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4926b33742
rocksdb/utilities/backupable/backupable_db.cc
Adam Retter 4926b33742 Improvements to Env::GetChildren (#7819) 
Summary:
The main improvement here is to not include `.` or `..` in the results of `Env::GetChildren`. The occurrence of `.` or `..`; it is non-portable, dependent on the Operating System and the File System. See: https://www.gnu.org/software/libc/manual/html_node/Reading_002fClosing-Directory.html

There were lots of duplicate checks spread through the RocksDB codebase previously to skip `.` and `..`. This new removes the need for those at the source.

Also some minor fixes to `Env::GetChildren`:
* Improve error handling in POSIX implementation
* Remove unnecessary array allocation on Windows
* Fix struct name for Windows Non-UTF-8 API

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7819

Reviewed By: ajkr

Differential Revision: D25837394

Pulled By: jay-zhuang

fbshipit-source-id: 1e137e7218d38b450af9c083f73d5357abcbba2e
2021-01-09 09:44:34 -08:00

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// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#ifndef ROCKSDB_LITE
#include "rocksdb/utilities/backupable_db.h"
#include <stdlib.h>
#include <algorithm>
#include <atomic>
#include <cinttypes>
#include <functional>
#include <future>
#include <limits>
#include <map>
#include <mutex>
#include <sstream>
#include <string>
#include <thread>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "env/composite_env_wrapper.h"
#include "file/filename.h"
#include "file/sequence_file_reader.h"
#include "file/writable_file_writer.h"
#include "logging/logging.h"
#include "port/port.h"
#include "rocksdb/rate_limiter.h"
#include "rocksdb/transaction_log.h"
#include "table/sst_file_dumper.h"
#include "test_util/sync_point.h"
#include "util/channel.h"
#include "util/coding.h"
#include "util/crc32c.h"
#include "util/string_util.h"
#include "utilities/checkpoint/checkpoint_impl.h"
namespace ROCKSDB_NAMESPACE {
namespace {
using ShareFilesNaming = BackupableDBOptions::ShareFilesNaming;
inline uint32_t ChecksumHexToInt32(const std::string& checksum_hex) {
std::string checksum_str;
Slice(checksum_hex).DecodeHex(&checksum_str);
return EndianSwapValue(DecodeFixed32(checksum_str.c_str()));
}
inline std::string ChecksumStrToHex(const std::string& checksum_str) {
return Slice(checksum_str).ToString(true);
}
inline std::string ChecksumInt32ToHex(const uint32_t& checksum_value) {
std::string checksum_str;
PutFixed32(&checksum_str, EndianSwapValue(checksum_value));
return ChecksumStrToHex(checksum_str);
}
} // namespace
void BackupStatistics::IncrementNumberSuccessBackup() {
number_success_backup++;
}
void BackupStatistics::IncrementNumberFailBackup() {
number_fail_backup++;
}
uint32_t BackupStatistics::GetNumberSuccessBackup() const {
return number_success_backup;
}
uint32_t BackupStatistics::GetNumberFailBackup() const {
return number_fail_backup;
}
std::string BackupStatistics::ToString() const {
char result[50];
snprintf(result, sizeof(result), "# success backup: %u, # fail backup: %u",
GetNumberSuccessBackup(), GetNumberFailBackup());
return result;
}
void BackupableDBOptions::Dump(Logger* logger) const {
ROCKS_LOG_INFO(logger, " Options.backup_dir: %s",
backup_dir.c_str());
ROCKS_LOG_INFO(logger, " Options.backup_env: %p", backup_env);
ROCKS_LOG_INFO(logger, " Options.share_table_files: %d",
static_cast<int>(share_table_files));
ROCKS_LOG_INFO(logger, " Options.info_log: %p", info_log);
ROCKS_LOG_INFO(logger, " Options.sync: %d",
static_cast<int>(sync));
ROCKS_LOG_INFO(logger, " Options.destroy_old_data: %d",
static_cast<int>(destroy_old_data));
ROCKS_LOG_INFO(logger, " Options.backup_log_files: %d",
static_cast<int>(backup_log_files));
ROCKS_LOG_INFO(logger, " Options.backup_rate_limit: %" PRIu64,
backup_rate_limit);
ROCKS_LOG_INFO(logger, " Options.restore_rate_limit: %" PRIu64,
restore_rate_limit);
ROCKS_LOG_INFO(logger, "Options.max_background_operations: %d",
max_background_operations);
}
// -------- BackupEngineImpl class ---------
class BackupEngineImpl : public BackupEngine {
public:
BackupEngineImpl(const BackupableDBOptions& options, Env* db_env,
bool read_only = false);
~BackupEngineImpl() override;
using BackupEngine::CreateNewBackupWithMetadata;
Status CreateNewBackupWithMetadata(const CreateBackupOptions& options, DB* db,
const std::string& app_metadata) override;
Status PurgeOldBackups(uint32_t num_backups_to_keep) override;
Status DeleteBackup(BackupID backup_id) override;
void StopBackup() override {
stop_backup_.store(true, std::memory_order_release);
}
Status GarbageCollect() override;
// The returned BackupInfos are in chronological order, which means the
// latest backup comes last.
void GetBackupInfo(std::vector<BackupInfo>* backup_info) override;
void GetCorruptedBackups(std::vector<BackupID>* corrupt_backup_ids) override;
using BackupEngine::RestoreDBFromBackup;
Status RestoreDBFromBackup(const RestoreOptions& options, BackupID backup_id,
const std::string& db_dir,
const std::string& wal_dir) override;
using BackupEngine::RestoreDBFromLatestBackup;
Status RestoreDBFromLatestBackup(const RestoreOptions& options,
const std::string& db_dir,
const std::string& wal_dir) override {
return RestoreDBFromBackup(options, latest_valid_backup_id_, db_dir,
wal_dir);
}
Status VerifyBackup(BackupID backup_id,
bool verify_with_checksum = false) override;
Status Initialize();
ShareFilesNaming GetNamingNoFlags() const {
return options_.share_files_with_checksum_naming &
BackupableDBOptions::kMaskNoNamingFlags;
}
ShareFilesNaming GetNamingFlags() const {
return options_.share_files_with_checksum_naming &
BackupableDBOptions::kMaskNamingFlags;
}
private:
void DeleteChildren(const std::string& dir, uint32_t file_type_filter = 0);
Status DeleteBackupInternal(BackupID backup_id);
// Extends the "result" map with pathname->size mappings for the contents of
// "dir" in "env". Pathnames are prefixed with "dir".
Status InsertPathnameToSizeBytes(
const std::string& dir, Env* env,
std::unordered_map<std::string, uint64_t>* result);
struct FileInfo {
FileInfo(const std::string& fname, uint64_t sz, const std::string& checksum,
const std::string& id = "", const std::string& sid = "")
: refs(0),
filename(fname),
size(sz),
checksum_hex(checksum),
db_id(id),
db_session_id(sid) {}
FileInfo(const FileInfo&) = delete;
FileInfo& operator=(const FileInfo&) = delete;
int refs;
const std::string filename;
const uint64_t size;
const std::string checksum_hex;
// DB identities
// db_id is obtained for potential usage in the future but not used
// currently
const std::string db_id;
// db_session_id appears in the backup SST filename if the table naming
// option is kUseDbSessionId
const std::string db_session_id;
};
class BackupMeta {
public:
BackupMeta(
const std::string& meta_filename, const std::string& meta_tmp_filename,
std::unordered_map<std::string, std::shared_ptr<FileInfo>>* file_infos,
Env* env)
: timestamp_(0),
sequence_number_(0),
size_(0),
meta_filename_(meta_filename),
meta_tmp_filename_(meta_tmp_filename),
file_infos_(file_infos),
env_(env) {}
BackupMeta(const BackupMeta&) = delete;
BackupMeta& operator=(const BackupMeta&) = delete;
~BackupMeta() {}
Status RecordTimestamp() { return env_->GetCurrentTime(&timestamp_); }
int64_t GetTimestamp() const {
return timestamp_;
}
uint64_t GetSize() const {
return size_;
}
uint32_t GetNumberFiles() { return static_cast<uint32_t>(files_.size()); }
void SetSequenceNumber(uint64_t sequence_number) {
sequence_number_ = sequence_number;
}
uint64_t GetSequenceNumber() {
return sequence_number_;
}
const std::string& GetAppMetadata() const { return app_metadata_; }
void SetAppMetadata(const std::string& app_metadata) {
app_metadata_ = app_metadata;
}
Status AddFile(std::shared_ptr<FileInfo> file_info);
Status Delete(bool delete_meta = true);
bool Empty() {
return files_.empty();
}
std::shared_ptr<FileInfo> GetFile(const std::string& filename) const {
auto it = file_infos_->find(filename);
if (it == file_infos_->end())
return nullptr;
return it->second;
}
const std::vector<std::shared_ptr<FileInfo>>& GetFiles() {
return files_;
}
// @param abs_path_to_size Pre-fetched file sizes (bytes).
Status LoadFromFile(
const std::string& backup_dir,
const std::unordered_map<std::string, uint64_t>& abs_path_to_size);
Status StoreToFile(bool sync);
std::string GetInfoString() {
std::ostringstream ss;
ss << "Timestamp: " << timestamp_ << std::endl;
char human_size[16];
AppendHumanBytes(size_, human_size, sizeof(human_size));
ss << "Size: " << human_size << std::endl;
ss << "Files:" << std::endl;
for (const auto& file : files_) {
AppendHumanBytes(file->size, human_size, sizeof(human_size));
ss << file->filename << ", size " << human_size << ", refs "
<< file->refs << std::endl;
}
return ss.str();
}
private:
int64_t timestamp_;
// sequence number is only approximate, should not be used
// by clients
uint64_t sequence_number_;
uint64_t size_;
std::string app_metadata_;
std::string const meta_filename_;
std::string const meta_tmp_filename_;
// files with relative paths (without "/" prefix!!)
