eb6d139666
Summary: - don't see a point exposing table.h to the public. - fixed make clean to remove also *.d files. Test Plan: make check; db_stress Reviewers: dhruba, heyongqiang Reviewed By: dhruba CC: leveldb Differential Revision: https://reviews.facebook.net/D10479
2500 lines
82 KiB
C++
2500 lines
82 KiB
C++
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#include "db/db_impl.h"
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#include <algorithm>
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#include <climits>
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#include <cstdio>
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#include <set>
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#include <string>
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#include <stdint.h>
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#include <vector>
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#include <unordered_set>
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#include "db/builder.h"
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#include "db/db_iter.h"
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#include "db/dbformat.h"
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#include "db/filename.h"
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#include "db/log_reader.h"
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#include "db/log_writer.h"
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#include "db/memtable.h"
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#include "db/memtablelist.h"
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#include "db/table_cache.h"
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#include "db/version_set.h"
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#include "db/write_batch_internal.h"
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#include "db/transaction_log_iterator_impl.h"
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#include "leveldb/db.h"
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#include "leveldb/env.h"
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#include "leveldb/statistics.h"
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#include "leveldb/status.h"
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#include "leveldb/table_builder.h"
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#include "port/port.h"
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#include "table/block.h"
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#include "table/merger.h"
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#include "table/table.h"
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#include "table/two_level_iterator.h"
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#include "util/auto_roll_logger.h"
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#include "util/build_version.h"
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#include "util/coding.h"
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#include "util/logging.h"
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#include "util/mutexlock.h"
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#include "util/stop_watch.h"
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namespace leveldb {
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void dumpLeveldbBuildVersion(Logger * log);
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// Information kept for every waiting writer
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struct DBImpl::Writer {
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Status status;
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WriteBatch* batch;
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bool sync;
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bool disableWAL;
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bool done;
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port::CondVar cv;
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explicit Writer(port::Mutex* mu) : cv(mu) { }
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};
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struct DBImpl::CompactionState {
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Compaction* const compaction;
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// If there were two snapshots with seq numbers s1 and
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// s2 and s1 < s2, and if we find two instances of a key k1 then lies
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// entirely within s1 and s2, then the earlier version of k1 can be safely
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// deleted because that version is not visible in any snapshot.
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std::vector<SequenceNumber> existing_snapshots;
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// Files produced by compaction
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struct Output {
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uint64_t number;
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uint64_t file_size;
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InternalKey smallest, largest;
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};
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std::vector<Output> outputs;
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std::list<uint64_t> allocated_file_numbers;
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// State kept for output being generated
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unique_ptr<WritableFile> outfile;
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unique_ptr<TableBuilder> builder;
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uint64_t total_bytes;
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Output* current_output() { return &outputs[outputs.size()-1]; }
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explicit CompactionState(Compaction* c)
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: compaction(c),
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total_bytes(0) {
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}
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};
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struct DBImpl::DeletionState {
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// the list of all live files that cannot be deleted
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std::vector<uint64_t> live;
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// a list of all siles that exists in the db directory
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std::vector<std::string> allfiles;
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// the current filenumber, lognumber and prevlognumber
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// that corresponds to the set of files in 'live'.
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uint64_t filenumber, lognumber, prevlognumber;
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// the list of all files to be evicted from the table cache
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std::vector<uint64_t> files_to_evict;
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};
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// Fix user-supplied options to be reasonable
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template <class T,class V>
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static void ClipToRange(T* ptr, V minvalue, V maxvalue) {
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if (static_cast<V>(*ptr) > maxvalue) *ptr = maxvalue;
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if (static_cast<V>(*ptr) < minvalue) *ptr = minvalue;
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}
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Options SanitizeOptions(const std::string& dbname,
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const InternalKeyComparator* icmp,
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const InternalFilterPolicy* ipolicy,
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const Options& src) {
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Options result = src;
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result.comparator = icmp;
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result.filter_policy = (src.filter_policy != nullptr) ? ipolicy : nullptr;
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ClipToRange(&result.max_open_files, 20, 1000000);
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ClipToRange(&result.write_buffer_size, 64<<10, 1<<30);
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ClipToRange(&result.block_size, 1<<10, 4<<20);
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if (result.info_log == nullptr) {
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Status s = CreateLoggerFromOptions(dbname, result.db_log_dir, src.env,
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result, &result.info_log);
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if (!s.ok()) {
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// No place suitable for logging
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result.info_log = nullptr;
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}
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}
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if (result.block_cache == nullptr && !result.no_block_cache) {
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result.block_cache = NewLRUCache(8 << 20);
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}
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result.compression_per_level = src.compression_per_level;
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return result;
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}
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DBImpl::DBImpl(const Options& options, const std::string& dbname)
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: env_(options.env),
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dbname_(dbname),
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internal_comparator_(options.comparator),
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options_(SanitizeOptions(
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dbname, &internal_comparator_, &internal_filter_policy_, options)),
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internal_filter_policy_(options.filter_policy),
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owns_info_log_(options_.info_log != options.info_log),
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db_lock_(nullptr),
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shutting_down_(nullptr),
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bg_cv_(&mutex_),
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mem_(new MemTable(internal_comparator_, NumberLevels())),
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logfile_number_(0),
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tmp_batch_(),
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bg_compaction_scheduled_(0),
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bg_logstats_scheduled_(false),
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manual_compaction_(nullptr),
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logger_(nullptr),
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disable_delete_obsolete_files_(false),
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delete_obsolete_files_last_run_(0),
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stall_level0_slowdown_(0),
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stall_memtable_compaction_(0),
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stall_level0_num_files_(0),
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started_at_(options.env->NowMicros()),
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flush_on_destroy_(false),
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stats_(options.num_levels),
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delayed_writes_(0),
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last_flushed_sequence_(0),
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storage_options_(options) {
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mem_->Ref();
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env_->GetAbsolutePath(dbname, &db_absolute_path_);
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stall_leveln_slowdown_.resize(options.num_levels);
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for (int i = 0; i < options.num_levels; ++i)
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stall_leveln_slowdown_[i] = 0;
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// Reserve ten files or so for other uses and give the rest to TableCache.
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const int table_cache_size = options_.max_open_files - 10;
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table_cache_.reset(new TableCache(dbname_, &options_,
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storage_options_, table_cache_size));
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versions_.reset(new VersionSet(dbname_, &options_, storage_options_,
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table_cache_.get(), &internal_comparator_));
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dumpLeveldbBuildVersion(options_.info_log.get());
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options_.Dump(options_.info_log.get());
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#ifdef USE_SCRIBE
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logger_.reset(new ScribeLogger("localhost", 1456));
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#endif
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char name[100];
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Status st = env_->GetHostName(name, 100L);
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if(st.ok()) {
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host_name_ = name;
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} else {
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Log(options_.info_log, "Can't get hostname, use localhost as host name.");
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host_name_ = "localhost";
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}
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last_log_ts = 0;
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}
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DBImpl::~DBImpl() {
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// Wait for background work to finish
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if (flush_on_destroy_) {
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FlushMemTable(FlushOptions());
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}
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mutex_.Lock();
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shutting_down_.Release_Store(this); // Any non-nullptr value is ok
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while (bg_compaction_scheduled_ || bg_logstats_scheduled_) {
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bg_cv_.Wait();
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}
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mutex_.Unlock();
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if (db_lock_ != nullptr) {
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env_->UnlockFile(db_lock_);
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}
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if (mem_ != nullptr) mem_->Unref();
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imm_.UnrefAll();
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}
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// Do not flush and close database elegantly. Simulate a crash.
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void DBImpl::TEST_Destroy_DBImpl() {
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// ensure that no new memtable flushes can occur
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flush_on_destroy_ = false;
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// wait till all background compactions are done.
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mutex_.Lock();
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while (bg_compaction_scheduled_ || bg_logstats_scheduled_) {
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bg_cv_.Wait();
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}
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// Prevent new compactions from occuring.
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const int LargeNumber = 10000000;
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bg_compaction_scheduled_ += LargeNumber;
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mutex_.Unlock();
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// force release the lock file.
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if (db_lock_ != nullptr) {
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env_->UnlockFile(db_lock_);
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}
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log_.reset();
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versions_.reset();
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table_cache_.reset();
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}
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uint64_t DBImpl::TEST_Current_Manifest_FileNo() {
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return versions_->ManifestFileNumber();
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}
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Status DBImpl::NewDB() {
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VersionEdit new_db(NumberLevels());
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new_db.SetComparatorName(user_comparator()->Name());
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new_db.SetLogNumber(0);
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new_db.SetNextFile(2);
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new_db.SetLastSequence(0);
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const std::string manifest = DescriptorFileName(dbname_, 1);
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unique_ptr<WritableFile> file;
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Status s = env_->NewWritableFile(manifest, &file, storage_options_);
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if (!s.ok()) {
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return s;
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}
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file->SetPreallocationBlockSize(options_.manifest_preallocation_size);
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{
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log::Writer log(std::move(file));
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std::string record;
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new_db.EncodeTo(&record);
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s = log.AddRecord(record);
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}
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if (s.ok()) {
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// Make "CURRENT" file that points to the new manifest file.
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s = SetCurrentFile(env_, dbname_, 1);
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} else {
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env_->DeleteFile(manifest);
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}
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return s;
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}
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void DBImpl::MaybeIgnoreError(Status* s) const {
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if (s->ok() || options_.paranoid_checks) {
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// No change needed
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} else {
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Log(options_.info_log, "Ignoring error %s", s->ToString().c_str());
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*s = Status::OK();
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}
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}
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const Status DBImpl::CreateArchivalDirectory() {
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if (options_.WAL_ttl_seconds > 0) {
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std::string archivalPath = ArchivalDirectory(dbname_);
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return env_->CreateDirIfMissing(archivalPath);
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}
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return Status::OK();
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}
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// Returns the list of live files in 'live' and the list
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// of all files in the filesystem in 'allfiles'.
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void DBImpl::FindObsoleteFiles(DeletionState& deletion_state) {
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mutex_.AssertHeld();
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// if deletion is disabled, do nothing
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if (disable_delete_obsolete_files_) {
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return;
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}
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// This method is costly when the number of files is large.
