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cb9104c92c
rocksdb/utilities/blob_db/blob_db_impl.cc
Yi Wu cb9104c92c Blob DB: option to enable garbage collection 
Summary:
Add an option to enable/disable auto garbage collection, where we keep counting how many keys have been evicted by either deletion or compaction and decide whether to garbage collect a blob file.

Default disable auto garbage collection for now since the whole logic is not fully tested and we plan to make major change to it.
Closes https://github.com/facebook/rocksdb/pull/3117

Differential Revision: D6224756

Pulled By: yiwu-arbug

fbshipit-source-id: cdf53bdccec96a4580a2b3a342110ad9e8864dfe
2017-11-19 19:04:05 -08:00

2160 lines
70 KiB
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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).
#ifndef ROCKSDB_LITE
#include "utilities/blob_db/blob_db_impl.h"
#include <algorithm>
#include <cinttypes>
#include <iomanip>
#include <limits>
#include <memory>
#include "db/db_impl.h"
#include "db/write_batch_internal.h"
#include "monitoring/instrumented_mutex.h"
#include "rocksdb/convenience.h"
#include "rocksdb/env.h"
#include "rocksdb/iterator.h"
#include "rocksdb/utilities/stackable_db.h"
#include "rocksdb/utilities/transaction.h"
#include "table/block.h"
#include "table/block_based_table_builder.h"
#include "table/block_builder.h"
#include "table/meta_blocks.h"
#include "util/cast_util.h"
#include "util/crc32c.h"
#include "util/file_reader_writer.h"
#include "util/filename.h"
#include "util/logging.h"
#include "util/mutexlock.h"
#include "util/random.h"
#include "util/sync_point.h"
#include "util/timer_queue.h"
#include "utilities/blob_db/blob_db_iterator.h"
#include "utilities/blob_db/blob_index.h"
namespace {
int kBlockBasedTableVersionFormat = 2;
} // end namespace
namespace rocksdb {
namespace blob_db {
Random blob_rgen(static_cast<uint32_t>(time(nullptr)));
void BlobDBFlushBeginListener::OnFlushBegin(DB* db, const FlushJobInfo& info) {
if (impl_) impl_->OnFlushBeginHandler(db, info);
}
WalFilter::WalProcessingOption BlobReconcileWalFilter::LogRecordFound(
unsigned long long log_number, const std::string& log_file_name,
const WriteBatch& batch, WriteBatch* new_batch, bool* batch_changed) {
return WalFilter::WalProcessingOption::kContinueProcessing;
}
bool blobf_compare_ttl::operator()(const std::shared_ptr<BlobFile>& lhs,
const std::shared_ptr<BlobFile>& rhs) const {
if (lhs->expiration_range_.first < rhs->expiration_range_.first) {
return true;
}
if (lhs->expiration_range_.first > rhs->expiration_range_.first) {
return false;
}
return lhs->BlobFileNumber() > rhs->BlobFileNumber();
}
void EvictAllVersionsCompactionListener::InternalListener::OnCompaction(
int level, const Slice& key,
CompactionEventListener::CompactionListenerValueType value_type,
const Slice& existing_value, const SequenceNumber& sn, bool is_new) {
assert(impl_->bdb_options_.enable_garbage_collection);
if (!is_new &&
value_type ==
CompactionEventListener::CompactionListenerValueType::kValue) {
BlobIndex blob_index;
Status s = blob_index.DecodeFrom(existing_value);
if (s.ok()) {
if (impl_->debug_level_ >= 3)
ROCKS_LOG_INFO(
impl_->db_options_.info_log,
"CALLBACK COMPACTED OUT KEY: %s SN: %d "
"NEW: %d FN: %" PRIu64 " OFFSET: %" PRIu64 " SIZE: %" PRIu64,
key.ToString().c_str(), sn, is_new, blob_index.file_number(),
blob_index.offset(), blob_index.size());
impl_->override_vals_q_.enqueue({blob_index.file_number(), key.size(),
blob_index.offset(), blob_index.size(),
sn});
}
} else {
if (impl_->debug_level_ >= 3)
ROCKS_LOG_INFO(impl_->db_options_.info_log,
"CALLBACK NEW KEY: %s SN: %d NEW: %d",
key.ToString().c_str(), sn, is_new);
}
}
BlobDBImpl::BlobDBImpl(const std::string& dbname,
const BlobDBOptions& blob_db_options,
const DBOptions& db_options)
: BlobDB(nullptr),
db_impl_(nullptr),
env_(db_options.env),
ttl_extractor_(blob_db_options.ttl_extractor.get()),
bdb_options_(blob_db_options),
db_options_(db_options),
env_options_(db_options),
dir_change_(false),
next_file_number_(1),
epoch_of_(0),
shutdown_(false),
current_epoch_(0),
open_file_count_(0),
last_period_write_(0),
last_period_ampl_(0),
total_periods_write_(0),
total_periods_ampl_(0),
total_blob_space_(0),
open_p1_done_(false),
debug_level_(0) {
blob_dir_ = (bdb_options_.path_relative)
? dbname + "/" + bdb_options_.blob_dir
: bdb_options_.blob_dir;
}
Status BlobDBImpl::LinkToBaseDB(DB* db) {
assert(db_ == nullptr);
assert(open_p1_done_);
db_ = db;
// the Base DB in-itself can be a stackable DB
db_impl_ = static_cast_with_check<DBImpl, DB>(db_->GetRootDB());
env_ = db_->GetEnv();
Status s = env_->CreateDirIfMissing(blob_dir_);
if (!s.ok()) {
ROCKS_LOG_WARN(db_options_.info_log,
"Failed to create blob directory: %s status: '%s'",
blob_dir_.c_str(), s.ToString().c_str());
}
s = env_->NewDirectory(blob_dir_, &dir_ent_);
if (!s.ok()) {
ROCKS_LOG_WARN(db_options_.info_log,
"Failed to open blob directory: %s status: '%s'",
blob_dir_.c_str(), s.ToString().c_str());
}
if (!bdb_options_.disable_background_tasks) {
StartBackgroundTasks();
}
return s;
}
BlobDBOptions BlobDBImpl::GetBlobDBOptions() const { return bdb_options_; }
BlobDBImpl::BlobDBImpl(DB* db, const BlobDBOptions& blob_db_options)
: BlobDB(db),
db_impl_(static_cast_with_check<DBImpl, DB>(db)),
bdb_options_(blob_db_options),
db_options_(db->GetOptions()),
env_options_(db_->GetOptions()),
dir_change_(false),
next_file_number_(1),
epoch_of_(0),
shutdown_(false),
current_epoch_(0),
open_file_count_(0),
last_period_write_(0),
last_period_ampl_(0),
total_periods_write_(0),
total_periods_ampl_(0),
total_blob_space_(0) {
if (!bdb_options_.blob_dir.empty())
blob_dir_ = (bdb_options_.path_relative)
? db_->GetName() + "/" + bdb_options_.blob_dir
: bdb_options_.blob_dir;
}
BlobDBImpl::~BlobDBImpl() {
// CancelAllBackgroundWork(db_, true);
Shutdown();
}
Status BlobDBImpl::OpenPhase1() {
assert(db_ == nullptr);
if (blob_dir_.empty())
return Status::NotSupported("No blob directory in options");
std::unique_ptr<Directory> dir_ent;
Status s = env_->NewDirectory(blob_dir_, &dir_ent);
if (!s.ok()) {
ROCKS_LOG_WARN(db_options_.info_log,
"Failed to open blob directory: %s status: '%s'",
blob_dir_.c_str(), s.ToString().c_str());
open_p1_done_ = true;
return Status::OK();
}
s = OpenAllFiles();
open_p1_done_ = true;
return s;
}
void BlobDBImpl::StartBackgroundTasks() {
// store a call to a member function and object
tqueue_.add(
kReclaimOpenFilesPeriodMillisecs,
std::bind(&BlobDBImpl::ReclaimOpenFiles, this, std::placeholders::_1));
tqueue_.add(kGCCheckPeriodMillisecs,
std::bind(&BlobDBImpl::RunGC, this, std::placeholders::_1));
if (bdb_options_.enable_garbage_collection) {
tqueue_.add(
kDeleteCheckPeriodMillisecs,
std::bind(&BlobDBImpl::EvictDeletions, this, std::placeholders::_1));
tqueue_.add(
kDeleteCheckPeriodMillisecs,
std::bind(&BlobDBImpl::EvictCompacted, this, std::placeholders::_1));
}
tqueue_.add(
kDeleteObsoleteFilesPeriodMillisecs,
std::bind(&BlobDBImpl::DeleteObsoleteFiles, this, std::placeholders::_1));
tqueue_.add(kSanityCheckPeriodMillisecs,
std::bind(&BlobDBImpl::SanityCheck, this, std::placeholders::_1));
tqueue_.add(kWriteAmplificationStatsPeriodMillisecs,
std::bind(&BlobDBImpl::WaStats, this, std::placeholders::_1));
tqueue_.add(kFSyncFilesPeriodMillisecs,
std::bind(&BlobDBImpl::FsyncFiles, this, std::placeholders::_1));
tqueue_.add(
kCheckSeqFilesPeriodMillisecs,
std::bind(&BlobDBImpl::CheckSeqFiles, this, std::placeholders::_1));
}
void BlobDBImpl::Shutdown() { shutdown_.store(true); }
void BlobDBImpl::OnFlushBeginHandler(DB* db, const FlushJobInfo& info) {
if (shutdown_.load()) return;
// a callback that happens too soon needs to be ignored
if (!db_) return;
FsyncFiles(false);
}
Status BlobDBImpl::GetAllLogFiles(