std::vector<std::shared_ptr<FileInfo>> files_;
std::unordered_map<std::string, std::shared_ptr<FileInfo>>* file_infos_;
Env* env_;
static const size_t max_backup_meta_file_size_ = 10 * 1024 * 1024; // 10MB
}; // BackupMeta
inline std::string GetAbsolutePath(
const std::string &relative_path = "") const {
assert(relative_path.size() == 0 || relative_path[0] != '/');
return options_.backup_dir + "/" + relative_path;
}
inline std::string GetPrivateDirRel() const {
return "private";
}
inline std::string GetSharedDirRel() const { return "shared"; }
inline std::string GetSharedChecksumDirRel() const {
return "shared_checksum";
}
inline std::string GetPrivateFileRel(BackupID backup_id,
bool tmp = false,
const std::string& file = "") const {
assert(file.size() == 0 || file[0] != '/');
return GetPrivateDirRel() + "/" + ROCKSDB_NAMESPACE::ToString(backup_id) +
(tmp ? ".tmp" : "") + "/" + file;
}
inline std::string GetSharedFileRel(const std::string& file = "",
bool tmp = false) const {
assert(file.size() == 0 || file[0] != '/');
return GetSharedDirRel() + "/" + (tmp ? "." : "") + file +
(tmp ? ".tmp" : "");
}
inline std::string GetSharedFileWithChecksumRel(const std::string& file = "",
bool tmp = false) const {
assert(file.size() == 0 || file[0] != '/');
return GetSharedChecksumDirRel() + "/" + (tmp ? "." : "") + file +
(tmp ? ".tmp" : "");
}
inline bool UseLegacyNaming(const std::string& sid) const {
return GetNamingNoFlags() ==
BackupableDBOptions::kLegacyCrc32cAndFileSize ||
sid.empty();
}
inline bool UseInterimNaming(const std::string& sid) const {
// The indicator of SST file from early internal 6.12 release
// is a '-' in the DB session id. DB session id was made more
// concise without '-' after that.
return (GetNamingFlags() & BackupableDBOptions::kFlagMatchInterimNaming) &&
sid.find('-') != std::string::npos;
}
inline std::string GetSharedFileWithChecksum(
const std::string& file, bool has_checksum,
const std::string& checksum_hex, const uint64_t file_size,
const std::string& db_session_id) const {
assert(file.size() == 0 || file[0] != '/');
std::string file_copy = file;
if (UseLegacyNaming(db_session_id)) {
assert(has_checksum);
(void)has_checksum;
file_copy.insert(file_copy.find_last_of('.'),
"_" + ToString(ChecksumHexToInt32(checksum_hex)) + "_" +
ToString(file_size));
} else if (UseInterimNaming(db_session_id)) {
file_copy.insert(file_copy.find_last_of('.'), "_" + db_session_id);
} else {
file_copy.insert(file_copy.find_last_of('.'), "_s" + db_session_id);
if (GetNamingFlags() & BackupableDBOptions::kFlagIncludeFileSize) {
file_copy.insert(file_copy.find_last_of('.'),
"_" + ToString(file_size));
}
}
return file_copy;
}
inline std::string GetFileFromChecksumFile(const std::string& file) const {
assert(file.size() == 0 || file[0] != '/');
std::string file_copy = file;
size_t first_underscore = file_copy.find_first_of('_');
return file_copy.erase(first_underscore,
file_copy.find_last_of('.') - first_underscore);
}
inline std::string GetBackupMetaDir() const {
return GetAbsolutePath("meta");
}
inline std::string GetBackupMetaFile(BackupID backup_id, bool tmp) const {
return GetBackupMetaDir() + "/" + (tmp ? "." : "") +
ROCKSDB_NAMESPACE::ToString(backup_id) + (tmp ? ".tmp" : "");
}
// If size_limit == 0, there is no size limit, copy everything.
//
// Exactly one of src and contents must be non-empty.
//
// @param src If non-empty, the file is copied from this pathname.
// @param contents If non-empty, the file will be created with these contents.
Status CopyOrCreateFile(const std::string& src, const std::string& dst,
const std::string& contents, Env* src_env,
Env* dst_env, const EnvOptions& src_env_options,
bool sync, RateLimiter* rate_limiter,
uint64_t* size = nullptr,
std::string* checksum_hex = nullptr,
uint64_t size_limit = 0,
std::function<void()> progress_callback = []() {});
Status ReadFileAndComputeChecksum(const std::string& src, Env* src_env,
const EnvOptions& src_env_options,
uint64_t size_limit,
std::string* checksum_hex);
// Obtain db_id and db_session_id from the table properties of file_path
Status GetFileDbIdentities(Env* src_env, const EnvOptions& src_env_options,
const std::string& file_path, std::string* db_id,
std::string* db_session_id);
struct CopyOrCreateResult {
~CopyOrCreateResult() {
// The Status needs to be ignored here for two reasons.
// First, if the BackupEngineImpl shuts down with jobs outstanding, then
// it is possible that the Status in the future/promise is never read,
// resulting in an unchecked Status. Second, if there are items in the
// channel when the BackupEngineImpl is shutdown, these will also have
// Status that have not been checked. This
// TODO: Fix those issues so that the Status
status.PermitUncheckedError();
}
uint64_t size;
std::string checksum_hex;
std::string db_id;
std::string db_session_id;
Status status;
};
// Exactly one of src_path and contents must be non-empty. If src_path is
// non-empty, the file is copied from this pathname. Otherwise, if contents is
// non-empty, the file will be created at dst_path with these contents.
struct CopyOrCreateWorkItem {
std::string src_path;
std::string dst_path;
std::string contents;
Env* src_env;
Env* dst_env;
EnvOptions src_env_options;
bool sync;
RateLimiter* rate_limiter;
uint64_t size_limit;
std::promise<CopyOrCreateResult> result;
std::function<void()> progress_callback;
bool verify_checksum_after_work;
std::string src_checksum_func_name;
std::string src_checksum_hex;
std::string db_id;
std::string db_session_id;
CopyOrCreateWorkItem()
: src_path(""),
dst_path(""),
contents(""),
src_env(nullptr),
dst_env(nullptr),
src_env_options(),
sync(false),
rate_limiter(nullptr),
size_limit(0),
verify_checksum_after_work(false),
src_checksum_func_name(kUnknownFileChecksumFuncName),
src_checksum_hex(""),
db_id(""),
db_session_id("") {}
CopyOrCreateWorkItem(const CopyOrCreateWorkItem&) = delete;
CopyOrCreateWorkItem& operator=(const CopyOrCreateWorkItem&) = delete;
CopyOrCreateWorkItem(CopyOrCreateWorkItem&& o) ROCKSDB_NOEXCEPT {
*this = std::move(o);
}
CopyOrCreateWorkItem& operator=(CopyOrCreateWorkItem&& o) ROCKSDB_NOEXCEPT {
src_path = std::move(o.src_path);
dst_path = std::move(o.dst_path);
contents = std::move(o.contents);
src_env = o.src_env;
dst_env = o.dst_env;
src_env_options = std::move(o.src_env_options);
sync = o.sync;
rate_limiter = o.rate_limiter;
size_limit = o.size_limit;
result = std::move(o.result);
progress_callback = std::move(o.progress_callback);
verify_checksum_after_work = o.verify_checksum_after_work;
src_checksum_func_name = std::move(o.src_checksum_func_name);
src_checksum_hex = std::move(o.src_checksum_hex);
db_id = std::move(o.db_id);
db_session_id = std::move(o.db_session_id);
return *this;
}
CopyOrCreateWorkItem(
std::string _src_path, std::string _dst_path, std::string _contents,
Env* _src_env, Env* _dst_env, EnvOptions _src_env_options, bool _sync,
RateLimiter* _rate_limiter, uint64_t _size_limit,
std::function<void()> _progress_callback = []() {},
bool _verify_checksum_after_work = false,
const std::string& _src_checksum_func_name =
kUnknownFileChecksumFuncName,
const std::string& _src_checksum_hex = "",
const std::string& _db_id = "", const std::string& _db_session_id = "")
: src_path(std::move(_src_path)),
dst_path(std::move(_dst_path)),
contents(std::move(_contents)),
src_env(_src_env),
dst_env(_dst_env),
src_env_options(std::move(_src_env_options)),
sync(_sync),
rate_limiter(_rate_limiter),
size_limit(_size_limit),
progress_callback(_progress_callback),
verify_checksum_after_work(_verify_checksum_after_work),
src_checksum_func_name(_src_checksum_func_name),
src_checksum_hex(_src_checksum_hex),
db_id(_db_id),
db_session_id(_db_session_id) {}
};
struct BackupAfterCopyOrCreateWorkItem {
std::future<CopyOrCreateResult> result;
bool shared;
bool needed_to_copy;
Env* backup_env;
std::string dst_path_tmp;
std::string dst_path;
std::string dst_relative;
BackupAfterCopyOrCreateWorkItem()
: shared(false),
needed_to_copy(false),
backup_env(nullptr),
dst_path_tmp(""),
dst_path(""),
dst_relative("") {}
BackupAfterCopyOrCreateWorkItem(BackupAfterCopyOrCreateWorkItem&& o)
ROCKSDB_NOEXCEPT {
*this = std::move(o);
}
BackupAfterCopyOrCreateWorkItem& operator=(
BackupAfterCopyOrCreateWorkItem&& o) ROCKSDB_NOEXCEPT {
result = std::move(o.result);
shared = o.shared;
needed_to_copy = o.needed_to_copy;
backup_env = o.backup_env;
dst_path_tmp = std::move(o.dst_path_tmp);
dst_path = std::move(o.dst_path);
dst_relative = std::move(o.dst_relative);
return *this;
}
BackupAfterCopyOrCreateWorkItem(std::future<CopyOrCreateResult>&& _result,
bool _shared, bool _needed_to_copy,
Env* _backup_env, std::string _dst_path_tmp,
std::string _dst_path,
std::string _dst_relative)
: result(std::move(_result)),
shared(_shared),
needed_to_copy(_needed_to_copy),
backup_env(_backup_env),
dst_path_tmp(std::move(_dst_path_tmp)),
dst_path(std::move(_dst_path)),
dst_relative(std::move(_dst_relative)) {}
};
struct RestoreAfterCopyOrCreateWorkItem {
std::future<CopyOrCreateResult> result;
std::string checksum_hex;
RestoreAfterCopyOrCreateWorkItem() : checksum_hex("") {}
RestoreAfterCopyOrCreateWorkItem(std::future<CopyOrCreateResult>&& _result,
const std::string& _checksum_hex)
: result(std::move(_result)), checksum_hex(_checksum_hex) {}
RestoreAfterCopyOrCreateWorkItem(RestoreAfterCopyOrCreateWorkItem&& o)
ROCKSDB_NOEXCEPT {
*this = std::move(o);
}
RestoreAfterCopyOrCreateWorkItem& operator=(
RestoreAfterCopyOrCreateWorkItem&& o) ROCKSDB_NOEXCEPT {
result = std::move(o.result);
checksum_hex = std::move(o.checksum_hex);
return *this;
}
};
bool initialized_;
std::mutex byte_report_mutex_;
channel<CopyOrCreateWorkItem> files_to_copy_or_create_;
std::vector<port::Thread> threads_;
std::atomic<CpuPriority> threads_cpu_priority_;
// Certain operations like PurgeOldBackups and DeleteBackup will trigger
// automatic GarbageCollect (true) unless we've already done one in this
// session and have not failed to delete backup files since then (false).
bool might_need_garbage_collect_ = true;
// Adds a file to the backup work queue to be copied or created if it doesn't
// already exist.
