f4c2b7cf97
Summary: Leveldb has an api OpenForReadOnly() that opens the database in readonly mode. This call had an option to not process the transaction log. This patch removes this option and always processes all transactions that had been committed. It has been done in such a way that it does not create/write to any new files in the process. The invariant of "no-writes" to the leveldb data directory is still true. This enhancement allows multiple threads to open the same database in readonly mode and access all trancations that were committed right upto the OpenForReadOnly call. I changed the public API to match the new semantics because there are no users who are currently using this api. Test Plan: make clean check Reviewers: sheki Reviewed By: sheki CC: leveldb Differential Revision: https://reviews.facebook.net/D7479
2384 lines
76 KiB
C++
2384 lines
76 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 "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.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/two_level_iterator.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/build_version.h"
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#include "util/auto_split_logger.h"
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namespace leveldb {
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void dumpLeveldbBuildVersion(Logger * log);
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static Status NewLogger(const std::string& dbname,
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const std::string& db_log_dir,
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Env* env,
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size_t max_log_file_size,
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Logger** logger) {
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std::string db_absolute_path;
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env->GetAbsolutePath(dbname, &db_absolute_path);
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if (max_log_file_size > 0) { // need to auto split the log file?
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AutoSplitLogger<Logger>* auto_split_logger =
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new AutoSplitLogger<Logger>(env, dbname, db_log_dir, max_log_file_size);
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Status s = auto_split_logger->GetStatus();
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if (!s.ok()) {
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delete auto_split_logger;
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} else {
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*logger = auto_split_logger;
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}
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return s;
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} else {
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// Open a log file in the same directory as the db
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env->CreateDir(dbname); // In case it does not exist
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std::string fname = InfoLogFileName(dbname, db_absolute_path, db_log_dir);
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env->RenameFile(fname, OldInfoLogFileName(dbname, env->NowMicros(),
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db_absolute_path, db_log_dir));
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return env->NewLogger(fname, logger);
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}
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}
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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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WritableFile* outfile;
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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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outfile(NULL),
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builder(NULL),
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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 set of all live files that cannot be deleted
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std::set<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 cahce
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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 != NULL) ? ipolicy : NULL;
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ClipToRange(&result.max_open_files, 20, 50000);
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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 == NULL) {
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Status s = NewLogger(dbname, result.db_log_dir, src.env,
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result.max_log_file_size, &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 = NULL;
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}
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}
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if (result.block_cache == NULL && !result.no_block_cache) {
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result.block_cache = NewLRUCache(8 << 20);
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}
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if (src.compression_per_level != NULL) {
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result.compression_per_level = new CompressionType[src.num_levels];
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for (int i = 0; i < src.num_levels; i++) {
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result.compression_per_level[i] = src.compression_per_level[i];
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}
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}
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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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owns_cache_(options_.block_cache != options.block_cache),
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db_lock_(NULL),
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shutting_down_(NULL),
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bg_cv_(&mutex_),
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mem_(new MemTable(internal_comparator_, NumberLevels())),
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logfile_(NULL),
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logfile_number_(0),
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log_(NULL),
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tmp_batch_(new WriteBatch),
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bg_compaction_scheduled_(0),
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bg_logstats_scheduled_(false),
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manual_compaction_(NULL),
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logger_(NULL),
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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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stall_leveln_slowdown_(0),
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started_at_(options.env->NowMicros()),
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flush_on_destroy_(false),
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delayed_writes_(0) {
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mem_->Ref();