std::set<std::pair<uint64_t, std::string>>* file_nums) {
std::vector<std::string> all_files;
Status status = env_->GetChildren(blob_dir_, &all_files);
if (!status.ok()) {
return status;
}
for (const auto& f : all_files) {
uint64_t number;
FileType type;
bool psucc = ParseFileName(f, &number, &type);
if (psucc && type == kBlobFile) {
file_nums->insert(std::make_pair(number, f));
} else {
ROCKS_LOG_WARN(db_options_.info_log,
"Skipping file in blob directory %s parse: %d type: %d",
f.c_str(), psucc, ((psucc) ? type : -1));
}
}
return status;
}
Status BlobDBImpl::OpenAllFiles() {
WriteLock wl(&mutex_);
std::set<std::pair<uint64_t, std::string>> file_nums;
Status status = GetAllLogFiles(&file_nums);
if (!status.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to collect files from blob dir: %s status: '%s'",
blob_dir_.c_str(), status.ToString().c_str());
return status;
}
ROCKS_LOG_INFO(db_options_.info_log,
"BlobDir files path: %s count: %d min: %" PRIu64
" max: %" PRIu64,
blob_dir_.c_str(), static_cast<int>(file_nums.size()),
(file_nums.empty()) ? -1 : (file_nums.begin())->first,
(file_nums.empty()) ? -1 : (file_nums.end())->first);
if (!file_nums.empty())
next_file_number_.store((file_nums.rbegin())->first + 1);
for (auto f_iter : file_nums) {
std::string bfpath = BlobFileName(blob_dir_, f_iter.first);
uint64_t size_bytes;
Status s1 = env_->GetFileSize(bfpath, &size_bytes);
if (!s1.ok()) {
ROCKS_LOG_WARN(
db_options_.info_log,
"Unable to get size of %s. File skipped from open status: '%s'",
bfpath.c_str(), s1.ToString().c_str());
continue;
}
if (debug_level_ >= 1)
ROCKS_LOG_INFO(db_options_.info_log, "Blob File open: %s size: %" PRIu64,
bfpath.c_str(), size_bytes);
std::shared_ptr<BlobFile> bfptr =
std::make_shared<BlobFile>(this, blob_dir_, f_iter.first);
bfptr->SetFileSize(size_bytes);
// since this file already existed, we will try to reconcile
// deleted count with LSM
bfptr->gc_once_after_open_ = true;
// read header
std::shared_ptr<Reader> reader;
reader = bfptr->OpenSequentialReader(env_, db_options_, env_options_);
s1 = reader->ReadHeader(&bfptr->header_);
if (!s1.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failure to read header for blob-file %s "
"status: '%s' size: %" PRIu64,
bfpath.c_str(), s1.ToString().c_str(), size_bytes);
continue;
}
bfptr->SetHasTTL(bfptr->header_.has_ttl);
bfptr->header_valid_ = true;
std::shared_ptr<RandomAccessFileReader> ra_reader =
GetOrOpenRandomAccessReader(bfptr, env_, env_options_);
BlobLogFooter bf;
s1 = bfptr->ReadFooter(&bf);
bfptr->CloseRandomAccessLocked();
if (s1.ok()) {
s1 = bfptr->SetFromFooterLocked(bf);
if (!s1.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Header Footer mismatch for blob-file %s "
"status: '%s' size: %" PRIu64,
bfpath.c_str(), s1.ToString().c_str(), size_bytes);
continue;
}
} else {
ROCKS_LOG_INFO(db_options_.info_log,
"File found incomplete (w/o footer) %s", bfpath.c_str());
// sequentially iterate over the file and read all the records
ExpirationRange expiration_range(std::numeric_limits<uint32_t>::max(),
std::numeric_limits<uint32_t>::min());
uint64_t blob_count = 0;
BlobLogRecord record;
Reader::ReadLevel shallow = Reader::kReadHeaderKey;
uint64_t record_start = reader->GetNextByte();
// TODO(arahut) - when we detect corruption, we should truncate
while (reader->ReadRecord(&record, shallow).ok()) {
++blob_count;
if (bfptr->HasTTL()) {
expiration_range.first =
std::min(expiration_range.first, record.expiration);
expiration_range.second =
std::max(expiration_range.second, record.expiration);
}
record_start = reader->GetNextByte();
}
if (record_start != bfptr->GetFileSize()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Blob file is corrupted or crashed during write %s"
" good_size: %" PRIu64 " file_size: %" PRIu64,
bfpath.c_str(), record_start, bfptr->GetFileSize());
}
if (!blob_count) {
ROCKS_LOG_INFO(db_options_.info_log, "BlobCount = 0 in file %s",
bfpath.c_str());
continue;
}
bfptr->SetBlobCount(blob_count);
bfptr->SetSequenceRange({0, 0});
ROCKS_LOG_INFO(db_options_.info_log,
"Blob File: %s blob_count: %" PRIu64
" size_bytes: %" PRIu64 " has_ttl: %d",
bfpath.c_str(), blob_count, size_bytes, bfptr->HasTTL());
if (bfptr->HasTTL()) {
expiration_range.second = std::max(
expiration_range.second,
expiration_range.first + (uint32_t)bdb_options_.ttl_range_secs);
bfptr->set_expiration_range(expiration_range);
uint64_t now = EpochNow();
if (expiration_range.second < now) {
Status fstatus = CreateWriterLocked(bfptr);
if (fstatus.ok()) fstatus = bfptr->WriteFooterAndCloseLocked();
if (!fstatus.ok()) {
ROCKS_LOG_ERROR(
db_options_.info_log,
"Failed to close Blob File: %s status: '%s'. Skipped",
bfpath.c_str(), fstatus.ToString().c_str());
continue;
} else {
ROCKS_LOG_ERROR(
db_options_.info_log,
"Blob File Closed: %s now: %d expiration_range: (%d, %d)",
bfpath.c_str(), now, expiration_range.first,
expiration_range.second);
}
} else {
open_ttl_files_.insert(bfptr);
}
}
}
blob_files_.insert(std::make_pair(f_iter.first, bfptr));
}
return status;
}
void BlobDBImpl::CloseRandomAccessLocked(
const std::shared_ptr<BlobFile>& bfile) {
bfile->CloseRandomAccessLocked();
open_file_count_--;
}
std::shared_ptr<RandomAccessFileReader> BlobDBImpl::GetOrOpenRandomAccessReader(
const std::shared_ptr<BlobFile>& bfile, Env* env,
const EnvOptions& env_options) {
bool fresh_open = false;
auto rar = bfile->GetOrOpenRandomAccessReader(env, env_options, &fresh_open);
if (fresh_open) open_file_count_++;
return rar;
}
std::shared_ptr<BlobFile> BlobDBImpl::NewBlobFile(const std::string& reason) {
uint64_t file_num = next_file_number_++;
auto bfile = std::make_shared<BlobFile>(this, blob_dir_, file_num);
ROCKS_LOG_DEBUG(db_options_.info_log, "New blob file created: %s reason='%s'",
bfile->PathName().c_str(), reason.c_str());
LogFlush(db_options_.info_log);
return bfile;
}
Status BlobDBImpl::CreateWriterLocked(const std::shared_ptr<BlobFile>& bfile) {
std::string fpath(bfile->PathName());
std::unique_ptr<WritableFile> wfile;
Status s = env_->ReopenWritableFile(fpath, &wfile, env_options_);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to open blob file for write: %s status: '%s'"
" exists: '%s'",
fpath.c_str(), s.ToString().c_str(),
env_->FileExists(fpath).ToString().c_str());
return s;
}
std::unique_ptr<WritableFileWriter> fwriter;
fwriter.reset(new WritableFileWriter(std::move(wfile), env_options_));
uint64_t boffset = bfile->GetFileSize();
if (debug_level_ >= 2 && boffset) {
ROCKS_LOG_DEBUG(db_options_.info_log, "Open blob file: %s with offset: %d",
fpath.c_str(), boffset);
}
Writer::ElemType et = Writer::kEtNone;
if (bfile->file_size_ == BlobLogHeader::kSize) {
et = Writer::kEtFileHdr;
} else if (bfile->file_size_ > BlobLogHeader::kSize) {
et = Writer::kEtRecord;
} else if (bfile->file_size_) {
ROCKS_LOG_WARN(db_options_.info_log,
"Open blob file: %s with wrong size: %d", fpath.c_str(),
boffset);
return Status::Corruption("Invalid blob file size");
}
bfile->log_writer_ = std::make_shared<Writer>(
std::move(fwriter), bfile->file_number_, bdb_options_.bytes_per_sync,
db_options_.use_fsync, boffset);
bfile->log_writer_->last_elem_type_ = et;
return s;
}
std::shared_ptr<BlobFile> BlobDBImpl::FindBlobFileLocked(
uint64_t expiration) const {
if (open_ttl_files_.empty()) return nullptr;
std::shared_ptr<BlobFile> tmp = std::make_shared<BlobFile>();
tmp->expiration_range_ = std::make_pair(expiration, 0);
auto citr = open_ttl_files_.equal_range(tmp);
if (citr.first == open_ttl_files_.end()) {
assert(citr.second == open_ttl_files_.end());
std::shared_ptr<BlobFile> check = *(open_ttl_files_.rbegin());
return (check->expiration_range_.second < expiration) ? nullptr : check;
}
if (citr.first != citr.second) return *(citr.first);