//
// Exactly one of src_dir and contents must be non-empty.
//
// @param src_dir If non-empty, the file in this directory named fname will be
// copied.
// @param fname Name of destination file and, in case of copy, source file.
// @param contents If non-empty, the file will be created with these contents.
Status AddBackupFileWorkItem(
std::unordered_set<std::string>& live_dst_paths,
std::vector<BackupAfterCopyOrCreateWorkItem>& backup_items_to_finish,
BackupID backup_id, bool shared, const std::string& src_dir,
const std::string& fname, // starts with "/"
const EnvOptions& src_env_options, RateLimiter* rate_limiter,
uint64_t size_bytes, uint64_t size_limit = 0,
bool shared_checksum = false,
std::function<void()> progress_callback = []() {},
const std::string& contents = std::string(),
const std::string& src_checksum_func_name = kUnknownFileChecksumFuncName,
const std::string& src_checksum_str = kUnknownFileChecksum);
// backup state data
BackupID latest_backup_id_;
BackupID latest_valid_backup_id_;
std::map<BackupID, std::unique_ptr<BackupMeta>> backups_;
std::map<BackupID, std::pair<Status, std::unique_ptr<BackupMeta>>>
corrupt_backups_;
std::unordered_map<std::string,
std::shared_ptr<FileInfo>> backuped_file_infos_;
std::atomic<bool> stop_backup_;
// options data
BackupableDBOptions options_;
Env* db_env_;
Env* backup_env_;
// directories
std::unique_ptr<Directory> backup_directory_;
std::unique_ptr<Directory> shared_directory_;
std::unique_ptr<Directory> meta_directory_;
std::unique_ptr<Directory> private_directory_;
static const size_t kDefaultCopyFileBufferSize = 5 * 1024 * 1024LL; // 5MB
size_t copy_file_buffer_size_;
bool read_only_;
BackupStatistics backup_statistics_;
static const size_t kMaxAppMetaSize = 1024 * 1024; // 1MB
};
Status BackupEngine::Open(const BackupableDBOptions& options, Env* env,
BackupEngine** backup_engine_ptr) {
std::unique_ptr<BackupEngineImpl> backup_engine(
new BackupEngineImpl(options, env));
auto s = backup_engine->Initialize();
if (!s.ok()) {
*backup_engine_ptr = nullptr;
return s;
}
*backup_engine_ptr = backup_engine.release();
return Status::OK();
}
BackupEngineImpl::BackupEngineImpl(const BackupableDBOptions& options,
Env* db_env, bool read_only)
: initialized_(false),
threads_cpu_priority_(),
latest_backup_id_(0),
latest_valid_backup_id_(0),
stop_backup_(false),
options_(options),
db_env_(db_env),
backup_env_(options.backup_env != nullptr ? options.backup_env : db_env_),
copy_file_buffer_size_(kDefaultCopyFileBufferSize),
read_only_(read_only) {
if (options_.backup_rate_limiter == nullptr &&
options_.backup_rate_limit > 0) {
options_.backup_rate_limiter.reset(
NewGenericRateLimiter(options_.backup_rate_limit));
}
if (options_.restore_rate_limiter == nullptr &&
options_.restore_rate_limit > 0) {
options_.restore_rate_limiter.reset(
NewGenericRateLimiter(options_.restore_rate_limit));
}
}
BackupEngineImpl::~BackupEngineImpl() {
files_to_copy_or_create_.sendEof();
for (auto& t : threads_) {
t.join();
}
LogFlush(options_.info_log);
for (const auto& it : corrupt_backups_) {
it.second.first.PermitUncheckedError();
}
}
Status BackupEngineImpl::Initialize() {
assert(!initialized_);
initialized_ = true;
if (read_only_) {
ROCKS_LOG_INFO(options_.info_log, "Starting read_only backup engine");
}
options_.Dump(options_.info_log);
if (!read_only_) {
// we might need to clean up from previous crash or I/O errors
might_need_garbage_collect_ = true;
if (options_.max_valid_backups_to_open != port::kMaxInt32) {
options_.max_valid_backups_to_open = port::kMaxInt32;
ROCKS_LOG_WARN(
options_.info_log,
"`max_valid_backups_to_open` is not set to the default value. Ignoring "
"its value since BackupEngine is not read-only.");
}
// gather the list of directories that we need to create
std::vector<std::pair<std::string, std::unique_ptr<Directory>*>>
directories;
directories.emplace_back(GetAbsolutePath(), &backup_directory_);
if (options_.share_table_files) {
if (options_.share_files_with_checksum) {
directories.emplace_back(
GetAbsolutePath(GetSharedFileWithChecksumRel()),
&shared_directory_);
} else {
directories.emplace_back(GetAbsolutePath(GetSharedFileRel()),
&shared_directory_);
}
}
directories.emplace_back(GetAbsolutePath(GetPrivateDirRel()),
&private_directory_);
directories.emplace_back(GetBackupMetaDir(), &meta_directory_);
// create all the dirs we need
for (const auto& d : directories) {
auto s = backup_env_->CreateDirIfMissing(d.first);
if (s.ok()) {
s = backup_env_->NewDirectory(d.first, d.second);
}
if (!s.ok()) {
return s;
}
}
}
std::vector<std::string> backup_meta_files;
{
auto s = backup_env_->GetChildren(GetBackupMetaDir(), &backup_meta_files);
if (s.IsNotFound()) {
return Status::NotFound(GetBackupMetaDir() + " is missing");
} else if (!s.ok()) {
return s;
}
}
// create backups_ structure
for (auto& file : backup_meta_files) {
ROCKS_LOG_INFO(options_.info_log, "Detected backup %s", file.c_str());
BackupID backup_id = 0;
sscanf(file.c_str(), "%u", &backup_id);
if (backup_id == 0 || file != ROCKSDB_NAMESPACE::ToString(backup_id)) {
if (!read_only_) {
// invalid file name, delete that
auto s = backup_env_->DeleteFile(GetBackupMetaDir() + "/" + file);
ROCKS_LOG_INFO(options_.info_log,
"Unrecognized meta file %s, deleting -- %s",
file.c_str(), s.ToString().c_str());
}
continue;
}
assert(backups_.find(backup_id) == backups_.end());
// Insert all the (backup_id, BackupMeta) that will be loaded later
// The loading performed later will check whether there are corrupt backups
// and move the corrupt backups to corrupt_backups_
backups_.insert(std::make_pair(
backup_id, std::unique_ptr<BackupMeta>(new BackupMeta(
GetBackupMetaFile(backup_id, false /* tmp */),
GetBackupMetaFile(backup_id, true /* tmp */),
&backuped_file_infos_, backup_env_))));
}
latest_backup_id_ = 0;
latest_valid_backup_id_ = 0;
if (options_.destroy_old_data) { // Destroy old data
assert(!read_only_);
ROCKS_LOG_INFO(
options_.info_log,
"Backup Engine started with destroy_old_data == true, deleting all "
"backups");
auto s = PurgeOldBackups(0);
if (s.ok()) {
s = GarbageCollect();
}
if (!s.ok()) {
return s;
}
} else { // Load data from storage
// abs_path_to_size: maps absolute paths of files in backup directory to
// their corresponding sizes
std::unordered_map<std::string, uint64_t> abs_path_to_size;
// Insert files and their sizes in backup sub-directories (shared and
// shared_checksum) to abs_path_to_size
for (const auto& rel_dir :
{GetSharedFileRel(), GetSharedFileWithChecksumRel()}) {
const auto abs_dir = GetAbsolutePath(rel_dir);
// TODO: What do do on error?
InsertPathnameToSizeBytes(abs_dir, backup_env_, &abs_path_to_size)
.PermitUncheckedError();
}
// load the backups if any, until valid_backups_to_open of the latest
// non-corrupted backups have been successfully opened.
int valid_backups_to_open = options_.max_valid_backups_to_open;
for (auto backup_iter = backups_.rbegin();
backup_iter != backups_.rend();
++backup_iter) {
assert(latest_backup_id_ == 0 || latest_backup_id_ > backup_iter->first);
if (latest_backup_id_ == 0) {
latest_backup_id_ = backup_iter->first;
}
if (valid_backups_to_open == 0) {
break;
}
// Insert files and their sizes in backup sub-directories
// (private/backup_id) to abs_path_to_size
Status s = InsertPathnameToSizeBytes(
GetAbsolutePath(GetPrivateFileRel(backup_iter->first)), backup_env_,
&abs_path_to_size);
if (s.ok()) {
s = backup_iter->second->LoadFromFile(options_.backup_dir,
abs_path_to_size);
}
if (s.IsCorruption()) {
ROCKS_LOG_INFO(options_.info_log, "Backup %u corrupted -- %s",
backup_iter->first, s.ToString().c_str());
corrupt_backups_.insert(
std::make_pair(backup_iter->first,
std::make_pair(s, std::move(backup_iter->second))));
} else if (!s.ok()) {
// Distinguish corruption errors from errors in the backup Env.
