| /* |
| * Copyright (C) 2016 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. |
| */ |
| |
| #include "boot_event_record_store.h" |
| |
| #include <dirent.h> |
| #include <fcntl.h> |
| #include <sys/stat.h> |
| #include <utime.h> |
| #include <cstdlib> |
| #include <utility> |
| #include <android-base/file.h> |
| #include <android-base/logging.h> |
| |
| namespace { |
| |
| const char BOOTSTAT_DATA_DIR[] = "/data/misc/bootstat/"; |
| |
| // Given a boot even record file at |path|, extracts the event's relative time |
| // from the record into |uptime|. |
| bool ParseRecordEventTime(const std::string& path, int32_t* uptime) { |
| DCHECK_NE(static_cast<int32_t*>(nullptr), uptime); |
| |
| struct stat file_stat; |
| if (stat(path.c_str(), &file_stat) == -1) { |
| PLOG(ERROR) << "Failed to read " << path; |
| return false; |
| } |
| |
| *uptime = file_stat.st_mtime; |
| return true; |
| } |
| |
| } // namespace |
| |
| BootEventRecordStore::BootEventRecordStore() { |
| SetStorePath(BOOTSTAT_DATA_DIR); |
| } |
| |
| void BootEventRecordStore::AddBootEvent(const std::string& name) { |
| std::string uptime_str; |
| if (!android::base::ReadFileToString("/proc/uptime", &uptime_str)) { |
| LOG(ERROR) << "Failed to read /proc/uptime"; |
| } |
| |
| // Cast intentionally rounds down. |
| int32_t uptime = static_cast<int32_t>(strtod(uptime_str.c_str(), NULL)); |
| AddBootEventWithValue(name, uptime); |
| } |
| |
| // The implementation of AddBootEventValue makes use of the mtime file |
| // attribute to store the value associated with a boot event in order to |
| // optimize on-disk size requirements and small-file thrashing. |
| void BootEventRecordStore::AddBootEventWithValue( |
| const std::string& name, int32_t value) { |
| std::string record_path = GetBootEventPath(name); |
| if (creat(record_path.c_str(), S_IRUSR | S_IWUSR) == -1) { |
| PLOG(ERROR) << "Failed to create " << record_path; |
| } |
| |
| // Fill out the stat structure for |record_path| in order to get the atime to |
| // set in the utime() call. |
| struct stat file_stat; |
| if (stat(record_path.c_str(), &file_stat) == -1) { |
| PLOG(ERROR) << "Failed to read " << record_path; |
| } |
| |
| // Set the |modtime| of the file to store the value of the boot event while |
| // preserving the |actime| (as read by stat). |
| struct utimbuf times = {/* actime */ file_stat.st_atime, /* modtime */ value}; |
| if (utime(record_path.c_str(), ×) == -1) { |
| PLOG(ERROR) << "Failed to set mtime for " << record_path; |
| } |
| } |
| |
| std::vector<BootEventRecordStore::BootEventRecord> BootEventRecordStore:: |
| GetAllBootEvents() const { |
| std::vector<BootEventRecord> events; |
| |
| std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(store_path_.c_str()), closedir); |
| |
| // This case could happen due to external manipulation of the filesystem, |
| // so crash out if the record store doesn't exist. |
| CHECK_NE(static_cast<DIR*>(nullptr), dir.get()); |
| |
| struct dirent* entry; |
| while ((entry = readdir(dir.get())) != NULL) { |
| // Only parse regular files. |
| if (entry->d_type != DT_REG) { |
| continue; |
| } |
| |
| const std::string event = entry->d_name; |
| const std::string record_path = GetBootEventPath(event); |
| int32_t uptime; |
| if (!ParseRecordEventTime(record_path, &uptime)) { |
| LOG(ERROR) << "Failed to parse boot time record: " << record_path; |
| continue; |
| } |
| |
| events.push_back(std::make_pair(event, uptime)); |
| } |
| |
| return events; |
| } |
| |
| void BootEventRecordStore::SetStorePath(const std::string& path) { |
| DCHECK_EQ('/', path.back()); |
| store_path_ = path; |
| } |
| |
| std::string BootEventRecordStore::GetBootEventPath( |
| const std::string& event) const { |
| DCHECK_EQ('/', store_path_.back()); |
| return store_path_ + event; |
| } |