// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same 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.
#include "db/db_impl.h"
#define __STDC_FORMAT_MACROS
#include <inttypes.h>
#include <algorithm>
#include <climits>
#include <cstdio>
#include <set>
#include <stdexcept>
#include <stdint.h>
#include <string>
#include <unordered_set>
#include <unordered_map>
#include <utility>
#include <vector>
#include "db/builder.h"
#include "db/db_iter.h"
#include "db/dbformat.h"
#include "db/filename.h"
#include "db/log_reader.h"
#include "db/log_writer.h"
#include "db/memtable.h"
#include "db/memtable_list.h"
#include "db/merge_context.h"
#include "db/merge_helper.h"
#include "db/table_cache.h"
#include "db/table_properties_collector.h"
#include "db/tailing_iter.h"
#include "db/transaction_log_impl.h"
#include "db/version_set.h"
#include "db/write_batch_internal.h"
#include "port/port.h"
#include "rocksdb/cache.h"
#include "port/likely.h"
#include "rocksdb/compaction_filter.h"
#include "rocksdb/db.h"
#include "rocksdb/env.h"
#include "rocksdb/merge_operator.h"
#include "rocksdb/statistics.h"
#include "rocksdb/status.h"
#include "rocksdb/table.h"
#include "table/block.h"
#include "table/block_based_table_factory.h"
#include "table/merger.h"
#include "table/table_builder.h"
#include "table/two_level_iterator.h"
#include "util/auto_roll_logger.h"
#include "util/autovector.h"
#include "util/build_version.h"
#include "util/coding.h"
#include "util/hash_skiplist_rep.h"
#include "util/hash_linklist_rep.h"
#include "util/logging.h"
#include "util/log_buffer.h"
#include "util/mutexlock.h"
#include "util/perf_context_imp.h"
#include "util/stop_watch.h"
#include "util/sync_point.h"
namespace rocksdb {
const std::string kDefaultColumnFamilyName("default");
void DumpLeveldbBuildVersion(Logger * log);
// Information kept for every waiting writer
struct DBImpl::Writer {
Status status;
WriteBatch* batch;
bool sync;
bool disableWAL;
bool done;
port::CondVar cv;
explicit Writer(port::Mutex* mu) : cv(mu) { }
};
struct DBImpl::CompactionState {
Compaction* const compaction;
// If there were two snapshots with seq numbers s1 and
// s2 and s1 < s2, and if we find two instances of a key k1 then lies
// entirely within s1 and s2, then the earlier version of k1 can be safely
// deleted because that version is not visible in any snapshot.
std::vector<SequenceNumber> existing_snapshots;
// Files produced by compaction
struct Output {
uint64_t number;
uint64_t file_size;
InternalKey smallest, largest;
SequenceNumber smallest_seqno, largest_seqno;
};
std::vector<Output> outputs;
std::list<uint64_t> allocated_file_numbers;
// State kept for output being generated
unique_ptr<WritableFile> outfile;
unique_ptr<TableBuilder> builder;
uint64_t total_bytes;
Output* current_output() { return &outputs[outputs.size()-1]; }
explicit CompactionState(Compaction* c)
: compaction(c),
total_bytes(0) {
}
// Create a client visible context of this compaction
CompactionFilter::Context GetFilterContextV1() {
CompactionFilter::Context context;
context.is_full_compaction = compaction->IsFullCompaction();
context.is_manual_compaction = compaction->IsManualCompaction();
return context;
}
// Create a client visible context of this compaction
CompactionFilterContext GetFilterContext() {
CompactionFilterContext context;
context.is_full_compaction = compaction->IsFullCompaction();
context.is_manual_compaction = compaction->IsManualCompaction();
return context;
}
std::vector<Slice> key_buf_;
std::vector<Slice> existing_value_buf_;
std::vector<std::string> key_str_buf_;
std::vector<std::string> existing_value_str_buf_;
// new_value_buf_ will only be appended if a value changes
std::vector<std::string> new_value_buf_;
// if values_changed_buf_[i] is true
// new_value_buf_ will add a new entry with the changed value
std::vector<bool> value_changed_buf_;
// to_delete_buf_[i] is true iff key_buf_[i] is deleted
std::vector<bool> to_delete_buf_;
// buffer for the parsed internal keys, the string buffer is backed
// by key_str_buf_
std::vector<ParsedInternalKey> ikey_buf_;
std::vector<Slice> other_key_buf_;
std::vector<Slice> other_value_buf_;
std::vector<std::string> other_key_str_buf_;
std::vector<std::string> other_value_str_buf_;
std::vector<Slice> combined_key_buf_;
std::vector<Slice> combined_value_buf_;
std::string cur_prefix_;
// Buffers the kv-pair that will be run through compaction filter V2
// in the future.
void BufferKeyValueSlices(const Slice& key, const Slice& value) {
key_str_buf_.emplace_back(key.ToString());
existing_value_str_buf_.emplace_back(value.ToString());
key_buf_.emplace_back(Slice(key_str_buf_.back()));
existing_value_buf_.emplace_back(Slice(existing_value_str_buf_.back()));
ParsedInternalKey ikey;
ParseInternalKey(key_buf_.back(), &ikey);
ikey_buf_.emplace_back(ikey);
}
// Buffers the kv-pair that will not be run through compaction filter V2
// in the future.
void BufferOtherKeyValueSlices(const Slice& key, const Slice& value) {
other_key_str_buf_.emplace_back(key.ToString());
other_value_str_buf_.emplace_back(value.ToString());
other_key_buf_.emplace_back(Slice(other_key_str_buf_.back()));
other_value_buf_.emplace_back(Slice(other_value_str_buf_.back()));
}
// Add a kv-pair to the combined buffer
void AddToCombinedKeyValueSlices(const Slice& key, const Slice& value) {
// The real strings are stored in the batch buffers
combined_key_buf_.emplace_back(key);
combined_value_buf_.emplace_back(value);
}
// Merging the two buffers
void MergeKeyValueSliceBuffer(const InternalKeyComparator* comparator) {
size_t i = 0;
size_t j = 0;
size_t total_size = key_buf_.size() + other_key_buf_.size();
combined_key_buf_.reserve(total_size);
combined_value_buf_.reserve(total_size);
while (i + j < total_size) {
int comp_res = 0;
if (i < key_buf_.size() && j < other_key_buf_.size()) {
comp_res = comparator->Compare(key_buf_[i], other_key_buf_[j]);
} else if (i >= key_buf_.size() && j < other_key_buf_.size()) {
comp_res = 1;
} else if (j >= other_key_buf_.size() && i < key_buf_.size()) {
comp_res = -1;
}
if (comp_res > 0) {
AddToCombinedKeyValueSlices(other_key_buf_[j], other_value_buf_[j]);
j++;
} else if (comp_res < 0) {
AddToCombinedKeyValueSlices(key_buf_[i], existing_value_buf_[i]);
i++;
}
}
}
void CleanupBatchBuffer() {
to_delete_buf_.clear();
key_buf_.clear();
existing_value_buf_.clear();
key_str_buf_.clear();
existing_value_str_buf_.clear();
new_value_buf_.clear();
value_changed_buf_.clear();
ikey_buf_.clear();
to_delete_buf_.shrink_to_fit();
key_buf_.shrink_to_fit();
existing_value_buf_.shrink_to_fit();
key_str_buf_.shrink_to_fit();
existing_value_str_buf_.shrink_to_fit();
new_value_buf_.shrink_to_fit();
value_changed_buf_.shrink_to_fit();
ikey_buf_.shrink_to_fit();
other_key_buf_.clear();
other_value_buf_.clear();
other_key_str_buf_.clear();
other_value_str_buf_.clear();
other_key_buf_.shrink_to_fit();
other_value_buf_.shrink_to_fit();
other_key_str_buf_.shrink_to_fit();
other_value_str_buf_.shrink_to_fit();
}
void CleanupMergedBuffer() {
combined_key_buf_.clear();
combined_value_buf_.clear();
combined_key_buf_.shrink_to_fit();
combined_value_buf_.shrink_to_fit();
}
};
namespace {
// Fix user-supplied options to be reasonable
template <class T, class V>
static void ClipToRange(T* ptr, V minvalue, V maxvalue) {
if (static_cast<V>(*ptr) > maxvalue) *ptr = maxvalue;
if (static_cast<V>(*ptr) < minvalue) *ptr = minvalue;
}
} // anonymous namespace
Options SanitizeOptions(const std::string& dbname,
const InternalKeyComparator* icmp,
const InternalFilterPolicy* ipolicy,
const Options& src) {
auto db_options = SanitizeOptions(dbname, DBOptions(src));
auto cf_options = SanitizeOptions(icmp, ipolicy, ColumnFamilyOptions(src));
return Options(db_options, cf_options);
}
DBOptions SanitizeOptions(const std::string& dbname, const DBOptions& src) {
DBOptions result = src;
// result.max_open_files means an "infinite" open files.
if (result.max_open_files != -1) {
ClipToRange(&result.max_open_files, 20, 1000000);
}
if (result.info_log == nullptr) {
Status s = CreateLoggerFromOptions(dbname, result.db_log_dir, src.env,
result, &result.info_log);
if (!s.ok()) {
// No place suitable for logging
result.info_log = nullptr;
}
}
if (result.wal_dir.empty()) {
// Use dbname as default
result.wal_dir = dbname;
}
if (result.wal_dir.back() == '/') {
result.wal_dir = result.wal_dir.substr(0, result.wal_dir.size() - 1);
}
return result;
}
CompressionType GetCompressionType(const Options& options, int level,
const bool enable_compression) {
if (!enable_compression) {
// disable compression
return kNoCompression;
}
// If the use has specified a different compression level for each level,
// then pick the compresison for that level.
if (!options.compression_per_level.empty()) {
const int n = options.compression_per_level.size() - 1;
// It is possible for level_ to be -1; in that case, we use level
// 0's compression. This occurs mostly in backwards compatibility
// situations when the builder doesn't know what level the file
// belongs to. Likewise, if level_ is beyond the end of the
// specified compression levels, use the last value.
return options.compression_per_level[std::max(0, std::min(level, n))];
} else {
return options.compression;
}
}
CompressionType GetCompressionFlush(const Options& options) {
// Compressing memtable flushes might not help unless the sequential load
// optimization is used for leveled compaction. Otherwise the CPU and
// latency overhead is not offset by saving much space.
bool can_compress;
if (options.compaction_style == kCompactionStyleUniversal) {
can_compress =
(options.compaction_options_universal.compression_size_percent < 0);
} else {
// For leveled compress when min_level_to_compress == 0.
can_compress = (GetCompressionType(options, 0, true) != kNoCompression);
}
if (can_compress) {
return options.compression;
} else {
return kNoCompression;
}
}
DBImpl::DBImpl(const DBOptions& options, const std::string& dbname)
: env_(options.env),
dbname_(dbname),
options_(SanitizeOptions(dbname, options)),
db_lock_(nullptr),
mutex_(options.use_adaptive_mutex),
shutting_down_(nullptr),
bg_cv_(&mutex_),
logfile_number_(0),
log_empty_(true),
default_cf_handle_(nullptr),
total_log_size_(0),
max_total_in_memory_state_(0),
tmp_batch_(),
bg_schedule_needed_(false),
bg_compaction_scheduled_(0),
bg_manual_only_(0),
bg_flush_scheduled_(0),
bg_logstats_scheduled_(false),
manual_compaction_(nullptr),
logger_(nullptr),
disable_delete_obsolete_files_(0),
delete_obsolete_files_last_run_(options.env->NowMicros()),
purge_wal_files_last_run_(0),
last_stats_dump_time_microsec_(0),
default_interval_to_delete_obsolete_WAL_(600),
flush_on_destroy_(false),
delayed_writes_(0),
storage_options_(options),
bg_work_gate_closed_(false),
refitting_level_(false),
opened_successfully_(false) {
env_->GetAbsolutePath(dbname, &db_absolute_path_);
// Reserve ten files or so for other uses and give the rest to TableCache.
// Give a large number for setting of "infinite" open files.
const int table_cache_size =
(options_.max_open_files == -1) ? 4194304 : options_.max_open_files - 10;
// Reserve ten files or so for other uses and give the rest to TableCache.
table_cache_ =
NewLRUCache(table_cache_size, options_.table_cache_numshardbits,
options_.table_cache_remove_scan_count_limit);
versions_.reset(
new VersionSet(dbname_, &options_, storage_options_, table_cache_.get()));
column_family_memtables_.reset(
new ColumnFamilyMemTablesImpl(versions_->GetColumnFamilySet()));
DumpLeveldbBuildVersion(options_.info_log.get());
options_.Dump(options_.info_log.get());
char name[100];
Status s = env_->GetHostName(name, 100L);
if (s.ok()) {
host_name_ = name;
} else {
Log(options_.info_log, "Can't get hostname, use localhost as host name.");
host_name_ = "localhost";
}
last_log_ts = 0;
LogFlush(options_.info_log);
}
DBImpl::~DBImpl() {
mutex_.Lock();
if (flush_on_destroy_) {
for (auto cfd : *versions_->GetColumnFamilySet()) {
if (cfd->mem()->GetFirstSequenceNumber() != 0) {
cfd->Ref();
mutex_.Unlock();
FlushMemTable(cfd, FlushOptions());
mutex_.Lock();
cfd->Unref();
}
}
versions_->GetColumnFamilySet()->FreeDeadColumnFamilies();
}
// Wait for background work to finish
shutting_down_.Release_Store(this); // Any non-nullptr value is ok
while (bg_compaction_scheduled_ ||
bg_flush_scheduled_ ||
bg_logstats_scheduled_) {
bg_cv_.Wait();
}
if (default_cf_handle_ != nullptr) {
// we need to delete handle outside of lock because it does its own locking
mutex_.Unlock();
delete default_cf_handle_;
mutex_.Lock();
}
if (options_.allow_thread_local) {
// Clean up obsolete files due to SuperVersion release.
// (1) Need to delete to obsolete files before closing because RepairDB()
// scans all existing files in the file system and builds manifest file.
// Keeping obsolete files confuses the repair process.
// (2) Need to check if we Open()/Recover() the DB successfully before
// deleting because if VersionSet recover fails (may be due to corrupted
// manifest file), it is not able to identify live files correctly. As a
// result, all "live" files can get deleted by accident. However, corrupted
// manifest is recoverable by RepairDB().
if (opened_successfully_) {
DeletionState deletion_state;
FindObsoleteFiles(deletion_state, true);
// manifest number starting from 2
deletion_state.manifest_file_number = 1;
if (deletion_state.HaveSomethingToDelete()) {
PurgeObsoleteFiles(deletion_state);
}
}
}
// versions need to be destroyed before table_cache since it can hold
// references to table_cache.
versions_.reset();
mutex_.Unlock();
if (db_lock_ != nullptr) {
env_->UnlockFile(db_lock_);
}
LogFlush(options_.info_log);
}
Status DBImpl::NewDB() {
VersionEdit new_db;
new_db.SetLogNumber(0);
new_db.SetNextFile(2);
new_db.SetLastSequence(0);
const std::string manifest = DescriptorFileName(dbname_, 1);
unique_ptr<WritableFile> file;
Status s = env_->NewWritableFile(
manifest, &file, env_->OptimizeForManifestWrite(storage_options_));
if (!s.ok()) {
return s;
}
file->SetPreallocationBlockSize(options_.manifest_preallocation_size);
{
log::Writer log(std::move(file));
std::string record;
new_db.EncodeTo(&record);
s = log.AddRecord(record);
}
if (s.ok()) {
// Make "CURRENT" file that points to the new manifest file.
s = SetCurrentFile(env_, dbname_, 1);
} else {
env_->DeleteFile(manifest);
}
return s;
}
void DBImpl::MaybeIgnoreError(Status* s) const {
if (s->ok() || options_.paranoid_checks) {
// No change needed
} else {
Log(options_.info_log, "Ignoring error %s", s->ToString().c_str());
*s = Status::OK();
}
}
const Status DBImpl::CreateArchivalDirectory() {
if (options_.WAL_ttl_seconds > 0 || options_.WAL_size_limit_MB > 0) {
std::string archivalPath = ArchivalDirectory(options_.wal_dir);
return env_->CreateDirIfMissing(archivalPath);
}
return Status::OK();
}
void DBImpl::PrintStatistics() {
auto dbstats = options_.statistics.get();
if (dbstats) {
Log(options_.info_log,
"STATISTCS:\n %s",
dbstats->ToString().c_str());
}
}
void DBImpl::MaybeDumpStats() {
if (options_.stats_dump_period_sec == 0) return;
const uint64_t now_micros = env_->NowMicros();
if (last_stats_dump_time_microsec_ +
options_.stats_dump_period_sec * 1000000
<= now_micros) {
// Multiple threads could race in here simultaneously.
// However, the last one will update last_stats_dump_time_microsec_
// atomically. We could see more than one dump during one dump
// period in rare cases.
last_stats_dump_time_microsec_ = now_micros;
std::string stats;
GetProperty("rocksdb.stats", &stats);
Log(options_.info_log, "%s", stats.c_str());
PrintStatistics();
}
}
// Returns the list of live files in 'sst_live' and the list
// of all files in the filesystem in 'candidate_files'.
// no_full_scan = true -- never do the full scan using GetChildren()
// force = false -- don't force the full scan, except every
// options_.delete_obsolete_files_period_micros
// force = true -- force the full scan
void DBImpl::FindObsoleteFiles(DeletionState& deletion_state,
bool force,
bool no_full_scan) {
mutex_.AssertHeld();
// if deletion is disabled, do nothing
if (disable_delete_obsolete_files_ > 0) {
return;
}
bool doing_the_full_scan = false;
// logic for figurint out if we're doing the full scan
if (no_full_scan) {
doing_the_full_scan = false;
} else if (force || options_.delete_obsolete_files_period_micros == 0) {
doing_the_full_scan = true;
} else {
const uint64_t now_micros = env_->NowMicros();
if (delete_obsolete_files_last_run_ +
options_.delete_obsolete_files_period_micros < now_micros) {
doing_the_full_scan = true;
delete_obsolete_files_last_run_ = now_micros;
}
}
// get obsolete files
versions_->GetObsoleteFiles(&deletion_state.sst_delete_files);
// store the current filenum, lognum, etc
deletion_state.manifest_file_number = versions_->ManifestFileNumber();
deletion_state.pending_manifest_file_number =
versions_->PendingManifestFileNumber();
deletion_state.log_number = versions_->MinLogNumber();
deletion_state.prev_log_number = versions_->PrevLogNumber();
if (!doing_the_full_scan && !deletion_state.HaveSomethingToDelete()) {
// avoid filling up sst_live if we're sure that we
// are not going to do the full scan and that we don't have
// anything to delete at the moment
return;
}
// don't delete live files
deletion_state.sst_live.assign(pending_outputs_.begin(),
pending_outputs_.end());
versions_->AddLiveFiles(&deletion_state.sst_live);
if (doing_the_full_scan) {
// set of all files in the directory. We'll exclude files that are still
// alive in the subsequent processings.
env_->GetChildren(
dbname_, &deletion_state.candidate_files
); // Ignore errors
//Add log files in wal_dir
if (options_.wal_dir != dbname_) {
std::vector<std::string> log_files;
env_->GetChildren(options_.wal_dir, &log_files); // Ignore errors
deletion_state.candidate_files.insert(
deletion_state.candidate_files.end(),
log_files.begin(),
log_files.end()
);
}
}
}
// Diffs the files listed in filenames and those that do not
// belong to live files are posibly removed. Also, removes all the
// files in sst_delete_files and log_delete_files.