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env_->GetAbsolutePath(dbname, &db_absolute_path_);
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stats_ = new CompactionStats[options.num_levels];
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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_ = new TableCache(dbname_, &options_, table_cache_size);
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versions_ = new VersionSet(dbname_, &options_, table_cache_,
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&internal_comparator_);
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dumpLeveldbBuildVersion(options_.info_log);
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options_.Dump(options_.info_log);
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#ifdef USE_SCRIBE
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logger_ = 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-NULL 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_ != NULL) {
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env_->UnlockFile(db_lock_);
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}
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delete versions_;
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if (mem_ != NULL) mem_->Unref();
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imm_.UnrefAll();
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delete tmp_batch_;
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delete log_;
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delete logfile_;
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delete table_cache_;
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delete[] stats_;
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if (owns_info_log_) {
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delete options_.info_log;
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}
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if (owns_cache_) {
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delete options_.block_cache;
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}
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if (options_.compression_per_level != NULL) {
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delete options_.compression_per_level;
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}
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delete logger_;
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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_ != NULL) {
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env_->UnlockFile(db_lock_);
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}
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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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WritableFile* file;
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Status s = env_->NewWritableFile(manifest, &file);
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if (!s.ok()) {
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return s;
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}
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{
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log::Writer log(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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if (s.ok()) {
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s = file->Close();
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}
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}
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delete file;
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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 set of all of the live files
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deletion_state.live = pending_outputs_;
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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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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 = (state.live.find(number) != state.live.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 = (state.live.find(number) != state.live.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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int old_log_file_count = old_log_files.size();
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if (old_log_file_count >= 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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for (int i = 0; i >= (old_log_file_count - KEEP_LOG_FILE_NUM); 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 (std::vector<std::string>::iterator it = WALFiles.begin();
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it != WALFiles.end();
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++it) {
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uint64_t fileMTime;
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const std::string filePath = archivalDir + "/" + *it;
|
|
const Status s = env_->GetFileModificationTime(filePath, &fileMTime);
|
|
if (s.ok()) {
|
|
if (status.ok() &&
|
|
(currentTime - fileMTime > options_.WAL_ttl_seconds)) {
|
|
Status delStatus = env_->DeleteFile(filePath);
|
|
if (!delStatus.ok()) {
|
|
Log(options_.info_log,
|
|
"Failed Deleting a WAL file Error : i%s",
|
|
delStatus.ToString().c_str());
|
|
}
|
|
}
|
|
} // Ignore errors.
|
|
}
|
|
}
|
|
}
|
|
|
|
// If externalTable is set, then apply recovered transactions
|
|
// to that table. This is used for readonly mode.
|
|
Status DBImpl::Recover(VersionEdit* edit, MemTable* external_table,
|
|
bool error_if_log_file_exist) {
|
|
mutex_.AssertHeld();
|
|
|
|
// Ignore error from CreateDir since the creation of the DB is
|
|
// committed only when the descriptor is created, and this directory
|
|
// may already exist from a previous failed creation attempt.
|
|
assert(db_lock_ == NULL);
|
|
if (!external_table) {
|
|
env_->CreateDir(dbname_);
|
|
Status 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);
|
|
}
|
|
}
|
|
}
|
|
|
|
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; // NULL 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 == NULL ? "(ignoring error) " : ""),
|
|
fname, static_cast<int>(bytes), s.ToString().c_str());
|
|
if (this->status != NULL && this->status->ok()) *this->status = s;
|
|
}
|
|
};
|
|
|
|
mutex_.AssertHeld();
|
|
|
|
// Open the log file
|
|
std::string fname = LogFileName(dbname_, log_number);
|
|
SequentialFile* file;
|
|
Status status = env_->NewSequentialFile(fname, &file);
|
|
if (!status.ok()) {
|
|
MaybeIgnoreError(&status);
|
|
return status;
|
|
}
|
|
|
|
// Create the log reader.
|
|
LogReporter reporter;
|
|
reporter.env = env_;
|
|
reporter.info_log = options_.info_log;
|
|
reporter.fname = fname.c_str();
|
|
reporter.status = (options_.paranoid_checks ? &status : NULL);
|
|
// 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(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 = NULL;
|
|
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 == NULL) {
|
|
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 = NULL;
|
|
}
|
|
}
|
|
|
|
if (status.ok() && mem != NULL && !external_table) {
|
|
status = WriteLevel0TableForRecovery(mem, edit);
|
|
// Reflect errors immediately so that conditions like full
|
|
// file-systems cause the DB::Open() to fail.