auto finditr = citr.second;
if (finditr != open_ttl_files_.begin()) --finditr;
bool b2 = (*finditr)->expiration_range_.second < expiration;
bool b1 = (*finditr)->expiration_range_.first > expiration;
return (b1 || b2) ? nullptr : (*finditr);
}
std::shared_ptr<Writer> BlobDBImpl::CheckOrCreateWriterLocked(
const std::shared_ptr<BlobFile>& bfile) {
std::shared_ptr<Writer> writer = bfile->GetWriter();
if (writer) return writer;
Status s = CreateWriterLocked(bfile);
if (!s.ok()) return nullptr;
writer = bfile->GetWriter();
return writer;
}
std::shared_ptr<BlobFile> BlobDBImpl::SelectBlobFile() {
{
ReadLock rl(&mutex_);
if (open_non_ttl_file_ != nullptr) {
return open_non_ttl_file_;
}
}
// CHECK again
WriteLock wl(&mutex_);
if (open_non_ttl_file_ != nullptr) {
return open_non_ttl_file_;
}
std::shared_ptr<BlobFile> bfile = NewBlobFile("SelectBlobFile");
assert(bfile);
// file not visible, hence no lock
std::shared_ptr<Writer> writer = CheckOrCreateWriterLocked(bfile);
if (!writer) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to get writer from blob file: %s",
bfile->PathName().c_str());
return nullptr;
}
bfile->file_size_ = BlobLogHeader::kSize;
bfile->header_.compression = bdb_options_.compression;
bfile->header_.has_ttl = false;
bfile->header_.column_family_id =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily())->GetID();
bfile->header_valid_ = true;
bfile->SetHasTTL(false);
Status s = writer->WriteHeader(bfile->header_);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to write header to new blob file: %s"
" status: '%s'",
bfile->PathName().c_str(), s.ToString().c_str());
return nullptr;
}
dir_change_.store(true);
blob_files_.insert(std::make_pair(bfile->BlobFileNumber(), bfile));
open_non_ttl_file_ = bfile;
return bfile;
}
std::shared_ptr<BlobFile> BlobDBImpl::SelectBlobFileTTL(uint64_t expiration) {
assert(expiration != kNoExpiration);
uint64_t epoch_read = 0;
std::shared_ptr<BlobFile> bfile;
{
ReadLock rl(&mutex_);
bfile = FindBlobFileLocked(expiration);
epoch_read = epoch_of_.load();
}
if (bfile) {
assert(!bfile->Immutable());
return bfile;
}
uint64_t exp_low =
(expiration / bdb_options_.ttl_range_secs) * bdb_options_.ttl_range_secs;
uint64_t exp_high = exp_low + bdb_options_.ttl_range_secs;
ExpirationRange expiration_range = std::make_pair(exp_low, exp_high);
bfile = NewBlobFile("SelectBlobFileTTL");
assert(bfile);
ROCKS_LOG_INFO(db_options_.info_log, "New blob file TTL range: %s %d %d",
bfile->PathName().c_str(), exp_low, exp_high);
LogFlush(db_options_.info_log);
// we don't need to take lock as no other thread is seeing bfile yet
std::shared_ptr<Writer> writer = CheckOrCreateWriterLocked(bfile);
if (!writer) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to get writer from blob file with TTL: %s",
bfile->PathName().c_str());
return nullptr;
}
bfile->header_.expiration_range = expiration_range;
bfile->header_.compression = bdb_options_.compression;
bfile->header_.has_ttl = true;
bfile->header_.column_family_id =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily())->GetID();
;
bfile->header_valid_ = true;
bfile->SetHasTTL(true);
bfile->file_size_ = BlobLogHeader::kSize;
// set the first value of the range, since that is
// concrete at this time. also necessary to add to open_ttl_files_
bfile->expiration_range_ = expiration_range;
WriteLock wl(&mutex_);
// in case the epoch has shifted in the interim, then check
// check condition again - should be rare.
if (epoch_of_.load() != epoch_read) {
auto bfile2 = FindBlobFileLocked(expiration);
if (bfile2) return bfile2;
}
Status s = writer->WriteHeader(bfile->header_);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to write header to new blob file: %s"
" status: '%s'",
bfile->PathName().c_str(), s.ToString().c_str());
return nullptr;
}
dir_change_.store(true);
blob_files_.insert(std::make_pair(bfile->BlobFileNumber(), bfile));
open_ttl_files_.insert(bfile);
epoch_of_++;
return bfile;
}
Status BlobDBImpl::Delete(const WriteOptions& options, const Slice& key) {
SequenceNumber lsn = db_impl_->GetLatestSequenceNumber();
Status s = db_->Delete(options, key);
if (bdb_options_.enable_garbage_collection) {
// add deleted key to list of keys that have been deleted for book-keeping
delete_keys_q_.enqueue({DefaultColumnFamily(), key.ToString(), lsn});
}
return s;
}
class BlobDBImpl::BlobInserter : public WriteBatch::Handler {
private:
const WriteOptions& options_;
BlobDBImpl* blob_db_impl_;
uint32_t default_cf_id_;
SequenceNumber sequence_;
WriteBatch batch_;
public:
BlobInserter(const WriteOptions& options, BlobDBImpl* blob_db_impl,
uint32_t default_cf_id, SequenceNumber seq)
: options_(options),
blob_db_impl_(blob_db_impl),
default_cf_id_(default_cf_id),
sequence_(seq) {}
SequenceNumber sequence() { return sequence_; }
WriteBatch* batch() { return &batch_; }
virtual Status PutCF(uint32_t column_family_id, const Slice& key,
const Slice& value) override {
if (column_family_id != default_cf_id_) {
return Status::NotSupported(
"Blob DB doesn't support non-default column family.");
}
std::string new_value;
Slice value_slice;
uint64_t expiration =
blob_db_impl_->ExtractExpiration(key, value, &value_slice, &new_value);
Status s = blob_db_impl_->PutBlobValue(options_, key, value_slice,
expiration, sequence_, &batch_);
sequence_++;
return s;
}
virtual Status DeleteCF(uint32_t column_family_id,
const Slice& key) override {
if (column_family_id != default_cf_id_) {
return Status::NotSupported(
"Blob DB doesn't support non-default column family.");
}
Status s = WriteBatchInternal::Delete(&batch_, column_family_id, key);
sequence_++;
return s;
}
virtual Status DeleteRange(uint32_t column_family_id, const Slice& begin_key,
const Slice& end_key) {
if (column_family_id != default_cf_id_) {
return Status::NotSupported(
"Blob DB doesn't support non-default column family.");
}
Status s = WriteBatchInternal::DeleteRange(&batch_, column_family_id,
begin_key, end_key);
sequence_++;
return s;
}
virtual Status SingleDeleteCF(uint32_t /*column_family_id*/,
const Slice& /*key*/) override {
return Status::NotSupported("Not supported operation in blob db.");
}
virtual Status MergeCF(uint32_t /*column_family_id*/, const Slice& /*key*/,
const Slice& /*value*/) override {
return Status::NotSupported("Not supported operation in blob db.");
}
virtual void LogData(const Slice& blob) override { batch_.PutLogData(blob); }
};
Status BlobDBImpl::Write(const WriteOptions& options, WriteBatch* updates) {
MutexLock l(&write_mutex_);
uint32_t default_cf_id =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily())->GetID();
SequenceNumber current_seq = GetLatestSequenceNumber() + 1;
BlobInserter blob_inserter(options, this, default_cf_id, current_seq);
Status s = updates->Iterate(&blob_inserter);
if (!s.ok()) {
return s;
}
s = db_->Write(options, blob_inserter.batch());
if (!s.ok()) {
return s;
}
assert(blob_inserter.sequence() == GetLatestSequenceNumber() + 1);
// add deleted key to list of keys that have been deleted for book-keeping
class DeleteBookkeeper : public WriteBatch::Handler {
public:
explicit DeleteBookkeeper(BlobDBImpl* impl, const SequenceNumber& seq)
: impl_(impl), sequence_(seq) {}
virtual Status PutCF(uint32_t /*column_family_id*/, const Slice& /*key*/,
const Slice& /*value*/) override {
sequence_++;
return Status::OK();
}
virtual Status DeleteCF(uint32_t column_family_id,
const Slice& key) override {
ColumnFamilyHandle* cfh =
impl_->db_impl_->GetColumnFamilyHandleUnlocked(column_family_id);
impl_->delete_keys_q_.enqueue({cfh, key.ToString(), sequence_});
sequence_++;
return Status::OK();
}
private:
BlobDBImpl* impl_;
SequenceNumber sequence_;
};
if (bdb_options_.enable_garbage_collection) {
// add deleted key to list of keys that have been deleted for book-keeping
