mirror of https://github.com/facebook/rocksdb.git
743 lines
31 KiB
C++
743 lines
31 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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//
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// 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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#pragma once
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#include <atomic>
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#include <deque>
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#include <functional>
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#include <memory>
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#include <string>
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#include <unordered_set>
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#include <vector>
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#include "db/dbformat.h"
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#include "db/kv_checksum.h"
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#include "db/range_tombstone_fragmenter.h"
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#include "db/read_callback.h"
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#include "db/seqno_to_time_mapping.h"
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#include "db/version_edit.h"
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#include "memory/allocator.h"
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#include "memory/concurrent_arena.h"
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#include "monitoring/instrumented_mutex.h"
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#include "options/cf_options.h"
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#include "rocksdb/db.h"
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#include "rocksdb/memtablerep.h"
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#include "table/multiget_context.h"
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#include "util/cast_util.h"
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#include "util/dynamic_bloom.h"
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#include "util/hash.h"
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#include "util/hash_containers.h"
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namespace ROCKSDB_NAMESPACE {
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struct FlushJobInfo;
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class Mutex;
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class MemTableIterator;
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class MergeContext;
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class SystemClock;
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struct ImmutableMemTableOptions {
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explicit ImmutableMemTableOptions(const ImmutableOptions& ioptions,
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const MutableCFOptions& mutable_cf_options);
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size_t arena_block_size;
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uint32_t memtable_prefix_bloom_bits;
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size_t memtable_huge_page_size;
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bool memtable_whole_key_filtering;
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bool inplace_update_support;
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size_t inplace_update_num_locks;
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UpdateStatus (*inplace_callback)(char* existing_value,
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uint32_t* existing_value_size,
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Slice delta_value,
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std::string* merged_value);
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size_t max_successive_merges;
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bool strict_max_successive_merges;
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Statistics* statistics;
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MergeOperator* merge_operator;
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Logger* info_log;
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uint32_t protection_bytes_per_key;
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bool allow_data_in_errors;
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bool paranoid_memory_checks;
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};
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// Batched counters to updated when inserting keys in one write batch.
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// In post process of the write batch, these can be updated together.
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// Only used in concurrent memtable insert case.
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struct MemTablePostProcessInfo {
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uint64_t data_size = 0;
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uint64_t num_entries = 0;
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uint64_t num_deletes = 0;
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uint64_t num_range_deletes = 0;
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};
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using MultiGetRange = MultiGetContext::Range;
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// Note: Many of the methods in this class have comments indicating that
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// external synchronization is required as these methods are not thread-safe.
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// It is up to higher layers of code to decide how to prevent concurrent
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// invocation of these methods. This is usually done by acquiring either
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// the db mutex or the single writer thread.
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//
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// Some of these methods are documented to only require external
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// synchronization if this memtable is immutable. Calling MarkImmutable() is
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// not sufficient to guarantee immutability. It is up to higher layers of
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// code to determine if this MemTable can still be modified by other threads.
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// Eg: The Superversion stores a pointer to the current MemTable (that can
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// be modified) and a separate list of the MemTables that can no longer be
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// written to (aka the 'immutable memtables').
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class MemTable {
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public:
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struct KeyComparator : public MemTableRep::KeyComparator {
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const InternalKeyComparator comparator;
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explicit KeyComparator(const InternalKeyComparator& c) : comparator(c) {}
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int operator()(const char* prefix_len_key1,
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const char* prefix_len_key2) const override;
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int operator()(const char* prefix_len_key,
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const DecodedType& key) const override;
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};
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// MemTables are reference counted. The initial reference count
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// is zero and the caller must call Ref() at least once.
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//
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// earliest_seq should be the current SequenceNumber in the db such that any
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// key inserted into this memtable will have an equal or larger seq number.
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// (When a db is first created, the earliest sequence number will be 0).
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// If the earliest sequence number is not known, kMaxSequenceNumber may be
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// used, but this may prevent some transactions from succeeding until the
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// first key is inserted into the memtable.
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explicit MemTable(const InternalKeyComparator& comparator,
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const ImmutableOptions& ioptions,
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const MutableCFOptions& mutable_cf_options,
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WriteBufferManager* write_buffer_manager,
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SequenceNumber earliest_seq, uint32_t column_family_id);
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// No copying allowed
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MemTable(const MemTable&) = delete;
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MemTable& operator=(const MemTable&) = delete;
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// Do not delete this MemTable unless Unref() indicates it not in use.
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~MemTable();
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// Increase reference count.
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable.