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// Do not allow it to trigger more often than once in
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// delete_obsolete_files_period_micros.
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if (options_.delete_obsolete_files_period_micros != 0) {
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const uint64_t now_micros = env_->NowMicros();
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if (delete_obsolete_files_last_run_ +
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options_.delete_obsolete_files_period_micros > now_micros) {
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return;
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}
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delete_obsolete_files_last_run_ = now_micros;
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}
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// Make a list of all of the live files; set is slow, should not
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// be used.
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deletion_state.live.assign(pending_outputs_.begin(),
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pending_outputs_.end());
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versions_->AddLiveFiles(&deletion_state.live);
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// set of all files in the directory
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env_->GetChildren(dbname_, &deletion_state.allfiles); // Ignore errors
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// store the current filenum, lognum, etc
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deletion_state.filenumber = versions_->ManifestFileNumber();
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deletion_state.lognumber = versions_->LogNumber();
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deletion_state.prevlognumber = versions_->PrevLogNumber();
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}
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// Diffs the files listed in filenames and those that do not
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// belong to live files are posibly removed. If the removed file
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// is a sst file, then it returns the file number in files_to_evict.
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// It is not necesary to hold the mutex when invoking this method.
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void DBImpl::PurgeObsoleteFiles(DeletionState& state) {
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uint64_t number;
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FileType type;
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std::vector<std::string> old_log_files;
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// Now, convert live list to an unordered set, WITHOUT mutex held;
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// set is slow.
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std::unordered_set<uint64_t> live_set(state.live.begin(),
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state.live.end());
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for (size_t i = 0; i < state.allfiles.size(); i++) {
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if (ParseFileName(state.allfiles[i], &number, &type)) {
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bool keep = true;
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switch (type) {
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case kLogFile:
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keep = ((number >= state.lognumber) ||
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(number == state.prevlognumber));
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break;
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case kDescriptorFile:
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// Keep my manifest file, and any newer incarnations'
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// (in case there is a race that allows other incarnations)
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keep = (number >= state.filenumber);
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break;
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case kTableFile:
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keep = (live_set.find(number) != live_set.end());
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break;
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case kTempFile:
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// Any temp files that are currently being written to must
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// be recorded in pending_outputs_, which is inserted into "live"
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keep = (live_set.find(number) != live_set.end());
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break;
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case kInfoLogFile:
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keep = true;
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if (number != 0) {
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old_log_files.push_back(state.allfiles[i]);
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}
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break;
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case kCurrentFile:
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case kDBLockFile:
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case kMetaDatabase:
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keep = true;
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break;
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}
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if (!keep) {
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if (type == kTableFile) {
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// record the files to be evicted from the cache
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state.files_to_evict.push_back(number);
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}
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Log(options_.info_log, "Delete type=%d #%lld\n",
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int(type),
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static_cast<unsigned long long>(number));
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if (type == kLogFile && options_.WAL_ttl_seconds > 0) {
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Status st = env_->RenameFile(LogFileName(dbname_, number),
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ArchivedLogFileName(dbname_, number));
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if (!st.ok()) {
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Log(options_.info_log, "RenameFile type=%d #%lld FAILED\n",
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int(type),
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static_cast<unsigned long long>(number));
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}
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} else {
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Status st = env_->DeleteFile(dbname_ + "/" + state.allfiles[i]);
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if(!st.ok()) {
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Log(options_.info_log, "Delete type=%d #%lld FAILED\n",
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int(type),
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static_cast<unsigned long long>(number));
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}
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}
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}
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}
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}
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// Delete old log files.
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size_t old_log_file_count = old_log_files.size();
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// NOTE: Currently we only support log purge when options_.db_log_dir is
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// located in `dbname` directory.
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if (old_log_file_count >= options_.keep_log_file_num &&
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options_.db_log_dir.empty()) {
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std::sort(old_log_files.begin(), old_log_files.end());
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size_t end = old_log_file_count - options_.keep_log_file_num;
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for (unsigned int i = 0; i <= end; i++) {
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std::string& to_delete = old_log_files.at(i);
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// Log(options_.info_log, "Delete type=%d %s\n",
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// int(kInfoLogFile), to_delete.c_str());
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env_->DeleteFile(dbname_ + "/" + to_delete);
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}
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}
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}
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void DBImpl::EvictObsoleteFiles(DeletionState& state) {
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for (unsigned int i = 0; i < state.files_to_evict.size(); i++) {
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table_cache_->Evict(state.files_to_evict[i]);
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}
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}
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void DBImpl::DeleteObsoleteFiles() {
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mutex_.AssertHeld();
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DeletionState deletion_state;
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FindObsoleteFiles(deletion_state);
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PurgeObsoleteFiles(deletion_state);
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EvictObsoleteFiles(deletion_state);
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PurgeObsoleteWALFiles();
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}
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void DBImpl::PurgeObsoleteWALFiles() {
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if (options_.WAL_ttl_seconds != ULONG_MAX && options_.WAL_ttl_seconds > 0) {
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std::vector<std::string> WALFiles;
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std::string archivalDir = ArchivalDirectory(dbname_);
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env_->GetChildren(archivalDir, &WALFiles);
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int64_t currentTime;
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const Status status = env_->GetCurrentTime(¤tTime);
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assert(status.ok());
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for (const auto& f : WALFiles) {
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uint64_t fileMTime;
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const std::string filePath = archivalDir + "/" + f;
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const Status s = env_->GetFileModificationTime(filePath, &fileMTime);
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if (s.ok()) {
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if (status.ok() &&
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(currentTime - fileMTime > options_.WAL_ttl_seconds)) {
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Status delStatus = env_->DeleteFile(filePath);
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if (!delStatus.ok()) {
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Log(options_.info_log,
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"Failed Deleting a WAL file Error : i%s",
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delStatus.ToString().c_str());
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}
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}
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} // Ignore errors.
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}
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}
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}
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// If externalTable is set, then apply recovered transactions
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// to that table. This is used for readonly mode.
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Status DBImpl::Recover(VersionEdit* edit, MemTable* external_table,
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bool error_if_log_file_exist) {
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mutex_.AssertHeld();
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assert(db_lock_ == nullptr);
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if (!external_table) {
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// We call CreateDirIfMissing() as the directory may already exist (if we
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// are reopening a DB), when this happens we don't want creating the
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// directory to cause an error. However, we need to check if creating the
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// directory fails or else we may get an obscure message about the lock
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// file not existing. One real-world example of this occurring is if
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// env->CreateDirIfMissing() doesn't create intermediate directories, e.g.
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// when dbname_ is "dir/db" but when "dir" doesn't exist.
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Status s = env_->CreateDirIfMissing(dbname_);
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if (!s.ok()) {
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return s;
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}
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s = env_->LockFile(LockFileName(dbname_), &db_lock_);
|
|
if (!s.ok()) {
|
|
return s;
|
|
}
|
|
|
|
if (!env_->FileExists(CurrentFileName(dbname_))) {
|
|
if (options_.create_if_missing) {
|
|
s = NewDB();
|
|
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)");
|
|
}
|
|
}
|
|
}
|
|
|
|
Status s = versions_->Recover();
|
|
if (s.ok()) {
|
|
SequenceNumber max_sequence(0);
|
|
|
|
// 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 leveldb.
|
|
const uint64_t min_log = versions_->LogNumber();
|
|
const uint64_t prev_log = versions_->PrevLogNumber();
|
|
std::vector<std::string> filenames;
|
|
s = env_->GetChildren(dbname_, &filenames);
|
|
if (!s.ok()) {
|
|
return s;
|
|
}
|
|
uint64_t number;
|
|
FileType type;
|
|
std::vector<uint64_t> logs;
|
|
for (size_t i = 0; i < filenames.size(); i++) {
|
|
if (ParseFileName(filenames[i], &number, &type)
|
|
&& type == kLogFile
|
|
&& ((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 (size_t i = 0; i < logs.size(); i++) {
|
|
s = RecoverLogFile(logs[i], edit, &max_sequence, external_table);
|
|
// 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(logs[i]);
|
|
}
|
|
|
|
if (s.ok()) {
|
|
if (versions_->LastSequence() < max_sequence) {
|
|
versions_->SetLastSequence(max_sequence);
|
|
last_flushed_sequence_ = max_sequence;
|
|
} else {
|
|
last_flushed_sequence_ = versions_->LastSequence();
|
|
}
|
|
}
|
|
}
|
|
|
|
return s;
|
|
}
|
|
|
|
Status DBImpl::RecoverLogFile(uint64_t log_number,
|
|
VersionEdit* edit,
|
|
SequenceNumber* max_sequence,
|
|
MemTable* external_table) {
|
|
struct LogReporter : public log::Reader::Reporter {
|
|
Env* env;
|
|
Logger* info_log;
|
|
const char* fname;
|
|
Status* status; // nullptr if options_.paranoid_checks==false
|
|
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();
|
|
|
|
// Open the log file
|
|
std::string fname = LogFileName(dbname_, 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 ? &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 #%llu",
|
|
(unsigned long long) log_number);
|
|
|
|
// Read all the records and add to a memtable
|
|
std::string scratch;
|
|
Slice record;
|
|
WriteBatch batch;
|
|
MemTable* mem = nullptr;
|
|
if (external_table) {
|
|
mem = external_table;
|
|
}
|
|
while (reader.ReadRecord(&record, &scratch) &&
|
|
status.ok()) {
|
|
if (record.size() < 12) {
|
|
reporter.Corruption(
|
|
record.size(), Status::Corruption("log record too small"));
|
|
continue;
|
|
}
|
|
WriteBatchInternal::SetContents(&batch, record);
|
|
|
|
if (mem == nullptr) {
|
|
mem = new MemTable(internal_comparator_, NumberLevels());
|
|
mem->Ref();
|
|
}
|
|
status = WriteBatchInternal::InsertInto(&batch, mem);
|
|
MaybeIgnoreError(&status);
|
|
if (!status.ok()) {
|
|
break;
|
|
}
|
|
const SequenceNumber last_seq =
|
|
WriteBatchInternal::Sequence(&batch) +
|
|
WriteBatchInternal::Count(&batch) - 1;
|
|
if (last_seq > *max_sequence) {
|
|
*max_sequence = last_seq;
|
|
}
|
|
|
|
if (!external_table &&
|
|
mem->ApproximateMemoryUsage() > options_.write_buffer_size) {
|
|
status = WriteLevel0TableForRecovery(mem, edit);
|
|
if (!status.ok()) {
|
|
// Reflect errors immediately so that conditions like full
|
|
// file-systems cause the DB::Open() to fail.