DeleteBookkeeper delete_bookkeeper(this, current_seq);
s = updates->Iterate(&delete_bookkeeper);
}
return s;
}
Status BlobDBImpl::GetLiveFiles(std::vector<std::string>& ret,
uint64_t* manifest_file_size,
bool flush_memtable) {
// Hold a lock in the beginning to avoid updates to base DB during the call
ReadLock rl(&mutex_);
Status s = db_->GetLiveFiles(ret, manifest_file_size, flush_memtable);
if (!s.ok()) {
return s;
}
ret.reserve(ret.size() + blob_files_.size());
for (auto bfile_pair : blob_files_) {
auto blob_file = bfile_pair.second;
ret.emplace_back(blob_file->PathName());
}
return Status::OK();
}
void BlobDBImpl::GetLiveFilesMetaData(std::vector<LiveFileMetaData>* metadata) {
// Hold a lock in the beginning to avoid updates to base DB during the call
ReadLock rl(&mutex_);
db_->GetLiveFilesMetaData(metadata);
for (auto bfile_pair : blob_files_) {
auto blob_file = bfile_pair.second;
LiveFileMetaData filemetadata;
filemetadata.size = blob_file->GetFileSize();
filemetadata.name = blob_file->PathName();
auto cfh =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily());
filemetadata.column_family_name = cfh->GetName();
metadata->emplace_back(filemetadata);
}
}
Status BlobDBImpl::Put(const WriteOptions& options, const Slice& key,
const Slice& value) {
std::string new_value;
Slice value_slice;
uint64_t expiration = ExtractExpiration(key, value, &value_slice, &new_value);
return PutUntil(options, key, value_slice, expiration);
}
Status BlobDBImpl::PutWithTTL(const WriteOptions& options,
const Slice& key, const Slice& value,
uint64_t ttl) {
uint64_t now = EpochNow();
uint64_t expiration = kNoExpiration - now > ttl ? now + ttl : kNoExpiration;
return PutUntil(options, key, value, expiration);
}
Status BlobDBImpl::PutUntil(const WriteOptions& options, const Slice& key,
const Slice& value, uint64_t expiration) {
TEST_SYNC_POINT("BlobDBImpl::PutUntil:Start");
MutexLock l(&write_mutex_);
SequenceNumber sequence = GetLatestSequenceNumber() + 1;
WriteBatch batch;
Status s = PutBlobValue(options, key, value, expiration, sequence, &batch);
if (s.ok()) {
s = db_->Write(options, &batch);
}
TEST_SYNC_POINT("BlobDBImpl::PutUntil:Finish");
return s;
}
Status BlobDBImpl::PutBlobValue(const WriteOptions& options, const Slice& key,
const Slice& value, uint64_t expiration,
SequenceNumber sequence, WriteBatch* batch) {
Status s;
std::string index_entry;
uint32_t column_family_id =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily())->GetID();
if (value.size() < bdb_options_.min_blob_size) {
if (expiration == kNoExpiration) {
// Put as normal value
s = batch->Put(key, value);
} else {
// Inlined with TTL
BlobIndex::EncodeInlinedTTL(&index_entry, expiration, value);
s = WriteBatchInternal::PutBlobIndex(batch, column_family_id, key,
index_entry);
}
} else {
std::shared_ptr<BlobFile> bfile = (expiration != kNoExpiration)
? SelectBlobFileTTL(expiration)
: SelectBlobFile();
if (!bfile) {
return Status::NotFound("Blob file not found");
}
std::string compression_output;
Slice value_compressed = GetCompressedSlice(value, &compression_output);
std::string headerbuf;
Writer::ConstructBlobHeader(&headerbuf, key, value_compressed, expiration);
s = AppendBlob(bfile, headerbuf, key, value_compressed, expiration,
&index_entry);
if (s.ok()) {
bfile->ExtendSequenceRange(sequence);
if (expiration != kNoExpiration) {
bfile->ExtendExpirationRange(expiration);
}
s = CloseBlobFileIfNeeded(bfile);
if (s.ok()) {
s = WriteBatchInternal::PutBlobIndex(batch, column_family_id, key,
index_entry);
}
} else {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to append blob to FILE: %s: KEY: %s VALSZ: %d"
" status: '%s' blob_file: '%s'",
bfile->PathName().c_str(), key.ToString().c_str(),
value.size(), s.ToString().c_str(),
bfile->DumpState().c_str());
}
}
return s;
}
Slice BlobDBImpl::GetCompressedSlice(const Slice& raw,
std::string* compression_output) const {
if (bdb_options_.compression == kNoCompression) {
return raw;
}
CompressionType ct = bdb_options_.compression;
CompressionOptions compression_opts;
CompressBlock(raw, compression_opts, &ct, kBlockBasedTableVersionFormat,
Slice(), compression_output);
return *compression_output;
}
uint64_t BlobDBImpl::ExtractExpiration(const Slice& key, const Slice& value,
Slice* value_slice,
std::string* new_value) {
uint64_t expiration = kNoExpiration;
bool has_expiration = false;
bool value_changed = false;
if (ttl_extractor_ != nullptr) {
has_expiration = ttl_extractor_->ExtractExpiration(
key, value, EpochNow(), &expiration, new_value, &value_changed);
}
*value_slice = value_changed ? Slice(*new_value) : value;
return has_expiration ? expiration : kNoExpiration;
}
Status BlobDBImpl::AppendBlob(const std::shared_ptr<BlobFile>& bfile,
const std::string& headerbuf, const Slice& key,
const Slice& value, uint64_t expiration,
std::string* index_entry) {
auto size_put = BlobLogRecord::kHeaderSize + key.size() + value.size();
if (bdb_options_.blob_dir_size > 0 &&
(total_blob_space_.load() + size_put) > bdb_options_.blob_dir_size) {
if (!bdb_options_.is_fifo) {
return Status::NoSpace("Blob DB reached the maximum configured size.");
}
}
Status s;
uint64_t blob_offset = 0;
uint64_t key_offset = 0;
{
WriteLock lockbfile_w(&bfile->mutex_);
std::shared_ptr<Writer> writer = CheckOrCreateWriterLocked(bfile);
if (!writer) return Status::IOError("Failed to create blob writer");
// write the blob to the blob log.
s = writer->EmitPhysicalRecord(headerbuf, key, value, &key_offset,
&blob_offset);
}
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Invalid status in AppendBlob: %s status: '%s'",
bfile->PathName().c_str(), s.ToString().c_str());
return s;
}
// increment blob count
bfile->blob_count_++;
bfile->file_size_ += size_put;
last_period_write_ += size_put;
total_blob_space_ += size_put;
if (expiration == kNoExpiration) {
BlobIndex::EncodeBlob(index_entry, bfile->BlobFileNumber(), blob_offset,
value.size(), bdb_options_.compression);
} else {
BlobIndex::EncodeBlobTTL(index_entry, expiration, bfile->BlobFileNumber(),
blob_offset, value.size(),
bdb_options_.compression);
}
return s;
}
std::vector<Status> BlobDBImpl::MultiGet(
const ReadOptions& read_options,
const std::vector<Slice>& keys, std::vector<std::string>* values) {
// Get a snapshot to avoid blob file get deleted between we
// fetch and index entry and reading from the file.
ReadOptions ro(read_options);
bool snapshot_created = SetSnapshotIfNeeded(&ro);
std::vector<Status> statuses;
statuses.reserve(keys.size());
values->clear();
values->reserve(keys.size());
PinnableSlice value;
for (size_t i = 0; i < keys.size(); i++) {
statuses.push_back(Get(ro, DefaultColumnFamily(), keys[i], &value));
values->push_back(value.ToString());
value.Reset();
}
if (snapshot_created) {
db_->ReleaseSnapshot(ro.snapshot);
}
return statuses;
}
bool BlobDBImpl::SetSnapshotIfNeeded(ReadOptions* read_options) {
assert(read_options != nullptr);
if (read_options->snapshot != nullptr) {
return false;
}
read_options->snapshot = db_->GetSnapshot();
return true;
}
Status BlobDBImpl::GetBlobValue(const Slice& key, const Slice& index_entry,
PinnableSlice* value) {
assert(value != nullptr);
BlobIndex blob_index;
Status s = blob_index.DecodeFrom(index_entry);
if (!s.ok()) {
return s;
}
if (blob_index.HasTTL() && blob_index.expiration() <= EpochNow()) {
return Status::NotFound("Key expired");
}
if (blob_index.IsInlined()) {
// TODO(yiwu): If index_entry is a PinnableSlice, we can also pin the same
// memory buffer to avoid extra copy.
value->PinSelf(blob_index.value());
return Status::OK();
}
if (blob_index.size() == 0) {
value->PinSelf("");
return Status::OK();
}
// offset has to have certain min, as we will read CRC
// later from the Blob Header, which needs to be also a
// valid offset.
