | #include <algorithm> |
| 23 | #include <iterator> |
| 24 | #include <limits> |
| 25 | #include <memory> |
| 26 | |
| 27 | #include <dirent.h> |
| 28 | #include <stdlib.h> |
| 29 | #include <sys/types.h> |
| 30 | #include <unistd.h> |
| 31 | |
| 32 | using namespace std::literals; |
| 33 | |
| 34 | namespace android::incremental::path { |
| 35 | |
| 36 | bool PathCharsLess::operator()(char l, char r) const { |
| 37 | int ll = l == '/' ? std::numeric_limits<char>::min() - 1 : l; |
| 38 | int rr = r == '/' ? std::numeric_limits<char>::min() - 1 : r; |
| 39 | return ll < rr; |
| 40 | } |
| 41 | |
| 42 | bool PathLess::operator()(std::string_view l, std::string_view r) const { |
| 43 | return std::lexicographical_compare(std::begin(l), std::end(l), std::begin(r), std::end(r), |
| 44 | PathCharsLess()); |
| 45 | } |
| 46 | |
Yurii Zubrytskyi | 529a37d | 2020-04-22 00:38:21 -0700 | [diff] [blame] | 47 | static void preparePathComponent(std::string_view& path, bool trimFront) { |
Yurii Zubrytskyi | 4a25dfb | 2020-01-10 11:53:24 -0800 | [diff] [blame] | 48 | if (trimFront) { |
| 49 | while (!path.empty() && path.front() == '/') { |
| 50 | path.remove_prefix(1); |
| 51 | } |
| 52 | } |
| 53 | while (!path.empty() && path.back() == '/') { |
| 54 | path.remove_suffix(1); |
| 55 | } |
| 56 | } |
| 57 | |
Songchun Fan | 3c82a30 | 2019-11-29 14:23:45 -0800 | [diff] [blame] | 58 | void details::append_next_path(std::string& target, std::string_view path) { |
Yurii Zubrytskyi | 4a25dfb | 2020-01-10 11:53:24 -0800 | [diff] [blame] | 59 | preparePathComponent(path, true); |
Songchun Fan | 3c82a30 | 2019-11-29 14:23:45 -0800 | [diff] [blame] | 60 | if (path.empty()) { |
| 61 | return; |
| 62 | } |
Yurii Zubrytskyi | 4a25dfb | 2020-01-10 11:53:24 -0800 | [diff] [blame] | 63 | if (!target.empty() && !target.ends_with('/')) { |
Songchun Fan | 3c82a30 | 2019-11-29 14:23:45 -0800 | [diff] [blame] | 64 | target.push_back('/'); |
| 65 | } |
| 66 | target += path; |
| 67 | } |
| 68 | |
Yurii Zubrytskyi | 4a25dfb | 2020-01-10 11:53:24 -0800 | [diff] [blame] | 69 | std::string_view relativize(std::string_view parent, std::string_view nested) { |
| 70 | if (!nested.starts_with(parent)) { |
| 71 | return nested; |
| 72 | } |
| 73 | if (nested.size() == parent.size()) { |
| 74 | return {}; |
| 75 | } |
| 76 | if (nested[parent.size()] != '/') { |
| 77 | return nested; |
| 78 | } |
| 79 | auto relative = nested.substr(parent.size()); |
| 80 | while (relative.front() == '/') { |
| 81 | relative.remove_prefix(1); |
| 82 | } |
| 83 | return relative; |
| 84 | } |
| 85 | |
Songchun Fan | 3c82a30 | 2019-11-29 14:23:45 -0800 | [diff] [blame] | 86 | bool isAbsolute(std::string_view path) { |
| 87 | return !path.empty() && path[0] == '/'; |
| 88 | } |
| 89 | |
| 90 | std::string normalize(std::string_view path) { |
| 91 | if (path.empty()) { |
| 92 | return {}; |
| 93 | } |
| 94 | if (path.starts_with("../"sv)) { |
| 95 | return {}; |
| 96 | } |
| 97 | |
| 98 | std::string result; |
| 99 | if (isAbsolute(path)) { |
| 100 | path.remove_prefix(1); |