// Errors in the backup Env (i.e., this code path) will cause Open() to
// fail, whereas corruption errors would not cause Open() failures.
return s;
} else {
ROCKS_LOG_INFO(options_.info_log, "Loading backup %" PRIu32 " OK:\n%s",
backup_iter->first,
backup_iter->second->GetInfoString().c_str());
assert(latest_valid_backup_id_ == 0 ||
latest_valid_backup_id_ > backup_iter->first);
if (latest_valid_backup_id_ == 0) {
latest_valid_backup_id_ = backup_iter->first;
}
--valid_backups_to_open;
}
}
for (const auto& corrupt : corrupt_backups_) {
backups_.erase(backups_.find(corrupt.first));
}
// erase the backups before max_valid_backups_to_open
int num_unopened_backups;
if (options_.max_valid_backups_to_open == 0) {
num_unopened_backups = 0;
} else {
num_unopened_backups =
std::max(0, static_cast<int>(backups_.size()) -
options_.max_valid_backups_to_open);
}
for (int i = 0; i < num_unopened_backups; ++i) {
assert(backups_.begin()->second->Empty());
backups_.erase(backups_.begin());
}
}
ROCKS_LOG_INFO(options_.info_log, "Latest backup is %u", latest_backup_id_);
ROCKS_LOG_INFO(options_.info_log, "Latest valid backup is %u",
latest_valid_backup_id_);
// set up threads perform copies from files_to_copy_or_create_ in the
// background
threads_cpu_priority_ = CpuPriority::kNormal;
threads_.reserve(options_.max_background_operations);
for (int t = 0; t < options_.max_background_operations; t++) {
threads_.emplace_back([this]() {
#if defined(_GNU_SOURCE) && defined(__GLIBC_PREREQ)
#if __GLIBC_PREREQ(2, 12)
pthread_setname_np(pthread_self(), "backup_engine");
#endif
#endif
CpuPriority current_priority = CpuPriority::kNormal;
CopyOrCreateWorkItem work_item;
while (files_to_copy_or_create_.read(work_item)) {
CpuPriority priority = threads_cpu_priority_;
if (current_priority != priority) {
TEST_SYNC_POINT_CALLBACK(
"BackupEngineImpl::Initialize:SetCpuPriority", &priority);
port::SetCpuPriority(0, priority);
current_priority = priority;
}
CopyOrCreateResult result;
result.status = CopyOrCreateFile(
work_item.src_path, work_item.dst_path, work_item.contents,
work_item.src_env, work_item.dst_env, work_item.src_env_options,
work_item.sync, work_item.rate_limiter, &result.size,
&result.checksum_hex, work_item.size_limit,
work_item.progress_callback);
result.db_id = work_item.db_id;
result.db_session_id = work_item.db_session_id;
if (result.status.ok() && work_item.verify_checksum_after_work) {
// unknown checksum function name implies no db table file checksum in
// db manifest; work_item.verify_checksum_after_work being true means
// backup engine has calculated its crc32c checksum for the table
// file; therefore, we are able to compare the checksums.
if (work_item.src_checksum_func_name ==
kUnknownFileChecksumFuncName ||
work_item.src_checksum_func_name == kDbFileChecksumFuncName) {
if (work_item.src_checksum_hex != result.checksum_hex) {
std::string checksum_info(
"Expected checksum is " + work_item.src_checksum_hex +
" while computed checksum is " + result.checksum_hex);
result.status =
Status::Corruption("Checksum mismatch after copying to " +
work_item.dst_path + ": " + checksum_info);
}
} else {
std::string checksum_function_info(
"Existing checksum function is " +
work_item.src_checksum_func_name +
" while provided checksum function is " +
kBackupFileChecksumFuncName);
ROCKS_LOG_INFO(
options_.info_log,
"Unable to verify checksum after copying to %s: %s\n",
work_item.dst_path.c_str(), checksum_function_info.c_str());
}
}
work_item.result.set_value(std::move(result));
}
});
}
ROCKS_LOG_INFO(options_.info_log, "Initialized BackupEngine");
return Status::OK();
}
Status BackupEngineImpl::CreateNewBackupWithMetadata(
const CreateBackupOptions& options, DB* db,
const std::string& app_metadata) {
assert(initialized_);
assert(!read_only_);
if (app_metadata.size() > kMaxAppMetaSize) {
return Status::InvalidArgument("App metadata too large");
}
if (options.decrease_background_thread_cpu_priority) {
if (options.background_thread_cpu_priority < threads_cpu_priority_) {
threads_cpu_priority_.store(options.background_thread_cpu_priority);
}
}
BackupID new_backup_id = latest_backup_id_ + 1;
assert(backups_.find(new_backup_id) == backups_.end());
auto private_dir = GetAbsolutePath(GetPrivateFileRel(new_backup_id));
Status s = backup_env_->FileExists(private_dir);
if (s.ok()) {
// maybe last backup failed and left partial state behind, clean it up.
// need to do this before updating backups_ such that a private dir
// named after new_backup_id will be cleaned up.
// (If an incomplete new backup is followed by an incomplete delete
// of the latest full backup, then there could be more than one next
// id with a private dir, the last thing to be deleted in delete
// backup, but all will be cleaned up with a GarbageCollect.)
s = GarbageCollect();
} else if (s.IsNotFound()) {
// normal case, the new backup's private dir doesn't exist yet
s = Status::OK();
}
auto ret = backups_.insert(std::make_pair(
new_backup_id, std::unique_ptr<BackupMeta>(new BackupMeta(
GetBackupMetaFile(new_backup_id, false /* tmp */),
GetBackupMetaFile(new_backup_id, true /* tmp */),
&backuped_file_infos_, backup_env_))));
assert(ret.second == true);
auto& new_backup = ret.first->second;
// TODO: What should we do on error here?
new_backup->RecordTimestamp().PermitUncheckedError();
new_backup->SetAppMetadata(app_metadata);
auto start_backup = backup_env_->NowMicros();
ROCKS_LOG_INFO(options_.info_log,
"Started the backup process -- creating backup %u",
new_backup_id);
if (s.ok()) {
s = backup_env_->CreateDir(private_dir);
}
RateLimiter* rate_limiter = options_.backup_rate_limiter.get();
if (rate_limiter) {
copy_file_buffer_size_ = static_cast<size_t>(rate_limiter->GetSingleBurstBytes());
}
// A set into which we will insert the dst_paths that are calculated for live
// files and live WAL files.
// This is used to check whether a live files shares a dst_path with another
// live file.
std::unordered_set<std::string> live_dst_paths;
std::vector<BackupAfterCopyOrCreateWorkItem> backup_items_to_finish;
// Add a CopyOrCreateWorkItem to the channel for each live file
Status disabled = db->DisableFileDeletions();
if (s.ok()) {
CheckpointImpl checkpoint(db);
uint64_t sequence_number = 0;
DBOptions db_options = db->GetDBOptions();
FileChecksumGenFactory* db_checksum_factory =
db_options.file_checksum_gen_factory.get();
const std::string kFileChecksumGenFactoryName =
"FileChecksumGenCrc32cFactory";
bool compare_checksum =
db_checksum_factory != nullptr &&
db_checksum_factory->Name() == kFileChecksumGenFactoryName
? true
: false;
EnvOptions src_raw_env_options(db_options);
s = checkpoint.CreateCustomCheckpoint(
db_options,
[&](const std::string& /*src_dirname*/, const std::string& /*fname*/,
FileType) {
// custom checkpoint will switch to calling copy_file_cb after it sees
// NotSupported returned from link_file_cb.
return Status::NotSupported();
} /* link_file_cb */,
[&](const std::string& src_dirname, const std::string& fname,
uint64_t size_limit_bytes, FileType type,
const std::string& checksum_func_name,
const std::string& checksum_val) {
if (type == kWalFile && !options_.backup_log_files) {
return Status::OK();
}
Log(options_.info_log, "add file for backup %s", fname.c_str());
uint64_t size_bytes = 0;
Status st;
if (type == kTableFile) {
st = db_env_->GetFileSize(src_dirname + fname, &size_bytes);
}
EnvOptions src_env_options;
switch (type) {
case kWalFile:
src_env_options =
db_env_->OptimizeForLogRead(src_raw_env_options);
break;
case kTableFile:
src_env_options = db_env_->OptimizeForCompactionTableRead(
src_raw_env_options, ImmutableDBOptions(db_options));
break;
case kDescriptorFile:
src_env_options =
db_env_->OptimizeForManifestRead(src_raw_env_options);
break;
default:
// Other backed up files (like options file) are not read by live
// DB, so don't need to worry about avoiding mixing buffered and
// direct I/O. Just use plain defaults.
src_env_options = src_raw_env_options;
break;
}
if (st.ok()) {
st = AddBackupFileWorkItem(
live_dst_paths, backup_items_to_finish, new_backup_id,
options_.share_table_files && type == kTableFile, src_dirname,
fname, src_env_options, rate_limiter, size_bytes,
size_limit_bytes,
options_.share_files_with_checksum && type == kTableFile,
options.progress_callback, "" /* contents */,
checksum_func_name, checksum_val);
}
return st;
} /* copy_file_cb */,
[&](const std::string& fname, const std::string& contents, FileType) {
Log(options_.info_log, "add file for backup %s", fname.c_str());
return AddBackupFileWorkItem(
live_dst_paths, backup_items_to_finish, new_backup_id,
false /* shared */, "" /* src_dir */, fname,
EnvOptions() /* src_env_options */, rate_limiter, contents.size(),
0 /* size_limit */, false /* shared_checksum */,
options.progress_callback, contents);
} /* create_file_cb */,
&sequence_number, options.flush_before_backup ? 0 : port::kMaxUint64,
compare_checksum);
if (s.ok()) {
new_backup->SetSequenceNumber(sequence_number);
}
}
ROCKS_LOG_INFO(options_.info_log, "add files for backup done, wait finish.");
Status item_status;
for (auto& item : backup_items_to_finish) {
item.result.wait();
auto result = item.result.get();
item_status = result.status;
if (item_status.ok() && item.shared && item.needed_to_copy) {
item_status =
item.backup_env->RenameFile(item.dst_path_tmp, item.dst_path);
}
if (item_status.ok()) {
item_status = new_backup.get()->AddFile(std::make_shared<FileInfo>(
item.dst_relative, result.size, result.checksum_hex, result.db_id,
result.db_session_id));
}
if (!item_status.ok()) {
s = item_status;
}
}
// we copied all the files, enable file deletions
if (disabled.ok()) { // If we successfully disabled file deletions
db->EnableFileDeletions(false).PermitUncheckedError();
}
auto backup_time = backup_env_->NowMicros() - start_backup;
if (s.ok()) {
// persist the backup metadata on the disk
s = new_backup->StoreToFile(options_.sync);
}
if (s.ok() && options_.sync) {
std::unique_ptr<Directory> backup_private_directory;
backup_env_->NewDirectory(
GetAbsolutePath(GetPrivateFileRel(new_backup_id, false)),
&backup_private_directory);
if (backup_private_directory != nullptr) {
s = backup_private_directory->Fsync();
}
if (s.ok() && private_directory_ != nullptr) {
s = private_directory_->Fsync();
}
if (s.ok() && meta_directory_ != nullptr) {
s = meta_directory_->Fsync();
}
if (s.ok() && shared_directory_ != nullptr) {
s = shared_directory_->Fsync();
}
if (s.ok() && backup_directory_ != nullptr) {
s = backup_directory_->Fsync();
}
}
if (s.ok()) {
backup_statistics_.IncrementNumberSuccessBackup();
}
if (!s.ok()) {
backup_statistics_.IncrementNumberFailBackup();
// clean all the files we might have created
ROCKS_LOG_INFO(options_.info_log, "Backup failed -- %s",
s.ToString().c_str());
ROCKS_LOG_INFO(options_.info_log, "Backup Statistics %s\n",
backup_statistics_.ToString().c_str());
// delete files that we might have already written
might_need_garbage_collect_ = true;
DeleteBackup(new_backup_id).PermitUncheckedError();
return s;
}
// here we know that we succeeded and installed the new backup
// in the LATEST_BACKUP file
latest_backup_id_ = new_backup_id;
latest_valid_backup_id_ = new_backup_id;
ROCKS_LOG_INFO(options_.info_log, "Backup DONE. All is good");
// backup_speed is in byte/second
double backup_speed = new_backup->GetSize() / (1.048576 * backup_time);
ROCKS_LOG_INFO(options_.info_log, "Backup number of files: %u",
new_backup->GetNumberFiles());
char human_size[16];
AppendHumanBytes(new_backup->GetSize(), human_size, sizeof(human_size));
ROCKS_LOG_INFO(options_.info_log, "Backup size: %s", human_size);
ROCKS_LOG_INFO(options_.info_log, "Backup time: %" PRIu64 " microseconds",
backup_time);
ROCKS_LOG_INFO(options_.info_log, "Backup speed: %.3f MB/s", backup_speed);
ROCKS_LOG_INFO(options_.info_log, "Backup Statistics %s",
backup_statistics_.ToString().c_str());
return s;
}
Status BackupEngineImpl::PurgeOldBackups(uint32_t num_backups_to_keep) {
assert(initialized_);
assert(!read_only_);
// Best effort deletion even with errors
Status overall_status = Status::OK();
ROCKS_LOG_INFO(options_.info_log, "Purging old backups, keeping %u",
num_backups_to_keep);
std::vector<BackupID> to_delete;
auto itr = backups_.begin();
while ((backups_.size() - to_delete.size()) > num_backups_to_keep) {
to_delete.push_back(itr->first);
itr++;
}
for (auto backup_id : to_delete) {
auto s = DeleteBackupInternal(backup_id);
if (!s.ok()) {
overall_status = s;
}
}
// Clean up after any incomplete backup deletion, potentially from
// earlier session.