|
|
break;
|
|
}
|
|
mem->Unref();
|
|
mem = nullptr;
|
|
}
|
|
}
|
|
|
|
if (status.ok() && mem != nullptr && !external_table) {
|
|
status = WriteLevel0TableForRecovery(mem, edit);
|
|
// Reflect errors immediately so that conditions like full
|
|
// file-systems cause the DB::Open() to fail.
|
|
}
|
|
|
|
if (mem != nullptr && !external_table) mem->Unref();
|
|
return status;
|
|
}
|
|
|
|
Status DBImpl::WriteLevel0TableForRecovery(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();
|
|
const SequenceNumber newest_snapshot = snapshots_.GetNewest();
|
|
const SequenceNumber earliest_seqno_in_memtable =
|
|
mem->GetFirstSequenceNumber();
|
|
Log(options_.info_log, "Level-0 table #%llu: started",
|
|
(unsigned long long) meta.number);
|
|
|
|
Status s;
|
|
{
|
|
mutex_.Unlock();
|
|
s = BuildTable(dbname_, env_, options_, storage_options_,
|
|
table_cache_.get(), iter, &meta,
|
|
user_comparator(), newest_snapshot,
|
|
earliest_seqno_in_memtable);
|
|
mutex_.Lock();
|
|
}
|
|
|
|
Log(options_.info_log, "Level-0 table #%llu: %lld bytes %s",
|
|
(unsigned long long) meta.number,
|
|
(unsigned long 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);
|
|
}
|
|
|
|
CompactionStats stats;
|
|
stats.micros = env_->NowMicros() - start_micros;
|
|
stats.bytes_written = meta.file_size;
|
|
stats.files_out_levelnp1 = 1;
|
|
stats_[level].Add(stats);
|
|
return s;
|
|
}
|
|
|
|
|
|
Status DBImpl::WriteLevel0Table(MemTable* mem, VersionEdit* edit,
|
|
uint64_t* filenumber) {
|
|
mutex_.AssertHeld();
|
|
const uint64_t start_micros = env_->NowMicros();
|
|
FileMetaData meta;
|
|
meta.number = versions_->NewFileNumber();
|
|
*filenumber = meta.number;
|
|
pending_outputs_.insert(meta.number);
|
|
Iterator* iter = mem->NewIterator();
|
|
const SequenceNumber newest_snapshot = snapshots_.GetNewest();
|
|
const SequenceNumber earliest_seqno_in_memtable =
|
|
mem->GetFirstSequenceNumber();
|
|
Log(options_.info_log, "Level-0 flush table #%llu: started",
|
|
(unsigned long long) meta.number);
|
|
|
|
Version* base = versions_->current();
|
|
base->Ref();
|
|
Status s;
|
|
{
|
|
mutex_.Unlock();
|
|
s = BuildTable(dbname_, env_, options_, storage_options_,
|
|
table_cache_.get(), iter, &meta,
|
|
user_comparator(), newest_snapshot,
|
|
earliest_seqno_in_memtable);
|
|
mutex_.Lock();
|
|
}
|
|
base->Unref();
|
|
|
|
Log(options_.info_log, "Level-0 flush table #%llu: %lld bytes %s",
|
|
(unsigned long long) meta.number,
|
|
(unsigned long long) meta.file_size,
|
|
s.ToString().c_str());
|
|
delete iter;
|
|
|
|
// re-acquire the most current version
|
|
base = versions_->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) {
|
|
level = base->PickLevelForMemTableOutput(min_user_key, max_user_key);
|
|
}
|
|
edit->AddFile(level, meta.number, meta.file_size,
|
|
meta.smallest, meta.largest);
|
|
}
|
|
|
|
CompactionStats stats;
|
|
stats.micros = env_->NowMicros() - start_micros;
|
|
stats.bytes_written = meta.file_size;
|
|
stats_[level].Add(stats);
|
|
return s;
|
|
}
|
|
|
|
Status DBImpl::CompactMemTable(bool* madeProgress) {
|
|
mutex_.AssertHeld();
|
|
assert(imm_.size() != 0);
|
|
|
|
if (!imm_.IsFlushPending()) {
|
|
Log(options_.info_log, "Memcompaction already in progress");
|
|
Status s = Status::IOError("Memcompaction already in progress");
|
|
return s;
|
|
}
|
|
|
|
// Save the contents of the earliest memtable as a new Table
|
|
// This will release and re-acquire the mutex.
|
|
uint64_t file_number;
|
|
MemTable* m = imm_.PickMemtableToFlush();
|
|
if (m == nullptr) {
|
|
Log(options_.info_log, "Nothing in memstore to flush");
|
|
Status s = Status::IOError("Nothing in memstore to flush");
|
|
return s;
|
|
}
|
|
|
|
// record the logfile_number_ before we release the mutex
|
|
VersionEdit* edit = m->GetEdits();
|
|
edit->SetPrevLogNumber(0);
|
|
edit->SetLogNumber(logfile_number_); // Earlier logs no longer needed
|
|
|
|
Status s = WriteLevel0Table(m, edit, &file_number);
|
|
|
|
if (s.ok() && shutting_down_.Acquire_Load()) {
|
|
s = Status::IOError(
|
|
"Database shutdown started during memtable compaction"
|
|
);
|
|
}
|
|
|
|
// Replace immutable memtable with the generated Table
|
|
s = imm_.InstallMemtableFlushResults(
|
|
m, versions_.get(), s, &mutex_, options_.info_log.get(),
|
|
file_number, pending_outputs_);
|
|
|
|
if (s.ok()) {
|
|
if (madeProgress) {
|
|
*madeProgress = 1;
|
|
}
|
|
MaybeScheduleLogDBDeployStats();
|
|
// we could have deleted obsolete files here, but it is not
|
|
// absolutely necessary because it could be also done as part
|
|
// of other background compaction
|
|
}
|
|
return s;
|
|
}
|
|
|
|
void DBImpl::CompactRange(const Slice* begin, const Slice* end) {
|
|
int max_level_with_files = 1;
|
|
{
|
|
MutexLock l(&mutex_);
|
|
Version* base = versions_->current();
|
|
for (int level = 1; level < NumberLevels(); level++) {
|
|
if (base->OverlapInLevel(level, begin, end)) {
|
|
max_level_with_files = level;
|
|
}
|
|
}
|
|
}
|
|
TEST_CompactMemTable(); // TODO(sanjay): Skip if memtable does not overlap
|
|
for (int level = 0; level < max_level_with_files; level++) {
|
|
TEST_CompactRange(level, begin, end);
|
|
}
|
|
}
|
|
|
|
int DBImpl::NumberLevels() {
|
|
return options_.num_levels;
|
|
}
|
|
|
|
int DBImpl::MaxMemCompactionLevel() {
|
|
return options_.max_mem_compaction_level;
|
|
}
|
|
|
|
int DBImpl::Level0StopWriteTrigger() {
|
|
return options_.level0_stop_writes_trigger;
|
|
}
|
|
|
|
Status DBImpl::Flush(const FlushOptions& options) {
|
|
Status status = FlushMemTable(options);
|
|
return status;
|
|
}
|
|
|
|
SequenceNumber DBImpl::GetLatestSequenceNumber() {
|
|
return versions_->LastSequence();
|
|
}
|
|
|
|
Status DBImpl::GetUpdatesSince(SequenceNumber seq,
|
|
unique_ptr<TransactionLogIterator>* iter) {
|
|
|
|
// Get All Log Files.
|
|
// Sort Files
|
|
// Get the first entry from each file.
|
|
// Do binary search and open files and find the seq number.
|
|
|
|
std::vector<LogFile> walFiles;
|
|
// list wal files in main db dir.
|
|
Status s = ListAllWALFiles(dbname_, &walFiles, kAliveLogFile);
|
|
if (!s.ok()) {
|
|
return s;
|
|
}
|
|
// list wal files in archive dir.
|
|
std::string archivedir = ArchivalDirectory(dbname_);
|
|
if (env_->FileExists(archivedir)) {
|
|
s = ListAllWALFiles(archivedir, &walFiles, kArchivedLogFile);
|
|
if (!s.ok()) {
|
|
return s;
|
|
}
|
|
}
|
|
|
|
if (walFiles.empty()) {
|
|
return Status::IOError(" NO WAL Files present in the db");
|
|
}
|
|
// std::shared_ptr would have been useful here.
|
|
|
|
std::unique_ptr<std::vector<LogFile>> probableWALFiles(
|
|
new std::vector<LogFile>());
|
|
s = FindProbableWALFiles(&walFiles, probableWALFiles.get(), seq);
|
|
if (!s.ok()) {
|
|
return s;
|
|
}
|
|
iter->reset(
|
|
new TransactionLogIteratorImpl(dbname_,
|
|
&options_,
|
|
storage_options_,
|
|
seq,
|
|
std::move(probableWALFiles),
|
|
&last_flushed_sequence_));
|
|
iter->get()->Next();
|
|
return iter->get()->status();
|
|
}
|
|
|
|
Status DBImpl::FindProbableWALFiles(std::vector<LogFile>* const allLogs,
|
|
std::vector<LogFile>* const result,
|
|
const SequenceNumber target) {
|
|
assert(allLogs != nullptr);
|
|
assert(result != nullptr);
|
|
|
|
std::sort(allLogs->begin(), allLogs->end());
|
|
long start = 0; // signed to avoid overflow when target is < first file.