// It is not necessary to hold the mutex when invoking this method.
void DBImpl::PurgeObsoleteFiles(DeletionState& state) {
// we'd better have sth to delete
assert(state.HaveSomethingToDelete());
// this checks if FindObsoleteFiles() was run before. If not, don't do
// PurgeObsoleteFiles(). If FindObsoleteFiles() was run, we need to also
// run PurgeObsoleteFiles(), even if disable_delete_obsolete_files_ is true
if (state.manifest_file_number == 0) {
return;
}
// Now, convert live list to an unordered set, WITHOUT mutex held;
// set is slow.
std::unordered_set<uint64_t> sst_live(state.sst_live.begin(),
state.sst_live.end());
auto& candidate_files = state.candidate_files;
candidate_files.reserve(
candidate_files.size() +
state.sst_delete_files.size() +
state.log_delete_files.size());
// We may ignore the dbname when generating the file names.
const char* kDumbDbName = "";
for (auto file : state.sst_delete_files) {
candidate_files.push_back(
TableFileName(kDumbDbName, file->number).substr(1)
);
delete file;
}
for (auto file_num : state.log_delete_files) {
if (file_num > 0) {
candidate_files.push_back(LogFileName(kDumbDbName, file_num).substr(1));
}
}
// dedup state.candidate_files so we don't try to delete the same
// file twice
sort(candidate_files.begin(), candidate_files.end());
candidate_files.erase(unique(candidate_files.begin(), candidate_files.end()),
candidate_files.end());
std::vector<std::string> old_info_log_files;
for (const auto& to_delete : candidate_files) {
uint64_t number;
FileType type;
// Ignore file if we cannot recognize it.
if (!ParseFileName(to_delete, &number, &type)) {
continue;
}
bool keep = true;
switch (type) {
case kLogFile:
keep = ((number >= state.log_number) ||
(number == state.prev_log_number));
break;
case kDescriptorFile:
// Keep my manifest file, and any newer incarnations'
// (can happen during manifest roll)
keep = (number >= state.manifest_file_number);
break;
case kTableFile:
keep = (sst_live.find(number) != sst_live.end());
break;
case kTempFile:
// Any temp files that are currently being written to must
// be recorded in pending_outputs_, which is inserted into "live".
// Also, SetCurrentFile creates a temp file when writing out new
// manifest, which is equal to state.pending_manifest_file_number. We
// should not delete that file
keep = (sst_live.find(number) != sst_live.end()) ||
(number == state.pending_manifest_file_number);
break;
case kInfoLogFile:
keep = true;
if (number != 0) {
old_info_log_files.push_back(to_delete);
}
break;
case kCurrentFile:
case kDBLockFile:
case kIdentityFile:
case kMetaDatabase:
keep = true;
break;
}
if (keep) {
continue;
}
if (type == kTableFile) {
// evict from cache
TableCache::Evict(table_cache_.get(), number);
}
std::string fname = ((type == kLogFile) ? options_.wal_dir : dbname_) +
"/" + to_delete;
if (type == kLogFile &&
(options_.WAL_ttl_seconds > 0 || options_.WAL_size_limit_MB > 0)) {
auto archived_log_name = ArchivedLogFileName(options_.wal_dir, number);
// The sync point below is used in (DBTest,TransactionLogIteratorRace)
TEST_SYNC_POINT("DBImpl::PurgeObsoleteFiles:1");
Status s = env_->RenameFile(fname, archived_log_name);
// The sync point below is used in (DBTest,TransactionLogIteratorRace)
TEST_SYNC_POINT("DBImpl::PurgeObsoleteFiles:2");
Log(options_.info_log,
"Move log file %s to %s -- %s\n",
fname.c_str(), archived_log_name.c_str(), s.ToString().c_str());
} else {
Status s = env_->DeleteFile(fname);
Log(options_.info_log, "Delete %s type=%d #%lu -- %s\n",
fname.c_str(), type, (unsigned long)number,
s.ToString().c_str());
}
}
// Delete old info log files.
size_t old_info_log_file_count = old_info_log_files.size();
// NOTE: Currently we only support log purge when options_.db_log_dir is
// located in `dbname` directory.
if (old_info_log_file_count >= options_.keep_log_file_num &&
options_.db_log_dir.empty()) {
std::sort(old_info_log_files.begin(), old_info_log_files.end());
size_t end = old_info_log_file_count - options_.keep_log_file_num;
for (unsigned int i = 0; i <= end; i++) {
std::string& to_delete = old_info_log_files.at(i);
Log(options_.info_log, "Delete info log file %s\n", to_delete.c_str());
Status s = env_->DeleteFile(dbname_ + "/" + to_delete);
if (!s.ok()) {
Log(options_.info_log, "Delete info log file %s FAILED -- %s\n",
to_delete.c_str(), s.ToString().c_str());
}
}
}
PurgeObsoleteWALFiles();
LogFlush(options_.info_log);
}
void DBImpl::DeleteObsoleteFiles() {
mutex_.AssertHeld();
DeletionState deletion_state;
FindObsoleteFiles(deletion_state, true);
if (deletion_state.HaveSomethingToDelete()) {
PurgeObsoleteFiles(deletion_state);
}
}
#ifndef ROCKSDB_LITE
// 1. Go through all archived files and
// a. if ttl is enabled, delete outdated files
// b. if archive size limit is enabled, delete empty files,
// compute file number and size.
// 2. If size limit is enabled:
// a. compute how many files should be deleted
// b. get sorted non-empty archived logs
// c. delete what should be deleted
void DBImpl::PurgeObsoleteWALFiles() {
bool const ttl_enabled = options_.WAL_ttl_seconds > 0;
bool const size_limit_enabled = options_.WAL_size_limit_MB > 0;
if (!ttl_enabled && !size_limit_enabled) {
return;
}
int64_t current_time;
Status s = env_->GetCurrentTime(¤t_time);
if (!s.ok()) {
Log(options_.info_log, "Can't get current time: %s", s.ToString().c_str());
assert(false);
return;
}
uint64_t const now_seconds = static_cast<uint64_t>(current_time);
uint64_t const time_to_check = (ttl_enabled && !size_limit_enabled) ?
options_.WAL_ttl_seconds / 2 : default_interval_to_delete_obsolete_WAL_;
if (purge_wal_files_last_run_ + time_to_check > now_seconds) {
return;
}
purge_wal_files_last_run_ = now_seconds;
std::string archival_dir = ArchivalDirectory(options_.wal_dir);
std::vector<std::string> files;
s = env_->GetChildren(archival_dir, &files);
if (!s.ok()) {
Log(options_.info_log, "Can't get archive files: %s", s.ToString().c_str());
assert(false);
return;
}
size_t log_files_num = 0;
uint64_t log_file_size = 0;
for (auto& f : files) {
uint64_t number;
FileType type;
if (ParseFileName(f, &number, &type) && type == kLogFile) {
std::string const file_path = archival_dir + "/" + f;
if (ttl_enabled) {
uint64_t file_m_time;
Status const s = env_->GetFileModificationTime(file_path,
&file_m_time);
if (!s.ok()) {
Log(options_.info_log, "Can't get file mod time: %s: %s",
file_path.c_str(), s.ToString().c_str());
continue;
}
if (now_seconds - file_m_time > options_.WAL_ttl_seconds) {
Status const s = env_->DeleteFile(file_path);
if (!s.ok()) {
Log(options_.info_log, "Can't delete file: %s: %s",
file_path.c_str(), s.ToString().c_str());
continue;
} else {
MutexLock l(&read_first_record_cache_mutex_);
read_first_record_cache_.erase(number);
}
continue;
}
}
if (size_limit_enabled) {
uint64_t file_size;
Status const s = env_->GetFileSize(file_path, &file_size);
if (!s.ok()) {
Log(options_.info_log, "Can't get file size: %s: %s",
file_path.c_str(), s.ToString().c_str());
return;
} else {
if (file_size > 0) {
log_file_size = std::max(log_file_size, file_size);
++log_files_num;
} else {
Status s = env_->DeleteFile(file_path);
if (!s.ok()) {
Log(options_.info_log, "Can't delete file: %s: %s",
file_path.c_str(), s.ToString().c_str());
continue;
} else {
MutexLock l(&read_first_record_cache_mutex_);
read_first_record_cache_.erase(number);
}
}
}
}
}
}
if (0 == log_files_num || !size_limit_enabled) {
return;
}
size_t const files_keep_num = options_.WAL_size_limit_MB *
1024 * 1024 / log_file_size;
if (log_files_num <= files_keep_num) {
return;
}
size_t files_del_num = log_files_num - files_keep_num;
VectorLogPtr archived_logs;
GetSortedWalsOfType(archival_dir, archived_logs, kArchivedLogFile);
if (files_del_num > archived_logs.size()) {
Log(options_.info_log, "Trying to delete more archived log files than "
"exist. Deleting all");
files_del_num = archived_logs.size();
}
for (size_t i = 0; i < files_del_num; ++i) {
std::string const file_path = archived_logs[i]->PathName();
Status const s = DeleteFile(file_path);
if (!s.ok()) {
Log(options_.info_log, "Can't delete file: %s: %s",
file_path.c_str(), s.ToString().c_str());
continue;
} else {
MutexLock l(&read_first_record_cache_mutex_);
read_first_record_cache_.erase(archived_logs[i]->LogNumber());
}
}
}
namespace {
struct CompareLogByPointer {
bool operator()(const unique_ptr<LogFile>& a, const unique_ptr<LogFile>& b) {
LogFileImpl* a_impl = dynamic_cast<LogFileImpl*>(a.get());
LogFileImpl* b_impl = dynamic_cast<LogFileImpl*>(b.get());
return *a_impl < *b_impl;
}
};
}
Status DBImpl::GetSortedWalsOfType(const std::string& path,
VectorLogPtr& log_files,
WalFileType log_type) {
std::vector<std::string> all_files;
const Status status = env_->GetChildren(path, &all_files);
if (!status.ok()) {
return status;
}
log_files.reserve(all_files.size());
for (const auto& f : all_files) {
uint64_t number;
FileType type;
if (ParseFileName(f, &number, &type) && type == kLogFile) {
SequenceNumber sequence;
Status s = ReadFirstRecord(log_type, number, &sequence);
if (!s.ok()) {
return s;
}
if (sequence == 0) {
// empty file
continue;
}
uint64_t size_bytes;
s = env_->GetFileSize(LogFileName(path, number), &size_bytes);
if (!s.ok()) {
return s;
}
log_files.push_back(std::move(unique_ptr<LogFile>(
new LogFileImpl(number, log_type, sequence, size_bytes))));
}
}
CompareLogByPointer compare_log_files;
std::sort(log_files.begin(), log_files.end(), compare_log_files);
return status;
}
Status DBImpl::RetainProbableWalFiles(VectorLogPtr& all_logs,
const SequenceNumber target) {
int64_t start = 0; // signed to avoid overflow when target is < first file.
int64_t end = static_cast<int64_t>(all_logs.size()) - 1;
// Binary Search. avoid opening all files.
while (end >= start) {
int64_t mid = start + (end - start) / 2; // Avoid overflow.
SequenceNumber current_seq_num = all_logs.at(mid)->StartSequence();
if (current_seq_num == target) {
end = mid;
break;
} else if (current_seq_num < target) {
start = mid + 1;
} else {
end = mid - 1;
}
}
// end could be -ve.
size_t start_index = std::max(static_cast<int64_t>(0), end);
// The last wal file is always included
all_logs.erase(all_logs.begin(), all_logs.begin() + start_index);
return Status::OK();
}
Status DBImpl::ReadFirstRecord(const WalFileType type, const uint64_t number,
SequenceNumber* sequence) {
if (type != kAliveLogFile && type != kArchivedLogFile) {
return Status::NotSupported("File Type Not Known " + std::to_string(type));
}
{
MutexLock l(&read_first_record_cache_mutex_);
auto itr = read_first_record_cache_.find(number);
if (itr != read_first_record_cache_.end()) {
*sequence = itr->second;
return Status::OK();
}
}
Status s;
if (type == kAliveLogFile) {
std::string fname = LogFileName(options_.wal_dir, number);
s = ReadFirstLine(fname, sequence);
if (env_->FileExists(fname) && !s.ok()) {
// return any error that is not caused by non-existing file
return s;
}
}
if (type == kArchivedLogFile || !s.ok()) {
// check if the file got moved to archive.
std::string archived_file = ArchivedLogFileName(options_.wal_dir, number);
s = ReadFirstLine(archived_file, sequence);
}
if (s.ok() && *sequence != 0) {
MutexLock l(&read_first_record_cache_mutex_);
read_first_record_cache_.insert({number, *sequence});
}
return s;
}
// the function returns status.ok() and sequence == 0 if the file exists, but is
// empty
Status DBImpl::ReadFirstLine(const std::string& fname,
SequenceNumber* sequence) {
struct LogReporter : public log::Reader::Reporter {
Env* env;
Logger* info_log;
const char* fname;
Status* status;
bool ignore_error; // true if options_.paranoid_checks==false
virtual void Corruption(size_t bytes, const Status& s) {
Log(info_log, "%s%s: dropping %d bytes; %s",
(this->ignore_error ? "(ignoring error) " : ""), fname,
static_cast<int>(bytes), s.ToString().c_str());
if (this->status->ok()) {
// only keep the first error
*this->status = s;
}
}
};
unique_ptr<SequentialFile> file;
Status status = env_->NewSequentialFile(fname, &file, storage_options_);
if (!status.ok()) {
return status;
}
LogReporter reporter;
reporter.env = env_;
reporter.info_log = options_.info_log.get();
reporter.fname = fname.c_str();
reporter.status = &status;
reporter.ignore_error = !options_.paranoid_checks;
log::Reader reader(std::move(file), &reporter, true /*checksum*/,
0 /*initial_offset*/);
std::string scratch;
Slice record;
if (reader.ReadRecord(&record, &scratch) &&
(status.ok() || !options_.paranoid_checks)) {
if (record.size() < 12) {
reporter.Corruption(record.size(),
Status::Corruption("log record too small"));
// TODO read record's till the first no corrupt entry?
} else {
WriteBatch batch;
WriteBatchInternal::SetContents(&batch, record);
*sequence = WriteBatchInternal::Sequence(&batch);
return Status::OK();
}
}
// ReadRecord returns false on EOF, which means that the log file is empty. we
// return status.ok() in that case and set sequence number to 0
*sequence = 0;
return status;
}
#endif // ROCKSDB_LITE
Status DBImpl::Recover(
const std::vector<ColumnFamilyDescriptor>& column_families, bool read_only,
bool error_if_log_file_exist) {
mutex_.AssertHeld();
bool is_new_db = false;
assert(db_lock_ == nullptr);
if (!read_only) {
// We call CreateDirIfMissing() as the directory may already exist (if we
// are reopening a DB), when this happens we don't want creating the
// directory to cause an error. However, we need to check if creating the
// directory fails or else we may get an obscure message about the lock
// file not existing. One real-world example of this occurring is if
// env->CreateDirIfMissing() doesn't create intermediate directories, e.g.
// when dbname_ is "dir/db" but when "dir" doesn't exist.
Status s = env_->CreateDirIfMissing(dbname_);
if (!s.ok()) {
return s;
}
s = env_->NewDirectory(dbname_, &db_directory_);
if (!s.ok()) {
return s;
}
s = env_->LockFile(LockFileName(dbname_), &db_lock_);
if (!s.ok()) {
return s;
}
if (!env_->FileExists(CurrentFileName(dbname_))) {
if (options_.create_if_missing) {
// TODO: add merge_operator name check
s = NewDB();
is_new_db = true;
if (!s.ok()) {
return s;
}
} else {
return Status::InvalidArgument(
dbname_, "does not exist (create_if_missing is false)");
}
} else {
if (options_.error_if_exists) {
return Status::InvalidArgument(
dbname_, "exists (error_if_exists is true)");
}
}
// Check for the IDENTITY file and create it if not there
if (!env_->FileExists(IdentityFileName(dbname_))) {
s = SetIdentityFile(env_, dbname_);
if (!s.ok()) {
return s;
}
}
}
Status s = versions_->Recover(column_families, read_only);
if (options_.paranoid_checks && s.ok()) {
s = CheckConsistency();
}
if (s.ok()) {
SequenceNumber max_sequence(0);
default_cf_handle_ = new ColumnFamilyHandleImpl(
versions_->GetColumnFamilySet()->GetDefault(), this, &mutex_);
// Recover from all newer log files than the ones named in the
// descriptor (new log files may have been added by the previous
// incarnation without registering them in the descriptor).
//
// Note that PrevLogNumber() is no longer used, but we pay
// attention to it in case we are recovering a database
// produced by an older version of rocksdb.
const uint64_t min_log = versions_->MinLogNumber();
const uint64_t prev_log = versions_->PrevLogNumber();
std::vector<std::string> filenames;
s = env_->GetChildren(options_.wal_dir, &filenames);
if (!s.ok()) {
return s;
}
std::vector<uint64_t> logs;
for (size_t i = 0; i < filenames.size(); i++) {
uint64_t number;
FileType type;
if (ParseFileName(filenames[i], &number, &type) && type == kLogFile) {
if (is_new_db) {
return Status::Corruption(
"While creating a new Db, wal_dir contains "
"existing log file: ",
filenames[i]);
} else if ((number >= min_log) || (number == prev_log)) {
logs.push_back(number);
}
}
}
if (logs.size() > 0 && error_if_log_file_exist) {
return Status::Corruption(""
"The db was opened in readonly mode with error_if_log_file_exist"
"flag but a log file already exists");
}
// Recover in the order in which the logs were generated
std::sort(logs.begin(), logs.end());
for (const auto& log : logs) {
// The previous incarnation may not have written any MANIFEST
// records after allocating this log number. So we manually
// update the file number allocation counter in VersionSet.
versions_->MarkFileNumberUsed(log);
s = RecoverLogFile(log, &max_sequence, read_only);
}
SetTickerCount(options_.statistics.get(), SEQUENCE_NUMBER,
versions_->LastSequence());
}
for (auto cfd : *versions_->GetColumnFamilySet()) {
max_total_in_memory_state_ += cfd->options()->write_buffer_size *
cfd->options()->max_write_buffer_number;
}
return s;
}
Status DBImpl::RecoverLogFile(uint64_t log_number, SequenceNumber* max_sequence,
bool read_only) {
struct LogReporter : public log::Reader::Reporter {
Env* env;
Logger* info_log;
const char* fname;
Status* status; // nullptr if options_.paranoid_checks==false or
// options_.skip_log_error_on_recovery==true
virtual void Corruption(size_t bytes, const Status& s) {
Log(info_log, "%s%s: dropping %d bytes; %s",
(this->status == nullptr ? "(ignoring error) " : ""),
fname, static_cast<int>(bytes), s.ToString().c_str());
if (this->status != nullptr && this->status->ok()) *this->status = s;
}
};
mutex_.AssertHeld();
std::unordered_map<int, VersionEdit> version_edits;
// no need to refcount because iteration is under mutex
for (auto cfd : *versions_->GetColumnFamilySet()) {
VersionEdit edit;
edit.SetColumnFamily(cfd->GetID());
version_edits.insert({cfd->GetID(), edit});
}
// Open the log file
std::string fname = LogFileName(options_.wal_dir, log_number);
unique_ptr<SequentialFile> file;
Status status = env_->NewSequentialFile(fname, &file, storage_options_);
if (!status.ok()) {
MaybeIgnoreError(&status);
return status;
}
// Create the log reader.