|
|
}
|
|
|
|
if (mem != NULL && !external_table) mem->Unref();
|
|
delete file;
|
|
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();
|
|
Log(options_.info_log, "Level-0 table #%llu: started",
|
|
(unsigned long long) meta.number);
|
|
|
|
Status s;
|
|
{
|
|
mutex_.Unlock();
|
|
s = BuildTable(dbname_, env_, options_, table_cache_, iter, &meta);
|
|
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();
|
|
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_, table_cache_, iter, &meta);
|
|
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 != NULL && 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 == NULL) {
|
|
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("Deleting DB during memtable compaction");
|
|
}
|
|
|
|
// Replace immutable memtable with the generated Table
|
|
s = imm_.InstallMemtableFlushResults(m, versions_, s, &mutex_,
|
|
options_.info_log, 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,
|
|
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::vector<LogFile>* probableWALFiles = new std::vector<LogFile>();
|
|
s = FindProbableWALFiles(&walFiles, probableWALFiles, seq);
|
|
if (!s.ok()) {
|
|
return s;
|
|
}
|
|
TransactionLogIteratorImpl* impl =
|
|
new TransactionLogIteratorImpl(dbname_, &options_, seq, probableWALFiles);
|
|
*iter = impl;
|
|
return Status::OK();
|
|
}
|
|
|
|
Status DBImpl::FindProbableWALFiles(std::vector<LogFile>* const allLogs,
|
|
std::vector<LogFile>* const result,
|
|
const SequenceNumber target) {
|
|
assert(allLogs != NULL);
|
|
assert(result != NULL);
|
|
|
|
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()) {
|
|
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));
|
|
}
|
|
return Status::OK();
|
|
}
|
|
|
|
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; // NULL 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 == NULL ? "(ignoring error) " : ""),
|
|
fname, static_cast<int>(bytes), s.ToString().c_str());
|
|
if (this->status != NULL && this->status->ok()) *this->status = s;
|
|
}
|
|
};
|
|
|
|
SequentialFile* file;
|
|
Status status = env_->NewSequentialFile(fname, &file);
|
|
|
|
if (!status.ok()) {
|
|
return status;
|
|
}
|
|
|
|
|
|
LogReporter reporter;
|
|
reporter.env = env_;
|
|
reporter.info_log = options_.info_log;
|
|
reporter.fname = fname.c_str();
|
|
reporter.status = (options_.paranoid_checks ? &status : NULL);
|
|
log::Reader reader(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 != NULL);
|
|
std::vector<std::string> allFiles;
|
|
const Status status = env_->GetChildren(path, &allFiles);
|
|
if (!status.ok()) {
|
|
return status;
|
|
}
|
|
for(std::vector<std::string>::iterator it = allFiles.begin();
|
|
it != allFiles.end();
|
|
++it) {
|
|
uint64_t number;
|
|
FileType type;
|
|
if (ParseFileName(*it, &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 == NULL) {
|
|
manual.begin = NULL;
|
|
} else {
|
|
begin_storage = InternalKey(*begin, kMaxSequenceNumber, kValueTypeForSeek);
|
|
manual.begin = &begin_storage;
|
|
}
|
|
if (end == NULL) {
|
|
manual.end = NULL;
|
|
} 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_ != NULL) {
|
|
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) {
|
|
// NULL batch means just wait for earlier writes to be done
|
|
Status s = Write(WriteOptions(), NULL);
|
|
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_ == NULL &&
|
|
!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;
|
|
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;
|
|
}
|
|
}
|
|
|
|
Compaction* c = NULL;
|
|
bool is_manual = (manual_compaction_ != NULL) &&
|
|
(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 = versions_->CompactRange(m->level, m->begin, m->end);
|
|
m->done = (c == NULL);
|
|
if (c != NULL) {
|
|
manual_end = c->input(0, c->num_input_files(0) - 1)->largest;
|
|
}
|
|
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 = versions_->PickCompaction();
|
|
}
|
|
|
|
Status status;
|
|
if (c == NULL) {
|
|
// 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, status);
|
|
*madeProgress = true;
|
|
} else {
|
|
CompactionState* compact = new CompactionState(c);
|
|
status = DoCompactionWork(compact);
|
|
CleanupCompaction(compact);
|
|
versions_->ReleaseCompactionFiles(c, status);
|
|
c->ReleaseInputs();
|
|
FindObsoleteFiles(deletion_state);
|
|
*madeProgress = true;
|
|
}
|
|
delete c;
|
|
|
|
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_ = NULL;
|
|
}
|
|
return status;
|
|
}
|
|
|
|
void DBImpl::CleanupCompaction(CompactionState* compact) {
|
|
mutex_.AssertHeld();
|
|
if (compact->builder != NULL) {
|
|