if (blob_index.offset() <
(BlobLogHeader::kSize + BlobLogRecord::kHeaderSize + key.size())) {
if (debug_level_ >= 2) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Invalid blob index file_number: %" PRIu64
" blob_offset: %" PRIu64 " blob_size: %" PRIu64
" key: %s",
blob_index.file_number(), blob_index.offset(),
blob_index.size(), key.data());
}
return Status::NotFound("Invalid blob offset");
}
std::shared_ptr<BlobFile> bfile;
{
ReadLock rl(&mutex_);
auto hitr = blob_files_.find(blob_index.file_number());
// file was deleted
if (hitr == blob_files_.end()) {
return Status::NotFound("Blob Not Found as blob file missing");
}
bfile = hitr->second;
}
if (blob_index.size() == 0 && value != nullptr) {
value->PinSelf("");
return Status::OK();
}
// takes locks when called
std::shared_ptr<RandomAccessFileReader> reader =
GetOrOpenRandomAccessReader(bfile, env_, env_options_);
std::string* valueptr = value->GetSelf();
std::string value_c;
if (bdb_options_.compression != kNoCompression) {
valueptr = &value_c;
}
// Allocate the buffer. This is safe in C++11
// Note that std::string::reserved() does not work, since previous value
// of the buffer can be larger than blob_index.size().
valueptr->resize(blob_index.size());
char* buffer = &(*valueptr)[0];
Slice blob_value;
s = reader->Read(blob_index.offset(), blob_index.size(), &blob_value, buffer);
if (!s.ok() || blob_value.size() != blob_index.size()) {
if (debug_level_ >= 2) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to read blob from file: %s blob_offset: %" PRIu64
" blob_size: %" PRIu64 " read: %d key: %s status: '%s'",
bfile->PathName().c_str(), blob_index.offset(),
blob_index.size(), static_cast<int>(blob_value.size()),
key.data(), s.ToString().c_str());
}
return Status::NotFound("Blob Not Found as couldnt retrieve Blob");
}
// TODO(yiwu): Add an option to skip crc checking.
Slice crc_slice;
uint32_t crc_exp;
std::string crc_str;
crc_str.resize(sizeof(uint32_t));
char* crc_buffer = &(crc_str[0]);
s = reader->Read(blob_index.offset() - (key.size() + sizeof(uint32_t)),
sizeof(uint32_t), &crc_slice, crc_buffer);
if (!s.ok() || !GetFixed32(&crc_slice, &crc_exp)) {
if (debug_level_ >= 2) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to fetch blob crc file: %s blob_offset: %" PRIu64
" blob_size: %" PRIu64 " key: %s status: '%s'",
bfile->PathName().c_str(), blob_index.offset(),
blob_index.size(), key.data(), s.ToString().c_str());
}
return Status::NotFound("Blob Not Found as couldnt retrieve CRC");
}
uint32_t crc = crc32c::Value(key.data(), key.size());
crc = crc32c::Extend(crc, blob_value.data(), blob_value.size());
crc = crc32c::Mask(crc); // Adjust for storage
if (crc != crc_exp) {
if (debug_level_ >= 2) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Blob crc mismatch file: %s blob_offset: %" PRIu64
" blob_size: %" PRIu64 " key: %s status: '%s'",
bfile->PathName().c_str(), blob_index.offset(),
blob_index.size(), key.data(), s.ToString().c_str());
}
return Status::Corruption("Corruption. Blob CRC mismatch");
}
// TODO(yiwu): Should use compression flag in the blob file instead of
// current compression option.
if (bdb_options_.compression != kNoCompression) {
BlockContents contents;
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily());
s = UncompressBlockContentsForCompressionType(
blob_value.data(), blob_value.size(), &contents,
kBlockBasedTableVersionFormat, Slice(), bdb_options_.compression,
*(cfh->cfd()->ioptions()));
*(value->GetSelf()) = contents.data.ToString();
}
value->PinSelf();
return s;
}
Status BlobDBImpl::Get(const ReadOptions& read_options,
ColumnFamilyHandle* column_family, const Slice& key,
PinnableSlice* value) {
if (column_family != DefaultColumnFamily()) {
return Status::NotSupported(
"Blob DB doesn't support non-default column family.");
}
// Get a snapshot to avoid blob file get deleted between we
// fetch and index entry and reading from the file.
// TODO(yiwu): For Get() retry if file not found would be a simpler strategy.
ReadOptions ro(read_options);
bool snapshot_created = SetSnapshotIfNeeded(&ro);
Status s;
bool is_blob_index = false;
s = db_impl_->GetImpl(ro, column_family, key, value, nullptr /*value_found*/,
nullptr /*read_callback*/, &is_blob_index);
TEST_SYNC_POINT("BlobDBImpl::Get:AfterIndexEntryGet:1");
TEST_SYNC_POINT("BlobDBImpl::Get:AfterIndexEntryGet:2");
if (s.ok()) {
if (is_blob_index) {
PinnableSlice index_entry = std::move(*value);
s = GetBlobValue(key, index_entry, value);
}
}
if (snapshot_created) {
db_->ReleaseSnapshot(ro.snapshot);
}
return s;
}
std::pair<bool, int64_t> BlobDBImpl::SanityCheck(bool aborted) {
if (aborted) return std::make_pair(false, -1);
ROCKS_LOG_INFO(db_options_.info_log, "Starting Sanity Check");
ROCKS_LOG_INFO(db_options_.info_log, "Number of files %" PRIu64,
blob_files_.size());
ROCKS_LOG_INFO(db_options_.info_log, "Number of open files %" PRIu64,
open_ttl_files_.size());
for (auto bfile : open_ttl_files_) {
assert(!bfile->Immutable());
}
uint64_t epoch_now = EpochNow();
for (auto bfile_pair : blob_files_) {
auto bfile = bfile_pair.second;
ROCKS_LOG_INFO(
db_options_.info_log,
"Blob File %s %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64,
bfile->PathName().c_str(), bfile->GetFileSize(), bfile->BlobCount(),
bfile->deleted_count_, bfile->deleted_size_,
(bfile->expiration_range_.second - epoch_now));
}
// reschedule
return std::make_pair(true, -1);
}
Status BlobDBImpl::CloseBlobFile(std::shared_ptr<BlobFile> bfile) {
assert(bfile != nullptr);
Status s;
ROCKS_LOG_INFO(db_options_.info_log, "Close blob file %" PRIu64,
bfile->BlobFileNumber());
{
WriteLock wl(&mutex_);
if (bfile->HasTTL()) {
size_t erased __attribute__((__unused__));
erased = open_ttl_files_.erase(bfile);
assert(erased == 1);
} else {
assert(bfile == open_non_ttl_file_);
open_non_ttl_file_ = nullptr;
}
}
if (!bfile->closed_.load()) {
WriteLock lockbfile_w(&bfile->mutex_);
s = bfile->WriteFooterAndCloseLocked();
}
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to close blob file %" PRIu64 "with error: %s",
bfile->BlobFileNumber(), s.ToString().c_str());
}
return s;
}
Status BlobDBImpl::CloseBlobFileIfNeeded(std::shared_ptr<BlobFile>& bfile) {
// atomic read
if (bfile->GetFileSize() < bdb_options_.blob_file_size) {
return Status::OK();
}
return CloseBlobFile(bfile);
}
bool BlobDBImpl::FileDeleteOk_SnapshotCheckLocked(
const std::shared_ptr<BlobFile>& bfile) {
assert(bfile->Obsolete());
SequenceNumber esn = bfile->GetSequenceRange().first;
// TODO(yiwu): Here we should check instead if there is an active snapshot
// lies between the first sequence in the file, and the last sequence by
// the time the file finished being garbage collect.
bool notok = db_impl_->HasActiveSnapshotLaterThanSN(esn);
if (notok) {
ROCKS_LOG_INFO(db_options_.info_log,
"Could not delete file due to snapshot failure %s",
bfile->PathName().c_str());
return false;
} else {
ROCKS_LOG_INFO(db_options_.info_log,
"Will delete file due to snapshot success %s",
bfile->PathName().c_str());
return true;
}
}
bool BlobDBImpl::FindFileAndEvictABlob(uint64_t file_number, uint64_t key_size,
uint64_t blob_offset,
uint64_t blob_size) {
assert(bdb_options_.enable_garbage_collection);
(void)blob_offset;
std::shared_ptr<BlobFile> bfile;
{
ReadLock rl(&mutex_);
auto hitr = blob_files_.find(file_number);
// file was deleted
if (hitr == blob_files_.end()) {
return false;
}
bfile = hitr->second;
}
WriteLock lockbfile_w(&bfile->mutex_);
bfile->deleted_count_++;
bfile->deleted_size_ += key_size + blob_size + BlobLogRecord::kHeaderSize;
return true;
}
bool BlobDBImpl::MarkBlobDeleted(const Slice& key, const Slice& index_entry) {
assert(bdb_options_.enable_garbage_collection);
BlobIndex blob_index;
Status s = blob_index.DecodeFrom(index_entry);
if (!s.ok()) {
ROCKS_LOG_INFO(db_options_.info_log,
"Could not parse lsm val in MarkBlobDeleted %s",
index_entry.ToString().c_str());
return false;
}
bool succ = FindFileAndEvictABlob(blob_index.file_number(), key.size(),
blob_index.offset(), blob_index.size());
return succ;
}
std::pair<bool, int64_t> BlobDBImpl::EvictCompacted(bool aborted) {
assert(bdb_options_.enable_garbage_collection);
if (aborted) return std::make_pair(false, -1);
override_packet_t packet;
size_t total_vals = 0;
size_t mark_evicted = 0;
while (override_vals_q_.dequeue(&packet)) {
bool succeeded =
FindFileAndEvictABlob(packet.file_number_, packet.key_size_,
packet.blob_offset_, packet.blob_size_);
total_vals++;
if (succeeded) {
mark_evicted++;
}
}
ROCKS_LOG_INFO(db_options_.info_log,
"Mark %" ROCKSDB_PRIszt
" values to evict, out of %" ROCKSDB_PRIszt
" compacted values.",
mark_evicted, total_vals);
return std::make_pair(true, -1);
}
std::pair<bool, int64_t> BlobDBImpl::EvictDeletions(bool aborted) {
assert(bdb_options_.enable_garbage_collection);
if (aborted) return std::make_pair(false, -1);
ColumnFamilyHandle* last_cfh = nullptr;
Options last_op;
Arena arena;
ScopedArenaIterator iter;
// we will use same RangeDelAggregator for all cf's.