LogReporter reporter;
reporter.env = env_;
reporter.info_log = options_.info_log.get();
reporter.fname = fname.c_str();
reporter.status = (options_.paranoid_checks &&
!options_.skip_log_error_on_recovery ? &status : nullptr);
// We intentially make log::Reader do checksumming even if
// paranoid_checks==false so that corruptions cause entire commits
// to be skipped instead of propagating bad information (like overly
// large sequence numbers).
log::Reader reader(std::move(file), &reporter, true/*checksum*/,
0/*initial_offset*/);
Log(options_.info_log, "Recovering log #%lu",
(unsigned long) log_number);
// Read all the records and add to a memtable
std::string scratch;
Slice record;
WriteBatch batch;
while (reader.ReadRecord(&record, &scratch)) {
if (record.size() < 12) {
reporter.Corruption(
record.size(), Status::Corruption("log record too small"));
continue;
}
WriteBatchInternal::SetContents(&batch, record);
status = WriteBatchInternal::InsertInto(
&batch, column_family_memtables_.get(), true, log_number);
MaybeIgnoreError(&status);
if (!status.ok()) {
return status;
}
const SequenceNumber last_seq =
WriteBatchInternal::Sequence(&batch) +
WriteBatchInternal::Count(&batch) - 1;
if (last_seq > *max_sequence) {
*max_sequence = last_seq;
}
if (!read_only) {
// no need to refcount since client still doesn't have access
// to the DB and can not drop column families while we iterate
for (auto cfd : *versions_->GetColumnFamilySet()) {
if (cfd->mem()->ShouldFlush()) {
// If this asserts, it means that InsertInto failed in
// filtering updates to already-flushed column families
assert(cfd->GetLogNumber() <= log_number);
auto iter = version_edits.find(cfd->GetID());
assert(iter != version_edits.end());
VersionEdit* edit = &iter->second;
status = WriteLevel0TableForRecovery(cfd, cfd->mem(), edit);
// we still want to clear the memtable, even if the recovery failed
cfd->CreateNewMemtable();
if (!status.ok()) {
// Reflect errors immediately so that conditions like full
// file-systems cause the DB::Open() to fail.
return status;
}
}
}
}
}
if (versions_->LastSequence() < *max_sequence) {
versions_->SetLastSequence(*max_sequence);
}
if (!read_only) {
// no need to refcount since client still doesn't have access
// to the DB and can not drop column families while we iterate
for (auto cfd : *versions_->GetColumnFamilySet()) {
auto iter = version_edits.find(cfd->GetID());
assert(iter != version_edits.end());
VersionEdit* edit = &iter->second;
if (cfd->GetLogNumber() > log_number) {
// Column family cfd has already flushed the data
// from log_number. Memtable has to be empty because
// we filter the updates based on log_number
// (in WriteBatch::InsertInto)
assert(cfd->mem()->GetFirstSequenceNumber() == 0);
assert(edit->NumEntries() == 0);
continue;
}
// flush the final memtable (if non-empty)
if (cfd->mem()->GetFirstSequenceNumber() != 0) {
status = WriteLevel0TableForRecovery(cfd, cfd->mem(), edit);
}
// we still want to clear the memtable, even if the recovery failed
cfd->CreateNewMemtable();
if (!status.ok()) {
return status;
}
// write MANIFEST with update
// writing log number in the manifest means that any log file
// with number strongly less than (log_number + 1) is already
// recovered and should be ignored on next reincarnation.
// Since we already recovered log_number, we want all logs
// with numbers `<= log_number` (includes this one) to be ignored
edit->SetLogNumber(log_number + 1);
// we must mark the next log number as used, even though it's
// not actually used. that is because VersionSet assumes
// VersionSet::next_file_number_ always to be strictly greater than any
// log number
versions_->MarkFileNumberUsed(log_number + 1);
status = versions_->LogAndApply(cfd, edit, &mutex_);
if (!status.ok()) {
return status;
}
}
}
return status;
}
Status DBImpl::WriteLevel0TableForRecovery(ColumnFamilyData* cfd, MemTable* mem,
VersionEdit* edit) {
mutex_.AssertHeld();
const uint64_t start_micros = env_->NowMicros();
FileMetaData meta;
meta.number = versions_->NewFileNumber();
pending_outputs_.insert(meta.number);
Iterator* iter = mem->NewIterator(ReadOptions(), true);
const SequenceNumber newest_snapshot = snapshots_.GetNewest();
const SequenceNumber earliest_seqno_in_memtable =
mem->GetFirstSequenceNumber();
Log(options_.info_log, "[%s] Level-0 table #%lu: started",
cfd->GetName().c_str(), (unsigned long)meta.number);
Status s;
{
mutex_.Unlock();
s = BuildTable(dbname_, env_, *cfd->options(), storage_options_,
cfd->table_cache(), iter, &meta, cfd->internal_comparator(),
newest_snapshot, earliest_seqno_in_memtable,
GetCompressionFlush(*cfd->options()));
LogFlush(options_.info_log);
mutex_.Lock();
}
Log(options_.info_log, "[%s] Level-0 table #%lu: %lu bytes %s",
cfd->GetName().c_str(), (unsigned long)meta.number,
(unsigned long)meta.file_size, s.ToString().c_str());
delete iter;
pending_outputs_.erase(meta.number);
// Note that if file_size is zero, the file has been deleted and
// should not be added to the manifest.
int level = 0;
if (s.ok() && meta.file_size > 0) {
edit->AddFile(level, meta.number, meta.file_size,
meta.smallest, meta.largest,
meta.smallest_seqno, meta.largest_seqno);
}
InternalStats::CompactionStats stats;
stats.micros = env_->NowMicros() - start_micros;
stats.bytes_written = meta.file_size;
stats.files_out_levelnp1 = 1;
cfd->internal_stats()->AddCompactionStats(level, stats);
RecordTick(options_.statistics.get(), COMPACT_WRITE_BYTES, meta.file_size);
return s;
}
Status DBImpl::WriteLevel0Table(ColumnFamilyData* cfd,
autovector<MemTable*>& mems, VersionEdit* edit,
uint64_t* filenumber, LogBuffer* log_buffer) {
mutex_.AssertHeld();
const uint64_t start_micros = env_->NowMicros();
FileMetaData meta;
meta.number = versions_->NewFileNumber();
*filenumber = meta.number;
pending_outputs_.insert(meta.number);
const SequenceNumber newest_snapshot = snapshots_.GetNewest();
const SequenceNumber earliest_seqno_in_memtable =
mems[0]->GetFirstSequenceNumber();
Version* base = cfd->current();
base->Ref(); // it is likely that we do not need this reference
Status s;
{
mutex_.Unlock();
log_buffer->FlushBufferToLog();
std::vector<Iterator*> memtables;
for (MemTable* m : mems) {
Log(options_.info_log, "[%s] Flushing memtable with next log file: %lu\n",
cfd->GetName().c_str(), (unsigned long)m->GetNextLogNumber());
memtables.push_back(m->NewIterator(ReadOptions(), true));
}
Iterator* iter = NewMergingIterator(&cfd->internal_comparator(),
&memtables[0], memtables.size());
Log(options_.info_log, "[%s] Level-0 flush table #%lu: started",
cfd->GetName().c_str(), (unsigned long)meta.number);
s = BuildTable(dbname_, env_, *cfd->options(), storage_options_,
cfd->table_cache(), iter, &meta, cfd->internal_comparator(),
newest_snapshot, earliest_seqno_in_memtable,
GetCompressionFlush(*cfd->options()));
LogFlush(options_.info_log);
delete iter;
Log(options_.info_log, "[%s] Level-0 flush table #%lu: %lu bytes %s",
cfd->GetName().c_str(), (unsigned long)meta.number,
(unsigned long)meta.file_size, s.ToString().c_str());
if (!options_.disableDataSync) {
db_directory_->Fsync();
}
mutex_.Lock();
}
base->Unref();
// re-acquire the most current version
base = cfd->current();
// There could be multiple threads writing to its own level-0 file.
// The pending_outputs cannot be cleared here, otherwise this newly
// created file might not be considered as a live-file by another
// compaction thread that is concurrently deleting obselete files.
// The pending_outputs can be cleared only after the new version is
// committed so that other threads can recognize this file as a
// valid one.
// pending_outputs_.erase(meta.number);
// Note that if file_size is zero, the file has been deleted and
// should not be added to the manifest.
int level = 0;
if (s.ok() && meta.file_size > 0) {
const Slice min_user_key = meta.smallest.user_key();
const Slice max_user_key = meta.largest.user_key();
// if we have more than 1 background thread, then we cannot
// insert files directly into higher levels because some other
// threads could be concurrently producing compacted files for
// that key range.
if (base != nullptr && options_.max_background_compactions <= 1 &&
cfd->options()->compaction_style == kCompactionStyleLevel) {
level = base->PickLevelForMemTableOutput(min_user_key, max_user_key);
}
edit->AddFile(level, meta.number, meta.file_size,
meta.smallest, meta.largest,
meta.smallest_seqno, meta.largest_seqno);
}
InternalStats::CompactionStats stats;
stats.micros = env_->NowMicros() - start_micros;
stats.bytes_written = meta.file_size;
cfd->internal_stats()->AddCompactionStats(level, stats);
RecordTick(options_.statistics.get(), COMPACT_WRITE_BYTES, meta.file_size);
return s;
}
Status DBImpl::FlushMemTableToOutputFile(ColumnFamilyData* cfd,
bool* madeProgress,
DeletionState& deletion_state,
LogBuffer* log_buffer) {
mutex_.AssertHeld();
assert(cfd->imm()->size() != 0);
assert(cfd->imm()->IsFlushPending());
// Save the contents of the earliest memtable as a new Table
uint64_t file_number;
autovector<MemTable*> mems;
cfd->imm()->PickMemtablesToFlush(&mems);
if (mems.empty()) {
LogToBuffer(log_buffer, "[%s] Nothing in memtable to flush",
cfd->GetName().c_str());
return Status::OK();
}
// record the logfile_number_ before we release the mutex
// entries mems are (implicitly) sorted in ascending order by their created
// time. We will use the first memtable's `edit` to keep the meta info for
// this flush.
MemTable* m = mems[0];
VersionEdit* edit = m->GetEdits();
edit->SetPrevLogNumber(0);
// SetLogNumber(log_num) indicates logs with number smaller than log_num
// will no longer be picked up for recovery.
edit->SetLogNumber(mems.back()->GetNextLogNumber());
edit->SetColumnFamily(cfd->GetID());
// This will release and re-acquire the mutex.
Status s = WriteLevel0Table(cfd, mems, edit, &file_number, log_buffer);
if (s.ok() && shutting_down_.Acquire_Load() && cfd->IsDropped()) {
s = Status::ShutdownInProgress(
"Database shutdown or Column family drop during flush");
}
if (!s.ok()) {
cfd->imm()->RollbackMemtableFlush(mems, file_number, &pending_outputs_);
} else {
// Replace immutable memtable with the generated Table
s = cfd->imm()->InstallMemtableFlushResults(
cfd, mems, versions_.get(), &mutex_, options_.info_log.get(),
file_number, pending_outputs_, &deletion_state.memtables_to_free,
db_directory_.get(), log_buffer);
}
if (s.ok()) {
InstallSuperVersion(cfd, deletion_state);
if (madeProgress) {
*madeProgress = 1;
}
Version::LevelSummaryStorage tmp;
LogToBuffer(log_buffer, "[%s] Level summary: %s\n", cfd->GetName().c_str(),
cfd->current()->LevelSummary(&tmp));
MaybeScheduleLogDBDeployStats();
if (disable_delete_obsolete_files_ == 0) {
// add to deletion state
while (alive_log_files_.size() &&
alive_log_files_.begin()->number < versions_->MinLogNumber()) {
const auto& earliest = *alive_log_files_.begin();
deletion_state.log_delete_files.push_back(earliest.number);
total_log_size_ -= earliest.size;
alive_log_files_.pop_front();
}
}
}
if (!s.ok() && !s.IsShutdownInProgress() && options_.paranoid_checks &&
bg_error_.ok()) {
// if a bad error happened (not ShutdownInProgress) and paranoid_checks is
// true, mark DB read-only
bg_error_ = s;
}
return s;
}
Status DBImpl::CompactRange(ColumnFamilyHandle* column_family,
const Slice* begin, const Slice* end,
bool reduce_level, int target_level) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
auto cfd = cfh->cfd();
Status s = FlushMemTable(cfd, FlushOptions());
if (!s.ok()) {
LogFlush(options_.info_log);
return s;
}
int max_level_with_files = 1;
{
MutexLock l(&mutex_);
Version* base = cfd->current();
for (int level = 1; level < cfd->NumberLevels(); level++) {
if (base->OverlapInLevel(level, begin, end)) {
max_level_with_files = level;
}
}
}
for (int level = 0; level <= max_level_with_files; level++) {
// in case the compaction is unversal or if we're compacting the
// bottom-most level, the output level will be the same as input one
if (cfd->options()->compaction_style == kCompactionStyleUniversal ||
level == max_level_with_files) {
s = RunManualCompaction(cfd, level, level, begin, end);
} else {
s = RunManualCompaction(cfd, level, level + 1, begin, end);
}
if (!s.ok()) {
LogFlush(options_.info_log);
return s;
}
}
if (reduce_level) {
s = ReFitLevel(cfd, max_level_with_files, target_level);
}
LogFlush(options_.info_log);
return s;
}
// return the same level if it cannot be moved
int DBImpl::FindMinimumEmptyLevelFitting(ColumnFamilyData* cfd, int level) {
mutex_.AssertHeld();
Version* current = cfd->current();
int minimum_level = level;
for (int i = level - 1; i > 0; --i) {
// stop if level i is not empty
if (current->NumLevelFiles(i) > 0) break;
// stop if level i is too small (cannot fit the level files)
if (cfd->compaction_picker()->MaxBytesForLevel(i) <
current->NumLevelBytes(level)) {
break;
}
minimum_level = i;
}
return minimum_level;
}
Status DBImpl::ReFitLevel(ColumnFamilyData* cfd, int level, int target_level) {
assert(level < cfd->NumberLevels());
SuperVersion* superversion_to_free = nullptr;
SuperVersion* new_superversion = new SuperVersion();
mutex_.Lock();
// only allow one thread refitting
if (refitting_level_) {
mutex_.Unlock();
Log(options_.info_log, "ReFitLevel: another thread is refitting");
delete new_superversion;
return Status::NotSupported("another thread is refitting");
}
refitting_level_ = true;
// wait for all background threads to stop
bg_work_gate_closed_ = true;
while (bg_compaction_scheduled_ > 0 || bg_flush_scheduled_) {
Log(options_.info_log,
"RefitLevel: waiting for background threads to stop: %d %d",
bg_compaction_scheduled_, bg_flush_scheduled_);
bg_cv_.Wait();
}
// move to a smaller level
int to_level = target_level;
if (target_level < 0) {
to_level = FindMinimumEmptyLevelFitting(cfd, level);
}
assert(to_level <= level);
Status status;
if (to_level < level) {
Log(options_.info_log, "[%s] Before refitting:\n%s", cfd->GetName().c_str(),
cfd->current()->DebugString().data());
VersionEdit edit;
edit.SetColumnFamily(cfd->GetID());
for (const auto& f : cfd->current()->files_[level]) {
edit.DeleteFile(level, f->number);
edit.AddFile(to_level, f->number, f->file_size, f->smallest, f->largest,
f->smallest_seqno, f->largest_seqno);
}
Log(options_.info_log, "[%s] Apply version edit:\n%s",
cfd->GetName().c_str(), edit.DebugString().data());
status = versions_->LogAndApply(cfd, &edit, &mutex_, db_directory_.get());
superversion_to_free = cfd->InstallSuperVersion(new_superversion, &mutex_);
new_superversion = nullptr;
Log(options_.info_log, "[%s] LogAndApply: %s\n", cfd->GetName().c_str(),
status.ToString().data());
if (status.ok()) {
Log(options_.info_log, "[%s] After refitting:\n%s",
cfd->GetName().c_str(), cfd->current()->DebugString().data());
}
}
refitting_level_ = false;
bg_work_gate_closed_ = false;
mutex_.Unlock();
delete superversion_to_free;
delete new_superversion;
return status;
}
int DBImpl::NumberLevels(ColumnFamilyHandle* column_family) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
return cfh->cfd()->NumberLevels();
}
int DBImpl::MaxMemCompactionLevel(ColumnFamilyHandle* column_family) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
return cfh->cfd()->options()->max_mem_compaction_level;
}
int DBImpl::Level0StopWriteTrigger(ColumnFamilyHandle* column_family) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
return cfh->cfd()->options()->level0_stop_writes_trigger;
}
Status DBImpl::Flush(const FlushOptions& options,
ColumnFamilyHandle* column_family) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
return FlushMemTable(cfh->cfd(), options);
}
SequenceNumber DBImpl::GetLatestSequenceNumber() const {
return versions_->LastSequence();
}
Status DBImpl::RunManualCompaction(ColumnFamilyData* cfd, int input_level,
int output_level, const Slice* begin,
const Slice* end) {
assert(input_level >= 0);
InternalKey begin_storage, end_storage;
ManualCompaction manual;
manual.cfd = cfd;
manual.input_level = input_level;
manual.output_level = output_level;
manual.done = false;
manual.in_progress = false;
// For universal compaction, we enforce every manual compaction to compact
// all files.
if (begin == nullptr ||
cfd->options()->compaction_style == kCompactionStyleUniversal) {
manual.begin = nullptr;
} else {
begin_storage = InternalKey(*begin, kMaxSequenceNumber, kValueTypeForSeek);
manual.begin = &begin_storage;
}
if (end == nullptr ||
cfd->options()->compaction_style == kCompactionStyleUniversal) {
manual.end = nullptr;
} else {
end_storage = InternalKey(*end, 0, static_cast<ValueType>(0));
manual.end = &end_storage;
}
MutexLock l(&mutex_);
// When a manual compaction arrives, temporarily disable scheduling of
// non-manual compactions and wait until the number of scheduled compaction
// jobs drops to zero. This is needed to ensure that this manual compaction
// can compact any range of keys/files.