|
|
long end = static_cast<long>(allLogs->size()) - 1;
|
|
// Binary Search. avoid opening all files.
|
|
while (end >= start) {
|
|
long mid = start + (end - start) / 2; // Avoid overflow.
|
|
WriteBatch batch;
|
|
Status s = ReadFirstRecord(allLogs->at(mid), &batch);
|
|
if (!s.ok()) {
|
|
if (CheckFileExistsAndEmpty(allLogs->at(mid))) {
|
|
allLogs->erase(allLogs->begin() + mid);
|
|
--end;
|
|
continue;
|
|
}
|
|
return s;
|
|
}
|
|
SequenceNumber currentSeqNum = WriteBatchInternal::Sequence(&batch);
|
|
if (currentSeqNum == target) {
|
|
start = mid;
|
|
end = mid;
|
|
break;
|
|
} else if (currentSeqNum < target) {
|
|
start = mid + 1;
|
|
} else {
|
|
end = mid - 1;
|
|
}
|
|
}
|
|
size_t startIndex = std::max(0l, end); // end could be -ve.
|
|
for( size_t i = startIndex; i < allLogs->size(); ++i) {
|
|
result->push_back(allLogs->at(i));
|
|
}
|
|
if (result->empty()) {
|
|
return Status::IOError(
|
|
"No probable files. Check if the db contains log files");
|
|
}
|
|
return Status::OK();
|
|
}
|
|
|
|
bool DBImpl::CheckFileExistsAndEmpty(const LogFile& file) {
|
|
if (file.type == kAliveLogFile) {
|
|
const std::string fname = LogFileName(dbname_, file.logNumber);
|
|
uint64_t file_size;
|
|
Status s = env_->GetFileSize(fname, &file_size);
|
|
if (s.ok() && file_size == 0) {
|
|
return true;
|
|
}
|
|
}
|
|
const std::string fname = ArchivedLogFileName(dbname_, file.logNumber);
|
|
uint64_t file_size;
|
|
Status s = env_->GetFileSize(fname, &file_size);
|
|
if (s.ok() && file_size == 0) {
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
Status DBImpl::ReadFirstRecord(const LogFile& file, WriteBatch* const result) {
|
|
|
|
if (file.type == kAliveLogFile) {
|
|
std::string fname = LogFileName(dbname_, file.logNumber);
|
|
Status status = ReadFirstLine(fname, result);
|
|
if (!status.ok()) {
|
|
// check if the file got moved to archive.
|
|
std::string archivedFile = ArchivedLogFileName(dbname_, file.logNumber);
|
|
Status s = ReadFirstLine(archivedFile, result);
|
|
if (!s.ok()) {
|
|
return Status::IOError("Log File Has been deleted");
|
|
}
|
|
}
|
|
return Status::OK();
|
|
} else if (file.type == kArchivedLogFile) {
|
|
std::string fname = ArchivedLogFileName(dbname_, file.logNumber);
|
|
Status status = ReadFirstLine(fname, result);
|
|
return status;
|
|
}
|
|
return Status::NotSupported("File Type Not Known");
|
|
}
|
|
|
|
Status DBImpl::ReadFirstLine(const std::string& fname,
|
|
WriteBatch* const batch) {
|
|
struct LogReporter : public log::Reader::Reporter {
|
|
Env* env;
|
|
Logger* info_log;
|
|
const char* fname;
|
|
Status* status; // nullptr if options_.paranoid_checks==false
|
|
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;
|
|
}
|
|
};
|
|
|
|
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 = (options_.paranoid_checks ? &status : nullptr);
|
|
log::Reader reader(std::move(file), &reporter, true/*checksum*/,
|
|
0/*initial_offset*/);
|
|
std::string scratch;
|
|
Slice record;
|
|
if (reader.ReadRecord(&record, &scratch) && status.ok()) {
|
|
if (record.size() < 12) {
|
|
reporter.Corruption(
|
|
record.size(), Status::Corruption("log record too small"));
|
|
return Status::IOError("Corruption noted");
|
|
// TODO read record's till the first no corrupt entry?
|
|
}
|
|
WriteBatchInternal::SetContents(batch, record);
|
|
return Status::OK();
|
|
}
|
|
return Status::IOError("Error reading from file " + fname);
|
|
}
|
|
|
|
Status DBImpl::ListAllWALFiles(const std::string& path,
|
|
std::vector<LogFile>* const logFiles,
|
|
WalFileType logType) {
|
|
assert(logFiles != nullptr);
|
|
std::vector<std::string> allFiles;
|
|
const Status status = env_->GetChildren(path, &allFiles);
|
|
if (!status.ok()) {
|
|
return status;
|
|
}
|
|
for (const auto& f : allFiles) {
|
|
uint64_t number;
|
|
FileType type;
|
|
if (ParseFileName(f, &number, &type) && type == kLogFile){
|
|
logFiles->push_back(LogFile(number, logType));
|
|
}
|
|
}
|
|
return status;
|
|
}
|
|
|
|
void DBImpl::TEST_CompactRange(int level, const Slice* begin,const Slice* end) {
|
|
assert(level >= 0);
|
|
|
|
InternalKey begin_storage, end_storage;
|
|
|
|
ManualCompaction manual;
|
|
manual.level = level;
|
|
manual.done = false;
|
|
manual.in_progress = false;
|
|
if (begin == nullptr) {
|
|
manual.begin = nullptr;
|
|
} else {
|
|
begin_storage = InternalKey(*begin, kMaxSequenceNumber, kValueTypeForSeek);
|
|
manual.begin = &begin_storage;
|
|
}
|
|
if (end == nullptr) {
|
|
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 throttle down
|
|
// the number of background compaction threads to 1. This is
|
|
// needed to ensure that this manual compaction can compact
|
|
// any range of keys/files. We artificialy increase
|
|
// bg_compaction_scheduled_ by a large number, this causes
|
|
// the system to have a single background thread. Now,
|
|
// this manual compaction can progress without stomping
|
|
// on any other concurrent compactions.
|
|
const int LargeNumber = 10000000;
|
|
const int newvalue = options_.max_background_compactions-1;
|
|
bg_compaction_scheduled_ += LargeNumber;
|
|
while (bg_compaction_scheduled_ > LargeNumber) {
|
|
Log(options_.info_log, "Manual compaction request waiting for background threads to fall below 1");
|
|
bg_cv_.Wait();
|
|
}
|
|
Log(options_.info_log, "Manual compaction starting");
|
|
|
|
while (!manual.done) {
|
|
while (manual_compaction_ != nullptr) {
|
|
bg_cv_.Wait();
|
|
}
|
|
manual_compaction_ = &manual;
|
|
if (bg_compaction_scheduled_ == LargeNumber) {
|
|
bg_compaction_scheduled_ = newvalue;
|
|
}
|
|
MaybeScheduleCompaction();
|
|
while (manual_compaction_ == &manual) {
|
|
bg_cv_.Wait();
|
|
}
|
|
}
|
|
assert(!manual.in_progress);
|
|
|
|
// wait till there are no background threads scheduled
|
|
bg_compaction_scheduled_ += LargeNumber;
|
|
while (bg_compaction_scheduled_ > LargeNumber + newvalue) {
|
|
Log(options_.info_log, "Manual compaction resetting background threads");
|
|
bg_cv_.Wait();
|
|
}
|
|
bg_compaction_scheduled_ = 0;
|
|
}
|
|
|
|
Status DBImpl::FlushMemTable(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 = WaitForCompactMemTable();
|
|
}
|
|
return s;
|
|
}
|
|
|
|
Status DBImpl::WaitForCompactMemTable() {
|
|
Status s;
|
|
// Wait until the compaction completes
|
|
MutexLock l(&mutex_);
|
|
while (imm_.size() > 0 && bg_error_.ok()) {
|
|
bg_cv_.Wait();
|
|
}
|
|
if (imm_.size() != 0) {
|
|
s = bg_error_;
|
|
}
|
|
return s;
|
|
}
|
|
|
|
Status DBImpl::TEST_CompactMemTable() {
|
|
return FlushMemTable(FlushOptions());
|
|
}
|
|
|
|
Status DBImpl::TEST_WaitForCompactMemTable() {
|
|
return WaitForCompactMemTable();
|
|
}
|
|
|
|
Status DBImpl::TEST_WaitForCompact() {
|
|
// Wait until the compaction completes
|
|
MutexLock l(&mutex_);
|
|
while (bg_compaction_scheduled_ && bg_error_.ok()) {
|
|
bg_cv_.Wait();
|
|
}
|
|
return bg_error_;
|
|
}
|
|
|
|
void DBImpl::MaybeScheduleCompaction() {
|
|
mutex_.AssertHeld();
|
|
if (bg_compaction_scheduled_ >= options_.max_background_compactions) {
|
|
// Already scheduled
|
|
} else if (shutting_down_.Acquire_Load()) {
|
|
// DB is being deleted; no more background compactions
|
|
} else if (!imm_.IsFlushPending() &&
|
|
manual_compaction_ == nullptr &&
|
|
!versions_->NeedsCompaction()) {
|
|
// No work to be done
|
|
} else {
|
|
bg_compaction_scheduled_++;
|
|
env_->Schedule(&DBImpl::BGWork, this);
|
|
}
|
|
}
|
|
|
|
void DBImpl::BGWork(void* db) {
|
|
reinterpret_cast<DBImpl*>(db)->BackgroundCall();
|
|
}
|
|
|
|
void DBImpl::BackgroundCall() {
|
|
bool madeProgress = false;
|
|
DeletionState deletion_state;
|
|
MutexLock l(&mutex_);
|
|
// Log(options_.info_log, "XXX BG Thread %llx process new work item", pthread_self());
|
|
assert(bg_compaction_scheduled_);
|
|
if (!shutting_down_.Acquire_Load()) {
|
|
Status s = BackgroundCompaction(&madeProgress, deletion_state);
|
|
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.