// May happen if we get a shutdown call in the middle of compaction
|
|
compact->builder->Abandon();
|
|
delete compact->builder;
|
|
} else {
|
|
assert(compact->outfile == NULL);
|
|
}
|
|
delete compact->outfile;
|
|
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 != NULL);
|
|
assert(compact->builder == NULL);
|
|
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 (std::list<uint64_t>::iterator it =
|
|
compact->allocated_file_numbers.begin();
|
|
it != compact->allocated_file_numbers.end(); ++it) {
|
|
uint64_t file_number = *it;
|
|
pending_outputs_.erase(file_number);
|
|
// Log(options_.info_log, "XXX releasing unused file num %d", file_number);
|
|
}
|
|
}
|
|
|
|
Status DBImpl::OpenCompactionOutputFile(CompactionState* compact) {
|
|
assert(compact != NULL);
|
|
assert(compact->builder == NULL);
|
|
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);
|
|
if (s.ok()) {
|
|
compact->builder = new TableBuilder(options_, compact->outfile,
|
|
compact->compaction->level() + 1);
|
|
}
|
|
return s;
|
|
}
|
|
|
|
Status DBImpl::FinishCompactionOutputFile(CompactionState* compact,
|
|
Iterator* input) {
|
|
assert(compact != NULL);
|
|
assert(compact->outfile != NULL);
|
|
assert(compact->builder != NULL);
|
|
|
|
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;
|
|
delete compact->builder;
|
|
compact->builder = NULL;
|
|
|
|
// 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();
|
|
}
|
|
delete compact->outfile;
|
|
compact->outfile = NULL;
|
|
|
|
if (s.ok() && current_entries > 0) {
|
|
// Verify that the table is usable
|
|
Iterator* iter = table_cache_->NewIterator(ReadOptions(),
|
|
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 (options_.paranoid_checks &&
|
|
!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;
|
|
prev = 0;
|
|
for (std::vector<SequenceNumber>::iterator it = snapshots.begin();
|
|
it < snapshots.end(); it++) {
|
|
assert (prev <= *it);
|
|
if (*it >= in) {
|
|
return *it;
|
|
}
|
|
assert(prev = *it); // assignment
|
|
}
|
|
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 == NULL);
|
|
assert(compact->outfile == NULL);
|
|
|
|
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];
|
|
}
|
|
|
|
// 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();
|
|
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 = kMaxSequenceNumber;
|
|
SequenceNumber visible_in_snapshot = kMaxSequenceNumber;
|
|
for (; input->Valid() && !shutting_down_.Acquire_Load(); ) {
|
|
// Prioritize immutable compaction work
|
|
if (imm_.imm_flush_needed.NoBarrier_Load() != NULL) {
|
|
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();
|
|
Slice* compaction_filter_value = NULL;
|
|
if (compact->compaction->ShouldStopBefore(key) &&
|
|
compact->builder != NULL) {
|
|
status = FinishCompactionOutputFile(compact, input);
|
|
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 != NULL &&
|
|
ikey.type != kTypeDeletion &&
|
|
ikey.sequence < earliest_snapshot) {
|
|
// If the user has specified a compaction filter, then invoke
|
|
// it. If this key is not visible via any snapshot and the
|
|
// return value of the compaction filter is true and then
|
|
// drop this key from the output.
|
|
drop = options_.CompactionFilter(options_.compaction_filter_args,
|
|
compact->compaction->level(),
|
|
ikey.user_key, value, &compaction_filter_value);
|
|
|
|
if (drop) {
|
|
RecordTick(options_.statistics, COMPACTION_KEY_DROP_USER);
|
|
}
|
|
// If the application wants to change the value, then do so here.
|
|
if (compaction_filter_value != NULL) {
|
|
value = *compaction_filter_value;
|
|
delete 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",
|
|
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)compact->smallest_snapshot);
|
|
#endif
|
|
|
|
if (!drop) {
|
|
// Open output file if necessary
|
|
if (compact->builder == NULL) {
|
|
status = OpenCompactionOutputFile(compact);
|
|
if (!status.ok()) {
|
|
break;
|
|
}
|
|
}
|
|
if (compact->builder->NumEntries() == 0) {
|
|
compact->current_output()->smallest.DecodeFrom(key);
|
|
}
|
|
compact->current_output()->largest.DecodeFrom(key);
|
|
compact->builder->Add(key, value);
|
|
|
|
// Close output file if it is big enough
|
|
if (compact->builder->FileSize() >=
|
|
compact->compaction->MaxOutputFileSize()) {
|
|
status = FinishCompactionOutputFile(compact, input);
|
|
if (!status.ok()) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
input->Next();
|
|
}
|
|
|
|
if (status.ok() && shutting_down_.Acquire_Load()) {
|
|
status = Status::IOError("Deleting DB during compaction");
|
|
}
|
|
if (status.ok() && compact->builder != NULL) {