// essentially we do not support Range Deletes now
std::unique_ptr<RangeDelAggregator> range_del_agg;
delete_packet_t dpacket;
while (delete_keys_q_.dequeue(&dpacket)) {
if (last_cfh != dpacket.cfh_) {
if (!range_del_agg) {
auto cfhi = reinterpret_cast<ColumnFamilyHandleImpl*>(dpacket.cfh_);
auto cfd = cfhi->cfd();
range_del_agg.reset(new RangeDelAggregator(cfd->internal_comparator(),
kMaxSequenceNumber));
}
// this can be expensive
last_cfh = dpacket.cfh_;
last_op = db_impl_->GetOptions(last_cfh);
iter.set(db_impl_->NewInternalIterator(&arena, range_del_agg.get(),
dpacket.cfh_));
// this will not work for multiple CF's.
}
Slice user_key(dpacket.key_);
InternalKey target(user_key, dpacket.dsn_, kTypeValue);
Slice eslice = target.Encode();
iter->Seek(eslice);
if (!iter->status().ok()) {
ROCKS_LOG_INFO(db_options_.info_log, "Invalid iterator seek %s",
dpacket.key_.c_str());
continue;
}
const Comparator* bwc = BytewiseComparator();
while (iter->Valid()) {
if (!bwc->Equal(ExtractUserKey(iter->key()), ExtractUserKey(eslice)))
break;
ParsedInternalKey ikey(Slice(), 0, kTypeValue);
if (!ParseInternalKey(iter->key(), &ikey)) {
continue;
}
// once you hit a DELETE, assume the keys below have been
// processed previously
if (ikey.type == kTypeDeletion || ikey.type == kTypeSingleDeletion) break;
Slice val = iter->value();
MarkBlobDeleted(ikey.user_key, val);
iter->Next();
}
}
return std::make_pair(true, -1);
}
std::pair<bool, int64_t> BlobDBImpl::CheckSeqFiles(bool aborted) {
if (aborted) return std::make_pair(false, -1);
std::vector<std::shared_ptr<BlobFile>> process_files;
{
uint64_t epoch_now = EpochNow();
ReadLock rl(&mutex_);
for (auto bfile : open_ttl_files_) {
{
ReadLock lockbfile_r(&bfile->mutex_);
if (bfile->expiration_range_.second > epoch_now) continue;
process_files.push_back(bfile);
}
}
}
for (auto bfile : process_files) {
CloseBlobFile(bfile);
}
return std::make_pair(true, -1);
}
std::pair<bool, int64_t> BlobDBImpl::FsyncFiles(bool aborted) {
if (aborted) return std::make_pair(false, -1);
MutexLock l(&write_mutex_);
std::vector<std::shared_ptr<BlobFile>> process_files;
{
ReadLock rl(&mutex_);
for (auto fitr : open_ttl_files_) {
if (fitr->NeedsFsync(true, bdb_options_.bytes_per_sync))
process_files.push_back(fitr);
}
if (open_non_ttl_file_ != nullptr &&
open_non_ttl_file_->NeedsFsync(true, bdb_options_.bytes_per_sync)) {
process_files.push_back(open_non_ttl_file_);
}
}
for (auto fitr : process_files) {
if (fitr->NeedsFsync(true, bdb_options_.bytes_per_sync)) fitr->Fsync();
}
bool expected = true;
if (dir_change_.compare_exchange_weak(expected, false)) dir_ent_->Fsync();
return std::make_pair(true, -1);
}
std::pair<bool, int64_t> BlobDBImpl::ReclaimOpenFiles(bool aborted) {
if (aborted) return std::make_pair(false, -1);
if (open_file_count_.load() < kOpenFilesTrigger) {
return std::make_pair(true, -1);
}
// in the future, we should sort by last_access_
// instead of closing every file
ReadLock rl(&mutex_);
for (auto const& ent : blob_files_) {
auto bfile = ent.second;
if (bfile->last_access_.load() == -1) continue;
WriteLock lockbfile_w(&bfile->mutex_);
CloseRandomAccessLocked(bfile);
}
return std::make_pair(true, -1);
}
// TODO(yiwu): correct the stats and expose it.
std::pair<bool, int64_t> BlobDBImpl::WaStats(bool aborted) {
if (aborted) return std::make_pair(false, -1);
WriteLock wl(&mutex_);
if (all_periods_write_.size() >= kWriteAmplificationStatsPeriods) {
total_periods_write_ -= (*all_periods_write_.begin());
total_periods_ampl_ = (*all_periods_ampl_.begin());
all_periods_write_.pop_front();
all_periods_ampl_.pop_front();
}
uint64_t val1 = last_period_write_.load();
uint64_t val2 = last_period_ampl_.load();
all_periods_write_.push_back(val1);
all_periods_ampl_.push_back(val2);
last_period_write_ = 0;
last_period_ampl_ = 0;
total_periods_write_ += val1;
total_periods_ampl_ += val2;
return std::make_pair(true, -1);
}
// Write callback for garbage collection to check if key has been updated
// since last read. Similar to how OptimisticTransaction works. See inline
// comment in GCFileAndUpdateLSM().
class BlobDBImpl::GarbageCollectionWriteCallback : public WriteCallback {
public:
GarbageCollectionWriteCallback(ColumnFamilyData* cfd, const Slice& key,
SequenceNumber upper_bound)
: cfd_(cfd), key_(key), upper_bound_(upper_bound) {}
virtual Status Callback(DB* db) override {
auto* db_impl = reinterpret_cast<DBImpl*>(db);
auto* sv = db_impl->GetAndRefSuperVersion(cfd_);
SequenceNumber latest_seq = 0;
bool found_record_for_key = false;
bool is_blob_index = false;
Status s = db_impl->GetLatestSequenceForKey(
sv, key_, false /*cache_only*/, &latest_seq, &found_record_for_key,
&is_blob_index);
db_impl->ReturnAndCleanupSuperVersion(cfd_, sv);
if (!s.ok() && !s.IsNotFound()) {
// Error.
assert(!s.IsBusy());
return s;
}
if (s.IsNotFound()) {
assert(!found_record_for_key);
return Status::Busy("Key deleted");
}
assert(found_record_for_key);
assert(is_blob_index);
if (latest_seq > upper_bound_) {
return Status::Busy("Key overwritten");
}
return s;
}
virtual bool AllowWriteBatching() override { return false; }
private:
ColumnFamilyData* cfd_;
// Key to check
Slice key_;
// Upper bound of sequence number to proceed.
SequenceNumber upper_bound_;
};
// iterate over the blobs sequentially and check if the blob sequence number
// is the latest. If it is the latest, preserve it, otherwise delete it
// if it is TTL based, and the TTL has expired, then
// we can blow the entity if the key is still the latest or the Key is not
// found
// WHAT HAPPENS IF THE KEY HAS BEEN OVERRIDEN. Then we can drop the blob
// without doing anything if the earliest snapshot is not
// referring to that sequence number, i.e. it is later than the sequence number
// of the new key
//
// if it is not TTL based, then we can blow the key if the key has been
// DELETED in the LSM
Status BlobDBImpl::GCFileAndUpdateLSM(const std::shared_ptr<BlobFile>& bfptr,
GCStats* gc_stats) {
uint64_t now = EpochNow();
std::shared_ptr<Reader> reader =
bfptr->OpenSequentialReader(env_, db_options_, env_options_);
if (!reader) {
ROCKS_LOG_ERROR(db_options_.info_log,
"File sequential reader could not be opened",
bfptr->PathName().c_str());
return Status::IOError("failed to create sequential reader");
}
BlobLogHeader header;
Status s = reader->ReadHeader(&header);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failure to read header for blob-file %s",
bfptr->PathName().c_str());
return s;
}
bool first_gc = bfptr->gc_once_after_open_;
auto* cfh =
db_impl_->GetColumnFamilyHandleUnlocked(bfptr->column_family_id());
auto* cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(cfh)->cfd();
auto column_family_id = cfd->GetID();
bool has_ttl = header.has_ttl;
// this reads the key but skips the blob
Reader::ReadLevel shallow = Reader::kReadHeaderKey;
bool no_relocation_ttl =
(has_ttl && now >= bfptr->GetExpirationRange().second);
bool no_relocation_lsmdel = false;
{
ReadLock lockbfile_r(&bfptr->mutex_);
no_relocation_lsmdel =
(bfptr->GetFileSize() ==
(BlobLogHeader::kSize + bfptr->deleted_size_ + BlobLogFooter::kSize));
}
bool no_relocation = no_relocation_ttl || no_relocation_lsmdel;
if (!no_relocation) {
// read the blob because you have to write it back to new file
shallow = Reader::kReadHeaderKeyBlob;
}
BlobLogRecord record;
std::shared_ptr<BlobFile> newfile;
std::shared_ptr<Writer> new_writer;
uint64_t blob_offset = 0;
while (true) {
assert(s.ok());
// Read the next blob record.