//
// bg_manual_only_ is non-zero when at least one thread is inside
// RunManualCompaction(), i.e. during that time no other compaction will
// get scheduled (see MaybeScheduleFlushOrCompaction).
//
// Note that the following loop doesn't stop more that one thread calling
// RunManualCompaction() from getting to the second while loop below.
// However, only one of them will actually schedule compaction, while
// others will wait on a condition variable until it completes.
++bg_manual_only_;
while (bg_compaction_scheduled_ > 0) {
Log(options_.info_log,
"[%s] Manual compaction waiting for all other scheduled background "
"compactions to finish",
cfd->GetName().c_str());
bg_cv_.Wait();
}
Log(options_.info_log, "[%s] Manual compaction starting",
cfd->GetName().c_str());
while (!manual.done && !shutting_down_.Acquire_Load() && bg_error_.ok()) {
assert(bg_manual_only_ > 0);
if (manual_compaction_ != nullptr) {
// Running either this or some other manual compaction
bg_cv_.Wait();
} else {
manual_compaction_ = &manual;
MaybeScheduleFlushOrCompaction();
}
}
assert(!manual.in_progress);
assert(bg_manual_only_ > 0);
--bg_manual_only_;
return manual.status;
}
Status DBImpl::FlushMemTable(ColumnFamilyData* cfd,
const FlushOptions& options) {
// nullptr batch means just wait for earlier writes to be done
Status s = Write(WriteOptions(), nullptr);
if (s.ok() && options.wait) {
// Wait until the compaction completes
s = WaitForFlushMemTable(cfd);
}
return s;
}
Status DBImpl::WaitForFlushMemTable(ColumnFamilyData* cfd) {
Status s;
// Wait until the compaction completes
MutexLock l(&mutex_);
while (cfd->imm()->size() > 0 && bg_error_.ok()) {
bg_cv_.Wait();
}
if (!bg_error_.ok()) {
s = bg_error_;
}
return s;
}
void DBImpl::MaybeScheduleFlushOrCompaction() {
mutex_.AssertHeld();
bg_schedule_needed_ = false;
if (bg_work_gate_closed_) {
// gate closed for backgrond work
} else if (shutting_down_.Acquire_Load()) {
// DB is being deleted; no more background compactions
} else {
bool is_flush_pending = false;
// no need to refcount since we're under a mutex
for (auto cfd : *versions_->GetColumnFamilySet()) {
if (cfd->imm()->IsFlushPending()) {
is_flush_pending = true;
}
}
if (is_flush_pending) {
// memtable flush needed
if (bg_flush_scheduled_ < options_.max_background_flushes) {
bg_flush_scheduled_++;
env_->Schedule(&DBImpl::BGWorkFlush, this, Env::Priority::HIGH);
} else if (options_.max_background_flushes > 0) {
bg_schedule_needed_ = true;
}
}
bool is_compaction_needed = false;
// no need to refcount since we're under a mutex
for (auto cfd : *versions_->GetColumnFamilySet()) {
if (cfd->current()->NeedsCompaction()) {
is_compaction_needed = true;
break;
}
}
// Schedule BGWorkCompaction if there's a compaction pending (or a memtable
// flush, but the HIGH pool is not enabled)
// Do it only if max_background_compactions hasn't been reached and, in case
// bg_manual_only_ > 0, if it's a manual compaction.
if ((manual_compaction_ || is_compaction_needed ||
(is_flush_pending && options_.max_background_flushes == 0)) &&
(!bg_manual_only_ || manual_compaction_)) {
if (bg_compaction_scheduled_ < options_.max_background_compactions) {
bg_compaction_scheduled_++;
env_->Schedule(&DBImpl::BGWorkCompaction, this, Env::Priority::LOW);
} else {
bg_schedule_needed_ = true;
}
}
}
}
void DBImpl::BGWorkFlush(void* db) {
reinterpret_cast<DBImpl*>(db)->BackgroundCallFlush();
}
void DBImpl::BGWorkCompaction(void* db) {
reinterpret_cast<DBImpl*>(db)->BackgroundCallCompaction();
}
Status DBImpl::BackgroundFlush(bool* madeProgress,
DeletionState& deletion_state,
LogBuffer* log_buffer) {
mutex_.AssertHeld();
// call_status is failure if at least one flush was a failure. even if
// flushing one column family reports a failure, we will continue flushing
// other column families. however, call_status will be a failure in that case.
Status call_status;
// refcounting in iteration
for (auto cfd : *versions_->GetColumnFamilySet()) {
cfd->Ref();
Status flush_status;
while (flush_status.ok() && cfd->imm()->IsFlushPending()) {
LogToBuffer(
log_buffer,
"BackgroundCallFlush doing FlushMemTableToOutputFile with column "
"family [%s], flush slots available %d",
cfd->GetName().c_str(),
options_.max_background_flushes - bg_flush_scheduled_);
flush_status = FlushMemTableToOutputFile(cfd, madeProgress,
deletion_state, log_buffer);
}
if (call_status.ok() && !flush_status.ok()) {
call_status = flush_status;
}
cfd->Unref();
}
versions_->GetColumnFamilySet()->FreeDeadColumnFamilies();
return call_status;
}
void DBImpl::BackgroundCallFlush() {
bool madeProgress = false;
DeletionState deletion_state(true);
assert(bg_flush_scheduled_);
LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, options_.info_log.get());
{
MutexLock l(&mutex_);
Status s;
if (!shutting_down_.Acquire_Load()) {
s = BackgroundFlush(&madeProgress, deletion_state, &log_buffer);
if (!s.ok()) {
// Wait a little bit before retrying background compaction in
// case this is an environmental problem and we do not want to
// chew up resources for failed compactions for the duration of
// the problem.
uint64_t error_cnt = default_cf_handle_->cfd()
->internal_stats()
->BumpAndGetBackgroundErrorCount();
bg_cv_.SignalAll(); // In case a waiter can proceed despite the error
mutex_.Unlock();
Log(options_.info_log,
"Waiting after background flush error: %s"
"Accumulated background error counts: %" PRIu64,
s.ToString().c_str(), error_cnt);
log_buffer.FlushBufferToLog();
LogFlush(options_.info_log);
env_->SleepForMicroseconds(1000000);
mutex_.Lock();
}
}
// If !s.ok(), this means that Flush failed. In that case, we want
// to delete all obsolete files and we force FindObsoleteFiles()
FindObsoleteFiles(deletion_state, !s.ok());
// delete unnecessary files if any, this is done outside the mutex
if (deletion_state.HaveSomethingToDelete() || !log_buffer.IsEmpty()) {
mutex_.Unlock();
// Have to flush the info logs before bg_flush_scheduled_--
// because if bg_flush_scheduled_ becomes 0 and the lock is
// released, the deconstructor of DB can kick in and destroy all the
// states of DB so info_log might not be available after that point.
// It also applies to access other states that DB owns.
log_buffer.FlushBufferToLog();
if (deletion_state.HaveSomethingToDelete()) {
PurgeObsoleteFiles(deletion_state);
}
mutex_.Lock();
}
bg_flush_scheduled_--;
// Any time the mutex is released After finding the work to do, another
// thread might execute MaybeScheduleFlushOrCompaction(). It is possible
// that there is a pending job but it is not scheduled because of the
// max thread limit.
if (madeProgress || bg_schedule_needed_) {
MaybeScheduleFlushOrCompaction();
}
bg_cv_.SignalAll();
// IMPORTANT: there should be no code after calling SignalAll. This call may
// signal the DB destructor that it's OK to proceed with destruction. In
// that case, all DB variables will be dealloacated and referencing them
// will cause trouble.
}
}
void DBImpl::BackgroundCallCompaction() {
bool madeProgress = false;
DeletionState deletion_state(true);
MaybeDumpStats();
LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, options_.info_log.get());
{
MutexLock l(&mutex_);
assert(bg_compaction_scheduled_);
Status s;
if (!shutting_down_.Acquire_Load()) {
s = BackgroundCompaction(&madeProgress, deletion_state, &log_buffer);
if (!s.ok()) {
// Wait a little bit before retrying background compaction in
// case this is an environmental problem and we do not want to
// chew up resources for failed compactions for the duration of
// the problem.
uint64_t error_cnt = default_cf_handle_->cfd()
->internal_stats()
->BumpAndGetBackgroundErrorCount();
bg_cv_.SignalAll(); // In case a waiter can proceed despite the error
mutex_.Unlock();
log_buffer.FlushBufferToLog();
Log(options_.info_log,
"Waiting after background compaction error: %s, "
"Accumulated background error counts: %" PRIu64,
s.ToString().c_str(), error_cnt);
LogFlush(options_.info_log);
env_->SleepForMicroseconds(1000000);
mutex_.Lock();
}
}
// If !s.ok(), this means that Compaction failed. In that case, we want
// to delete all obsolete files we might have created and we force
// FindObsoleteFiles(). This is because deletion_state does not catch
// all created files if compaction failed.
FindObsoleteFiles(deletion_state, !s.ok());
// delete unnecessary files if any, this is done outside the mutex
if (deletion_state.HaveSomethingToDelete() || !log_buffer.IsEmpty()) {
mutex_.Unlock();
// Have to flush the info logs before bg_compaction_scheduled_--
// because if bg_flush_scheduled_ becomes 0 and the lock is
// released, the deconstructor of DB can kick in and destroy all the
// states of DB so info_log might not be available after that point.
// It also applies to access other states that DB owns.
log_buffer.FlushBufferToLog();
if (deletion_state.HaveSomethingToDelete()) {
PurgeObsoleteFiles(deletion_state);
}
mutex_.Lock();
}
bg_compaction_scheduled_--;
MaybeScheduleLogDBDeployStats();
versions_->GetColumnFamilySet()->FreeDeadColumnFamilies();
// Previous compaction may have produced too many files in a level,
// So reschedule another compaction if we made progress in the
// last compaction.
//
// Also, any time the mutex is released After finding the work to do,
// another thread might execute MaybeScheduleFlushOrCompaction(). It is
// possible that there is a pending job but it is not scheduled because of
// the max thread limit.
if (madeProgress || bg_schedule_needed_) {
MaybeScheduleFlushOrCompaction();
}
bg_cv_.SignalAll();
// IMPORTANT: there should be no code after calling SignalAll. This call may
// signal the DB destructor that it's OK to proceed with destruction. In
// that case, all DB variables will be dealloacated and referencing them
// will cause trouble.
}
}
Status DBImpl::BackgroundCompaction(bool* madeProgress,
DeletionState& deletion_state,
LogBuffer* log_buffer) {
*madeProgress = false;
mutex_.AssertHeld();
bool is_manual = (manual_compaction_ != nullptr) &&
(manual_compaction_->in_progress == false);
if (is_manual) {
// another thread cannot pick up the same work
manual_compaction_->in_progress = true;
}
// FLUSH preempts compaction
Status flush_stat;
for (auto cfd : *versions_->GetColumnFamilySet()) {
while (cfd->imm()->IsFlushPending()) {
LogToBuffer(
log_buffer,
"BackgroundCompaction doing FlushMemTableToOutputFile, "
"compaction slots available %d",
options_.max_background_compactions - bg_compaction_scheduled_);
cfd->Ref();
flush_stat = FlushMemTableToOutputFile(cfd, madeProgress, deletion_state,
log_buffer);
cfd->Unref();
if (!flush_stat.ok()) {
if (is_manual) {
manual_compaction_->status = flush_stat;
manual_compaction_->done = true;
manual_compaction_->in_progress = false;
manual_compaction_ = nullptr;
}
return flush_stat;
}
}
}
unique_ptr<Compaction> c;
InternalKey manual_end_storage;
InternalKey* manual_end = &manual_end_storage;
if (is_manual) {
ManualCompaction* m = manual_compaction_;
assert(m->in_progress);
c.reset(m->cfd->CompactRange(m->input_level, m->output_level, m->begin,
m->end, &manual_end));
if (!c) {
m->done = true;
}
LogToBuffer(log_buffer,
"[%s] Manual compaction from level-%d to level-%d from %s .. "
"%s; will stop at %s\n",
m->cfd->GetName().c_str(), m->input_level, m->output_level,
(m->begin ? m->begin->DebugString().c_str() : "(begin)"),
(m->end ? m->end->DebugString().c_str() : "(end)"),
((m->done || manual_end == nullptr)
? "(end)"
: manual_end->DebugString().c_str()));
} else {
// no need to refcount in iteration since it's always under a mutex
for (auto cfd : *versions_->GetColumnFamilySet()) {
if (!cfd->options()->disable_auto_compactions) {
c.reset(cfd->PickCompaction(log_buffer));
if (c != nullptr) {
// update statistics
MeasureTime(options_.statistics.get(), NUM_FILES_IN_SINGLE_COMPACTION,
c->inputs(0)->size());
break;
}
}
}
}
Status status;
if (!c) {
// Nothing to do
LogToBuffer(log_buffer, "Compaction nothing to do");
} else if (!is_manual && c->IsTrivialMove()) {
// Move file to next level
assert(c->num_input_files(0) == 1);
FileMetaData* f = c->input(0, 0);
c->edit()->DeleteFile(c->level(), f->number);
c->edit()->AddFile(c->level() + 1, f->number, f->file_size,
f->smallest, f->largest,
f->smallest_seqno, f->largest_seqno);
status = versions_->LogAndApply(c->column_family_data(), c->edit(), &mutex_,
db_directory_.get());
InstallSuperVersion(c->column_family_data(), deletion_state);
Version::LevelSummaryStorage tmp;
LogToBuffer(log_buffer, "[%s] Moved #%lld to level-%d %lld bytes %s: %s\n",
c->column_family_data()->GetName().c_str(),
static_cast<unsigned long long>(f->number), c->level() + 1,
static_cast<unsigned long long>(f->file_size),
status.ToString().c_str(),
c->input_version()->LevelSummary(&tmp));
c->ReleaseCompactionFiles(status);
*madeProgress = true;
} else {
MaybeScheduleFlushOrCompaction(); // do more compaction work in parallel.
CompactionState* compact = new CompactionState(c.get());
status = DoCompactionWork(compact, deletion_state, log_buffer);
CleanupCompaction(compact, status);
c->ReleaseCompactionFiles(status);
c->ReleaseInputs();
*madeProgress = true;
}
c.reset();
if (status.ok()) {
// Done
} else if (shutting_down_.Acquire_Load()) {
// Ignore compaction errors found during shutting down
} else {
Log(InfoLogLevel::WARN_LEVEL, options_.info_log, "Compaction error: %s",
status.ToString().c_str());
if (options_.paranoid_checks && bg_error_.ok()) {
bg_error_ = status;
}
}
if (is_manual) {
ManualCompaction* m = manual_compaction_;
if (!status.ok()) {
m->status = status;
m->done = true;
}
// For universal compaction:
// Because universal compaction always happens at level 0, so one
// compaction will pick up all overlapped files. No files will be
// filtered out due to size limit and left for a successive compaction.
// So we can safely conclude the current compaction.
//
// Also note that, if we don't stop here, then the current compaction
// writes a new file back to level 0, which will be used in successive
// compaction. Hence the manual compaction will never finish.
//
// Stop the compaction if manual_end points to nullptr -- this means
// that we compacted the whole range. manual_end should always point
// to nullptr in case of universal compaction
if (manual_end == nullptr) {
m->done = true;
}
if (!m->done) {
// We only compacted part of the requested range. Update *m
// to the range that is left to be compacted.
// Universal compaction should always compact the whole range
assert(m->cfd->options()->compaction_style != kCompactionStyleUniversal);
m->tmp_storage = *manual_end;
m->begin = &m->tmp_storage;
}
m->in_progress = false; // not being processed anymore
manual_compaction_ = nullptr;
}
return status;
}
void DBImpl::CleanupCompaction(CompactionState* compact, Status status) {
mutex_.AssertHeld();
if (compact->builder != nullptr) {
// May happen if we get a shutdown call in the middle of compaction
compact->builder->Abandon();
compact->builder.reset();
} else {
assert(compact->outfile == nullptr);
}
for (size_t i = 0; i < compact->outputs.size(); i++) {
const CompactionState::Output& out = compact->outputs[i];
pending_outputs_.erase(out.number);
// If this file was inserted into the table cache then remove
// them here because this compaction was not committed.
if (!status.ok()) {
TableCache::Evict(table_cache_.get(), out.number);
}
}
delete compact;
}
// Allocate the file numbers for the output file. We allocate as
// many output file numbers as there are files in level+1 (at least one)
// Insert them into pending_outputs so that they do not get deleted.
void DBImpl::AllocateCompactionOutputFileNumbers(CompactionState* compact) {
mutex_.AssertHeld();
assert(compact != nullptr);
assert(compact->builder == nullptr);
int filesNeeded = compact->compaction->num_input_files(1);
for (int i = 0; i < std::max(filesNeeded, 1); i++) {
uint64_t file_number = versions_->NewFileNumber();
pending_outputs_.insert(file_number);
compact->allocated_file_numbers.push_back(file_number);
}
}
// Frees up unused file number.
void DBImpl::ReleaseCompactionUnusedFileNumbers(CompactionState* compact) {
mutex_.AssertHeld();
for (const auto file_number : compact->allocated_file_numbers) {
pending_outputs_.erase(file_number);
}
}
Status DBImpl::OpenCompactionOutputFile(CompactionState* compact) {
assert(compact != nullptr);
assert(compact->builder == nullptr);
uint64_t file_number;
// If we have not yet exhausted the pre-allocated file numbers,
// then use the one from the front. Otherwise, we have to acquire
// the heavyweight lock and allocate a new file number.
if (!compact->allocated_file_numbers.empty()) {
file_number = compact->allocated_file_numbers.front();
compact->allocated_file_numbers.pop_front();
} else {
mutex_.Lock();
file_number = versions_->NewFileNumber();
pending_outputs_.insert(file_number);
mutex_.Unlock();
}
CompactionState::Output out;
out.number = file_number;
out.smallest.Clear();
out.largest.Clear();
out.smallest_seqno = out.largest_seqno = 0;
compact->outputs.push_back(out);
// Make the output file
std::string fname = TableFileName(dbname_, file_number);
Status s = env_->NewWritableFile(fname, &compact->outfile, storage_options_);
if (s.ok()) {
// Over-estimate slightly so we don't end up just barely crossing
// the threshold.