if (might_need_garbage_collect_) {
auto s = GarbageCollect();
if (!s.ok() && overall_status.ok()) {
overall_status = s;
}
}
return overall_status;
}
Status BackupEngineImpl::DeleteBackup(BackupID backup_id) {
auto s1 = DeleteBackupInternal(backup_id);
auto s2 = Status::OK();
// Clean up after any incomplete backup deletion, potentially from
// earlier session.
if (might_need_garbage_collect_) {
s2 = GarbageCollect();
}
if (!s1.ok()) {
s2.PermitUncheckedError(); // What to do?
return s1;
} else {
return s2;
}
}
// Does not auto-GarbageCollect
Status BackupEngineImpl::DeleteBackupInternal(BackupID backup_id) {
assert(initialized_);
assert(!read_only_);
ROCKS_LOG_INFO(options_.info_log, "Deleting backup %u", backup_id);
auto backup = backups_.find(backup_id);
if (backup != backups_.end()) {
auto s = backup->second->Delete();
if (!s.ok()) {
return s;
}
backups_.erase(backup);
} else {
auto corrupt = corrupt_backups_.find(backup_id);
if (corrupt == corrupt_backups_.end()) {
return Status::NotFound("Backup not found");
}
auto s = corrupt->second.second->Delete();
if (!s.ok()) {
return s;
}
corrupt->second.first.PermitUncheckedError();
corrupt_backups_.erase(corrupt);
}
// After removing meta file, best effort deletion even with errors.
// (Don't delete other files if we can't delete the meta file right
// now.)
std::vector<std::string> to_delete;
for (auto& itr : backuped_file_infos_) {
if (itr.second->refs == 0) {
Status s = backup_env_->DeleteFile(GetAbsolutePath(itr.first));
ROCKS_LOG_INFO(options_.info_log, "Deleting %s -- %s", itr.first.c_str(),
s.ToString().c_str());
to_delete.push_back(itr.first);
if (!s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
}
for (auto& td : to_delete) {
backuped_file_infos_.erase(td);
}
// take care of private dirs -- GarbageCollect() will take care of them
// if they are not empty
std::string private_dir = GetPrivateFileRel(backup_id);
Status s = backup_env_->DeleteDir(GetAbsolutePath(private_dir));
ROCKS_LOG_INFO(options_.info_log, "Deleting private dir %s -- %s",
private_dir.c_str(), s.ToString().c_str());
if (!s.ok()) {
// Full gc or trying again later might work
might_need_garbage_collect_ = true;
}
return Status::OK();
}
void BackupEngineImpl::GetBackupInfo(std::vector<BackupInfo>* backup_info) {
assert(initialized_);
backup_info->reserve(backups_.size());
for (auto& backup : backups_) {
if (!backup.second->Empty()) {
backup_info->push_back(BackupInfo(
backup.first, backup.second->GetTimestamp(), backup.second->GetSize(),
backup.second->GetNumberFiles(), backup.second->GetAppMetadata()));
}
}
}
void
BackupEngineImpl::GetCorruptedBackups(
std::vector<BackupID>* corrupt_backup_ids) {
assert(initialized_);
corrupt_backup_ids->reserve(corrupt_backups_.size());
for (auto& backup : corrupt_backups_) {
corrupt_backup_ids->push_back(backup.first);
}
}
Status BackupEngineImpl::RestoreDBFromBackup(const RestoreOptions& options,
BackupID backup_id,
const std::string& db_dir,
const std::string& wal_dir) {
assert(initialized_);
auto corrupt_itr = corrupt_backups_.find(backup_id);
if (corrupt_itr != corrupt_backups_.end()) {
return corrupt_itr->second.first;
}
auto backup_itr = backups_.find(backup_id);
if (backup_itr == backups_.end()) {
return Status::NotFound("Backup not found");
}
auto& backup = backup_itr->second;
if (backup->Empty()) {
return Status::NotFound("Backup not found");
}
ROCKS_LOG_INFO(options_.info_log, "Restoring backup id %u\n", backup_id);
ROCKS_LOG_INFO(options_.info_log, "keep_log_files: %d\n",
static_cast<int>(options.keep_log_files));
// just in case. Ignore errors
db_env_->CreateDirIfMissing(db_dir).PermitUncheckedError();
db_env_->CreateDirIfMissing(wal_dir).PermitUncheckedError();
if (options.keep_log_files) {
// delete files in db_dir, but keep all the log files
DeleteChildren(db_dir, 1 << kWalFile);
// move all the files from archive dir to wal_dir
std::string archive_dir = ArchivalDirectory(wal_dir);
std::vector<std::string> archive_files;
db_env_->GetChildren(archive_dir, &archive_files)
.PermitUncheckedError(); // ignore errors
for (const auto& f : archive_files) {
uint64_t number;
FileType type;
bool ok = ParseFileName(f, &number, &type);
if (ok && type == kWalFile) {
ROCKS_LOG_INFO(options_.info_log,
"Moving log file from archive/ to wal_dir: %s",
f.c_str());
Status s =
db_env_->RenameFile(archive_dir + "/" + f, wal_dir + "/" + f);
if (!s.ok()) {
// if we can't move log file from archive_dir to wal_dir,
// we should fail, since it might mean data loss
return s;
}
}
}
} else {
DeleteChildren(wal_dir);
DeleteChildren(ArchivalDirectory(wal_dir));
DeleteChildren(db_dir);
}
RateLimiter* rate_limiter = options_.restore_rate_limiter.get();
if (rate_limiter) {
copy_file_buffer_size_ =
static_cast<size_t>(rate_limiter->GetSingleBurstBytes());
}
Status s;
std::vector<RestoreAfterCopyOrCreateWorkItem> restore_items_to_finish;
for (const auto& file_info : backup->GetFiles()) {
const std::string& file = file_info->filename;
std::string dst;
// 1. extract the filename
size_t slash = file.find_last_of('/');
// file will either be shared/<file>, shared_checksum/<file_crc32c_size>,
// shared_checksum/<file_session>, shared_checksum/<file_crc32c_session>,
// or private/<number>/<file>
assert(slash != std::string::npos);
dst = file.substr(slash + 1);
// if the file was in shared_checksum, extract the real file name
// in this case the file is <number>_<checksum>_<size>.<type>,
// <number>_<session>.<type>, or <number>_<checksum>_<session>.<type>
if (file.substr(0, slash) == GetSharedChecksumDirRel()) {
dst = GetFileFromChecksumFile(dst);
}
// 2. find the filetype
uint64_t number;
FileType type;
bool ok = ParseFileName(dst, &number, &type);
if (!ok) {
return Status::Corruption("Backup corrupted: Fail to parse filename " +
dst);
}
// 3. Construct the final path
// kWalFile lives in wal_dir and all the rest live in db_dir
dst = ((type == kWalFile) ? wal_dir : db_dir) + "/" + dst;
ROCKS_LOG_INFO(options_.info_log, "Restoring %s to %s\n", file.c_str(),
dst.c_str());
CopyOrCreateWorkItem copy_or_create_work_item(
GetAbsolutePath(file), dst, "" /* contents */, backup_env_, db_env_,
EnvOptions() /* src_env_options */, false, rate_limiter,
0 /* size_limit */);
RestoreAfterCopyOrCreateWorkItem after_copy_or_create_work_item(
copy_or_create_work_item.result.get_future(), file_info->checksum_hex);
files_to_copy_or_create_.write(std::move(copy_or_create_work_item));
restore_items_to_finish.push_back(
std::move(after_copy_or_create_work_item));
}
Status item_status;
for (auto& item : restore_items_to_finish) {
item.result.wait();
auto result = item.result.get();
item_status = result.status;
// Note: It is possible that both of the following bad-status cases occur
// during copying. But, we only return one status.
if (!item_status.ok()) {
s = item_status;
break;
} else if (item.checksum_hex != result.checksum_hex) {
s = Status::Corruption("Checksum check failed");
break;
}
}
ROCKS_LOG_INFO(options_.info_log, "Restoring done -- %s\n",
s.ToString().c_str());
return s;
}
Status BackupEngineImpl::VerifyBackup(BackupID backup_id,
bool verify_with_checksum) {
// Check if backup_id is corrupted, or valid and registered
assert(initialized_);
auto corrupt_itr = corrupt_backups_.find(backup_id);
if (corrupt_itr != corrupt_backups_.end()) {
return corrupt_itr->second.first;
}
auto backup_itr = backups_.find(backup_id);
if (backup_itr == backups_.end()) {
return Status::NotFound();
}
auto& backup = backup_itr->second;
if (backup->Empty()) {
return Status::NotFound();
}
ROCKS_LOG_INFO(options_.info_log, "Verifying backup id %u\n", backup_id);
// Find all existing backup files belong to backup_id
std::unordered_map<std::string, uint64_t> curr_abs_path_to_size;
for (const auto& rel_dir : {GetPrivateFileRel(backup_id), GetSharedFileRel(),
GetSharedFileWithChecksumRel()}) {
const auto abs_dir = GetAbsolutePath(rel_dir);
// TODO: What to do on error?