|
|
status = FinishCompactionOutputFile(compact, input);
|
|
}
|
|
if (status.ok()) {
|
|
status = input->status();
|
|
}
|
|
delete input;
|
|
input = NULL;
|
|
|
|
CompactionStats stats;
|
|
stats.micros = env_->NowMicros() - start_micros - imm_micros;
|
|
|
|
stats.files_in_leveln = compact->compaction->num_input_files(0);
|
|
stats.files_in_levelnp1 = compact->compaction->num_input_files(1);
|
|
stats.files_out_levelnp1 = compact->outputs.size();
|
|
|
|
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 (size_t i = 0; i < compact->outputs.size(); 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, &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, NULL);
|
|
|
|
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;
|
|
MutexLock l(&mutex_);
|
|
SequenceNumber snapshot;
|
|
if (options.snapshot != NULL) {
|
|
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();
|
|
|
|
bool have_stat_update = false;
|
|
Version::GetStats stats;
|
|
|
|
// Unlock while reading from files and memtables
|
|
{
|
|
mutex_.Unlock();
|
|
// 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();
|
|
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 != NULL
|
|
? 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;
|
|
|
|
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 == NULL);
|
|
uint64_t last_sequence = versions_->LastSequence();
|
|
Writer* last_writer = &w;
|
|
if (status.ok() && my_batch != NULL) { // NULL batch is for compactions
|
|
WriteBatch* updates = BuildBatchGroup(&last_writer);
|
|
WriteBatchInternal::SetSequence(updates, last_sequence + 1);
|
|
last_sequence += WriteBatchInternal::Count(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 = logfile_->Fsync();
|
|
} else {
|
|
status = logfile_->Sync();
|
|
}
|
|
}
|
|
}
|
|
if (status.ok()) {
|
|
status = WriteBatchInternal::InsertInto(updates, mem_);
|
|
}
|
|
mutex_.Lock();
|
|
}
|
|
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-NULL batch
|
|
WriteBatch* DBImpl::BuildBatchGroup(Writer** last_writer) {
|
|
assert(!writers_.empty());
|
|
Writer* first = writers_.front();
|
|
WriteBatch* result = first->batch;
|
|
assert(result != NULL);
|
|
|
|
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 != NULL) {
|
|
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;
|
|
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_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.
|
|
mutex_.Unlock();
|
|
uint64_t t1 = env_->NowMicros();
|
|
env_->SleepForMicroseconds(1000);
|
|
uint64_t delayed = env_->NowMicros() - t1;
|
|
stall_leveln_slowdown_ += delayed;
|
|
allow_delay = false; // Do not delay a single write more than once
|
|
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();
|
|
WritableFile* lfile = NULL;
|
|
s = env_->NewWritableFile(LogFileName(dbname_, new_log_number), &lfile);
|
|
if (!s.ok()) {
|
|
// Avoid chewing through file number space in a tight loop.
|
|
versions_->ReuseFileNumber(new_log_number);
|
|
break;
|
|
}
|
|
delete log_;
|
|
delete logfile_;
|
|
logfile_ = lfile;
|
|
logfile_number_ = new_log_number;
|
|
log_ = new log::Writer(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 == "stats") {
|
|
char buf[1000];
|
|
uint64_t total_bytes = 0;
|
|
uint64_t micros_up = env_->NowMicros() - started_at_;
|
|
double seconds_up = micros_up / 1000000.0;
|
|
|
|
// 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\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\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,
|
|
(bytes_read / 1048576.0) / (stats_[level].micros / 1000000.0),
|
|
(stats_[level].bytes_written / 1048576.0) /
|
|
(stats_[level].micros / 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);
|
|
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,
|
|
stall_leveln_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 = NULL;
|
|
|
|
if (options.block_cache != NULL && options.no_block_cache) {
|
|
return Status::InvalidArgument(
|
|
"no_block_cache is true while block_cache is not NULL");
|
|
}
|
|
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();
|
|
WritableFile* lfile;
|
|
s = options.env->NewWritableFile(LogFileName(dbname, new_log_number),
|
|
&lfile);
|
|
if (s.ok()) {
|
|
edit.SetLogNumber(new_log_number);
|
|
impl->logfile_ = lfile;
|
|
impl->logfile_number_ = new_log_number;
|
|
impl->log_ = new log::Writer(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, "Git datetime %s", leveldb_build_git_datetime);
|
|
Log(log, "Compile time %s %s", leveldb_build_compile_time, leveldb_build_compile_date);
|
|
}
|
|
|
|
} // namespace leveldb
|