| 101 | } else { |
| 102 | char buffer[PATH_MAX]; |
| 103 | if (!::getcwd(buffer, sizeof(buffer))) { |
| 104 | return {}; |
| 105 | } |
| 106 | result += buffer; |
| 107 | } |
| 108 | |
| 109 | size_t start = 0; |
| 110 | size_t end = 0; |
| 111 | for (; end != path.npos; start = end + 1) { |
| 112 | end = path.find('/', start); |
| 113 | // Next component, excluding the separator |
| 114 | auto part = path.substr(start, end - start); |
| 115 | if (part.empty() || part == "."sv) { |
| 116 | continue; |
| 117 | } |
| 118 | if (part == ".."sv) { |
| 119 | if (result.empty()) { |
| 120 | return {}; |
| 121 | } |
| 122 | auto lastPos = result.rfind('/'); |
| 123 | if (lastPos == result.npos) { |
| 124 | result.clear(); |
| 125 | } else { |
| 126 | result.resize(lastPos); |
| 127 | } |
| 128 | continue; |
| 129 | } |
| 130 | result += '/'; |
| 131 | result += part; |
| 132 | } |
| 133 | |
| 134 | return result; |
| 135 | } |
| 136 | |
| 137 | std::string_view basename(std::string_view path) { |
| 138 | if (path.empty()) { |
| 139 | return {}; |
| 140 | } |
| 141 | if (path == "/"sv) { |
| 142 | return "/"sv; |
| 143 | } |
| 144 | auto pos = path.rfind('/'); |
| 145 | while (!path.empty() && pos == path.size() - 1) { |
| 146 | path.remove_suffix(1); |
| 147 | pos = path.rfind('/'); |
| 148 | } |
| 149 | if (pos == path.npos) { |
| 150 | return path.empty() ? "/"sv : path; |
| 151 | } |
| 152 | return path.substr(pos + 1); |
| 153 | } |
| 154 | |
| 155 | std::string_view dirname(std::string_view path) { |
| 156 | if (path.empty()) { |
| 157 | return {}; |
| 158 | } |
| 159 | if (path == "/"sv) { |
| 160 | return "/"sv; |
| 161 | } |
| 162 | const auto pos = path.rfind('/'); |
| 163 | if (pos == 0) { |
| 164 | return "/"sv; |
| 165 | } |
| 166 | if (pos == path.npos) { |
| 167 | return "."sv; |
| 168 | } |
| 169 | return path.substr(0, pos); |
| 170 | } |
| 171 | |
| 172 | details::CStrWrapper::CStrWrapper(std::string_view sv) { |
| 173 | if (sv[sv.size()] == '\0') { |
| 174 | mCstr = sv.data(); |
| 175 | } else { |
| 176 | mCopy.emplace(sv); |
| 177 | mCstr = mCopy->c_str(); |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | std::optional<bool> isEmptyDir(std::string_view dir) { |
| 182 | const auto d = std::unique_ptr<DIR, decltype(&::closedir)>{::opendir(c_str(dir)), ::closedir}; |
| 183 | if (!d) { |
| 184 | if (errno == EPERM || errno == EACCES) { |
| 185 | return std::nullopt; |
| 186 | } |
| 187 | return false; |
| 188 | } |
| 189 | while (auto entry = ::readdir(d.get())) { |
| 190 | if (entry->d_type != DT_DIR) { |
| 191 | return false; |
| 192 | } |
| 193 | if (entry->d_name != "."sv && entry->d_name != ".."sv) { |
| 194 | return false; |
| 195 | } |
| 196 | } |
| 197 | return true; |
| 198 | } |
| 199 | |
| 200 | bool startsWith(std::string_view path, std::string_view prefix) { |
| 201 | if (!base::StartsWith(path, prefix)) { |
| 202 | return false; |
| 203 | } |
| 204 | return path.size() == prefix.size() || path[prefix.size()] == '/'; |
| 205 | } |
| 206 | |
| 207 | } // namespace android::incremental::path |