|
|
bg_cv_.SignalAll(); // In case a waiter can proceed despite the error
|
|
Log(options_.info_log, "Waiting after background compaction error: %s",
|
|
s.ToString().c_str());
|
|
mutex_.Unlock();
|
|
env_->SleepForMicroseconds(1000000);
|
|
mutex_.Lock();
|
|
}
|
|
}
|
|
|
|
// delete unnecessary files if any, this is done outside the mutex
|
|
if (!deletion_state.live.empty()) {
|
|
mutex_.Unlock();
|
|
PurgeObsoleteFiles(deletion_state);
|
|
EvictObsoleteFiles(deletion_state);
|
|
mutex_.Lock();
|
|
}
|
|
|
|
bg_compaction_scheduled_--;
|
|
|
|
MaybeScheduleLogDBDeployStats();
|
|
|
|
// Previous compaction may have produced too many files in a level,
|
|
// So reschedule another compaction if we made progress in the
|
|
// last compaction.
|
|
if (madeProgress) {
|
|
MaybeScheduleCompaction();
|
|
}
|
|
bg_cv_.SignalAll();
|
|
}
|
|
|
|
Status DBImpl::BackgroundCompaction(bool* madeProgress,
|
|
DeletionState& deletion_state) {
|
|
*madeProgress = false;
|
|
mutex_.AssertHeld();
|
|
|
|
while (imm_.IsFlushPending()) {
|
|
Log(options_.info_log,
|
|
"BackgroundCompaction doing CompactMemTable, compaction slots available %d",
|
|
options_.max_background_compactions - bg_compaction_scheduled_);
|
|
Status stat = CompactMemTable(madeProgress);
|
|
if (!stat.ok()) {
|
|
return stat;
|
|
}
|
|
}
|
|
|
|
unique_ptr<Compaction> c;
|
|
bool is_manual = (manual_compaction_ != nullptr) &&
|
|
(manual_compaction_->in_progress == false);
|
|
InternalKey manual_end;
|
|
if (is_manual) {
|
|
ManualCompaction* m = manual_compaction_;
|
|
assert(!m->in_progress);
|
|
m->in_progress = true; // another thread cannot pick up the same work
|
|
c.reset(versions_->CompactRange(m->level, m->begin, m->end));
|
|
if (c) {
|
|
manual_end = c->input(0, c->num_input_files(0) - 1)->largest;
|
|
} else {
|
|
m->done = true;
|
|
}
|
|
Log(options_.info_log,
|
|
"Manual compaction at level-%d from %s .. %s; will stop at %s\n",
|
|
m->level,
|
|
(m->begin ? m->begin->DebugString().c_str() : "(begin)"),
|
|
(m->end ? m->end->DebugString().c_str() : "(end)"),
|
|
(m->done ? "(end)" : manual_end.DebugString().c_str()));
|
|
} else if (!options_.disable_auto_compactions) {
|
|
c.reset(versions_->PickCompaction());
|
|
}
|
|
|
|
Status status;
|
|
if (!c) {
|
|
// Nothing to do
|
|
Log(options_.info_log, "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);
|
|
status = versions_->LogAndApply(c->edit(), &mutex_);
|
|
VersionSet::LevelSummaryStorage tmp;
|
|
Log(options_.info_log, "Moved #%lld to level-%d %lld bytes %s: %s\n",
|
|
static_cast<unsigned long long>(f->number),
|
|
c->level() + 1,
|
|
static_cast<unsigned long long>(f->file_size),
|
|
status.ToString().c_str(),
|
|
versions_->LevelSummary(&tmp));
|
|
versions_->ReleaseCompactionFiles(c.get(), status);
|
|
*madeProgress = true;
|
|
} else {
|
|
MaybeScheduleCompaction(); // do more compaction work in parallel.
|
|
CompactionState* compact = new CompactionState(c.get());
|
|
status = DoCompactionWork(compact);
|
|
CleanupCompaction(compact);
|
|
versions_->ReleaseCompactionFiles(c.get(), status);
|
|
c->ReleaseInputs();
|
|
FindObsoleteFiles(deletion_state);
|
|
*madeProgress = true;
|
|
}
|
|
c.reset();
|
|
|
|
if (status.ok()) {
|
|
// Done
|
|
} else if (shutting_down_.Acquire_Load()) {
|
|
// Ignore compaction errors found during shutting down
|
|
} else {
|
|
Log(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->done = true;
|
|
}
|
|
if (!m->done) {
|
|
// We only compacted part of the requested range. Update *m
|
|
// to the range that is left to be compacted.
|
|
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) {
|
|
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);
|
|
}
|
|
delete compact;
|
|
}
|
|
|
|
// Allocate the file numbers for the output file. We allocate as
|
|
// many output file numbers as there are files in level+1.
|
|
// 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 < filesNeeded; 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);
|
|
// Log(options_.info_log, "XXX releasing unused file num %d", 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();
|
|
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.
|
|
compact->outfile->SetPreallocationBlockSize(
|
|
1.1 * versions_->MaxFileSizeForLevel(compact->compaction->level() + 1));
|
|
|
|
compact->builder.reset(new TableBuilder(options_, compact->outfile.get(),
|
|
compact->compaction->level() + 1));
|
|
}
|
|
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) {
|
|
s = compact->outfile->Fsync();
|
|
} else {
|
|
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
|
|
Iterator* iter = table_cache_->NewIterator(ReadOptions(),
|
|
storage_options_,
|
|
output_number,
|
|
current_bytes);
|
|
s = iter->status();
|
|
delete iter;
|
|
if (s.ok()) {
|
|
Log(options_.info_log,
|
|
"Generated table #%llu: %lld keys, %lld bytes",
|
|
(unsigned long long) output_number,
|
|
(unsigned long long) current_entries,
|
|
(unsigned long long) current_bytes);
|
|
}
|
|
}
|
|
return s;
|
|
}
|
|
|
|
|
|
Status DBImpl::InstallCompactionResults(CompactionState* compact) {
|
|
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, "Compaction %d@%d + %d@%d files aborted",
|
|
compact->compaction->num_input_files(0),
|
|
compact->compaction->level(),
|
|
compact->compaction->num_input_files(1),
|
|
compact->compaction->level() + 1);
|
|
return Status::IOError("Compaction input files inconsistent");
|
|
}
|
|
|
|
Log(options_.info_log, "Compacted %d@%d + %d@%d files => %lld bytes",
|
|
compact->compaction->num_input_files(0),
|
|
compact->compaction->level(),
|
|
compact->compaction->num_input_files(1),
|
|
compact->compaction->level() + 1,
|
|
static_cast<long long>(compact->total_bytes));
|
|
|
|
// Add compaction outputs
|
|
compact->compaction->AddInputDeletions(compact->compaction->edit());
|
|
const int level = compact->compaction->level();
|
|
for (size_t i = 0; i < compact->outputs.size(); i++) {
|
|
const CompactionState::Output& out = compact->outputs[i];
|
|
compact->compaction->edit()->AddFile(
|
|
level + 1,
|
|
out.number, out.file_size, out.smallest, out.largest);
|
|
}
|
|
return versions_->LogAndApply(compact->compaction->edit(), &mutex_);
|
|
}
|
|
|
|
//
|
|
// 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 __attribute__((unused)) = 0;
|
|
for (const auto cur : snapshots) {
|
|
assert(prev <= cur);
|
|
if (cur >= in) {
|
|
return cur;
|
|
}
|
|
prev = cur; // assignment
|
|
assert(prev);
|
|
}
|
|
Log(options_.info_log,
|
|
"Looking for seqid %ld but maxseqid is %ld", in,
|
|
snapshots[snapshots.size()-1]);
|
|
assert(0);
|
|
return 0;
|
|
}
|
|
|
|
Status DBImpl::DoCompactionWork(CompactionState* compact) {
|
|
int64_t imm_micros = 0; // Micros spent doing imm_ compactions
|
|
|
|
Log(options_.info_log,
|
|
"Compacting %d@%d + %d@%d files, score %.2f slots available %d",
|
|
compact->compaction->num_input_files(0),
|
|
compact->compaction->level(),
|
|
compact->compaction->num_input_files(1),
|
|
compact->compaction->level() + 1,
|
|
compact->compaction->score(),
|
|
options_.max_background_compactions - bg_compaction_scheduled_);
|
|
char scratch[256];
|
|
compact->compaction->Summary(scratch, sizeof(scratch));
|
|
Log(options_.info_log, "Compaction start summary: %s\n", scratch);
|
|
|
|
assert(versions_->NumLevelFiles(compact->compaction->level()) > 0);
|
|
assert(compact->builder == nullptr);
|
|
assert(!compact->outfile);
|
|
|
|
SequenceNumber visible_at_tip = 0;
|
|
SequenceNumber earliest_snapshot;
|
|
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 {
|
|
// 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 = true;
|
|
for (int i = compact->compaction->level() + 2;
|
|
i < versions_->NumberLevels(); i++) {
|
|
if (versions_->NumLevelFiles(i) > 0) {
|
|
bottommost_level = false;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Allocate the output file numbers before we release the lock
|
|
AllocateCompactionOutputFileNumbers(compact);
|
|
|
|
// Release mutex while we're actually doing the compaction work
|
|
mutex_.Unlock();
|
|
|
|
const uint64_t start_micros = env_->NowMicros();
|
|
unique_ptr<Iterator> input(versions_->MakeInputIterator(compact->compaction));
|
|
input->SeekToFirst();
|
|
Status status;
|
|
ParsedInternalKey ikey;
|
|
std::string current_user_key;
|
|
bool has_current_user_key = false;
|
|
SequenceNumber last_sequence_for_key __attribute__((unused)) =
|
|
kMaxSequenceNumber;
|
|
SequenceNumber visible_in_snapshot = kMaxSequenceNumber;
|
|
std::string compaction_filter_value;
|
|
for (; input->Valid() && !shutting_down_.Acquire_Load(); ) {
|
|
// Prioritize immutable compaction work
|
|
if (imm_.imm_flush_needed.NoBarrier_Load() != nullptr) {
|
|
const uint64_t imm_start = env_->NowMicros();
|
|
mutex_.Lock();
|
|
if (imm_.IsFlushPending()) {
|
|
CompactMemTable();
|
|
bg_cv_.SignalAll(); // Wakeup MakeRoomForWrite() if necessary
|
|
}
|
|
mutex_.Unlock();
|
|
imm_micros += (env_->NowMicros() - imm_start);
|
|
}
|
|
|
|
Slice key = input->key();
|
|
Slice value = input->value();
|
|
|
|
if (compact->compaction->ShouldStopBefore(key) &&
|
|
compact->builder != nullptr) {
|
|
status = FinishCompactionOutputFile(compact, input.get());
|
|
if (!status.ok()) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Handle key/value, add to state, etc.