ColumnFamilyData* cfd = compact->compaction->column_family_data();
compact->outfile->SetPreallocationBlockSize(
1.1 * cfd->compaction_picker()->MaxFileSizeForLevel(
compact->compaction->output_level()));
CompressionType compression_type =
GetCompressionType(*cfd->options(), compact->compaction->output_level(),
compact->compaction->enable_compression());
compact->builder.reset(
NewTableBuilder(*cfd->options(), cfd->internal_comparator(),
compact->outfile.get(), compression_type));
}
LogFlush(options_.info_log);
return s;
}
Status DBImpl::FinishCompactionOutputFile(CompactionState* compact,
Iterator* input) {
assert(compact != nullptr);
assert(compact->outfile);
assert(compact->builder != nullptr);
const uint64_t output_number = compact->current_output()->number;
assert(output_number != 0);
// Check for iterator errors
Status s = input->status();
const uint64_t current_entries = compact->builder->NumEntries();
if (s.ok()) {
s = compact->builder->Finish();
} else {
compact->builder->Abandon();
}
const uint64_t current_bytes = compact->builder->FileSize();
compact->current_output()->file_size = current_bytes;
compact->total_bytes += current_bytes;
compact->builder.reset();
// Finish and check for file errors
if (s.ok() && !options_.disableDataSync) {
if (options_.use_fsync) {
StopWatch sw(env_, options_.statistics.get(),
COMPACTION_OUTFILE_SYNC_MICROS, false);
s = compact->outfile->Fsync();
} else {
StopWatch sw(env_, options_.statistics.get(),
COMPACTION_OUTFILE_SYNC_MICROS, false);
s = compact->outfile->Sync();
}
}
if (s.ok()) {
s = compact->outfile->Close();
}
compact->outfile.reset();
if (s.ok() && current_entries > 0) {
// Verify that the table is usable
ColumnFamilyData* cfd = compact->compaction->column_family_data();
FileMetaData meta(output_number, current_bytes);
Iterator* iter = cfd->table_cache()->NewIterator(
ReadOptions(), storage_options_, cfd->internal_comparator(), meta);
s = iter->status();
delete iter;
if (s.ok()) {
Log(options_.info_log, "[%s] Generated table #%lu: %lu keys, %lu bytes",
cfd->GetName().c_str(), (unsigned long)output_number,
(unsigned long)current_entries, (unsigned long)current_bytes);
}
}
return s;
}
Status DBImpl::InstallCompactionResults(CompactionState* compact,
LogBuffer* log_buffer) {
mutex_.AssertHeld();
// paranoia: verify that the files that we started with
// still exist in the current version and in the same original level.
// This ensures that a concurrent compaction did not erroneously
// pick the same files to compact.
if (!versions_->VerifyCompactionFileConsistency(compact->compaction)) {
Log(options_.info_log, "[%s] Compaction %d@%d + %d@%d files aborted",
compact->compaction->column_family_data()->GetName().c_str(),
compact->compaction->num_input_files(0), compact->compaction->level(),
compact->compaction->num_input_files(1),
compact->compaction->output_level());
return Status::Corruption("Compaction input files inconsistent");
}
LogToBuffer(log_buffer, "[%s] Compacted %d@%d + %d@%d files => %lld bytes",
compact->compaction->column_family_data()->GetName().c_str(),
compact->compaction->num_input_files(0),
compact->compaction->level(),
compact->compaction->num_input_files(1),
compact->compaction->output_level(),
static_cast<long long>(compact->total_bytes));
// Add compaction outputs
compact->compaction->AddInputDeletions(compact->compaction->edit());
for (size_t i = 0; i < compact->outputs.size(); i++) {
const CompactionState::Output& out = compact->outputs[i];
compact->compaction->edit()->AddFile(
compact->compaction->output_level(), out.number, out.file_size,
out.smallest, out.largest, out.smallest_seqno, out.largest_seqno);
}
return versions_->LogAndApply(compact->compaction->column_family_data(),
compact->compaction->edit(), &mutex_,
db_directory_.get());
}
// Given a sequence number, return the sequence number of the
// earliest snapshot that this sequence number is visible in.
// The snapshots themselves are arranged in ascending order of
// sequence numbers.
// Employ a sequential search because the total number of
// snapshots are typically small.
inline SequenceNumber DBImpl::findEarliestVisibleSnapshot(
SequenceNumber in, std::vector<SequenceNumber>& snapshots,
SequenceNumber* prev_snapshot) {
if (!IsSnapshotSupported()) {
return 0;
}
SequenceNumber prev __attribute__((unused)) = 0;
for (const auto cur : snapshots) {
assert(prev <= cur);
if (cur >= in) {
*prev_snapshot = prev;
return cur;
}
prev = cur; // assignment
assert(prev);
}
Log(options_.info_log,
"Looking for seqid %lu but maxseqid is %lu",
(unsigned long)in,
(unsigned long)snapshots[snapshots.size()-1]);
assert(0);
return 0;
}
uint64_t DBImpl::CallFlushDuringCompaction(ColumnFamilyData* cfd,
DeletionState& deletion_state,
LogBuffer* log_buffer) {
if (cfd->imm()->imm_flush_needed.NoBarrier_Load() != nullptr) {
const uint64_t imm_start = env_->NowMicros();
mutex_.Lock();
if (cfd->imm()->IsFlushPending()) {
cfd->Ref();
FlushMemTableToOutputFile(cfd, nullptr, deletion_state, log_buffer);
cfd->Unref();
bg_cv_.SignalAll(); // Wakeup MakeRoomForWrite() if necessary
}
mutex_.Unlock();
log_buffer->FlushBufferToLog();
return env_->NowMicros() - imm_start;
}
return 0;
}
Status DBImpl::ProcessKeyValueCompaction(
SequenceNumber visible_at_tip,
SequenceNumber earliest_snapshot,
SequenceNumber latest_snapshot,
DeletionState& deletion_state,
bool bottommost_level,
int64_t& imm_micros,
Iterator* input,
CompactionState* compact,
bool is_compaction_v2,
LogBuffer* log_buffer) {
size_t combined_idx = 0;
Status status;
std::string compaction_filter_value;
ParsedInternalKey ikey;
IterKey current_user_key;
bool has_current_user_key = false;
IterKey delete_key;
SequenceNumber last_sequence_for_key __attribute__((unused)) =
kMaxSequenceNumber;
SequenceNumber visible_in_snapshot = kMaxSequenceNumber;
ColumnFamilyData* cfd = compact->compaction->column_family_data();
MergeHelper merge(
cfd->user_comparator(), cfd->options()->merge_operator.get(),
options_.info_log.get(), cfd->options()->min_partial_merge_operands,
false /* internal key corruption is expected */);
auto compaction_filter = cfd->options()->compaction_filter;
std::unique_ptr<CompactionFilter> compaction_filter_from_factory = nullptr;
if (!compaction_filter) {
auto context = compact->GetFilterContextV1();
compaction_filter_from_factory =
cfd->options()->compaction_filter_factory->CreateCompactionFilter(
context);
compaction_filter = compaction_filter_from_factory.get();
}
while (input->Valid() && !shutting_down_.Acquire_Load() &&
!cfd->IsDropped()) {
// FLUSH preempts compaction
// TODO(icanadi) this currently only checks if flush is necessary on
// compacting column family. we should also check if flush is necessary on
// other column families, too
imm_micros += CallFlushDuringCompaction(cfd, deletion_state, log_buffer);
Slice key;
Slice value;
// If is_compaction_v2 is on, kv-pairs are reset to the prefix batch.
// This prefix batch should contain results after calling
// compaction_filter_v2.
//
// If is_compaction_v2 is off, this function will go through all the
// kv-pairs in input.
if (!is_compaction_v2) {
key = input->key();
value = input->value();
} else {
if (combined_idx >= compact->combined_key_buf_.size()) {
break;
}
assert(combined_idx < compact->combined_key_buf_.size());
key = compact->combined_key_buf_[combined_idx];
value = compact->combined_value_buf_[combined_idx];
++combined_idx;
}
if (compact->compaction->ShouldStopBefore(key) &&
compact->builder != nullptr) {
status = FinishCompactionOutputFile(compact, input);
if (!status.ok()) {
break;
}
}
// Handle key/value, add to state, etc.
bool drop = false;
bool current_entry_is_merging = false;
if (!ParseInternalKey(key, &ikey)) {
// Do not hide error keys
// TODO: error key stays in db forever? Figure out the intention/rationale
// v10 error v8 : we cannot hide v8 even though it's pretty obvious.
current_user_key.Clear();
has_current_user_key = false;
last_sequence_for_key = kMaxSequenceNumber;
visible_in_snapshot = kMaxSequenceNumber;
} else {
if (!has_current_user_key ||
cfd->user_comparator()->Compare(ikey.user_key,
current_user_key.GetKey()) != 0) {
// First occurrence of this user key
current_user_key.SetUserKey(ikey.user_key);
has_current_user_key = true;
last_sequence_for_key = kMaxSequenceNumber;
visible_in_snapshot = kMaxSequenceNumber;
// apply the compaction filter to the first occurrence of the user key
if (compaction_filter && !is_compaction_v2 &&
ikey.type == kTypeValue &&
(visible_at_tip || ikey.sequence > latest_snapshot)) {
// If the user has specified a compaction filter and the sequence
// number is greater than any external snapshot, then invoke the
// filter.
// If the return value of the compaction filter is true, replace
// the entry with a delete marker.
bool value_changed = false;
compaction_filter_value.clear();
bool to_delete = compaction_filter->Filter(
compact->compaction->level(), ikey.user_key, value,
&compaction_filter_value, &value_changed);
if (to_delete) {
// make a copy of the original key and convert it to a delete
delete_key.SetInternalKey(ExtractUserKey(key), ikey.sequence,
kTypeDeletion);
// anchor the key again
key = delete_key.GetKey();
// needed because ikey is backed by key
ParseInternalKey(key, &ikey);
// no value associated with delete
value.clear();
RecordTick(options_.statistics.get(), COMPACTION_KEY_DROP_USER);
} else if (value_changed) {
value = compaction_filter_value;
}
}
}
// If there are no snapshots, then this kv affect visibility at tip.
// Otherwise, search though all existing snapshots to find
// the earlist snapshot that is affected by this kv.
SequenceNumber prev_snapshot = 0; // 0 means no previous snapshot
SequenceNumber visible = visible_at_tip ?
visible_at_tip :
findEarliestVisibleSnapshot(ikey.sequence,
compact->existing_snapshots,
&prev_snapshot);
if (visible_in_snapshot == visible) {
// If the earliest snapshot is which this key is visible in
// is the same as the visibily of a previous instance of the
// same key, then this kv is not visible in any snapshot.
// Hidden by an newer entry for same user key
// TODO: why not > ?
assert(last_sequence_for_key >= ikey.sequence);
drop = true; // (A)
RecordTick(options_.statistics.get(), COMPACTION_KEY_DROP_NEWER_ENTRY);
} else if (ikey.type == kTypeDeletion &&
ikey.sequence <= earliest_snapshot &&
compact->compaction->IsBaseLevelForKey(ikey.user_key)) {
// For this user key:
// (1) there is no data in higher levels
// (2) data in lower levels will have larger sequence numbers
// (3) data in layers that are being compacted here and have
// smaller sequence numbers will be dropped in the next
// few iterations of this loop (by rule (A) above).
// Therefore this deletion marker is obsolete and can be dropped.
drop = true;
RecordTick(options_.statistics.get(), COMPACTION_KEY_DROP_OBSOLETE);
} else if (ikey.type == kTypeMerge) {
// We know the merge type entry is not hidden, otherwise we would
// have hit (A)
// We encapsulate the merge related state machine in a different
// object to minimize change to the existing flow. Turn out this
// logic could also be nicely re-used for memtable flush purge
// optimization in BuildTable.
int steps = 0;
merge.MergeUntil(input, prev_snapshot, bottommost_level,
options_.statistics.get(), &steps);
// Skip the Merge ops
combined_idx = combined_idx - 1 + steps;
current_entry_is_merging = true;
if (merge.IsSuccess()) {
// Successfully found Put/Delete/(end-of-key-range) while merging
// Get the merge result
key = merge.key();
ParseInternalKey(key, &ikey);
value = merge.value();
} else {
// Did not find a Put/Delete/(end-of-key-range) while merging
// We now have some stack of merge operands to write out.
// NOTE: key,value, and ikey are now referring to old entries.
// These will be correctly set below.
assert(!merge.keys().empty());
assert(merge.keys().size() == merge.values().size());
// Hack to make sure last_sequence_for_key is correct
ParseInternalKey(merge.keys().front(), &ikey);
}
}
last_sequence_for_key = ikey.sequence;
visible_in_snapshot = visible;
}
if (!drop) {
// We may write a single key (e.g.: for Put/Delete or successful merge).
// Or we may instead have to write a sequence/list of keys.
// We have to write a sequence iff we have an unsuccessful merge
bool has_merge_list = current_entry_is_merging && !merge.IsSuccess();
const std::deque<std::string>* keys = nullptr;
const std::deque<std::string>* values = nullptr;
std::deque<std::string>::const_reverse_iterator key_iter;
std::deque<std::string>::const_reverse_iterator value_iter;
if (has_merge_list) {
keys = &merge.keys();
values = &merge.values();
key_iter = keys->rbegin(); // The back (*rbegin()) is the first key
value_iter = values->rbegin();
key = Slice(*key_iter);
value = Slice(*value_iter);
}
// If we have a list of keys to write, traverse the list.
// If we have a single key to write, simply write that key.
while (true) {
// Invariant: key,value,ikey will always be the next entry to write
char* kptr = (char*)key.data();
std::string kstr;
// Zeroing out the sequence number leads to better compression.
// If this is the bottommost level (no files in lower levels)
// and the earliest snapshot is larger than this seqno
// then we can squash the seqno to zero.
if (bottommost_level && ikey.sequence < earliest_snapshot &&
ikey.type != kTypeMerge) {
assert(ikey.type != kTypeDeletion);
// make a copy because updating in place would cause problems
// with the priority queue that is managing the input key iterator
kstr.assign(key.data(), key.size());
kptr = (char *)kstr.c_str();
UpdateInternalKey(kptr, key.size(), (uint64_t)0, ikey.type);
}
Slice newkey(kptr, key.size());
assert((key.clear(), 1)); // we do not need 'key' anymore
// Open output file if necessary
if (compact->builder == nullptr) {
status = OpenCompactionOutputFile(compact);
if (!status.ok()) {
break;
}
}
SequenceNumber seqno = GetInternalKeySeqno(newkey);
if (compact->builder->NumEntries() == 0) {
compact->current_output()->smallest.DecodeFrom(newkey);
compact->current_output()->smallest_seqno = seqno;
} else {
compact->current_output()->smallest_seqno =
std::min(compact->current_output()->smallest_seqno, seqno);
}
compact->current_output()->largest.DecodeFrom(newkey);
compact->builder->Add(newkey, value);
compact->current_output()->largest_seqno =
std::max(compact->current_output()->largest_seqno, seqno);
// Close output file if it is big enough
if (compact->builder->FileSize() >=
compact->compaction->MaxOutputFileSize()) {
status = FinishCompactionOutputFile(compact, input);
if (!status.ok()) {
break;
}
}
// If we have a list of entries, move to next element
// If we only had one entry, then break the loop.
if (has_merge_list) {
++key_iter;
++value_iter;
// If at end of list
if (key_iter == keys->rend() || value_iter == values->rend()) {
// Sanity Check: if one ends, then both end
assert(key_iter == keys->rend() && value_iter == values->rend());
break;
}
// Otherwise not at end of list. Update key, value, and ikey.
key = Slice(*key_iter);
value = Slice(*value_iter);
ParseInternalKey(key, &ikey);
} else{
// Only had one item to begin with (Put/Delete)
break;
}
}
}
// MergeUntil has moved input to the next entry
if (!current_entry_is_merging) {
input->Next();
}
}
return status;
}
void DBImpl::CallCompactionFilterV2(CompactionState* compact,
CompactionFilterV2* compaction_filter_v2) {
if (compact == nullptr || compaction_filter_v2 == nullptr) {
return;
}
std::vector<Slice> user_key_buf;
for (const auto& key : compact->ikey_buf_) {
user_key_buf.emplace_back(key.user_key);
}
// If the user has specified a compaction filter and the sequence
// number is greater than any external snapshot, then invoke the
// filter.
// If the return value of the compaction filter is true, replace
// the entry with a delete marker.
compact->to_delete_buf_ = compaction_filter_v2->Filter(
compact->compaction->level(),
user_key_buf, compact->existing_value_buf_,
&compact->new_value_buf_,
&compact->value_changed_buf_);
// new_value_buf_.size() <= to_delete__buf_.size(). "=" iff all
// kv-pairs in this compaction run needs to be deleted.
assert(compact->to_delete_buf_.size() ==
compact->key_buf_.size());
assert(compact->to_delete_buf_.size() ==
compact->existing_value_buf_.size());
assert(compact->to_delete_buf_.size() ==
compact->value_changed_buf_.size());
int new_value_idx = 0;
for (unsigned int i = 0; i < compact->to_delete_buf_.size(); ++i) {
if (compact->to_delete_buf_[i]) {
// update the string buffer directly
// the Slice buffer points to the updated buffer
UpdateInternalKey(&compact->key_str_buf_[i][0],
compact->key_str_buf_[i].size(),
compact->ikey_buf_[i].sequence,
kTypeDeletion);
// no value associated with delete
compact->existing_value_buf_[i].clear();
RecordTick(options_.statistics.get(), COMPACTION_KEY_DROP_USER);
} else if (compact->value_changed_buf_[i]) {
compact->existing_value_buf_[i] =
Slice(compact->new_value_buf_[new_value_idx++]);
}
} // for
}
Status DBImpl::DoCompactionWork(CompactionState* compact,
DeletionState& deletion_state,
LogBuffer* log_buffer) {
assert(compact);
compact->CleanupBatchBuffer();
compact->CleanupMergedBuffer();
bool prefix_initialized = false;
int64_t imm_micros = 0; // Micros spent doing imm_ compactions
ColumnFamilyData* cfd = compact->compaction->column_family_data();
LogToBuffer(
log_buffer,
"[%s] Compacting %d@%d + %d@%d files, score %.2f slots available %d",
cfd->GetName().c_str(), compact->compaction->num_input_files(0),
compact->compaction->level(), compact->compaction->num_input_files(1),
compact->compaction->output_level(), compact->compaction->score(),
options_.max_background_compactions - bg_compaction_scheduled_);
char scratch[2345];
compact->compaction->Summary(scratch, sizeof(scratch));
LogToBuffer(log_buffer, "[%s] Compaction start summary: %s\n",
cfd->GetName().c_str(), scratch);
assert(cfd->current()->NumLevelFiles(compact->compaction->level()) > 0);
assert(compact->builder == nullptr);
assert(!compact->outfile);
SequenceNumber visible_at_tip = 0;
SequenceNumber earliest_snapshot;
SequenceNumber latest_snapshot = 0;
snapshots_.getAll(compact->existing_snapshots);
if (compact->existing_snapshots.size() == 0) {
// optimize for fast path if there are no snapshots
visible_at_tip = versions_->LastSequence();
earliest_snapshot = visible_at_tip;
} else {
latest_snapshot = compact->existing_snapshots.back();
// Add the current seqno as the 'latest' virtual
// snapshot to the end of this list.
compact->existing_snapshots.push_back(versions_->LastSequence());
earliest_snapshot = compact->existing_snapshots[0];
}
// Is this compaction producing files at the bottommost level?
bool bottommost_level = compact->compaction->BottomMostLevel();
// Allocate the output file numbers before we release the lock
AllocateCompactionOutputFileNumbers(compact);
// Release mutex while we're actually doing the compaction work
mutex_.Unlock();
log_buffer->FlushBufferToLog();
const uint64_t start_micros = env_->NowMicros();
unique_ptr<Iterator> input(versions_->MakeInputIterator(compact->compaction));
input->SeekToFirst();
shared_ptr<Iterator> backup_input(
versions_->MakeInputIterator(compact->compaction));
backup_input->SeekToFirst();
Status status;
ParsedInternalKey ikey;
std::unique_ptr<CompactionFilterV2> compaction_filter_from_factory_v2
= nullptr;
auto context = compact->GetFilterContext();
compaction_filter_from_factory_v2 =
cfd->options()->compaction_filter_factory_v2->CreateCompactionFilterV2(
context);
auto compaction_filter_v2 =
compaction_filter_from_factory_v2.get();
// temp_backup_input always point to the start of the current buffer
// temp_backup_input = backup_input;
// iterate through input,
// 1) buffer ineligible keys and value keys into 2 separate buffers;
// 2) send value_buffer to compaction filter and alternate the values;
// 3) merge value_buffer with ineligible_value_buffer;
// 4) run the modified "compaction" using the old for loop.
if (compaction_filter_v2) {
while (backup_input->Valid() && !shutting_down_.Acquire_Load() &&
!cfd->IsDropped()) {
// FLUSH preempts compaction
// TODO(icanadi) this currently only checks if flush is necessary on
// compacting column family. we should also check if flush is necessary on
// other column families, too
imm_micros += CallFlushDuringCompaction(cfd, deletion_state, log_buffer);
Slice key = backup_input->key();
Slice value = backup_input->value();
const SliceTransform* transformer =
cfd->options()->compaction_filter_factory_v2->GetPrefixExtractor();
const auto key_prefix = transformer->Transform(key);
if (!prefix_initialized) {
compact->cur_prefix_ = key_prefix.ToString();
prefix_initialized = true;
}
if (!ParseInternalKey(key, &ikey)) {
// log error
Log(options_.info_log, "[%s] Failed to parse key: %s",
cfd->GetName().c_str(), key.ToString().c_str());
continue;
} else {
// If the prefix remains the same, keep buffering
if (key_prefix.compare(Slice(compact->cur_prefix_)) == 0) {
// Apply the compaction filter V2 to all the kv pairs sharing
// the same prefix
if (ikey.type == kTypeValue &&
(visible_at_tip || ikey.sequence > latest_snapshot)) {
// Buffer all keys sharing the same prefix for CompactionFilterV2
// Iterate through keys to check prefix
compact->BufferKeyValueSlices(key, value);
} else {
// buffer ineligible keys
compact->BufferOtherKeyValueSlices(key, value);
}
backup_input->Next();
continue;
// finish changing values for eligible keys
} else {
// Now prefix changes, this batch is done.