Status read_record_status =
reader->ReadRecord(&record, shallow, &blob_offset);
// Exit if we reach the end of blob file.
// TODO(yiwu): properly handle ReadRecord error.
if (!read_record_status.ok()) {
break;
}
gc_stats->blob_count++;
// Similar to OptimisticTransaction, we obtain latest_seq from
// base DB, which is guaranteed to be no smaller than the sequence of
// current key. We use a WriteCallback on write to check the key sequence
// on write. If the key sequence is larger than latest_seq, we know
// a new versions is inserted and the old blob can be disgard.
//
// We cannot use OptimisticTransaction because we need to pass
// is_blob_index flag to GetImpl.
SequenceNumber latest_seq = GetLatestSequenceNumber();
bool is_blob_index = false;
PinnableSlice index_entry;
Status get_status = db_impl_->GetImpl(
ReadOptions(), cfh, record.key, &index_entry, nullptr /*value_found*/,
nullptr /*read_callback*/, &is_blob_index);
TEST_SYNC_POINT("BlobDBImpl::GCFileAndUpdateLSM:AfterGetFromBaseDB");
if (!get_status.ok() && !get_status.ok()) {
// error
s = get_status;
ROCKS_LOG_ERROR(db_options_.info_log,
"Error while getting index entry: %s",
s.ToString().c_str());
break;
}
if (get_status.IsNotFound() || !is_blob_index) {
// Either the key is deleted or updated with a newer version whish is
// inlined in LSM.
continue;
}
BlobIndex blob_index;
s = blob_index.DecodeFrom(index_entry);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Error while decoding index entry: %s",
s.ToString().c_str());
break;
}
if (blob_index.file_number() != bfptr->BlobFileNumber() ||
blob_index.offset() != blob_offset) {
// Key has been overwritten. Drop the blob record.
continue;
}
GarbageCollectionWriteCallback callback(cfd, record.key, latest_seq);
// If key has expired, remove it from base DB.
if (no_relocation_ttl || (has_ttl && now >= record.expiration)) {
gc_stats->num_deletes++;
gc_stats->deleted_size += record.value_size;
TEST_SYNC_POINT("BlobDBImpl::GCFileAndUpdateLSM:BeforeDelete");
WriteBatch delete_batch;
Status delete_status = delete_batch.Delete(record.key);
if (delete_status.ok()) {
delete_status = db_impl_->WriteWithCallback(WriteOptions(),
&delete_batch, &callback);
}
if (delete_status.ok()) {
gc_stats->delete_succeeded++;
} else if (delete_status.IsBusy()) {
// The key is overwritten in the meanwhile. Drop the blob record.
gc_stats->overwritten_while_delete++;
} else {
// We hit an error.
s = delete_status;
ROCKS_LOG_ERROR(db_options_.info_log,
"Error while deleting expired key: %s",
s.ToString().c_str());
break;
}
// Continue to next blob record or retry.
continue;
}
if (first_gc) {
// Do not relocate blob record for initial GC.
continue;
}
// Relocate the blob record to new file.
if (!newfile) {
// new file
std::string reason("GC of ");
reason += bfptr->PathName();
newfile = NewBlobFile(reason);
gc_stats->newfile = newfile;
new_writer = CheckOrCreateWriterLocked(newfile);
newfile->header_ = std::move(header);
// Can't use header beyond this point
newfile->header_valid_ = true;
newfile->file_size_ = BlobLogHeader::kSize;
s = new_writer->WriteHeader(newfile->header_);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"File: %s - header writing failed",
newfile->PathName().c_str());
break;
}
WriteLock wl(&mutex_);
dir_change_.store(true);
blob_files_.insert(std::make_pair(newfile->BlobFileNumber(), newfile));
}
gc_stats->num_relocate++;
std::string new_index_entry;
uint64_t new_blob_offset = 0;
uint64_t new_key_offset = 0;
// write the blob to the blob log.
s = new_writer->AddRecord(record.key, record.value, record.expiration,
&new_key_offset, &new_blob_offset);
BlobIndex::EncodeBlob(&new_index_entry, newfile->BlobFileNumber(),
new_blob_offset, record.value.size(),
bdb_options_.compression);
newfile->blob_count_++;
newfile->file_size_ +=
BlobLogRecord::kHeaderSize + record.key.size() + record.value.size();
TEST_SYNC_POINT("BlobDBImpl::GCFileAndUpdateLSM:BeforeRelocate");
WriteBatch rewrite_batch;
Status rewrite_status = WriteBatchInternal::PutBlobIndex(
&rewrite_batch, column_family_id, record.key, new_index_entry);
if (rewrite_status.ok()) {
rewrite_status = db_impl_->WriteWithCallback(WriteOptions(),
&rewrite_batch, &callback);
}
if (rewrite_status.ok()) {
gc_stats->relocate_succeeded++;
} else if (rewrite_status.IsBusy()) {
// The key is overwritten in the meanwhile. Drop the blob record.
gc_stats->overwritten_while_relocate++;
} else {
// We hit an error.
s = rewrite_status;
ROCKS_LOG_ERROR(db_options_.info_log, "Error while relocating key: %s",
s.ToString().c_str());
break;
}
} // end of ReadRecord loop
ROCKS_LOG_INFO(
db_options_.info_log,
"%s blob file %" PRIu64
". Total blob records: %" PRIu64 ", Deletes: %" PRIu64 "/%" PRIu64
" succeeded, Relocates: %" PRIu64 "/%" PRIu64 " succeeded.",
s.ok() ? "Successfully garbage collected" : "Failed to garbage collect",
bfptr->BlobFileNumber(), gc_stats->blob_count, gc_stats->delete_succeeded,
gc_stats->num_deletes, gc_stats->relocate_succeeded,
gc_stats->num_relocate);
if (newfile != nullptr) {
total_blob_space_ += newfile->file_size_;
ROCKS_LOG_INFO(db_options_.info_log, "New blob file %" PRIu64 ".",
newfile->BlobFileNumber());
}
return s;
}
// Ideally we should hold the lock during the entire function,
// but under the asusmption that this is only called when a
// file is Immutable, we can reduce the critical section
bool BlobDBImpl::ShouldGCFile(std::shared_ptr<BlobFile> bfile, uint64_t now,
bool is_oldest_non_ttl_file,
std::string* reason) {
if (bfile->HasTTL()) {
ExpirationRange expiration_range = bfile->GetExpirationRange();
if (now > expiration_range.second) {
*reason = "entire file ttl expired";
return true;
}
if (!bfile->file_size_.load()) {
ROCKS_LOG_ERROR(db_options_.info_log, "Invalid file size = 0 %s",
bfile->PathName().c_str());
*reason = "file is empty";
return false;
}
if (bfile->gc_once_after_open_.load()) {
return true;
}
if (bdb_options_.ttl_range_secs < kPartialExpirationGCRangeSecs) {
*reason = "has ttl but partial expiration not turned on";
return false;
}
ReadLock lockbfile_r(&bfile->mutex_);
bool ret = ((bfile->deleted_size_ * 100.0 / bfile->file_size_.load()) >
kPartialExpirationPercentage);
if (ret) {
*reason = "deleted blobs beyond threshold";
} else {
*reason = "deleted blobs below threshold";
}
return ret;
}
// when crash happens, we lose the in-memory account of deleted blobs.