InsertPathnameToSizeBytes(abs_dir, backup_env_, &curr_abs_path_to_size)
.PermitUncheckedError();
}
// For all files registered in backup
for (const auto& file_info : backup->GetFiles()) {
const auto abs_path = GetAbsolutePath(file_info->filename);
// check existence of the file
if (curr_abs_path_to_size.find(abs_path) == curr_abs_path_to_size.end()) {
return Status::NotFound("File missing: " + abs_path);
}
// verify file size
if (file_info->size != curr_abs_path_to_size[abs_path]) {
std::string size_info("Expected file size is " +
ToString(file_info->size) +
" while found file size is " +
ToString(curr_abs_path_to_size[abs_path]));
return Status::Corruption("File corrupted: File size mismatch for " +
abs_path + ": " + size_info);
}
if (verify_with_checksum) {
// verify file checksum
std::string checksum_hex;
ROCKS_LOG_INFO(options_.info_log, "Verifying %s checksum...\n",
abs_path.c_str());
Status s = ReadFileAndComputeChecksum(abs_path, backup_env_, EnvOptions(),
0 /* size_limit */, &checksum_hex);
if (!s.ok()) {
return s;
} else if (file_info->checksum_hex != checksum_hex) {
std::string checksum_info(
"Expected checksum is " + file_info->checksum_hex +
" while computed checksum is " + checksum_hex);
return Status::Corruption("File corrupted: Checksum mismatch for " +
abs_path + ": " + checksum_info);
}
}
}
return Status::OK();
}
Status BackupEngineImpl::CopyOrCreateFile(
const std::string& src, const std::string& dst, const std::string& contents,
Env* src_env, Env* dst_env, const EnvOptions& src_env_options, bool sync,
RateLimiter* rate_limiter, uint64_t* size, std::string* checksum_hex,
uint64_t size_limit, std::function<void()> progress_callback) {
assert(src.empty() != contents.empty());
Status s;
std::unique_ptr<WritableFile> dst_file;
std::unique_ptr<SequentialFile> src_file;
EnvOptions dst_env_options;
dst_env_options.use_mmap_writes = false;
// TODO:(gzh) maybe use direct reads/writes here if possible
if (size != nullptr) {
*size = 0;
}
uint32_t checksum_value = 0;
// Check if size limit is set. if not, set it to very big number
if (size_limit == 0) {
size_limit = std::numeric_limits<uint64_t>::max();
}
s = dst_env->NewWritableFile(dst, &dst_file, dst_env_options);
if (s.ok() && !src.empty()) {
s = src_env->NewSequentialFile(src, &src_file, src_env_options);
}
if (!s.ok()) {
return s;
}
std::unique_ptr<WritableFileWriter> dest_writer(new WritableFileWriter(
NewLegacyWritableFileWrapper(std::move(dst_file)), dst, dst_env_options));
std::unique_ptr<SequentialFileReader> src_reader;
std::unique_ptr<char[]> buf;
if (!src.empty()) {
src_reader.reset(new SequentialFileReader(
NewLegacySequentialFileWrapper(src_file), src));
buf.reset(new char[copy_file_buffer_size_]);
}
Slice data;
uint64_t processed_buffer_size = 0;
do {
if (stop_backup_.load(std::memory_order_acquire)) {
return Status::Incomplete("Backup stopped");
}
if (!src.empty()) {
size_t buffer_to_read = (copy_file_buffer_size_ < size_limit)
? copy_file_buffer_size_
: static_cast<size_t>(size_limit);
s = src_reader->Read(buffer_to_read, &data, buf.get());
processed_buffer_size += buffer_to_read;
} else {
data = contents;
}
size_limit -= data.size();
TEST_SYNC_POINT_CALLBACK(
"BackupEngineImpl::CopyOrCreateFile:CorruptionDuringBackup",
(src.length() > 4 && src.rfind(".sst") == src.length() - 4) ? &data
: nullptr);
if (!s.ok()) {
return s;
}
if (size != nullptr) {
*size += data.size();
}
if (checksum_hex != nullptr) {
checksum_value = crc32c::Extend(checksum_value, data.data(), data.size());
}
s = dest_writer->Append(data);
if (rate_limiter != nullptr) {
rate_limiter->Request(data.size(), Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kWrite);
}
if (processed_buffer_size > options_.callback_trigger_interval_size) {
processed_buffer_size -= options_.callback_trigger_interval_size;
std::lock_guard<std::mutex> lock(byte_report_mutex_);
progress_callback();
}
} while (s.ok() && contents.empty() && data.size() > 0 && size_limit > 0);
// Convert uint32_t checksum to hex checksum
if (checksum_hex != nullptr) {
checksum_hex->assign(ChecksumInt32ToHex(checksum_value));
}
if (s.ok() && sync) {
s = dest_writer->Sync(false);
}
if (s.ok()) {
s = dest_writer->Close();
}
return s;
}
// fname will always start with "/"
Status BackupEngineImpl::AddBackupFileWorkItem(
std::unordered_set<std::string>& live_dst_paths,
std::vector<BackupAfterCopyOrCreateWorkItem>& backup_items_to_finish,
BackupID backup_id, bool shared, const std::string& src_dir,
const std::string& fname, const EnvOptions& src_env_options,
RateLimiter* rate_limiter, uint64_t size_bytes, uint64_t size_limit,
bool shared_checksum, std::function<void()> progress_callback,
const std::string& contents, const std::string& src_checksum_func_name,
const std::string& src_checksum_str) {
assert(!fname.empty() && fname[0] == '/');
assert(contents.empty() != src_dir.empty());
std::string dst_relative = fname.substr(1);
std::string dst_relative_tmp;
std::string checksum_hex;
std::string db_id;
std::string db_session_id;
// whether the checksum for a table file is available
bool has_checksum = false;
// Whenever a default checksum function name is passed in, we will compares
// the corresponding checksum values after copying. Note that only table files
// may have a known checksum function name passed in.
//
// If no default checksum function name is passed in and db session id is not
// available, we will calculate the checksum *before* copying in two cases
// (we always calcuate checksums when copying or creating for any file types):
// a) share_files_with_checksum is true and file type is table;
// b) share_table_files is true and the file exists already.
//
// Step 0: Check if default checksum function name is passed in
if (kDbFileChecksumFuncName == src_checksum_func_name) {
if (src_checksum_str == kUnknownFileChecksum) {
return Status::Aborted("Unknown checksum value for " + fname);
}
checksum_hex = ChecksumStrToHex(src_checksum_str);
has_checksum = true;
}
// Step 1: Prepare the relative path to destination
if (shared && shared_checksum) {
if (GetNamingNoFlags() != BackupableDBOptions::kLegacyCrc32cAndFileSize) {
// Prepare db_session_id to add to the file name
// Ignore the returned status
// In the failed cases, db_id and db_session_id will be empty
GetFileDbIdentities(db_env_, src_env_options, src_dir + fname, &db_id,
&db_session_id)
.PermitUncheckedError();
}
// Calculate checksum if checksum and db session id are not available.
// If db session id is available, we will not calculate the checksum
// since the session id should suffice to avoid file name collision in
// the shared_checksum directory.
if (!has_checksum && db_session_id.empty()) {
Status s = ReadFileAndComputeChecksum(
src_dir + fname, db_env_, src_env_options, size_limit, &checksum_hex);
if (!s.ok()) {
return s;
}
has_checksum = true;
}
if (size_bytes == port::kMaxUint64) {
return Status::NotFound("File missing: " + src_dir + fname);
}
// dst_relative depends on the following conditions:
// 1) the naming scheme is kUseDbSessionId,
// 2) db_session_id is not empty,
// 3) checksum is available in the DB manifest.
// If 1,2,3) are satisfied, then dst_relative will be of the form:
// shared_checksum/<file_number>_<checksum>_<db_session_id>.sst
// If 1,2) are satisfied, then dst_relative will be of the form:
// shared_checksum/<file_number>_<db_session_id>.sst
// Otherwise, dst_relative is of the form
// shared_checksum/<file_number>_<checksum>_<size>.sst
dst_relative = GetSharedFileWithChecksum(
dst_relative, has_checksum, checksum_hex, size_bytes, db_session_id);
dst_relative_tmp = GetSharedFileWithChecksumRel(dst_relative, true);
dst_relative = GetSharedFileWithChecksumRel(dst_relative, false);
} else if (shared) {
dst_relative_tmp = GetSharedFileRel(dst_relative, true);
dst_relative = GetSharedFileRel(dst_relative, false);
} else {
dst_relative = GetPrivateFileRel(backup_id, false, dst_relative);
}
// We copy into `temp_dest_path` and, once finished, rename it to
// `final_dest_path`. This allows files to atomically appear at
// `final_dest_path`. We can copy directly to the final path when atomicity
// is unnecessary, like for files in private backup directories.
const std::string* copy_dest_path;
std::string temp_dest_path;
std::string final_dest_path = GetAbsolutePath(dst_relative);
if (!dst_relative_tmp.empty()) {
temp_dest_path = GetAbsolutePath(dst_relative_tmp);
copy_dest_path = &temp_dest_path;
} else {
copy_dest_path = &final_dest_path;
}
// Step 2: Determine whether to copy or not
// if it's shared, we also need to check if it exists -- if it does, no need
// to copy it again.
bool need_to_copy = true;
// true if final_dest_path is the same path as another live file
const bool same_path =
live_dst_paths.find(final_dest_path) != live_dst_paths.end();
bool file_exists = false;
if (shared && !same_path) {
// Should be in shared directory but not a live path, check existence in
// shared directory
Status exist = backup_env_->FileExists(final_dest_path);
if (exist.ok()) {
file_exists = true;
} else if (exist.IsNotFound()) {
file_exists = false;
} else {
return exist;
}
}
if (!contents.empty()) {
need_to_copy = false;
} else if (shared && (same_path || file_exists)) {
need_to_copy = false;
auto find_result = backuped_file_infos_.find(dst_relative);
if (find_result == backuped_file_infos_.end() && !same_path) {
// file exists but not referenced
ROCKS_LOG_INFO(
options_.info_log,
"%s already present, but not referenced by any backup. We will "
"overwrite the file.",
fname.c_str());
need_to_copy = true;
//**TODO: What to do on error?
backup_env_->DeleteFile(final_dest_path).PermitUncheckedError();
} else {
// file exists and referenced
if (!has_checksum) {
if (!same_path) {
assert(find_result != backuped_file_infos_.end());
// Note: to save I/O on incremental backups, we copy prior known
// checksum of the file instead of reading entire file contents
// to recompute it.
checksum_hex = find_result->second->checksum_hex;
has_checksum = true;
// Regarding corruption detection, consider:
// (a) the DB file is corrupt (since previous backup) and the backup
// file is OK: we failed to detect, but the backup is safe. DB can
// be repaired/restored once its corruption is detected.