// Call compaction filter on the buffered values to change the value
if (compact->key_buf_.size() > 0) {
CallCompactionFilterV2(compact, compaction_filter_v2);
}
compact->cur_prefix_ = key_prefix.ToString();
}
}
// Merge this batch of data (values + ineligible keys)
compact->MergeKeyValueSliceBuffer(&cfd->internal_comparator());
// Done buffering for the current prefix. Spit it out to disk
// Now just iterate through all the kv-pairs
status = ProcessKeyValueCompaction(
visible_at_tip,
earliest_snapshot,
latest_snapshot,
deletion_state,
bottommost_level,
imm_micros,
input.get(),
compact,
true,
log_buffer);
if (!status.ok()) {
break;
}
// After writing the kv-pairs, we can safely remove the reference
// to the string buffer and clean them up
compact->CleanupBatchBuffer();
compact->CleanupMergedBuffer();
// Buffer the key that triggers the mismatch in prefix
if (ikey.type == kTypeValue &&
(visible_at_tip || ikey.sequence > latest_snapshot)) {
compact->BufferKeyValueSlices(key, value);
} else {
compact->BufferOtherKeyValueSlices(key, value);
}
backup_input->Next();
if (!backup_input->Valid()) {
// If this is the single last value, we need to merge it.
if (compact->key_buf_.size() > 0) {
CallCompactionFilterV2(compact, compaction_filter_v2);
}
compact->MergeKeyValueSliceBuffer(&cfd->internal_comparator());
status = ProcessKeyValueCompaction(
visible_at_tip,
earliest_snapshot,
latest_snapshot,
deletion_state,
bottommost_level,
imm_micros,
input.get(),
compact,
true,
log_buffer);
compact->CleanupBatchBuffer();
compact->CleanupMergedBuffer();
}
} // done processing all prefix batches
// finish the last batch
if (compact->key_buf_.size() > 0) {
CallCompactionFilterV2(compact, compaction_filter_v2);
}
compact->MergeKeyValueSliceBuffer(&cfd->internal_comparator());
status = ProcessKeyValueCompaction(
visible_at_tip,
earliest_snapshot,
latest_snapshot,
deletion_state,
bottommost_level,
imm_micros,
input.get(),
compact,
true,
log_buffer);
} // checking for compaction filter v2
if (!compaction_filter_v2) {
status = ProcessKeyValueCompaction(
visible_at_tip,
earliest_snapshot,
latest_snapshot,
deletion_state,
bottommost_level,
imm_micros,
input.get(),
compact,
false,
log_buffer);
}
if (status.ok() && (shutting_down_.Acquire_Load() || cfd->IsDropped())) {
status = Status::ShutdownInProgress(
"Database shutdown or Column family drop during compaction");
}
if (status.ok() && compact->builder != nullptr) {
status = FinishCompactionOutputFile(compact, input.get());
}
if (status.ok()) {
status = input->status();
}
input.reset();
if (!options_.disableDataSync) {
db_directory_->Fsync();
}
InternalStats::CompactionStats stats;
stats.micros = env_->NowMicros() - start_micros - imm_micros;
MeasureTime(options_.statistics.get(), COMPACTION_TIME, stats.micros);
stats.files_in_leveln = compact->compaction->num_input_files(0);
stats.files_in_levelnp1 = compact->compaction->num_input_files(1);
int num_output_files = compact->outputs.size();
if (compact->builder != nullptr) {
// An error occurred so ignore the last output.
assert(num_output_files > 0);
--num_output_files;
}
stats.files_out_levelnp1 = num_output_files;
for (int i = 0; i < compact->compaction->num_input_files(0); i++) {
stats.bytes_readn += compact->compaction->input(0, i)->file_size;
RecordTick(options_.statistics.get(), COMPACT_READ_BYTES,
compact->compaction->input(0, i)->file_size);
}
for (int i = 0; i < compact->compaction->num_input_files(1); i++) {
stats.bytes_readnp1 += compact->compaction->input(1, i)->file_size;
RecordTick(options_.statistics.get(), COMPACT_READ_BYTES,
compact->compaction->input(1, i)->file_size);
}
for (int i = 0; i < num_output_files; i++) {
stats.bytes_written += compact->outputs[i].file_size;
RecordTick(options_.statistics.get(), COMPACT_WRITE_BYTES,
compact->outputs[i].file_size);
}
LogFlush(options_.info_log);
mutex_.Lock();
cfd->internal_stats()->AddCompactionStats(compact->compaction->output_level(),
stats);
// if there were any unused file number (mostly in case of
// compaction error), free up the entry from pending_putputs
ReleaseCompactionUnusedFileNumbers(compact);
if (status.ok()) {
status = InstallCompactionResults(compact, log_buffer);
InstallSuperVersion(cfd, deletion_state);
}
Version::LevelSummaryStorage tmp;
LogToBuffer(
log_buffer,
"[%s] compacted to: %s, %.1f MB/sec, level %d, files in(%d, %d) out(%d) "
"MB in(%.1f, %.1f) out(%.1f), read-write-amplify(%.1f) "
"write-amplify(%.1f) %s\n",
cfd->GetName().c_str(), cfd->current()->LevelSummary(&tmp),
(stats.bytes_readn + stats.bytes_readnp1 + stats.bytes_written) /
(double)stats.micros,
compact->compaction->output_level(), stats.files_in_leveln,
stats.files_in_levelnp1, stats.files_out_levelnp1,
stats.bytes_readn / 1048576.0, stats.bytes_readnp1 / 1048576.0,
stats.bytes_written / 1048576.0,
(stats.bytes_written + stats.bytes_readnp1 + stats.bytes_readn) /
(double)stats.bytes_readn,
stats.bytes_written / (double)stats.bytes_readn,
status.ToString().c_str());
return status;
}
namespace {
struct IterState {
IterState(DBImpl* db, port::Mutex* mu, SuperVersion* super_version)
: db(db), mu(mu), super_version(super_version) {}
DBImpl* db;
port::Mutex* mu;
SuperVersion* super_version;
};
static void CleanupIteratorState(void* arg1, void* arg2) {
IterState* state = reinterpret_cast<IterState*>(arg1);
if (state->super_version->Unref()) {
DBImpl::DeletionState deletion_state;
state->mu->Lock();
state->super_version->Cleanup();
state->db->FindObsoleteFiles(deletion_state, false, true);
state->mu->Unlock();
delete state->super_version;
if (deletion_state.HaveSomethingToDelete()) {
state->db->PurgeObsoleteFiles(deletion_state);
}
}
delete state;
}
} // namespace
Iterator* DBImpl::NewInternalIterator(const ReadOptions& options,
ColumnFamilyData* cfd,
SuperVersion* super_version) {
std::vector<Iterator*> iterator_list;
// Collect iterator for mutable mem
iterator_list.push_back(super_version->mem->NewIterator(options));
// Collect all needed child iterators for immutable memtables
super_version->imm->AddIterators(options, &iterator_list);
// Collect iterators for files in L0 - Ln
super_version->current->AddIterators(options, storage_options_,
&iterator_list);
Iterator* internal_iter = NewMergingIterator(
&cfd->internal_comparator(), &iterator_list[0], iterator_list.size());
IterState* cleanup = new IterState(this, &mutex_, super_version);
internal_iter->RegisterCleanup(CleanupIteratorState, cleanup, nullptr);
return internal_iter;
}
ColumnFamilyHandle* DBImpl::DefaultColumnFamily() const {
return default_cf_handle_;
}
Status DBImpl::Get(const ReadOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
std::string* value) {
return GetImpl(options, column_family, key, value);
}
// DeletionState gets created and destructed outside of the lock -- we
// use this convinently to:
// * malloc one SuperVersion() outside of the lock -- new_superversion
// * delete SuperVersion()s outside of the lock -- superversions_to_free
//
// However, if InstallSuperVersion() gets called twice with the same,
// deletion_state, we can't reuse the SuperVersion() that got malloced because
// first call already used it. In that rare case, we take a hit and create a
// new SuperVersion() inside of the mutex. We do similar thing
// for superversion_to_free
void DBImpl::InstallSuperVersion(ColumnFamilyData* cfd,
DeletionState& deletion_state) {
mutex_.AssertHeld();
// if new_superversion == nullptr, it means somebody already used it
SuperVersion* new_superversion =
(deletion_state.new_superversion != nullptr) ?
deletion_state.new_superversion : new SuperVersion();
SuperVersion* old_superversion =
cfd->InstallSuperVersion(new_superversion, &mutex_);
deletion_state.new_superversion = nullptr;
deletion_state.superversions_to_free.push_back(old_superversion);
}
Status DBImpl::GetImpl(const ReadOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
std::string* value, bool* value_found) {
StopWatch sw(env_, options_.statistics.get(), DB_GET, false);
PERF_TIMER_AUTO(get_snapshot_time);
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
auto cfd = cfh->cfd();
SequenceNumber snapshot;
if (options.snapshot != nullptr) {
snapshot = reinterpret_cast<const SnapshotImpl*>(options.snapshot)->number_;
} else {
snapshot = versions_->LastSequence();
}
// Acquire SuperVersion
SuperVersion* sv = nullptr;
// TODO(ljin): consider using GetReferencedSuperVersion() directly
if (LIKELY(options_.allow_thread_local)) {
sv = cfd->GetThreadLocalSuperVersion(&mutex_);
} else {
mutex_.Lock();
sv = cfd->GetSuperVersion()->Ref();
mutex_.Unlock();
}
bool have_stat_update = false;
Version::GetStats stats;
// Prepare to store a list of merge operations if merge occurs.
MergeContext merge_context;
Status s;
// First look in the memtable, then in the immutable memtable (if any).
// s is both in/out. When in, s could either be OK or MergeInProgress.
// merge_operands will contain the sequence of merges in the latter case.
LookupKey lkey(key, snapshot);
PERF_TIMER_STOP(get_snapshot_time);
if (sv->mem->Get(lkey, value, &s, merge_context, *cfd->options())) {
// Done
RecordTick(options_.statistics.get(), MEMTABLE_HIT);
} else if (sv->imm->Get(lkey, value, &s, merge_context, *cfd->options())) {
// Done
RecordTick(options_.statistics.get(), MEMTABLE_HIT);
} else {
PERF_TIMER_START(get_from_output_files_time);
sv->current->Get(options, lkey, value, &s, &merge_context, &stats,
value_found);
have_stat_update = true;
PERF_TIMER_STOP(get_from_output_files_time);
RecordTick(options_.statistics.get(), MEMTABLE_MISS);
}
PERF_TIMER_START(get_post_process_time);
if (!cfd->options()->disable_seek_compaction && have_stat_update) {
mutex_.Lock();
if (sv->current->UpdateStats(stats)) {
MaybeScheduleFlushOrCompaction();
}
mutex_.Unlock();
}
bool unref_sv = true;
if (LIKELY(options_.allow_thread_local)) {
unref_sv = !cfd->ReturnThreadLocalSuperVersion(sv);
}
if (unref_sv) {
// Release SuperVersion
if (sv->Unref()) {
mutex_.Lock();
sv->Cleanup();
mutex_.Unlock();
delete sv;
RecordTick(options_.statistics.get(), NUMBER_SUPERVERSION_CLEANUPS);
}
RecordTick(options_.statistics.get(), NUMBER_SUPERVERSION_RELEASES);
}
RecordTick(options_.statistics.get(), NUMBER_KEYS_READ);
RecordTick(options_.statistics.get(), BYTES_READ, value->size());
PERF_TIMER_STOP(get_post_process_time);
return s;
}
std::vector<Status> DBImpl::MultiGet(
const ReadOptions& options,
const std::vector<ColumnFamilyHandle*>& column_family,
const std::vector<Slice>& keys, std::vector<std::string>* values) {
StopWatch sw(env_, options_.statistics.get(), DB_MULTIGET, false);
PERF_TIMER_AUTO(get_snapshot_time);
SequenceNumber snapshot;
struct MultiGetColumnFamilyData {
ColumnFamilyData* cfd;
SuperVersion* super_version;
Version::GetStats stats;
bool have_stat_update = false;
};
std::unordered_map<uint32_t, MultiGetColumnFamilyData*> multiget_cf_data;
// fill up and allocate outside of mutex
for (auto cf : column_family) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(cf);
auto cfd = cfh->cfd();
if (multiget_cf_data.find(cfd->GetID()) == multiget_cf_data.end()) {
auto mgcfd = new MultiGetColumnFamilyData();
mgcfd->cfd = cfd;
multiget_cf_data.insert({cfd->GetID(), mgcfd});
}
}
mutex_.Lock();
if (options.snapshot != nullptr) {
snapshot = reinterpret_cast<const SnapshotImpl*>(options.snapshot)->number_;
} else {
snapshot = versions_->LastSequence();
}
for (auto mgd_iter : multiget_cf_data) {
mgd_iter.second->super_version =
mgd_iter.second->cfd->GetSuperVersion()->Ref();
}
mutex_.Unlock();
// Contain a list of merge operations if merge occurs.
MergeContext merge_context;
// Note: this always resizes the values array
size_t num_keys = keys.size();
std::vector<Status> stat_list(num_keys);
values->resize(num_keys);
// Keep track of bytes that we read for statistics-recording later
uint64_t bytes_read = 0;
PERF_TIMER_STOP(get_snapshot_time);
// For each of the given keys, apply the entire "get" process as follows:
// First look in the memtable, then in the immutable memtable (if any).
// s is both in/out. When in, s could either be OK or MergeInProgress.
// merge_operands will contain the sequence of merges in the latter case.
for (size_t i = 0; i < num_keys; ++i) {
merge_context.Clear();
Status& s = stat_list[i];
std::string* value = &(*values)[i];
LookupKey lkey(keys[i], snapshot);
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family[i]);
auto mgd_iter = multiget_cf_data.find(cfh->cfd()->GetID());
assert(mgd_iter != multiget_cf_data.end());
auto mgd = mgd_iter->second;
auto super_version = mgd->super_version;
auto cfd = mgd->cfd;
if (super_version->mem->Get(lkey, value, &s, merge_context,
*cfd->options())) {
// Done
} else if (super_version->imm->Get(lkey, value, &s, merge_context,
*cfd->options())) {
// Done
} else {
super_version->current->Get(options, lkey, value, &s, &merge_context,
&mgd->stats);
mgd->have_stat_update = true;
}
if (s.ok()) {
bytes_read += value->size();
}
}
// Post processing (decrement reference counts and record statistics)
PERF_TIMER_START(get_post_process_time);
autovector<SuperVersion*> superversions_to_delete;
bool schedule_flush_or_compaction = false;
mutex_.Lock();
for (auto mgd_iter : multiget_cf_data) {
auto mgd = mgd_iter.second;
auto cfd = mgd->cfd;
if (!cfd->options()->disable_seek_compaction && mgd->have_stat_update) {
if (mgd->super_version->current->UpdateStats(mgd->stats)) {
schedule_flush_or_compaction = true;
}
}
if (mgd->super_version->Unref()) {
mgd->super_version->Cleanup();
superversions_to_delete.push_back(mgd->super_version);
}
}
if (schedule_flush_or_compaction) {
MaybeScheduleFlushOrCompaction();
}
mutex_.Unlock();
for (auto td : superversions_to_delete) {
delete td;
}
for (auto mgd : multiget_cf_data) {
delete mgd.second;
}
RecordTick(options_.statistics.get(), NUMBER_MULTIGET_CALLS);
RecordTick(options_.statistics.get(), NUMBER_MULTIGET_KEYS_READ, num_keys);
RecordTick(options_.statistics.get(), NUMBER_MULTIGET_BYTES_READ, bytes_read);
PERF_TIMER_STOP(get_post_process_time);
return stat_list;
}
Status DBImpl::CreateColumnFamily(const ColumnFamilyOptions& options,
const std::string& column_family_name,
ColumnFamilyHandle** handle) {
*handle = nullptr;
MutexLock l(&mutex_);
if (versions_->GetColumnFamilySet()->GetColumnFamily(column_family_name) !=
nullptr) {
return Status::InvalidArgument("Column family already exists");
}
VersionEdit edit;
edit.AddColumnFamily(column_family_name);
uint32_t new_id = versions_->GetColumnFamilySet()->GetNextColumnFamilyID();
edit.SetColumnFamily(new_id);
edit.SetLogNumber(logfile_number_);
edit.SetComparatorName(options.comparator->Name());
// LogAndApply will both write the creation in MANIFEST and create
// ColumnFamilyData object
Status s = versions_->LogAndApply(nullptr, &edit, &mutex_,
db_directory_.get(), false, &options);
if (s.ok()) {
auto cfd =
versions_->GetColumnFamilySet()->GetColumnFamily(column_family_name);
assert(cfd != nullptr);
delete cfd->InstallSuperVersion(new SuperVersion(), &mutex_);
*handle = new ColumnFamilyHandleImpl(cfd, this, &mutex_);
Log(options_.info_log, "Created column family [%s] (ID %u)",
column_family_name.c_str(), (unsigned)cfd->GetID());
max_total_in_memory_state_ += cfd->options()->write_buffer_size *
cfd->options()->max_write_buffer_number;
} else {
Log(options_.info_log, "Creating column family [%s] FAILED -- %s",
column_family_name.c_str(), s.ToString().c_str());
}
return s;
}
Status DBImpl::DropColumnFamily(ColumnFamilyHandle* column_family) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
auto cfd = cfh->cfd();
if (cfd->GetID() == 0) {
return Status::InvalidArgument("Can't drop default column family");
}
VersionEdit edit;
edit.DropColumnFamily();
edit.SetColumnFamily(cfd->GetID());
Status s;
{
MutexLock l(&mutex_);
if (cfd->IsDropped()) {
s = Status::InvalidArgument("Column family already dropped!\n");
}
if (s.ok()) {
s = versions_->LogAndApply(cfd, &edit, &mutex_);
}
}
if (s.ok()) {
assert(cfd->IsDropped());
max_total_in_memory_state_ -= cfd->options()->write_buffer_size *
cfd->options()->max_write_buffer_number;
Log(options_.info_log, "Dropped column family with id %u\n", cfd->GetID());
// Flush the memtables. This will make all WAL files referencing dropped
// column family to be obsolete. They will be deleted once user deletes
// column family handle
Write(WriteOptions(), nullptr); // ignore error
} else {
Log(options_.info_log, "Dropping column family with id %u FAILED -- %s\n",
cfd->GetID(), s.ToString().c_str());
}
return s;
}
bool DBImpl::KeyMayExist(const ReadOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
std::string* value, bool* value_found) {
if (value_found != nullptr) {
// falsify later if key-may-exist but can't fetch value
*value_found = true;
}
ReadOptions roptions = options;
roptions.read_tier = kBlockCacheTier; // read from block cache only
auto s = GetImpl(roptions, column_family, key, value, value_found);
// If options.block_cache != nullptr and the index block of the table didn't
// not present in block_cache, the return value will be Status::Incomplete.
