blob: 22a67bb3a1b8262ce39cfe1e07486dffd469d347 [file] [log] [blame]
/*
* 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(), &times) == -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;
}