|
|
bool drop = false;
|
|
if (!ParseInternalKey(key, &ikey)) {
|
|
// Do not hide error keys
|
|
current_user_key.clear();
|
|
has_current_user_key = false;
|
|
last_sequence_for_key = kMaxSequenceNumber;
|
|
visible_in_snapshot = kMaxSequenceNumber;
|
|
} else {
|
|
if (!has_current_user_key ||
|
|
user_comparator()->Compare(ikey.user_key,
|
|
Slice(current_user_key)) != 0) {
|
|
// First occurrence of this user key
|
|
current_user_key.assign(ikey.user_key.data(), ikey.user_key.size());
|
|
has_current_user_key = true;
|
|
last_sequence_for_key = kMaxSequenceNumber;
|
|
visible_in_snapshot = kMaxSequenceNumber;
|
|
}
|
|
|
|
// 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 visible = visible_at_tip ? visible_at_tip :
|
|
findEarliestVisibleSnapshot(ikey.sequence,
|
|
compact->existing_snapshots);
|
|
|
|
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
|
|
assert(last_sequence_for_key >= ikey.sequence);
|
|
drop = true; // (A)
|
|
RecordTick(options_.statistics, 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, COMPACTION_KEY_DROP_OBSOLETE);
|
|
} else if (options_.CompactionFilter != nullptr &&
|
|
ikey.type != kTypeDeletion &&
|
|
ikey.sequence < earliest_snapshot) {
|
|
// If the user has specified a compaction filter, then invoke
|
|
// it. If the return value of the compaction filter is true,
|
|
// drop this key from the output.
|
|
bool value_changed = false;
|
|
compaction_filter_value.clear();
|
|
drop = options_.CompactionFilter(options_.compaction_filter_args,
|
|
compact->compaction->level(),
|
|
ikey.user_key, value,
|
|
&compaction_filter_value,
|
|
&value_changed);
|
|
// Another example of statistics update without holding the lock
|
|
// TODO: clean it up
|
|
if (drop) {
|
|
RecordTick(options_.statistics, COMPACTION_KEY_DROP_USER);
|
|
}
|
|
|
|
// If the application wants to change the value, then do so here.
|
|
if (value_changed) {
|
|
value = compaction_filter_value;
|
|
}
|
|
}
|
|
|
|
last_sequence_for_key = ikey.sequence;
|
|
visible_in_snapshot = visible;
|
|
}
|
|
#if 0
|
|
Log(options_.info_log,
|
|
" Compact: %s, seq %d, type: %d %d, drop: %d, is_base: %d, "
|
|
"%d smallest_snapshot: %d level: %d bottommost %d",
|
|
ikey.user_key.ToString().c_str(),
|
|
(int)ikey.sequence, ikey.type, kTypeValue, drop,
|
|
compact->compaction->IsBaseLevelForKey(ikey.user_key),
|
|
(int)last_sequence_for_key, (int)earliest_snapshot,
|
|
compact->compaction->level(), bottommost_level);
|
|
#endif
|
|
|
|
if (!drop) {
|
|
|
|
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) {
|
|
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;
|
|
}
|
|
}
|
|
if (compact->builder->NumEntries() == 0) {
|
|
compact->current_output()->smallest.DecodeFrom(newkey);
|
|
}
|
|
compact->current_output()->largest.DecodeFrom(newkey);
|
|
compact->builder->Add(newkey, value);
|
|
|
|
// Close output file if it is big enough
|
|
if (compact->builder->FileSize() >=
|
|
compact->compaction->MaxOutputFileSize()) {
|
|
status = FinishCompactionOutputFile(compact, input.get());
|
|
if (!status.ok()) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
input->Next();
|
|
}
|
|
|
|
if (status.ok() && shutting_down_.Acquire_Load()) {
|
|
status = Status::IOError("Database shutdown started during compaction");
|
|
}
|
|
if (status.ok() && compact->builder != nullptr) {
|
|
status = FinishCompactionOutputFile(compact, input.get());
|
|
}
|
|
if (status.ok()) {
|
|
status = input->status();
|
|
}
|
|
input.reset();
|
|
|
|
CompactionStats stats;
|
|
stats.micros = env_->NowMicros() - start_micros - imm_micros;
|
|
if (options_.statistics) {
|
|
options_.statistics->measureTime(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 occured 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;
|
|
|
|
for (int i = 0; i < compact->compaction->num_input_files(1); i++)
|
|
stats.bytes_readnp1 += compact->compaction->input(1, i)->file_size;
|
|
|
|
for (int i = 0; i < num_output_files; i++) {
|
|
stats.bytes_written += compact->outputs[i].file_size;
|
|
}
|
|
|
|
mutex_.Lock();
|
|
stats_[compact->compaction->level() + 1].Add(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);
|
|
}
|
|
VersionSet::LevelSummaryStorage tmp;
|
|
Log(options_.info_log,
|
|
"compacted to: %s, %.1f MB/sec, level %d, files in(%d, %d) out(%d) "
|
|
"MB in(%.1f, %.1f) out(%.1f), amplify(%.1f) %s\n",
|
|
versions_->LevelSummary(&tmp),
|
|
(stats.bytes_readn + stats.bytes_readnp1 + stats.bytes_written) /
|
|
(double) stats.micros,
|
|
compact->compaction->level() + 1,
|
|
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) /
|
|
(double) stats.bytes_readn,
|
|
status.ToString().c_str());
|
|
|
|
return status;
|
|
}
|
|
|
|
namespace {
|
|
struct IterState {
|
|
port::Mutex* mu;
|
|
Version* version;
|
|
std::vector<MemTable*> mem; // includes both mem_ and imm_
|
|
};
|
|
|
|
static void CleanupIteratorState(void* arg1, void* arg2) {
|
|
IterState* state = reinterpret_cast<IterState*>(arg1);
|
|
state->mu->Lock();
|
|
for (unsigned int i = 0; i < state->mem.size(); i++) {
|
|
state->mem[i]->Unref();
|
|
}
|
|
state->version->Unref();
|
|
state->mu->Unlock();
|
|
delete state;
|
|
}
|
|
} // namespace
|
|
|
|
Iterator* DBImpl::NewInternalIterator(const ReadOptions& options,
|
|
SequenceNumber* latest_snapshot) {
|
|
IterState* cleanup = new IterState;
|
|
mutex_.Lock();
|
|
*latest_snapshot = versions_->LastSequence();
|
|
|
|
// Collect together all needed child iterators for mem
|
|
std::vector<Iterator*> list;
|
|
mem_->Ref();
|
|
list.push_back(mem_->NewIterator());
|
|
cleanup->mem.push_back(mem_);
|
|
|
|
// Collect together all needed child iterators for imm_
|
|
std::vector<MemTable*> immutables;
|
|
imm_.GetMemTables(&immutables);
|
|
for (unsigned int i = 0; i < immutables.size(); i++) {
|
|
MemTable* m = immutables[i];
|
|
m->Ref();
|
|
list.push_back(m->NewIterator());
|
|
cleanup->mem.push_back(m);
|
|
}
|
|
|
|
// Collect iterators for files in L0 - Ln
|
|
versions_->current()->AddIterators(options, storage_options_, &list);
|
|
Iterator* internal_iter =
|
|
NewMergingIterator(&internal_comparator_, &list[0], list.size());
|
|
versions_->current()->Ref();
|
|
|
|
cleanup->mu = &mutex_;
|
|
cleanup->version = versions_->current();
|
|
internal_iter->RegisterCleanup(CleanupIteratorState, cleanup, nullptr);
|
|
|
|
mutex_.Unlock();
|
|
return internal_iter;
|
|
}
|
|
|
|
Iterator* DBImpl::TEST_NewInternalIterator() {
|
|
SequenceNumber ignored;
|
|
return NewInternalIterator(ReadOptions(), &ignored);
|
|
}
|
|
|
|
int64_t DBImpl::TEST_MaxNextLevelOverlappingBytes() {
|
|
MutexLock l(&mutex_);
|
|
return versions_->MaxNextLevelOverlappingBytes();
|
|
}
|
|
|
|
Status DBImpl::Get(const ReadOptions& options,
|
|
const Slice& key,
|
|
std::string* value) {
|
|
Status s;
|
|
|
|
std::unique_ptr<StopWatch> sw = stats::StartStopWatch(env_,
|
|
options_.statistics,
|
|
DB_GET);
|
|
SequenceNumber snapshot;
|
|
MutexLock l(&mutex_);
|
|
if (options.snapshot != nullptr) {
|
|
snapshot = reinterpret_cast<const SnapshotImpl*>(options.snapshot)->number_;
|
|
} else {
|
|
snapshot = versions_->LastSequence();
|
|
}
|
|
|
|
MemTable* mem = mem_;
|
|
MemTableList imm = imm_;
|
|
Version* current = versions_->current();
|
|
mem->Ref();
|
|
imm.RefAll();
|
|
current->Ref();
|
|
|
|
// Unlock while reading from files and memtables
|
|
|
|
mutex_.Unlock();
|
|
bool have_stat_update = false;
|
|
Version::GetStats stats;
|
|
// First look in the memtable, then in the immutable memtable (if any).
