1 // 2 // Copyright (C) 2012 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 "update_engine/common/prefs.h" 18 19 #include <algorithm> 20 21 #include <base/files/file_util.h> 22 #include <base/logging.h> 23 #include <base/strings/string_number_conversions.h> 24 #include <base/strings/string_util.h> 25 26 #include "update_engine/common/utils.h" 27 28 using std::string; 29 30 namespace chromeos_update_engine { 31 32 bool PrefsBase::GetString(const string& key, string* value) const { 33 return storage_->GetKey(key, value); 34 } 35 36 bool PrefsBase::SetString(const string& key, const string& value) { 37 TEST_AND_RETURN_FALSE(storage_->SetKey(key, value)); 38 const auto observers_for_key = observers_.find(key); 39 if (observers_for_key != observers_.end()) { 40 std::vector<ObserverInterface*> copy_observers(observers_for_key->second); 41 for (ObserverInterface* observer : copy_observers) 42 observer->OnPrefSet(key); 43 } 44 return true; 45 } 46 47 bool PrefsBase::GetInt64(const string& key, int64_t* value) const { 48 string str_value; 49 if (!GetString(key, &str_value)) 50 return false; 51 base::TrimWhitespaceASCII(str_value, base::TRIM_ALL, &str_value); 52 TEST_AND_RETURN_FALSE(base::StringToInt64(str_value, value)); 53 return true; 54 } 55 56 bool PrefsBase::SetInt64(const string& key, const int64_t value) { 57 return SetString(key, base::Int64ToString(value)); 58 } 59 60 bool PrefsBase::GetBoolean(const string& key, bool* value) const { 61 string str_value; 62 if (!GetString(key, &str_value)) 63 return false; 64 base::TrimWhitespaceASCII(str_value, base::TRIM_ALL, &str_value); 65 if (str_value == "false") { 66 *value = false; 67 return true; 68 } 69 if (str_value == "true") { 70 *value = true; 71 return true; 72 } 73 return false; 74 } 75 76 bool PrefsBase::SetBoolean(const string& key, const bool value) { 77 return SetString(key, value ? "true" : "false"); 78 } 79 80 bool PrefsBase::Exists(const string& key) const { 81 return storage_->KeyExists(key); 82 } 83 84 bool PrefsBase::Delete(const string& key) { 85 TEST_AND_RETURN_FALSE(storage_->DeleteKey(key)); 86 const auto observers_for_key = observers_.find(key); 87 if (observers_for_key != observers_.end()) { 88 std::vector<ObserverInterface*> copy_observers(observers_for_key->second); 89 for (ObserverInterface* observer : copy_observers) 90 observer->OnPrefDeleted(key); 91 } 92 return true; 93 } 94 95 void PrefsBase::AddObserver(const string& key, ObserverInterface* observer) { 96 observers_[key].push_back(observer); 97 } 98 99 void PrefsBase::RemoveObserver(const string& key, ObserverInterface* observer) { 100 std::vector<ObserverInterface*>& observers_for_key = observers_[key]; 101 auto observer_it = 102 std::find(observers_for_key.begin(), observers_for_key.end(), observer); 103 if (observer_it != observers_for_key.end()) 104 observers_for_key.erase(observer_it); 105 } 106 107 // Prefs 108 109 bool Prefs::Init(const base::FilePath& prefs_dir) { 110 return file_storage_.Init(prefs_dir); 111 } 112 113 bool Prefs::FileStorage::Init(const base::FilePath& prefs_dir) { 114 prefs_dir_ = prefs_dir; 115 return true; 116 } 117 118 bool Prefs::FileStorage::GetKey(const string& key, string* value) const { 119 base::FilePath filename; 120 TEST_AND_RETURN_FALSE(GetFileNameForKey(key, &filename)); 121 if (!base::ReadFileToString(filename, value)) { 122 LOG(INFO) << key << " not present in " << prefs_dir_.value(); 123 return false; 124 } 125 return true; 126 } 127 128 bool Prefs::FileStorage::SetKey(const string& key, const string& value) { 129 base::FilePath filename; 130 TEST_AND_RETURN_FALSE(GetFileNameForKey(key, &filename)); 131 if (!base::DirectoryExists(filename.DirName())) { 132 // Only attempt to create the directory if it doesn't exist to avoid calls 133 // to parent directories where we might not have permission to write to. 134 TEST_AND_RETURN_FALSE(base::CreateDirectory(filename.DirName())); 135 } 136 TEST_AND_RETURN_FALSE(base::WriteFile(filename, value.data(), value.size()) == 137 static_cast<int>(value.size())); 138 return true; 139 } 140 141 bool Prefs::FileStorage::KeyExists(const string& key) const { 142 base::FilePath filename; 143 TEST_AND_RETURN_FALSE(GetFileNameForKey(key, &filename)); 144 return base::PathExists(filename); 145 } 146 147 bool Prefs::FileStorage::DeleteKey(const string& key) { 148 base::FilePath filename; 149 TEST_AND_RETURN_FALSE(GetFileNameForKey(key, &filename)); 150 TEST_AND_RETURN_FALSE(base::DeleteFile(filename, false)); 151 return true; 152 } 153 154 bool Prefs::FileStorage::GetFileNameForKey(const string& key, 155 base::FilePath* filename) const { 156 // Allows only non-empty keys containing [A-Za-z0-9_-]. 157 TEST_AND_RETURN_FALSE(!key.empty()); 158 for (size_t i = 0; i < key.size(); ++i) { 159 char c = key.at(i); 160 TEST_AND_RETURN_FALSE(base::IsAsciiAlpha(c) || base::IsAsciiDigit(c) || 161 c == '_' || c == '-'); 162 } 163 *filename = prefs_dir_.Append(key); 164 return true; 165 } 166 167 // MemoryPrefs 168 169 bool MemoryPrefs::MemoryStorage::GetKey(const string& key, 170 string* value) const { 171 auto it = values_.find(key); 172 if (it == values_.end()) 173 return false; 174 *value = it->second; 175 return true; 176 } 177 178 bool MemoryPrefs::MemoryStorage::SetKey(const string& key, 179 const string& value) { 180 values_[key] = value; 181 return true; 182 } 183 184 bool MemoryPrefs::MemoryStorage::KeyExists(const string& key) const { 185 return values_.find(key) != values_.end(); 186 } 187 188 bool MemoryPrefs::MemoryStorage::DeleteKey(const string& key) { 189 auto it = values_.find(key); 190 if (it == values_.end()) 191 return false; 192 values_.erase(it); 193 return true; 194 } 195 196 } // namespace chromeos_update_engine 197