// (b) the backup file is corrupt (since previous backup) and the
// db file is OK: we failed to detect, but the backup is corrupt.
// CreateNewBackup should support fast incremental backups and
// there's no way to support that without reading all the files.
// We might add an option for extra checks on incremental backup,
// but until then, use VerifyBackups to check existing backup data.
// (c) file name collision with legitimately different content.
// This is almost inconceivable with a well-generated DB session
// ID, but even in that case, we double check the file sizes in
// BackupMeta::AddFile.
} else {
// same_path should not happen for a standard DB, so OK to
// read file contents to check for checksum mismatch between
// two files from same DB getting same name.
Status s = ReadFileAndComputeChecksum(src_dir + fname, db_env_,
src_env_options, size_limit,
&checksum_hex);
if (!s.ok()) {
return s;
}
}
}
if (!db_session_id.empty()) {
ROCKS_LOG_INFO(options_.info_log,
"%s already present, with checksum %s, size %" PRIu64
" and DB session identity %s",
fname.c_str(), checksum_hex.c_str(), size_bytes,
db_session_id.c_str());
} else {
ROCKS_LOG_INFO(options_.info_log,
"%s already present, with checksum %s and size %" PRIu64,
fname.c_str(), checksum_hex.c_str(), size_bytes);
}
}
}
live_dst_paths.insert(final_dest_path);
// Step 3: Add work item
if (!contents.empty() || need_to_copy) {
ROCKS_LOG_INFO(options_.info_log, "Copying %s to %s", fname.c_str(),
copy_dest_path->c_str());
CopyOrCreateWorkItem copy_or_create_work_item(
src_dir.empty() ? "" : src_dir + fname, *copy_dest_path, contents,
db_env_, backup_env_, src_env_options, options_.sync, rate_limiter,
size_limit, progress_callback, has_checksum, src_checksum_func_name,
checksum_hex, db_id, db_session_id);
BackupAfterCopyOrCreateWorkItem after_copy_or_create_work_item(
copy_or_create_work_item.result.get_future(), shared, need_to_copy,
backup_env_, temp_dest_path, final_dest_path, dst_relative);
files_to_copy_or_create_.write(std::move(copy_or_create_work_item));
backup_items_to_finish.push_back(std::move(after_copy_or_create_work_item));
} else {
std::promise<CopyOrCreateResult> promise_result;
BackupAfterCopyOrCreateWorkItem after_copy_or_create_work_item(
promise_result.get_future(), shared, need_to_copy, backup_env_,
temp_dest_path, final_dest_path, dst_relative);
backup_items_to_finish.push_back(std::move(after_copy_or_create_work_item));
CopyOrCreateResult result;
result.status = Status::OK();
result.size = size_bytes;
result.checksum_hex = std::move(checksum_hex);
result.db_id = std::move(db_id);
result.db_session_id = std::move(db_session_id);
promise_result.set_value(std::move(result));
}
return Status::OK();
}
Status BackupEngineImpl::ReadFileAndComputeChecksum(
const std::string& src, Env* src_env, const EnvOptions& src_env_options,
uint64_t size_limit, std::string* checksum_hex) {
if (checksum_hex == nullptr) {
return Status::Aborted("Checksum pointer is null");
}
uint32_t checksum_value = 0;
if (size_limit == 0) {
size_limit = std::numeric_limits<uint64_t>::max();
}
std::unique_ptr<SequentialFile> src_file;
Status s = src_env->NewSequentialFile(src, &src_file, src_env_options);
if (!s.ok()) {
return s;
}
std::unique_ptr<SequentialFileReader> src_reader(
new SequentialFileReader(NewLegacySequentialFileWrapper(src_file), src));
std::unique_ptr<char[]> buf(new char[copy_file_buffer_size_]);
Slice data;
do {
if (stop_backup_.load(std::memory_order_acquire)) {
return Status::Incomplete("Backup stopped");
}
size_t buffer_to_read = (copy_file_buffer_size_ < size_limit) ?
copy_file_buffer_size_ : static_cast<size_t>(size_limit);
s = src_reader->Read(buffer_to_read, &data, buf.get());
if (!s.ok()) {
return s;
}
size_limit -= data.size();
checksum_value = crc32c::Extend(checksum_value, data.data(), data.size());
} while (data.size() > 0 && size_limit > 0);
checksum_hex->assign(ChecksumInt32ToHex(checksum_value));
return s;
}
Status BackupEngineImpl::GetFileDbIdentities(Env* src_env,
const EnvOptions& src_env_options,
const std::string& file_path,
std::string* db_id,
std::string* db_session_id) {
assert(db_id != nullptr || db_session_id != nullptr);
Options options;
options.env = src_env;
SstFileDumper sst_reader(options, file_path,
2 * 1024 * 1024
/* readahead_size */,
false /* verify_checksum */, false /* output_hex */,
false /* decode_blob_index */, src_env_options,
true /* silent */);
const TableProperties* table_properties = nullptr;
std::shared_ptr<const TableProperties> tp;
Status s = sst_reader.getStatus();
if (s.ok()) {
// Try to get table properties from the table reader of sst_reader
if (!sst_reader.ReadTableProperties(&tp).ok()) {
// Try to use table properites from the initialization of sst_reader
table_properties = sst_reader.GetInitTableProperties();
} else {
table_properties = tp.get();
}
} else {
ROCKS_LOG_INFO(options_.info_log, "Failed to read %s: %s",
file_path.c_str(), s.ToString().c_str());
return s;
}
if (table_properties != nullptr) {
if (db_id != nullptr) {
db_id->assign(table_properties->db_id);
}
if (db_session_id != nullptr) {
db_session_id->assign(table_properties->db_session_id);
if (db_session_id->empty()) {
s = Status::NotFound("DB session identity not found in " + file_path);
ROCKS_LOG_INFO(options_.info_log, "%s", s.ToString().c_str());
return s;
}
}
return Status::OK();
} else {
s = Status::Corruption("Table properties missing in " + file_path);
ROCKS_LOG_INFO(options_.info_log, "%s", s.ToString().c_str());
return s;
}
}
void BackupEngineImpl::DeleteChildren(const std::string& dir,
uint32_t file_type_filter) {
std::vector<std::string> children;
db_env_->GetChildren(dir, &children).PermitUncheckedError(); // ignore errors
for (const auto& f : children) {
uint64_t number;
FileType type;
bool ok = ParseFileName(f, &number, &type);
if (ok && (file_type_filter & (1 << type))) {
// don't delete this file
continue;
}
db_env_->DeleteFile(dir + "/" + f).PermitUncheckedError(); // ignore errors
}
}
Status BackupEngineImpl::InsertPathnameToSizeBytes(
const std::string& dir, Env* env,
std::unordered_map<std::string, uint64_t>* result) {
assert(result != nullptr);
std::vector<Env::FileAttributes> files_attrs;
Status status = env->FileExists(dir);
if (status.ok()) {
status = env->GetChildrenFileAttributes(dir, &files_attrs);
} else if (status.IsNotFound()) {
// Insert no entries can be considered success
status = Status::OK();
}
const bool slash_needed = dir.empty() || dir.back() != '/';
for (const auto& file_attrs : files_attrs) {
result->emplace(dir + (slash_needed ? "/" : "") + file_attrs.name,
file_attrs.size_bytes);
}
return status;
}
Status BackupEngineImpl::GarbageCollect() {
assert(!read_only_);
// We will make a best effort to remove all garbage even in the presence
// of inconsistencies or I/O failures that inhibit finding garbage.
Status overall_status = Status::OK();
// If all goes well, we don't need another auto-GC this session
might_need_garbage_collect_ = false;
ROCKS_LOG_INFO(options_.info_log, "Starting garbage collection");
// delete obsolete shared files
for (bool with_checksum : {false, true}) {
std::vector<std::string> shared_children;
{
std::string shared_path;
if (with_checksum) {
shared_path = GetAbsolutePath(GetSharedFileWithChecksumRel());
} else {
shared_path = GetAbsolutePath(GetSharedFileRel());
}
auto s = backup_env_->FileExists(shared_path);
if (s.ok()) {
s = backup_env_->GetChildren(shared_path, &shared_children);
} else if (s.IsNotFound()) {
s = Status::OK();
}
if (!s.ok()) {
overall_status = s;
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
for (auto& child : shared_children) {
std::string rel_fname;
if (with_checksum) {
rel_fname = GetSharedFileWithChecksumRel(child);
} else {
rel_fname = GetSharedFileRel(child);
}
auto child_itr = backuped_file_infos_.find(rel_fname);
// if it's not refcounted, delete it
if (child_itr == backuped_file_infos_.end() ||
child_itr->second->refs == 0) {
// this might be a directory, but DeleteFile will just fail in that
// case, so we're good
Status s = backup_env_->DeleteFile(GetAbsolutePath(rel_fname));
ROCKS_LOG_INFO(options_.info_log, "Deleting %s -- %s",
rel_fname.c_str(), s.ToString().c_str());
backuped_file_infos_.erase(rel_fname);
if (!s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
}
}
// delete obsolete private files
std::vector<std::string> private_children;
{
auto s = backup_env_->GetChildren(GetAbsolutePath(GetPrivateDirRel()),
&private_children);
if (!s.ok()) {
overall_status = s;
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
for (auto& child : private_children) {
BackupID backup_id = 0;
bool tmp_dir = child.find(".tmp") != std::string::npos;
sscanf(child.c_str(), "%u", &backup_id);
if (!tmp_dir && // if it's tmp_dir, delete it
(backup_id == 0 || backups_.find(backup_id) != backups_.end())) {
// it's either not a number or it's still alive. continue
continue;
}
// here we have to delete the dir and all its children
std::string full_private_path =
GetAbsolutePath(GetPrivateFileRel(backup_id));
std::vector<std::string> subchildren;
if (backup_env_->GetChildren(full_private_path, &subchildren).ok()) {
for (auto& subchild : subchildren) {
Status s = backup_env_->DeleteFile(full_private_path + subchild);
ROCKS_LOG_INFO(options_.info_log, "Deleting %s -- %s",
(full_private_path + subchild).c_str(),
s.ToString().c_str());
if (!s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
}
// finally delete the private dir
Status s = backup_env_->DeleteDir(full_private_path);
ROCKS_LOG_INFO(options_.info_log, "Deleting dir %s -- %s",
full_private_path.c_str(), s.ToString().c_str());
if (!s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
assert(overall_status.ok() || might_need_garbage_collect_);
return overall_status;
}
// ------- BackupMeta class --------
Status BackupEngineImpl::BackupMeta::AddFile(
std::shared_ptr<FileInfo> file_info) {
auto itr = file_infos_->find(file_info->filename);
if (itr == file_infos_->end()) {
auto ret = file_infos_->insert({file_info->filename, file_info});
if (ret.second) {
itr = ret.first;
itr->second->refs = 1;
} else {
// if this happens, something is seriously wrong
return Status::Corruption("In memory metadata insertion error");
}
} else {
// Compare sizes, because we scanned that off the filesystem on both
// ends. This is like a check in VerifyBackup.