// we are therefore forced to do one GC to make sure delete accounting
// is OK
if (bfile->gc_once_after_open_.load()) {
return true;
}
ReadLock lockbfile_r(&bfile->mutex_);
if (bdb_options_.enable_garbage_collection) {
if ((bfile->deleted_size_ * 100.0 / bfile->file_size_.load()) >
kPartialExpirationPercentage) {
*reason = "deleted simple blobs beyond threshold";
return true;
}
}
// if we haven't reached limits of disk space, don't DELETE
if (bdb_options_.blob_dir_size == 0 ||
total_blob_space_.load() < bdb_options_.blob_dir_size) {
*reason = "disk space not exceeded";
return false;
}
if (is_oldest_non_ttl_file) {
*reason = "out of space and is the oldest simple blob file";
return true;
}
*reason = "out of space but is not the oldest simple blob file";
return false;
}
std::pair<bool, int64_t> BlobDBImpl::DeleteObsoleteFiles(bool aborted) {
if (aborted) return std::make_pair(false, -1);
{
ReadLock rl(&mutex_);
if (obsolete_files_.empty()) return std::make_pair(true, -1);
}
std::list<std::shared_ptr<BlobFile>> tobsolete;
{
WriteLock wl(&mutex_);
tobsolete.swap(obsolete_files_);
}
bool file_deleted = false;
for (auto iter = tobsolete.begin(); iter != tobsolete.end();) {
auto bfile = *iter;
{
ReadLock lockbfile_r(&bfile->mutex_);
if (!FileDeleteOk_SnapshotCheckLocked(bfile)) {
++iter;
continue;
}
}
blob_files_.erase(bfile->BlobFileNumber());
Status s = env_->DeleteFile(bfile->PathName());
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"File failed to be deleted as obsolete %s",
bfile->PathName().c_str());
++iter;
continue;
}
file_deleted = true;
total_blob_space_ -= bfile->file_size_;
ROCKS_LOG_INFO(db_options_.info_log,
"File deleted as obsolete from blob dir %s",
bfile->PathName().c_str());
iter = tobsolete.erase(iter);
}
// directory change. Fsync
if (file_deleted) dir_ent_->Fsync();
// put files back into obsolete if for some reason, delete failed
if (!tobsolete.empty()) {
WriteLock wl(&mutex_);
for (auto bfile : tobsolete) {
obsolete_files_.push_front(bfile);
}
}
return std::make_pair(!aborted, -1);
}
void BlobDBImpl::CopyBlobFiles(
std::vector<std::shared_ptr<BlobFile>>* bfiles_copy) {
ReadLock rl(&mutex_);
// take a copy
bfiles_copy->reserve(blob_files_.size());
for (auto const& p : blob_files_) {
bfiles_copy->push_back(p.second);
}
}
void BlobDBImpl::FilterSubsetOfFiles(
const std::vector<std::shared_ptr<BlobFile>>& blob_files,
std::vector<std::shared_ptr<BlobFile>>* to_process, uint64_t epoch,
size_t files_to_collect) {
// 100.0 / 15.0 = 7
uint64_t next_epoch_increment = static_cast<uint64_t>(
std::ceil(100 / static_cast<double>(kGCFilePercentage)));
uint64_t now = EpochNow();
size_t files_processed = 0;
bool non_ttl_file_found = false;
for (auto bfile : blob_files) {
if (files_processed >= files_to_collect) break;
// if this is the first time processing the file
// i.e. gc_epoch == -1, process it.
// else process the file if its processing epoch matches
// the current epoch. Typically the #of epochs should be
// around 5-10
if (bfile->gc_epoch_ != -1 && (uint64_t)bfile->gc_epoch_ != epoch) {
continue;
}
files_processed++;
// reset the epoch
bfile->gc_epoch_ = epoch + next_epoch_increment;
// file has already been GC'd or is still open for append,
// then it should not be GC'd
if (bfile->Obsolete() || !bfile->Immutable()) continue;
bool is_oldest_non_ttl_file = false;
if (!non_ttl_file_found && !bfile->HasTTL()) {
is_oldest_non_ttl_file = true;
non_ttl_file_found = true;
}
std::string reason;
bool shouldgc = ShouldGCFile(bfile, now, is_oldest_non_ttl_file, &reason);
if (!shouldgc) {
ROCKS_LOG_DEBUG(db_options_.info_log,
"File has been skipped for GC ttl %s %" PRIu64 " %" PRIu64
" reason='%s'",
bfile->PathName().c_str(), now,
bfile->GetExpirationRange().second, reason.c_str());
continue;
}
ROCKS_LOG_INFO(db_options_.info_log,
"File has been chosen for GC ttl %s %" PRIu64 " %" PRIu64
" reason='%s'",
bfile->PathName().c_str(), now,
bfile->GetExpirationRange().second, reason.c_str());
to_process->push_back(bfile);
}
}
std::pair<bool, int64_t> BlobDBImpl::RunGC(bool aborted) {
if (aborted) return std::make_pair(false, -1);
current_epoch_++;
std::vector<std::shared_ptr<BlobFile>> blob_files;
CopyBlobFiles(&blob_files);
if (!blob_files.size()) return std::make_pair(true, -1);
// 15% of files are collected each call to space out the IO and CPU
// consumption.
size_t files_to_collect = (kGCFilePercentage * blob_files.size()) / 100;
std::vector<std::shared_ptr<BlobFile>> to_process;
FilterSubsetOfFiles(blob_files, &to_process, current_epoch_,
files_to_collect);
// in this collect the set of files, which became obsolete
std::vector<std::shared_ptr<BlobFile>> obsoletes;
for (auto bfile : to_process) {
GCStats gc_stats;
Status s = GCFileAndUpdateLSM(bfile, &gc_stats);
if (!s.ok()) {
continue;
}
if (bfile->gc_once_after_open_.load()) {
WriteLock lockbfile_w(&bfile->mutex_);
bfile->deleted_size_ = gc_stats.deleted_size;
bfile->deleted_count_ = gc_stats.num_deletes;
bfile->gc_once_after_open_ = false;
} else {
obsoletes.push_back(bfile);
}
}
if (!obsoletes.empty()) {
WriteLock wl(&mutex_);
for (auto bfile : obsoletes) {
bfile->SetCanBeDeleted();
obsolete_files_.push_front(bfile);
}
}
// reschedule
return std::make_pair(true, -1);
}
Iterator* BlobDBImpl::NewIterator(const ReadOptions& read_options) {
auto* cfd =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily())->cfd();
// Get a snapshot to avoid blob file get deleted between we
// fetch and index entry and reading from the file.
ManagedSnapshot* own_snapshot = nullptr;
const Snapshot* snapshot = read_options.snapshot;
if (snapshot == nullptr) {
own_snapshot = new ManagedSnapshot(db_);
snapshot = own_snapshot->snapshot();
}
auto* iter = db_impl_->NewIteratorImpl(
read_options, cfd, snapshot->GetSequenceNumber(),
nullptr /*read_callback*/, true /*allow_blob*/);
return new BlobDBIterator(own_snapshot, iter, this);
}
Status DestroyBlobDB(const std::string& dbname, const Options& options,
const BlobDBOptions& bdb_options) {
const ImmutableDBOptions soptions(SanitizeOptions(dbname, options));
Env* env = soptions.env;
Status status;
std::string blobdir;
blobdir = (bdb_options.path_relative) ? dbname + "/" + bdb_options.blob_dir
: bdb_options.blob_dir;
std::vector<std::string> filenames;
env->GetChildren(blobdir, &filenames);
for (const auto& f : filenames) {
uint64_t number;
FileType type;
if (ParseFileName(f, &number, &type) && type == kBlobFile) {
Status del = env->DeleteFile(blobdir + "/" + f);
if (status.ok() && !del.ok()) {
status = del;
}
}
}
env->DeleteDir(blobdir);
Status destroy = DestroyDB(dbname, options);
if (status.ok() && !destroy.ok()) {
status = destroy;
}
return status;
}
#ifndef NDEBUG
Status BlobDBImpl::TEST_GetBlobValue(const Slice& key, const Slice& index_entry,
PinnableSlice* value) {
return GetBlobValue(key, index_entry, value);
}
std::vector<std::shared_ptr<BlobFile>> BlobDBImpl::TEST_GetBlobFiles() const {
ReadLock l(&mutex_);
std::vector<std::shared_ptr<BlobFile>> blob_files;
for (auto& p : blob_files_) {
blob_files.emplace_back(p.second);
}
return blob_files;
}
std::vector<std::shared_ptr<BlobFile>> BlobDBImpl::TEST_GetObsoleteFiles()
const {
ReadLock l(&mutex_);
std::vector<std::shared_ptr<BlobFile>> obsolete_files;
for (auto& bfile : obsolete_files_) {
obsolete_files.emplace_back(bfile);
}
return obsolete_files;
}
void BlobDBImpl::TEST_DeleteObsoleteFiles() {
DeleteObsoleteFiles(false /*abort*/);
}
Status BlobDBImpl::TEST_CloseBlobFile(std::shared_ptr<BlobFile>& bfile) {
return CloseBlobFile(bfile);
}
Status BlobDBImpl::TEST_GCFileAndUpdateLSM(std::shared_ptr<BlobFile>& bfile,
GCStats* gc_stats) {
return GCFileAndUpdateLSM(bfile, gc_stats);
}
void BlobDBImpl::TEST_RunGC() { RunGC(false /*abort*/); }
void BlobDBImpl::TEST_ObsoleteFile(std::shared_ptr<BlobFile>& bfile) {
uint64_t number = bfile->BlobFileNumber();
assert(blob_files_.count(number) > 0);
bfile->SetCanBeDeleted();
{
WriteLock l(&mutex_);
obsolete_files_.push_back(bfile);
}
}
#endif // !NDEBUG
} // namespace blob_db
} // namespace rocksdb
#endif // ROCKSDB_LITE
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