// In this case, key may still exist in the table.
return s.ok() || s.IsIncomplete();
}
Iterator* DBImpl::NewIterator(const ReadOptions& options,
ColumnFamilyHandle* column_family) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
auto cfd = cfh->cfd();
Iterator* iter;
if (options.tailing) {
#ifdef ROCKSDB_LITE
// not supported in lite version
return nullptr;
#else
iter = new TailingIterator(env_, this, options, cfd);
#endif
} else {
SequenceNumber latest_snapshot = versions_->LastSequence();
SuperVersion* sv = nullptr;
sv = cfd->GetReferencedSuperVersion(&mutex_);
iter = NewInternalIterator(options, cfd, sv);
auto snapshot =
options.snapshot != nullptr
? reinterpret_cast<const SnapshotImpl*>(options.snapshot)->number_
: latest_snapshot;
iter = NewDBIterator(env_, *cfd->options(),
cfd->user_comparator(), iter, snapshot);
}
return iter;
}
Status DBImpl::NewIterators(
const ReadOptions& options,
const std::vector<ColumnFamilyHandle*>& column_families,
std::vector<Iterator*>* iterators) {
iterators->clear();
iterators->reserve(column_families.size());
SequenceNumber latest_snapshot = 0;
std::vector<SuperVersion*> super_versions;
super_versions.reserve(column_families.size());
if (!options.tailing) {
mutex_.Lock();
latest_snapshot = versions_->LastSequence();
for (auto cfh : column_families) {
auto cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(cfh)->cfd();
super_versions.push_back(cfd->GetSuperVersion()->Ref());
}
mutex_.Unlock();
}
if (options.tailing) {
#ifdef ROCKSDB_LITE
return Status::InvalidArgument(
"Tailing interator not supported in RocksDB lite");
#else
for (auto cfh : column_families) {
auto cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(cfh)->cfd();
iterators->push_back(new TailingIterator(env_, this, options, cfd));
}
#endif
} else {
for (size_t i = 0; i < column_families.size(); ++i) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_families[i]);
auto cfd = cfh->cfd();
auto snapshot =
options.snapshot != nullptr
? reinterpret_cast<const SnapshotImpl*>(options.snapshot)->number_
: latest_snapshot;
auto iter = NewInternalIterator(options, cfd, super_versions[i]);
iter = NewDBIterator(env_, *cfd->options(),
cfd->user_comparator(), iter, snapshot);
iterators->push_back(iter);
}
}
return Status::OK();
}
bool DBImpl::IsSnapshotSupported() const {
for (auto cfd : *versions_->GetColumnFamilySet()) {
if (!cfd->mem()->IsSnapshotSupported()) {
return false;
}
}
return true;
}
const Snapshot* DBImpl::GetSnapshot() {
// returns null if the underlying memtable does not support snapshot.
if (!IsSnapshotSupported()) return nullptr;
MutexLock l(&mutex_);
return snapshots_.New(versions_->LastSequence());
}
void DBImpl::ReleaseSnapshot(const Snapshot* s) {
MutexLock l(&mutex_);
snapshots_.Delete(reinterpret_cast<const SnapshotImpl*>(s));
}
// Convenience methods
Status DBImpl::Put(const WriteOptions& o, ColumnFamilyHandle* column_family,
const Slice& key, const Slice& val) {
return DB::Put(o, column_family, key, val);
}
Status DBImpl::Merge(const WriteOptions& o, ColumnFamilyHandle* column_family,
const Slice& key, const Slice& val) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
if (!cfh->cfd()->options()->merge_operator) {
return Status::NotSupported("Provide a merge_operator when opening DB");
} else {
return DB::Merge(o, column_family, key, val);
}
}
Status DBImpl::Delete(const WriteOptions& options,
ColumnFamilyHandle* column_family, const Slice& key) {
return DB::Delete(options, column_family, key);
}
Status DBImpl::Write(const WriteOptions& options, WriteBatch* my_batch) {
PERF_TIMER_AUTO(write_pre_and_post_process_time);
Writer w(&mutex_);
w.batch = my_batch;
w.sync = options.sync;
w.disableWAL = options.disableWAL;
w.done = false;
StopWatch sw(env_, options_.statistics.get(), DB_WRITE, false);
mutex_.Lock();
writers_.push_back(&w);
while (!w.done && &w != writers_.front()) {
w.cv.Wait();
}
if (!options.disableWAL) {
RecordTick(options_.statistics.get(), WRITE_WITH_WAL, 1);
}
if (w.done) {
mutex_.Unlock();
RecordTick(options_.statistics.get(), WRITE_DONE_BY_OTHER, 1);
return w.status;
} else {
RecordTick(options_.statistics.get(), WRITE_DONE_BY_SELF, 1);
}
uint64_t flush_column_family_if_log_file = 0;
uint64_t max_total_wal_size = (options_.max_total_wal_size == 0)
? 2 * max_total_in_memory_state_
: options_.max_total_wal_size;
if (alive_log_files_.begin()->getting_flushed == false &&
total_log_size_ > max_total_wal_size) {
flush_column_family_if_log_file = alive_log_files_.begin()->number;
alive_log_files_.begin()->getting_flushed = true;
Log(options_.info_log,
"Flushing all column families with data in WAL number %" PRIu64,
flush_column_family_if_log_file);
}
Status status;
// refcounting cfd in iteration
bool dead_cfd = false;
autovector<SuperVersion*> superversions_to_free;
autovector<log::Writer*> logs_to_free;
for (auto cfd : *versions_->GetColumnFamilySet()) {
cfd->Ref();
bool force_flush = my_batch == nullptr ||
(flush_column_family_if_log_file != 0 &&
cfd->GetLogNumber() <= flush_column_family_if_log_file);
// May temporarily unlock and wait.
status = MakeRoomForWrite(cfd, force_flush, &superversions_to_free,
&logs_to_free);
if (cfd->Unref()) {
dead_cfd = true;
}
if (!status.ok()) {
break;
}
}
if (dead_cfd) {
versions_->GetColumnFamilySet()->FreeDeadColumnFamilies();
}
uint64_t last_sequence = versions_->LastSequence();
Writer* last_writer = &w;
if (status.ok() && my_batch != nullptr) { // nullptr batch is for compactions
autovector<WriteBatch*> write_batch_group;
BuildBatchGroup(&last_writer, &write_batch_group);
// Add to log and apply to memtable. We can release the lock
// during this phase since &w is currently responsible for logging
// and protects against concurrent loggers and concurrent writes
// into memtables
{
mutex_.Unlock();
WriteBatch* updates = nullptr;
if (write_batch_group.size() == 1) {
updates = write_batch_group[0];
} else {
updates = &tmp_batch_;
for (size_t i = 0; i < write_batch_group.size(); ++i) {
WriteBatchInternal::Append(updates, write_batch_group[i]);
}
}
const SequenceNumber current_sequence = last_sequence + 1;
WriteBatchInternal::SetSequence(updates, current_sequence);
int my_batch_count = WriteBatchInternal::Count(updates);
last_sequence += my_batch_count;
// Record statistics
RecordTick(options_.statistics.get(),
NUMBER_KEYS_WRITTEN, my_batch_count);
RecordTick(options_.statistics.get(),
BYTES_WRITTEN,
WriteBatchInternal::ByteSize(updates));
if (options.disableWAL) {
flush_on_destroy_ = true;
}
PERF_TIMER_STOP(write_pre_and_post_process_time);
if (!options.disableWAL) {
PERF_TIMER_START(write_wal_time);
Slice log_entry = WriteBatchInternal::Contents(updates);
status = log_->AddRecord(log_entry);
total_log_size_ += log_entry.size();
alive_log_files_.back().AddSize(log_entry.size());
log_empty_ = false;
RecordTick(options_.statistics.get(), WAL_FILE_SYNCED, 1);
RecordTick(options_.statistics.get(), WAL_FILE_BYTES, log_entry.size());
if (status.ok() && options.sync) {
if (options_.use_fsync) {
StopWatch(env_, options_.statistics.get(), WAL_FILE_SYNC_MICROS);
status = log_->file()->Fsync();
} else {
StopWatch(env_, options_.statistics.get(), WAL_FILE_SYNC_MICROS);
status = log_->file()->Sync();
}
}
PERF_TIMER_STOP(write_wal_time);
}
if (status.ok()) {
PERF_TIMER_START(write_memtable_time);
status = WriteBatchInternal::InsertInto(
updates, column_family_memtables_.get(), false, 0, this, false);
PERF_TIMER_STOP(write_memtable_time);
if (!status.ok()) {
// Iteration failed (either in-memory writebatch corruption (very
// bad), or the client specified invalid column family). Return
// failure.
// Note that existing logic was not sound. Any partial failure writing
// into the memtable would result in a state that some write ops might
// have succeeded in memtable but Status reports error for all writes.
return status;
}
SetTickerCount(options_.statistics.get(), SEQUENCE_NUMBER,
last_sequence);
}
PERF_TIMER_START(write_pre_and_post_process_time);
if (updates == &tmp_batch_) tmp_batch_.Clear();
mutex_.Lock();
if (status.ok()) {
versions_->SetLastSequence(last_sequence);
}
}
}
if (options_.paranoid_checks && !status.ok() && bg_error_.ok()) {
bg_error_ = status; // stop compaction & fail any further writes
}
while (true) {
Writer* ready = writers_.front();
writers_.pop_front();
if (ready != &w) {
ready->status = status;
ready->done = true;
ready->cv.Signal();
}
if (ready == last_writer) break;
}
// Notify new head of write queue
if (!writers_.empty()) {
writers_.front()->cv.Signal();
}
mutex_.Unlock();
for (auto& sv : superversions_to_free) {
delete sv;
}
for (auto& log : logs_to_free) {
delete log;
}
PERF_TIMER_STOP(write_pre_and_post_process_time);
return status;
}
// REQUIRES: Writer list must be non-empty
// REQUIRES: First writer must have a non-nullptr batch
void DBImpl::BuildBatchGroup(Writer** last_writer,
autovector<WriteBatch*>* write_batch_group) {
assert(!writers_.empty());
Writer* first = writers_.front();
assert(first->batch != nullptr);
size_t size = WriteBatchInternal::ByteSize(first->batch);
write_batch_group->push_back(first->batch);
// Allow the group to grow up to a maximum size, but if the
// original write is small, limit the growth so we do not slow
// down the small write too much.
size_t max_size = 1 << 20;
if (size <= (128<<10)) {
max_size = size + (128<<10);
}
*last_writer = first;
std::deque<Writer*>::iterator iter = writers_.begin();
++iter; // Advance past "first"
for (; iter != writers_.end(); ++iter) {
Writer* w = *iter;
if (w->sync && !first->sync) {
// Do not include a sync write into a batch handled by a non-sync write.
break;
}
if (!w->disableWAL && first->disableWAL) {
// Do not include a write that needs WAL into a batch that has
// WAL disabled.
break;
}
if (w->batch != nullptr) {
size += WriteBatchInternal::ByteSize(w->batch);
if (size > max_size) {
// Do not make batch too big
break;
}
write_batch_group->push_back(w->batch);
}
*last_writer = w;
}
}
// This function computes the amount of time in microseconds by which a write
// should be delayed based on the number of level-0 files according to the
// following formula:
// if n < bottom, return 0;
// if n >= top, return 1000;
// otherwise, let r = (n - bottom) /
// (top - bottom)
// and return r^2 * 1000.
// The goal of this formula is to gradually increase the rate at which writes
// are slowed. We also tried linear delay (r * 1000), but it seemed to do
// slightly worse. There is no other particular reason for choosing quadratic.
uint64_t DBImpl::SlowdownAmount(int n, double bottom, double top) {
uint64_t delay;
if (n >= top) {
delay = 1000;
}
else if (n < bottom) {
delay = 0;
}
else {
// If we are here, we know that:
// level0_start_slowdown <= n < level0_slowdown
// since the previous two conditions are false.
double how_much =
(double) (n - bottom) /
(top - bottom);
delay = std::max(how_much * how_much * 1000, 100.0);
}
assert(delay <= 1000);
return delay;
}
// REQUIRES: mutex_ is held
// REQUIRES: this thread is currently at the front of the writer queue
Status DBImpl::MakeRoomForWrite(
ColumnFamilyData* cfd, bool force,
autovector<SuperVersion*>* superversions_to_free,
autovector<log::Writer*>* logs_to_free) {
mutex_.AssertHeld();
assert(!writers_.empty());
bool allow_delay = !force;
bool allow_hard_rate_limit_delay = !force;
bool allow_soft_rate_limit_delay = !force;
uint64_t rate_limit_delay_millis = 0;
Status s;
double score;
while (true) {
if (!bg_error_.ok()) {
// Yield previous error
s = bg_error_;
break;
} else if (allow_delay && cfd->NeedSlowdownForNumLevel0Files()) {
// We are getting close to hitting a hard limit on the number of
// L0 files. Rather than delaying a single write by several
// seconds when we hit the hard limit, start delaying each
// individual write by 0-1ms to reduce latency variance. Also,
// this delay hands over some CPU to the compaction thread in
// case it is sharing the same core as the writer.
uint64_t slowdown =
SlowdownAmount(cfd->current()->NumLevelFiles(0),
cfd->options()->level0_slowdown_writes_trigger,
cfd->options()->level0_stop_writes_trigger);
mutex_.Unlock();
uint64_t delayed;
{
StopWatch sw(env_, options_.statistics.get(), STALL_L0_SLOWDOWN_COUNT);
env_->SleepForMicroseconds(slowdown);
delayed = sw.ElapsedMicros();
}
RecordTick(options_.statistics.get(), STALL_L0_SLOWDOWN_MICROS, delayed);
cfd->internal_stats()->RecordWriteStall(InternalStats::LEVEL0_SLOWDOWN,
delayed);
allow_delay = false; // Do not delay a single write more than once
mutex_.Lock();
delayed_writes_++;
} else if (!force && !cfd->mem()->ShouldFlush()) {
// There is room in current memtable
if (allow_delay) {
DelayLoggingAndReset();
}
break;
} else if (cfd->imm()->size() ==
cfd->options()->max_write_buffer_number - 1) {
// We have filled up the current memtable, but the previous
// ones are still being flushed, so we wait.
DelayLoggingAndReset();
Log(options_.info_log, "[%s] wait for memtable flush...\n",
cfd->GetName().c_str());
MaybeScheduleFlushOrCompaction();
uint64_t stall;
{
StopWatch sw(env_, options_.statistics.get(),
STALL_MEMTABLE_COMPACTION_COUNT);
bg_cv_.Wait();
stall = sw.ElapsedMicros();
}
RecordTick(options_.statistics.get(),
STALL_MEMTABLE_COMPACTION_MICROS, stall);
cfd->internal_stats()->RecordWriteStall(
InternalStats::MEMTABLE_COMPACTION, stall);
} else if (cfd->current()->NumLevelFiles(0) >=
cfd->options()->level0_stop_writes_trigger) {
// There are too many level-0 files.
DelayLoggingAndReset();
Log(options_.info_log, "[%s] wait for fewer level0 files...\n",
cfd->GetName().c_str());
uint64_t stall;
{
StopWatch sw(env_, options_.statistics.get(),
STALL_L0_NUM_FILES_COUNT);
bg_cv_.Wait();
stall = sw.ElapsedMicros();
}
RecordTick(options_.statistics.get(), STALL_L0_NUM_FILES_MICROS, stall);
cfd->internal_stats()->RecordWriteStall(InternalStats::LEVEL0_NUM_FILES,
stall);
} else if (allow_hard_rate_limit_delay &&
cfd->options()->hard_rate_limit > 1.0 &&
(score = cfd->current()->MaxCompactionScore()) >
cfd->options()->hard_rate_limit) {
// Delay a write when the compaction score for any level is too large.
int max_level = cfd->current()->MaxCompactionScoreLevel();
mutex_.Unlock();
uint64_t delayed;
{
StopWatch sw(env_, options_.statistics.get(),
HARD_RATE_LIMIT_DELAY_COUNT);
env_->SleepForMicroseconds(1000);
delayed = sw.ElapsedMicros();
}
cfd->internal_stats()->RecordLevelNSlowdown(max_level, delayed);
// Make sure the following value doesn't round to zero.
uint64_t rate_limit = std::max((delayed / 1000), (uint64_t) 1);
rate_limit_delay_millis += rate_limit;
RecordTick(options_.statistics.get(),
RATE_LIMIT_DELAY_MILLIS, rate_limit);
if (cfd->options()->rate_limit_delay_max_milliseconds > 0 &&
rate_limit_delay_millis >=
(unsigned)cfd->options()->rate_limit_delay_max_milliseconds) {
allow_hard_rate_limit_delay = false;
}
mutex_.Lock();
} else if (allow_soft_rate_limit_delay &&
cfd->options()->soft_rate_limit > 0.0 &&
(score = cfd->current()->MaxCompactionScore()) >
cfd->options()->soft_rate_limit) {
// Delay a write when the compaction score for any level is too large.