if (itr->second->size != file_info->size) {
std::string msg = "Size mismatch for existing backup file: ";
msg.append(file_info->filename);
msg.append(" Size in backup is " + ToString(itr->second->size) +
" while size in DB is " + ToString(file_info->size));
msg.append(
" If this DB file checks as not corrupt, try deleting old"
" backups or backing up to a different backup directory.");
return Status::Corruption(msg);
}
// Note: to save I/O, this check will pass trivially on already backed
// up files that don't have the checksum in their name. And it should
// never fail for files that do have checksum in their name.
if (itr->second->checksum_hex != file_info->checksum_hex) {
// Should never reach here, but produce an appropriate corruption
// message in case we do in a release build.
assert(false);
std::string msg = "Checksum mismatch for existing backup file: ";
msg.append(file_info->filename);
msg.append(" Expected checksum is " + itr->second->checksum_hex +
" while computed checksum is " + file_info->checksum_hex);
msg.append(
" If this DB file checks as not corrupt, try deleting old"
" backups or backing up to a different backup directory.");
return Status::Corruption(msg);
}
++itr->second->refs; // increase refcount if already present
}
size_ += file_info->size;
files_.push_back(itr->second);
return Status::OK();
}
Status BackupEngineImpl::BackupMeta::Delete(bool delete_meta) {
Status s;
for (const auto& file : files_) {
--file->refs; // decrease refcount
}
files_.clear();
// delete meta file
if (delete_meta) {
s = env_->FileExists(meta_filename_);
if (s.ok()) {
s = env_->DeleteFile(meta_filename_);
} else if (s.IsNotFound()) {
s = Status::OK(); // nothing to delete
}
}
timestamp_ = 0;
return s;
}
Slice kMetaDataPrefix("metadata ");
// each backup meta file is of the format:
// <timestamp>
// <seq number>
// <metadata(literal string)> <metadata> (optional)
// <number of files>
// <file1> <crc32(literal string)> <crc32c_value>
// <file2> <crc32(literal string)> <crc32c_value>
// ...
Status BackupEngineImpl::BackupMeta::LoadFromFile(
const std::string& backup_dir,
const std::unordered_map<std::string, uint64_t>& abs_path_to_size) {
assert(Empty());
Status s;
std::unique_ptr<SequentialFile> backup_meta_file;
s = env_->NewSequentialFile(meta_filename_, &backup_meta_file, EnvOptions());
if (!s.ok()) {
return s;
}
std::unique_ptr<SequentialFileReader> backup_meta_reader(
new SequentialFileReader(NewLegacySequentialFileWrapper(backup_meta_file),
meta_filename_));
std::unique_ptr<char[]> buf(new char[max_backup_meta_file_size_ + 1]);
Slice data;
s = backup_meta_reader->Read(max_backup_meta_file_size_, &data, buf.get());
if (!s.ok() || data.size() == max_backup_meta_file_size_) {
return s.ok() ? Status::Corruption("File size too big") : s;
}
buf[data.size()] = 0;
uint32_t num_files = 0;
char *next;
timestamp_ = strtoull(data.data(), &next, 10);
data.remove_prefix(next - data.data() + 1); // +1 for '\n'
sequence_number_ = strtoull(data.data(), &next, 10);
data.remove_prefix(next - data.data() + 1); // +1 for '\n'
if (data.starts_with(kMetaDataPrefix)) {
// app metadata present
data.remove_prefix(kMetaDataPrefix.size());
Slice hex_encoded_metadata = GetSliceUntil(&data, '\n');
bool decode_success = hex_encoded_metadata.DecodeHex(&app_metadata_);
if (!decode_success) {
return Status::Corruption(
"Failed to decode stored hex encoded app metadata");
}
}
num_files = static_cast<uint32_t>(strtoul(data.data(), &next, 10));
data.remove_prefix(next - data.data() + 1); // +1 for '\n'
std::vector<std::shared_ptr<FileInfo>> files;
// WART: The checksums are crc32c, not original crc32
Slice checksum_prefix("crc32 ");
for (uint32_t i = 0; s.ok() && i < num_files; ++i) {
auto line = GetSliceUntil(&data, '\n');
// filename is relative, i.e., shared/number.sst,
// shared_checksum/number.sst, or private/backup_id/number.sst
std::string filename = GetSliceUntil(&line, ' ').ToString();
uint64_t size;
const std::shared_ptr<FileInfo> file_info = GetFile(filename);
if (file_info) {
size = file_info->size;
} else {
std::string abs_path = backup_dir + "/" + filename;
try {
size = abs_path_to_size.at(abs_path);
} catch (std::out_of_range&) {
return Status::Corruption("Size missing for pathname: " + abs_path);
}
}
if (line.empty()) {
return Status::Corruption("File checksum is missing for " + filename +
" in " + meta_filename_);
}
uint32_t checksum_value = 0;
if (line.starts_with(checksum_prefix)) {
line.remove_prefix(checksum_prefix.size());
checksum_value = static_cast<uint32_t>(strtoul(line.data(), nullptr, 10));
if (line != ROCKSDB_NAMESPACE::ToString(checksum_value)) {
return Status::Corruption("Invalid checksum value for " + filename +
" in " + meta_filename_);
}
} else {
return Status::Corruption("Unknown checksum type for " + filename +
" in " + meta_filename_);
}
files.emplace_back(
new FileInfo(filename, size, ChecksumInt32ToHex(checksum_value)));
}
if (s.ok() && data.size() > 0) {
// file has to be read completely. if not, we count it as corruption
s = Status::Corruption("Tailing data in backup meta file in " +
meta_filename_);
}
if (s.ok()) {
files_.reserve(files.size());
for (const auto& file_info : files) {
s = AddFile(file_info);
if (!s.ok()) {
break;
}
}
}
return s;
}
Status BackupEngineImpl::BackupMeta::StoreToFile(bool sync) {
Status s;
std::unique_ptr<WritableFile> backup_meta_file;
EnvOptions env_options;
env_options.use_mmap_writes = false;
env_options.use_direct_writes = false;
s = env_->NewWritableFile(meta_tmp_filename_, &backup_meta_file, env_options);
if (!s.ok()) {
return s;
}
std::ostringstream buf;
buf << timestamp_ << "\n";
buf << sequence_number_ << "\n";
if (!app_metadata_.empty()) {
std::string hex_encoded_metadata =
Slice(app_metadata_).ToString(/* hex */ true);
buf << kMetaDataPrefix.ToString() << hex_encoded_metadata << "\n";
}
buf << files_.size() << "\n";
for (const auto& file : files_) {
// use crc32c for now, switch to something else if needed
// WART: The checksums are crc32c, not original crc32
buf << file->filename << " crc32 " << ChecksumHexToInt32(file->checksum_hex)
<< "\n";
}
s = backup_meta_file->Append(Slice(buf.str()));
if (s.ok() && sync) {
s = backup_meta_file->Sync();
}
if (s.ok()) {
s = backup_meta_file->Close();
}
if (s.ok()) {
s = env_->RenameFile(meta_tmp_filename_, meta_filename_);
}
return s;
}
// -------- BackupEngineReadOnlyImpl ---------
class BackupEngineReadOnlyImpl : public BackupEngineReadOnly {
public:
BackupEngineReadOnlyImpl(const BackupableDBOptions& options, Env* db_env)
: backup_engine_(new BackupEngineImpl(options, db_env, true)) {}
~BackupEngineReadOnlyImpl() override {}
// The returned BackupInfos are in chronological order, which means the
// latest backup comes last.
void GetBackupInfo(std::vector<BackupInfo>* backup_info) override {
backup_engine_->GetBackupInfo(backup_info);
}
void GetCorruptedBackups(std::vector<BackupID>* corrupt_backup_ids) override {
backup_engine_->GetCorruptedBackups(corrupt_backup_ids);
}
using BackupEngineReadOnly::RestoreDBFromBackup;
Status RestoreDBFromBackup(const RestoreOptions& options, BackupID backup_id,
const std::string& db_dir,
const std::string& wal_dir) override {
return backup_engine_->RestoreDBFromBackup(options, backup_id, db_dir,
wal_dir);
}
using BackupEngineReadOnly::RestoreDBFromLatestBackup;
Status RestoreDBFromLatestBackup(const RestoreOptions& options,
const std::string& db_dir,
const std::string& wal_dir) override {
return backup_engine_->RestoreDBFromLatestBackup(options, db_dir, wal_dir);
}
Status VerifyBackup(BackupID backup_id,
bool verify_with_checksum = false) override {
return backup_engine_->VerifyBackup(backup_id, verify_with_checksum);
}
Status Initialize() { return backup_engine_->Initialize(); }
private:
std::unique_ptr<BackupEngineImpl> backup_engine_;
};
Status BackupEngineReadOnly::Open(const BackupableDBOptions& options, Env* env,
BackupEngineReadOnly** backup_engine_ptr) {
if (options.destroy_old_data) {
return Status::InvalidArgument(
"Can't destroy old data with ReadOnly BackupEngine");
}
std::unique_ptr<BackupEngineReadOnlyImpl> backup_engine(
new BackupEngineReadOnlyImpl(options, env));
auto s = backup_engine->Initialize();
if (!s.ok()) {
*backup_engine_ptr = nullptr;
return s;
}
*backup_engine_ptr = backup_engine.release();
return Status::OK();
}
} // namespace ROCKSDB_NAMESPACE
#endif // ROCKSDB_LITE
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