|
|
LookupKey lkey(key, snapshot);
|
|
if (mem->Get(lkey, value, &s)) {
|
|
// Done
|
|
} else if (imm.Get(lkey, value, &s)) {
|
|
// Done
|
|
} else {
|
|
s = current->Get(options, lkey, value, &stats);
|
|
have_stat_update = true;
|
|
}
|
|
mutex_.Lock();
|
|
|
|
if (!options_.disable_seek_compaction &&
|
|
have_stat_update && current->UpdateStats(stats)) {
|
|
MaybeScheduleCompaction();
|
|
}
|
|
mem->Unref();
|
|
imm.UnrefAll();
|
|
current->Unref();
|
|
RecordTick(options_.statistics, NUMBER_KEYS_READ);
|
|
RecordTick(options_.statistics, BYTES_READ, value->size());
|
|
return s;
|
|
}
|
|
|
|
Iterator* DBImpl::NewIterator(const ReadOptions& options) {
|
|
SequenceNumber latest_snapshot;
|
|
Iterator* internal_iter = NewInternalIterator(options, &latest_snapshot);
|
|
return NewDBIterator(
|
|
&dbname_, env_, user_comparator(), internal_iter,
|
|
(options.snapshot != nullptr
|
|
? reinterpret_cast<const SnapshotImpl*>(options.snapshot)->number_
|
|
: latest_snapshot));
|
|
}
|
|
|
|
const Snapshot* DBImpl::GetSnapshot() {
|
|
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, const Slice& key, const Slice& val) {
|
|
return DB::Put(o, key, val);
|
|
}
|
|
|
|
Status DBImpl::Delete(const WriteOptions& options, const Slice& key) {
|
|
return DB::Delete(options, key);
|
|
}
|
|
|
|
Status DBImpl::Write(const WriteOptions& options, WriteBatch* my_batch) {
|
|
Writer w(&mutex_);
|
|
w.batch = my_batch;
|
|
w.sync = options.sync;
|
|
w.disableWAL = options.disableWAL;
|
|
w.done = false;
|
|
|
|
std::unique_ptr<StopWatch> sw = stats::StartStopWatch(env_,
|
|
options_.statistics,
|
|
DB_WRITE);
|
|
MutexLock l(&mutex_);
|
|
writers_.push_back(&w);
|
|
while (!w.done && &w != writers_.front()) {
|
|
w.cv.Wait();
|
|
}
|
|
if (w.done) {
|
|
return w.status;
|
|
}
|
|
|
|
// May temporarily unlock and wait.
|
|
Status status = MakeRoomForWrite(my_batch == nullptr);
|
|
uint64_t last_sequence = versions_->LastSequence();
|
|
Writer* last_writer = &w;
|
|
if (status.ok() && my_batch != nullptr) { // nullptr batch is for compactions
|
|
WriteBatch* updates = BuildBatchGroup(&last_writer);
|
|
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, NUMBER_KEYS_WRITTEN, my_batch_count);
|
|
RecordTick(options_.statistics,
|
|
BYTES_WRITTEN,
|
|
WriteBatchInternal::ByteSize(updates));
|
|
// 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 mem_.
|
|
{
|
|
mutex_.Unlock();
|
|
if (options.disableWAL) {
|
|
flush_on_destroy_ = true;
|
|
}
|
|
|
|
if (!options.disableWAL) {
|
|
status = log_->AddRecord(WriteBatchInternal::Contents(updates));
|
|
if (status.ok() && options.sync) {
|
|
if (options_.use_fsync) {
|
|
status = log_->file()->Fsync();
|
|
} else {
|
|
status = log_->file()->Sync();
|
|
}
|
|
}
|
|
}
|
|
if (status.ok()) {
|
|
status = WriteBatchInternal::InsertInto(updates, mem_);
|
|
}
|
|
mutex_.Lock();
|
|
}
|
|
last_flushed_sequence_ = current_sequence;
|
|
if (updates == &tmp_batch_) tmp_batch_.Clear();
|
|
|
|
versions_->SetLastSequence(last_sequence);
|
|
}
|
|
|
|
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();
|
|
}
|
|
return status;
|
|
}
|
|
|
|
// REQUIRES: Writer list must be non-empty
|
|
// REQUIRES: First writer must have a non-nullptr batch
|
|
WriteBatch* DBImpl::BuildBatchGroup(Writer** last_writer) {
|
|
assert(!writers_.empty());
|
|
Writer* first = writers_.front();
|
|
WriteBatch* result = first->batch;
|
|
assert(result != nullptr);
|
|
|
|
size_t size = WriteBatchInternal::ByteSize(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;
|
|
}
|
|
|
|
// Append to *reuslt
|
|
if (result == first->batch) {
|
|
// Switch to temporary batch instead of disturbing caller's batch
|
|
result = &tmp_batch_;
|
|
assert(WriteBatchInternal::Count(result) == 0);
|
|
WriteBatchInternal::Append(result, first->batch);
|
|
}
|
|
WriteBatchInternal::Append(result, w->batch);
|
|
}
|
|
*last_writer = w;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
// REQUIRES: mutex_ is held
|
|
// REQUIRES: this thread is currently at the front of the writer queue
|
|
Status DBImpl::MakeRoomForWrite(bool force) {
|
|
mutex_.AssertHeld();
|
|
assert(!writers_.empty());
|
|
bool allow_delay = !force;
|
|
bool allow_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 &&
|
|
versions_->NumLevelFiles(0) >=
|
|
options_.level0_slowdown_writes_trigger) {
|
|
// 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 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.
|
|
mutex_.Unlock();
|
|
uint64_t t1 = env_->NowMicros();
|
|
env_->SleepForMicroseconds(1000);
|
|
uint64_t delayed = env_->NowMicros() - t1;
|
|
stall_level0_slowdown_ += delayed;
|
|
allow_delay = false; // Do not delay a single write more than once
|
|
//Log(options_.info_log,
|
|
// "delaying write %llu usecs for level0_slowdown_writes_trigger\n",
|
|
// (long long unsigned int)delayed);
|
|
mutex_.Lock();
|
|
delayed_writes_++;
|
|
} else if (!force &&
|
|
(mem_->ApproximateMemoryUsage() <= options_.write_buffer_size)) {
|
|
// There is room in current memtable
|
|
if (allow_delay) {
|
|
DelayLoggingAndReset();
|
|
}
|
|
break;
|
|
} else if (imm_.size() == options_.max_write_buffer_number - 1) {
|
|
// We have filled up the current memtable, but the previous
|
|
// ones are still being compacted, so we wait.
|
|
DelayLoggingAndReset();
|
|
Log(options_.info_log, "wait for memtable compaction...\n");
|
|
uint64_t t1 = env_->NowMicros();
|
|
bg_cv_.Wait();
|
|
stall_memtable_compaction_ += env_->NowMicros() - t1;
|
|
} else if (versions_->NumLevelFiles(0) >=
|
|
options_.level0_stop_writes_trigger) {
|
|
// There are too many level-0 files.
|
|
DelayLoggingAndReset();
|
|
uint64_t t1 = env_->NowMicros();
|
|
Log(options_.info_log, "wait for fewer level0 files...\n");
|
|
bg_cv_.Wait();
|
|
stall_level0_num_files_ += env_->NowMicros() - t1;
|
|
} else if (
|
|
allow_rate_limit_delay &&
|
|
options_.rate_limit > 1.0 &&
|
|
(score = versions_->MaxCompactionScore()) > options_.rate_limit) {
|
|
// Delay a write when the compaction score for any level is too large.
|
|
int max_level = versions_->MaxCompactionScoreLevel();
|
|
mutex_.Unlock();
|
|
uint64_t t1 = env_->NowMicros();
|
|
env_->SleepForMicroseconds(1000);
|
|
uint64_t delayed = env_->NowMicros() - t1;
|
|
stall_leveln_slowdown_[max_level] += delayed;
|
|
// Make sure the following value doesn't round to zero.
|
|
rate_limit_delay_millis += std::max((delayed / 1000), (uint64_t) 1);
|
|
if (rate_limit_delay_millis >=
|
|
(unsigned)options_.rate_limit_delay_milliseconds) {
|
|
allow_rate_limit_delay = false;
|
|
}
|
|
// Log(options_.info_log,
|
|
// "delaying write %llu usecs for rate limits with max score %.2f\n",
|
|
// (long long unsigned int)delayed, score);
|
|
mutex_.Lock();
|
|
} else {
|
|
// Attempt to switch to a new memtable and trigger compaction of old
|
|
DelayLoggingAndReset();
|
|
assert(versions_->PrevLogNumber() == 0);
|
|
uint64_t new_log_number = versions_->NewFileNumber();
|
|
unique_ptr<WritableFile> lfile;
|
|
StorageOptions soptions(storage_options_);
|
|
soptions.DisableMmapWrites();
|
|
s = env_->NewWritableFile(
|
|
LogFileName(dbname_, new_log_number),
|
|
&lfile,
|
|
soptions
|
|
);
|
|
if (!s.ok()) {
|
|
// Avoid chewing through file number space in a tight loop.
|
|
versions_->ReuseFileNumber(new_log_number);
|
|
break;
|
|
}
|
|
// Our final size should be less than write_buffer_size
|
|
// (compression, etc) but err on the side of caution.