// TODO: add statistics
mutex_.Unlock();
{
StopWatch sw(env_, options_.statistics.get(),
SOFT_RATE_LIMIT_DELAY_COUNT);
env_->SleepForMicroseconds(
SlowdownAmount(score, cfd->options()->soft_rate_limit,
cfd->options()->hard_rate_limit));
rate_limit_delay_millis += sw.ElapsedMicros();
}
allow_soft_rate_limit_delay = false;
mutex_.Lock();
} else {
unique_ptr<WritableFile> lfile;
log::Writer* new_log = nullptr;
MemTable* new_mem = nullptr;
// Attempt to switch to a new memtable and trigger flush of old.
// Do this without holding the dbmutex lock.
assert(versions_->PrevLogNumber() == 0);
bool creating_new_log = !log_empty_;
uint64_t new_log_number =
creating_new_log ? versions_->NewFileNumber() : logfile_number_;
SuperVersion* new_superversion = nullptr;
mutex_.Unlock();
{
DelayLoggingAndReset();
if (creating_new_log) {
s = env_->NewWritableFile(
LogFileName(options_.wal_dir, new_log_number), &lfile,
env_->OptimizeForLogWrite(storage_options_));
if (s.ok()) {
// Our final size should be less than write_buffer_size
// (compression, etc) but err on the side of caution.
lfile->SetPreallocationBlockSize(1.1 *
cfd->options()->write_buffer_size);
new_log = new log::Writer(std::move(lfile));
}
}
if (s.ok()) {
new_mem = new MemTable(cfd->internal_comparator(), *cfd->options());
new_superversion = new SuperVersion();
}
}
mutex_.Lock();
if (!s.ok()) {
// how do we fail if we're not creating new log?
assert(creating_new_log);
// Avoid chewing through file number space in a tight loop.
versions_->ReuseFileNumber(new_log_number);
assert(!new_mem);
assert(!new_log);
break;
}
if (creating_new_log) {
logfile_number_ = new_log_number;
assert(new_log != nullptr);
logs_to_free->push_back(log_.release());
log_.reset(new_log);
log_empty_ = true;
alive_log_files_.push_back(LogFileNumberSize(logfile_number_));
for (auto cfd : *versions_->GetColumnFamilySet()) {
// all this is just optimization to delete logs that
// are no longer needed -- if CF is empty, that means it
// doesn't need that particular log to stay alive, so we just
// advance the log number. no need to persist this in the manifest
if (cfd->mem()->GetFirstSequenceNumber() == 0 &&
cfd->imm()->size() == 0) {
cfd->SetLogNumber(logfile_number_);
}
}
}
cfd->mem()->SetNextLogNumber(logfile_number_);
cfd->imm()->Add(cfd->mem());
if (force) {
cfd->imm()->FlushRequested();
}
new_mem->Ref();
cfd->SetMemtable(new_mem);
Log(options_.info_log, "[%s] New memtable created with log file: #%lu\n",
cfd->GetName().c_str(), (unsigned long)logfile_number_);
force = false; // Do not force another compaction if have room
MaybeScheduleFlushOrCompaction();
superversions_to_free->push_back(
cfd->InstallSuperVersion(new_superversion, &mutex_));
}
}
return s;
}
#ifndef ROCKSDB_LITE
Status DBImpl::GetPropertiesOfAllTables(ColumnFamilyHandle* column_family,
TablePropertiesCollection* props) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
auto cfd = cfh->cfd();
// Increment the ref count
mutex_.Lock();
auto version = cfd->current();
version->Ref();
mutex_.Unlock();
auto s = version->GetPropertiesOfAllTables(props);
// Decrement the ref count
mutex_.Lock();
version->Unref();
mutex_.Unlock();
return s;
}
#endif // ROCKSDB_LITE
const std::string& DBImpl::GetName() const {
return dbname_;
}
Env* DBImpl::GetEnv() const {
return env_;
}
const Options& DBImpl::GetOptions(ColumnFamilyHandle* column_family) const {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
return *cfh->cfd()->options();
}
bool DBImpl::GetProperty(ColumnFamilyHandle* column_family,
const Slice& property, std::string* value) {
value->clear();
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
auto cfd = cfh->cfd();
DBPropertyType property_type = GetPropertyType(property);
MutexLock l(&mutex_);
return cfd->internal_stats()->GetProperty(property_type, property, value,
cfd);
}
void DBImpl::GetApproximateSizes(ColumnFamilyHandle* column_family,
const Range* range, int n, uint64_t* sizes) {
// TODO(opt): better implementation
Version* v;
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
auto cfd = cfh->cfd();
{
MutexLock l(&mutex_);
v = cfd->current();
v->Ref();
}
for (int i = 0; i < n; i++) {
// Convert user_key into a corresponding internal key.
InternalKey k1(range[i].start, kMaxSequenceNumber, kValueTypeForSeek);
InternalKey k2(range[i].limit, kMaxSequenceNumber, kValueTypeForSeek);
uint64_t start = versions_->ApproximateOffsetOf(v, k1);
uint64_t limit = versions_->ApproximateOffsetOf(v, k2);
sizes[i] = (limit >= start ? limit - start : 0);
}
{
MutexLock l(&mutex_);
v->Unref();
}
}
inline void DBImpl::DelayLoggingAndReset() {
if (delayed_writes_ > 0) {
Log(options_.info_log, "delayed %d write...\n", delayed_writes_ );
delayed_writes_ = 0;
}
}
#ifndef ROCKSDB_LITE
Status DBImpl::GetUpdatesSince(
SequenceNumber seq, unique_ptr<TransactionLogIterator>* iter,
const TransactionLogIterator::ReadOptions& read_options) {
RecordTick(options_.statistics.get(), GET_UPDATES_SINCE_CALLS);
if (seq > versions_->LastSequence()) {
return Status::NotFound("Requested sequence not yet written in the db");
}
// Get all sorted Wal Files.
// Do binary search and open files and find the seq number.
std::unique_ptr<VectorLogPtr> wal_files(new VectorLogPtr);
Status s = GetSortedWalFiles(*wal_files);
if (!s.ok()) {
return s;
}
s = RetainProbableWalFiles(*wal_files, seq);
if (!s.ok()) {
return s;
}
iter->reset(new TransactionLogIteratorImpl(options_.wal_dir, &options_,
read_options, storage_options_,
seq, std::move(wal_files), this));
return (*iter)->status();
}
Status DBImpl::DeleteFile(std::string name) {
uint64_t number;
FileType type;
WalFileType log_type;
if (!ParseFileName(name, &number, &type, &log_type) ||
(type != kTableFile && type != kLogFile)) {
Log(options_.info_log, "DeleteFile %s failed.\n", name.c_str());
return Status::InvalidArgument("Invalid file name");
}
Status status;
if (type == kLogFile) {
// Only allow deleting archived log files
if (log_type != kArchivedLogFile) {
Log(options_.info_log, "DeleteFile %s failed - not archived log.\n",
name.c_str());
return Status::NotSupported("Delete only supported for archived logs");
}
status = env_->DeleteFile(options_.wal_dir + "/" + name.c_str());
if (!status.ok()) {
Log(options_.info_log, "DeleteFile %s failed -- %s.\n",
name.c_str(), status.ToString().c_str());
}
return status;
}
int level;
FileMetaData* metadata;
ColumnFamilyData* cfd;
VersionEdit edit;
DeletionState deletion_state(true);
{
MutexLock l(&mutex_);
status = versions_->GetMetadataForFile(number, &level, &metadata, &cfd);
if (!status.ok()) {
Log(options_.info_log, "DeleteFile %s failed. File not found\n",
name.c_str());
return Status::InvalidArgument("File not found");
}
assert((level > 0) && (level < cfd->NumberLevels()));
// If the file is being compacted no need to delete.
if (metadata->being_compacted) {
Log(options_.info_log,
"DeleteFile %s Skipped. File about to be compacted\n", name.c_str());
return Status::OK();
}
// Only the files in the last level can be deleted externally.
// This is to make sure that any deletion tombstones are not
// lost. Check that the level passed is the last level.
for (int i = level + 1; i < cfd->NumberLevels(); i++) {
if (cfd->current()->NumLevelFiles(i) != 0) {
Log(options_.info_log,
"DeleteFile %s FAILED. File not in last level\n", name.c_str());
return Status::InvalidArgument("File not in last level");
}
}
edit.DeleteFile(level, number);
status = versions_->LogAndApply(cfd, &edit, &mutex_, db_directory_.get());
if (status.ok()) {
InstallSuperVersion(cfd, deletion_state);
}
FindObsoleteFiles(deletion_state, false);
} // lock released here
LogFlush(options_.info_log);
// remove files outside the db-lock
if (deletion_state.HaveSomethingToDelete()) {
PurgeObsoleteFiles(deletion_state);
}
{
MutexLock l(&mutex_);
// schedule flush if file deletion means we freed the space for flushes to
// continue
MaybeScheduleFlushOrCompaction();
}
return status;
}
void DBImpl::GetLiveFilesMetaData(std::vector<LiveFileMetaData>* metadata) {
MutexLock l(&mutex_);
versions_->GetLiveFilesMetaData(metadata);
}
#endif // ROCKSDB_LITE
Status DBImpl::CheckConsistency() {
mutex_.AssertHeld();
std::vector<LiveFileMetaData> metadata;
versions_->GetLiveFilesMetaData(&metadata);
std::string corruption_messages;
for (const auto& md : metadata) {
std::string file_path = dbname_ + md.name;
uint64_t fsize = 0;
Status s = env_->GetFileSize(file_path, &fsize);
if (!s.ok()) {
corruption_messages +=
"Can't access " + md.name + ": " + s.ToString() + "\n";
} else if (fsize != md.size) {
corruption_messages += "Sst file size mismatch: " + md.name +
". Size recorded in manifest " +
std::to_string(md.size) + ", actual size " +
std::to_string(fsize) + "\n";
}
}
if (corruption_messages.size() == 0) {
return Status::OK();
} else {
return Status::Corruption(corruption_messages);
}
}
Status DBImpl::GetDbIdentity(std::string& identity) {
std::string idfilename = IdentityFileName(dbname_);
unique_ptr<SequentialFile> idfile;
const EnvOptions soptions;
Status s = env_->NewSequentialFile(idfilename, &idfile, soptions);
if (!s.ok()) {
return s;
}
uint64_t file_size;
s = env_->GetFileSize(idfilename, &file_size);
if (!s.ok()) {
return s;
}
char buffer[file_size];
Slice id;
s = idfile->Read(file_size, &id, buffer);
if (!s.ok()) {
return s;
}
identity.assign(id.ToString());
// If last character is '\n' remove it from identity
if (identity.size() > 0 && identity.back() == '\n') {
identity.pop_back();
}
return s;
}
// Default implementations of convenience methods that subclasses of DB
// can call if they wish
Status DB::Put(const WriteOptions& opt, ColumnFamilyHandle* column_family,
const Slice& key, const Slice& value) {
// Pre-allocate size of write batch conservatively.
// 8 bytes are taken by header, 4 bytes for count, 1 byte for type,
// and we allocate 11 extra bytes for key length, as well as value length.
WriteBatch batch(key.size() + value.size() + 24);
batch.Put(column_family, key, value);
return Write(opt, &batch);
}
Status DB::Delete(const WriteOptions& opt, ColumnFamilyHandle* column_family,
const Slice& key) {
WriteBatch batch;
batch.Delete(column_family, key);
return Write(opt, &batch);
}
Status DB::Merge(const WriteOptions& opt, ColumnFamilyHandle* column_family,
const Slice& key, const Slice& value) {
WriteBatch batch;
batch.Merge(column_family, key, value);
return Write(opt, &batch);
}
// Default implementation -- returns not supported status
Status DB::CreateColumnFamily(const ColumnFamilyOptions& options,
const std::string& column_family_name,
ColumnFamilyHandle** handle) {
return Status::NotSupported("");
}
Status DB::DropColumnFamily(ColumnFamilyHandle* column_family) {
return Status::NotSupported("");
}
DB::~DB() { }
Status DB::Open(const Options& options, const std::string& dbname, DB** dbptr) {
DBOptions db_options(options);
ColumnFamilyOptions cf_options(options);
std::vector<ColumnFamilyDescriptor> column_families;
column_families.push_back(
ColumnFamilyDescriptor(kDefaultColumnFamilyName, cf_options));
std::vector<ColumnFamilyHandle*> handles;
Status s = DB::Open(db_options, dbname, column_families, &handles, dbptr);
if (s.ok()) {
assert(handles.size() == 1);
// i can delete the handle since DBImpl is always holding a reference to
// default column family
delete handles[0];
}
return s;
}
Status DB::Open(const DBOptions& db_options, const std::string& dbname,
const std::vector<ColumnFamilyDescriptor>& column_families,
std::vector<ColumnFamilyHandle*>* handles, DB** dbptr) {
*dbptr = nullptr;
handles->clear();
size_t max_write_buffer_size = 0;
for (auto cf : column_families) {
max_write_buffer_size =
std::max(max_write_buffer_size, cf.options.write_buffer_size);
if (cf.options.block_cache != nullptr && cf.options.no_block_cache) {
return Status::InvalidArgument(
"no_block_cache is true while block_cache is not nullptr");
}
}
DBImpl* impl = new DBImpl(db_options, dbname);
Status s = impl->env_->CreateDirIfMissing(impl->options_.wal_dir);
if (!s.ok()) {
delete impl;
return s;
}
s = impl->CreateArchivalDirectory();
if (!s.ok()) {
delete impl;
return s;
}
impl->mutex_.Lock();
// Handles create_if_missing, error_if_exists
s = impl->Recover(column_families);
if (s.ok()) {
uint64_t new_log_number = impl->versions_->NewFileNumber();
unique_ptr<WritableFile> lfile;
EnvOptions soptions(db_options);
s = impl->options_.env->NewWritableFile(
LogFileName(impl->options_.wal_dir, new_log_number), &lfile,
impl->options_.env->OptimizeForLogWrite(soptions));
if (s.ok()) {
lfile->SetPreallocationBlockSize(1.1 * max_write_buffer_size);
impl->logfile_number_ = new_log_number;
impl->log_.reset(new log::Writer(std::move(lfile)));
// set column family handles
for (auto cf : column_families) {
auto cfd =
impl->versions_->GetColumnFamilySet()->GetColumnFamily(cf.name);
if (cfd == nullptr) {
s = Status::InvalidArgument("Column family not found: ", cf.name);
break;
}
handles->push_back(
new ColumnFamilyHandleImpl(cfd, impl, &impl->mutex_));
}
}
if (s.ok()) {
for (auto cfd : *impl->versions_->GetColumnFamilySet()) {
delete cfd->InstallSuperVersion(new SuperVersion(), &impl->mutex_);
}
impl->alive_log_files_.push_back(
DBImpl::LogFileNumberSize(impl->logfile_number_));
impl->DeleteObsoleteFiles();
impl->MaybeScheduleFlushOrCompaction();
impl->MaybeScheduleLogDBDeployStats();
s = impl->db_directory_->Fsync();
}
}
if (s.ok()) {
for (auto cfd : *impl->versions_->GetColumnFamilySet()) {
if (cfd->options()->compaction_style == kCompactionStyleUniversal) {
Version* current = cfd->current();
for (int i = 1; i < current->NumberLevels(); ++i) {
int num_files = current->NumLevelFiles(i);
if (num_files > 0) {
s = Status::InvalidArgument("Not all files are at level 0. Cannot "
"open with universal compaction style.");
break;
}
}
}
if (cfd->options()->merge_operator != nullptr &&
!cfd->mem()->IsMergeOperatorSupported()) {
s = Status::InvalidArgument(
"The memtable of column family %s does not support merge operator "
"its options.merge_operator is non-null", cfd->GetName().c_str());
}
if (!s.ok()) {
break;
}
}
}
impl->mutex_.Unlock();
if (s.ok()) {
impl->opened_successfully_ = true;
*dbptr = impl;
} else {
for (auto h : *handles) {
delete h;
}
handles->clear();
delete impl;
}
return s;
}
Status DB::ListColumnFamilies(const DBOptions& db_options,
const std::string& name,
std::vector<std::string>* column_families) {
return VersionSet::ListColumnFamilies(column_families, name, db_options.env);
}
Snapshot::~Snapshot() {
}
Status DestroyDB(const std::string& dbname, const Options& options) {
const InternalKeyComparator comparator(options.comparator);
const InternalFilterPolicy filter_policy(options.filter_policy);
const Options& soptions(SanitizeOptions(
dbname, &comparator, &filter_policy, options));
Env* env = soptions.env;
std::vector<std::string> filenames;
std::vector<std::string> archiveFiles;
std::string archivedir = ArchivalDirectory(dbname);
// Ignore error in case directory does not exist
env->GetChildren(dbname, &filenames);
if (dbname != soptions.wal_dir) {
std::vector<std::string> logfilenames;
env->GetChildren(soptions.wal_dir, &logfilenames);
filenames.insert(filenames.end(), logfilenames.begin(), logfilenames.end());
archivedir = ArchivalDirectory(soptions.wal_dir);
}
if (filenames.empty()) {
return Status::OK();
}
FileLock* lock;
const std::string lockname = LockFileName(dbname);
Status result = env->LockFile(lockname, &lock);
if (result.ok()) {
uint64_t number;
FileType type;
for (size_t i = 0; i < filenames.size(); i++) {
if (ParseFileName(filenames[i], &number, &type) &&
type != kDBLockFile) { // Lock file will be deleted at end
Status del;
if (type == kMetaDatabase) {
del = DestroyDB(dbname + "/" + filenames[i], options);
} else if (type == kLogFile) {
del = env->DeleteFile(soptions.wal_dir + "/" + filenames[i]);
} else {
del = env->DeleteFile(dbname + "/" + filenames[i]);
}
if (result.ok() && !del.ok()) {
result = del;
}
}
}
env->GetChildren(archivedir, &archiveFiles);
// Delete archival files.
for (size_t i = 0; i < archiveFiles.size(); ++i) {
if (ParseFileName(archiveFiles[i], &number, &type) &&
type == kLogFile) {
Status del = env->DeleteFile(archivedir + "/" + archiveFiles[i]);
if (result.ok() && !del.ok()) {
result = del;
}
}
}
// ignore case where no archival directory is present.
env->DeleteDir(archivedir);
env->UnlockFile(lock); // Ignore error since state is already gone
env->DeleteFile(lockname);
env->DeleteDir(dbname); // Ignore error in case dir contains other files
env->DeleteDir(soptions.wal_dir);
}
return result;
}
//
// A global method that can dump out the build version
void DumpLeveldbBuildVersion(Logger * log) {
#if !defined(IOS_CROSS_COMPILE)
// if we compile with Xcode, we don't run build_detect_vesion, so we don't generate util/build_version.cc
Log(log, "Git sha %s", rocksdb_build_git_sha);
Log(log, "Compile time %s %s",
rocksdb_build_compile_time, rocksdb_build_compile_date);
#endif
}
} // namespace rocksdb