|
|
lfile->SetPreallocationBlockSize(1.1 * options_.write_buffer_size);
|
|
logfile_number_ = new_log_number;
|
|
log_.reset(new log::Writer(std::move(lfile)));
|
|
imm_.Add(mem_);
|
|
mem_ = new MemTable(internal_comparator_, NumberLevels());
|
|
mem_->Ref();
|
|
force = false; // Do not force another compaction if have room
|
|
MaybeScheduleCompaction();
|
|
}
|
|
}
|
|
return s;
|
|
}
|
|
|
|
bool DBImpl::GetProperty(const Slice& property, std::string* value) {
|
|
value->clear();
|
|
|
|
MutexLock l(&mutex_);
|
|
Slice in = property;
|
|
Slice prefix("leveldb.");
|
|
if (!in.starts_with(prefix)) return false;
|
|
in.remove_prefix(prefix.size());
|
|
|
|
if (in.starts_with("num-files-at-level")) {
|
|
in.remove_prefix(strlen("num-files-at-level"));
|
|
uint64_t level;
|
|
bool ok = ConsumeDecimalNumber(&in, &level) && in.empty();
|
|
if (!ok || (int)level >= NumberLevels()) {
|
|
return false;
|
|
} else {
|
|
char buf[100];
|
|
snprintf(buf, sizeof(buf), "%d",
|
|
versions_->NumLevelFiles(static_cast<int>(level)));
|
|
*value = buf;
|
|
return true;
|
|
}
|
|
} else if (in == "levelstats") {
|
|
char buf[1000];
|
|
snprintf(buf, sizeof(buf),
|
|
"Level Files Size(MB)\n"
|
|
"--------------------\n");
|
|
value->append(buf);
|
|
|
|
for (int level = 0; level < NumberLevels(); level++) {
|
|
snprintf(buf, sizeof(buf),
|
|
"%3d %8d %8.0f\n",
|
|
level,
|
|
versions_->NumLevelFiles(level),
|
|
versions_->NumLevelBytes(level) / 1048576.0);
|
|
value->append(buf);
|
|
}
|
|
return true;
|
|
|
|
} else if (in == "stats") {
|
|
char buf[1000];
|
|
uint64_t total_bytes = 0;
|
|
uint64_t micros_up = env_->NowMicros() - started_at_;
|
|
double seconds_up = micros_up / 1000000.0;
|
|
uint64_t total_slowdown = 0;
|
|
|
|
// Pardon the long line but I think it is easier to read this way.
|
|
snprintf(buf, sizeof(buf),
|
|
" Compactions\n"
|
|
"Level Files Size(MB) Time(sec) Read(MB) Write(MB) Rn(MB) Rnp1(MB) Wnew(MB) Amplify Read(MB/s) Write(MB/s) Rn Rnp1 Wnp1 NewW Count Ln-stall\n"
|
|
"----------------------------------------------------------------------------------------------------------------------------------------------------------------------\n"
|
|
);
|
|
value->append(buf);
|
|
for (int level = 0; level < NumberLevels(); level++) {
|
|
int files = versions_->NumLevelFiles(level);
|
|
if (stats_[level].micros > 0 || files > 0) {
|
|
int64_t bytes_read = stats_[level].bytes_readn +
|
|
stats_[level].bytes_readnp1;
|
|
int64_t bytes_new = stats_[level].bytes_written -
|
|
stats_[level].bytes_readnp1;
|
|
double amplify = (stats_[level].bytes_readn == 0)
|
|
? 0.0
|
|
: (stats_[level].bytes_written + stats_[level].bytes_readnp1) /
|
|
(double) stats_[level].bytes_readn;
|
|
|
|
total_bytes += bytes_read + stats_[level].bytes_written;
|
|
snprintf(
|
|
buf, sizeof(buf),
|
|
"%3d %8d %8.0f %9.0f %9.0f %9.0f %9.0f %9.0f %9.0f %7.1f %9.1f %11.1f %8d %8d %8d %8d %8d %9.1f\n",
|
|
level,
|
|
files,
|
|
versions_->NumLevelBytes(level) / 1048576.0,
|
|
stats_[level].micros / 1e6,
|
|
bytes_read / 1048576.0,
|
|
stats_[level].bytes_written / 1048576.0,
|
|
stats_[level].bytes_readn / 1048576.0,
|
|
stats_[level].bytes_readnp1 / 1048576.0,
|
|
bytes_new / 1048576.0,
|
|
amplify,
|
|
// +1 to avoid division by 0
|
|
(bytes_read / 1048576.0) / ((stats_[level].micros+1) / 1000000.0),
|
|
(stats_[level].bytes_written / 1048576.0) /
|
|
((stats_[level].micros+1) / 1000000.0),
|
|
stats_[level].files_in_leveln,
|
|
stats_[level].files_in_levelnp1,
|
|
stats_[level].files_out_levelnp1,
|
|
stats_[level].files_out_levelnp1 - stats_[level].files_in_levelnp1,
|
|
stats_[level].count,
|
|
stall_leveln_slowdown_[level] / 1000000.0);
|
|
total_slowdown += stall_leveln_slowdown_[level];
|
|
value->append(buf);
|
|
}
|
|
}
|
|
|
|
snprintf(buf, sizeof(buf),
|
|
"Amplification: %.1f rate, %.2f GB in, %.2f GB out, %.2f MB/sec in, %.2f MB/sec out\n",
|
|
(double) total_bytes / stats_[0].bytes_written,
|
|
stats_[0].bytes_written / (1048576.0 * 1024),
|
|
total_bytes / (1048576.0 * 1024),
|
|
stats_[0].bytes_written / 1048576.0 / seconds_up,
|
|
total_bytes / 1048576.0 / seconds_up);
|
|
value->append(buf);
|
|
|
|
snprintf(buf, sizeof(buf), "Uptime(secs): %.1f\n", seconds_up);
|
|
value->append(buf);
|
|
|
|
snprintf(buf, sizeof(buf),
|
|
"Stalls(secs): %.3f level0_slowdown, %.3f level0_numfiles, "
|
|
"%.3f memtable_compaction, %.3f leveln_slowdown\n",
|
|
stall_level0_slowdown_ / 1000000.0,
|
|
stall_level0_num_files_ / 1000000.0,
|
|
stall_memtable_compaction_ / 1000000.0,
|
|
total_slowdown / 1000000.0);
|
|
value->append(buf);
|
|
|
|
return true;
|
|
} else if (in == "sstables") {
|
|
*value = versions_->current()->DebugString();
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
void DBImpl::GetApproximateSizes(
|
|
const Range* range, int n,
|
|
uint64_t* sizes) {
|
|
// TODO(opt): better implementation
|
|
Version* v;
|
|
{
|
|
MutexLock l(&mutex_);
|
|
versions_->current()->Ref();
|
|
v = versions_->current();
|
|
}
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
// Default implementations of convenience methods that subclasses of DB
|
|
// can call if they wish
|
|
Status DB::Put(const WriteOptions& opt, const Slice& key, const Slice& value) {
|
|
WriteBatch batch;
|
|
batch.Put(key, value);
|
|
return Write(opt, &batch);
|
|
}
|
|
|
|
Status DB::Delete(const WriteOptions& opt, const Slice& key) {
|
|
WriteBatch batch;
|
|
batch.Delete(key);
|
|
return Write(opt, &batch);
|
|
}
|
|
|
|
DB::~DB() { }
|
|
|
|
Status DB::Open(const Options& options, const std::string& dbname,
|
|
DB** dbptr) {
|
|
*dbptr = nullptr;
|
|
StorageOptions soptions;
|
|
|
|
if (options.block_cache != nullptr && options.no_block_cache) {
|
|
return Status::InvalidArgument(
|
|
"no_block_cache is true while block_cache is not nullptr");
|
|
}
|
|
DBImpl* impl = new DBImpl(options, dbname);
|
|
Status s = impl->CreateArchivalDirectory();
|
|
if (!s.ok()) {
|
|
delete impl;
|
|
return s;
|
|
}
|
|
impl->mutex_.Lock();
|
|
VersionEdit edit(impl->NumberLevels());
|
|
s = impl->Recover(&edit); // Handles create_if_missing, error_if_exists
|
|
if (s.ok()) {
|
|
uint64_t new_log_number = impl->versions_->NewFileNumber();
|
|
unique_ptr<WritableFile> lfile;
|
|
soptions.DisableMmapWrites();
|
|
s = options.env->NewWritableFile(LogFileName(dbname, new_log_number),
|
|
&lfile, soptions);
|
|
if (s.ok()) {
|
|
lfile->SetPreallocationBlockSize(1.1 * options.write_buffer_size);
|
|
edit.SetLogNumber(new_log_number);
|
|
impl->logfile_number_ = new_log_number;
|
|
impl->log_.reset(new log::Writer(std::move(lfile)));
|
|
s = impl->versions_->LogAndApply(&edit, &impl->mutex_);
|
|
}
|
|
if (s.ok()) {
|
|
impl->DeleteObsoleteFiles();
|
|
impl->MaybeScheduleCompaction();
|
|
impl->MaybeScheduleLogDBDeployStats();
|
|
}
|
|
}
|
|
impl->mutex_.Unlock();
|
|
if (s.ok()) {
|
|
*dbptr = impl;
|
|
} else {
|
|
delete impl;
|
|
}
|
|
return s;
|
|
}
|
|
|
|
Snapshot::~Snapshot() {
|
|
}
|
|
|
|
Status DestroyDB(const std::string& dbname, const Options& options) {
|
|
Env* env = options.env;
|
|
std::vector<std::string> filenames;
|
|
std::vector<std::string> archiveFiles;
|
|
|
|
// Ignore error in case directory does not exist
|
|
env->GetChildren(dbname, &filenames);
|
|
env->GetChildren(ArchivalDirectory(dbname), &archiveFiles);
|
|
|
|
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 {
|
|
del = env->DeleteFile(dbname + "/" + filenames[i]);
|
|
}
|
|
if (result.ok() && !del.ok()) {
|
|
result = del;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Delete archival files.
|
|
for (size_t i = 0; i < archiveFiles.size(); ++i) {
|
|
ParseFileName(archiveFiles[i], &number, &type);
|
|
if (type == kLogFile) {
|
|
Status del = env->DeleteFile(ArchivalDirectory(dbname) + "/" +
|
|
archiveFiles[i]);
|
|
if (result.ok() && !del.ok()) {
|
|
result = del;
|
|
}
|
|
}
|
|
}
|
|
// ignore case where no archival directory is present.
|
|
env->DeleteDir(ArchivalDirectory(dbname));
|
|
|
|
env->UnlockFile(lock); // Ignore error since state is already gone
|
|
env->DeleteFile(lockname);
|
|
env->DeleteDir(dbname); // Ignore error in case dir contains other files
|
|
}
|
|
return result;
|
|
}
|
|
|
|
//
|
|
// A global method that can dump out the build version
|
|
void dumpLeveldbBuildVersion(Logger * log) {
|
|
Log(log, "Git sha %s", leveldb_build_git_sha);
|
|
Log(log, "Compile time %s %s",
|
|
leveldb_build_compile_time, leveldb_build_compile_date);
|
|
}
|
|
|
|
} // namespace leveldb
|