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void Ref() { ++refs_; }
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// Drop reference count.
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// If the refcount goes to zero return this memtable, otherwise return null.
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable.
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MemTable* Unref() {
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--refs_;
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assert(refs_ >= 0);
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if (refs_ <= 0) {
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return this;
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}
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return nullptr;
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}
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// Returns an estimate of the number of bytes of data in use by this
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// data structure.
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//
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable (unless this Memtable is immutable).
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size_t ApproximateMemoryUsage();
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// As a cheap version of `ApproximateMemoryUsage()`, this function doesn't
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// require external synchronization. The value may be less accurate though
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size_t ApproximateMemoryUsageFast() const {
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return approximate_memory_usage_.load(std::memory_order_relaxed);
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}
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// used by MemTableListVersion::MemoryAllocatedBytesExcludingLast
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size_t MemoryAllocatedBytes() const {
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return table_->ApproximateMemoryUsage() +
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range_del_table_->ApproximateMemoryUsage() +
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arena_.MemoryAllocatedBytes();
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}
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// Returns a vector of unique random memtable entries of size 'sample_size'.
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//
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// Note: the entries are stored in the unordered_set as length-prefixed keys,
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// hence their representation in the set as "const char*".
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// Note2: the size of the output set 'entries' is not enforced to be strictly
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// equal to 'target_sample_size'. Its final size might be slightly
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// greater or slightly less than 'target_sample_size'
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//
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable (unless this Memtable is immutable).
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// REQUIRES: SkipList memtable representation. This function is not
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// implemented for any other type of memtable representation (vectorrep,
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// hashskiplist,...).
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void UniqueRandomSample(const uint64_t& target_sample_size,
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std::unordered_set<const char*>* entries) {
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// TODO(bjlemaire): at the moment, only supported by skiplistrep.
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// Extend it to all other memtable representations.
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table_->UniqueRandomSample(num_entries(), target_sample_size, entries);
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}
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// This method heuristically determines if the memtable should continue to
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// host more data.
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bool ShouldScheduleFlush() const {
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return flush_state_.load(std::memory_order_relaxed) == FLUSH_REQUESTED;
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}
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// Returns true if a flush should be scheduled and the caller should
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// be the one to schedule it
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bool MarkFlushScheduled() {
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auto before = FLUSH_REQUESTED;
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return flush_state_.compare_exchange_strong(before, FLUSH_SCHEDULED,
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std::memory_order_relaxed,
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std::memory_order_relaxed);
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}
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// Return an iterator that yields the contents of the memtable.
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//
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// The caller must ensure that the underlying MemTable remains live
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// while the returned iterator is live. The keys returned by this
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// iterator are internal keys encoded by AppendInternalKey in the
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// db/dbformat.{h,cc} module.
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//
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// By default, it returns an iterator for prefix seek if prefix_extractor
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// is configured in Options.
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// arena: If not null, the arena needs to be used to allocate the Iterator.
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// Calling ~Iterator of the iterator will destroy all the states but
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// those allocated in arena.
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// seqno_to_time_mapping: it's used to support return write unix time for the
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// data, currently only needed for iterators serving user reads.
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InternalIterator* NewIterator(
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const ReadOptions& read_options,
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UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping, Arena* arena,
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const SliceTransform* prefix_extractor);
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// Returns an iterator that wraps a MemTableIterator and logically strips the
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// user-defined timestamp of each key. This API is only used by flush when
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// user-defined timestamps in MemTable only feature is enabled.
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InternalIterator* NewTimestampStrippingIterator(
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const ReadOptions& read_options,
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UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping, Arena* arena,
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const SliceTransform* prefix_extractor, size_t ts_sz);
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// Returns an iterator that yields the range tombstones of the memtable.
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// The caller must ensure that the underlying MemTable remains live
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// while the returned iterator is live.
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// @param immutable_memtable Whether this memtable is an immutable memtable.
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// This information is not stored in memtable itself, so it needs to be
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// specified by the caller. This flag is used internally to decide whether a
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// cached fragmented range tombstone list can be returned. This cached version
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// is constructed when a memtable becomes immutable. Setting the flag to false
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// will always yield correct result, but may incur performance penalty as it
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// always creates a new fragmented range tombstone list.
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FragmentedRangeTombstoneIterator* NewRangeTombstoneIterator(
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const ReadOptions& read_options, SequenceNumber read_seq,
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bool immutable_memtable);
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// Returns an iterator that yields the range tombstones of the memtable and
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// logically strips the user-defined timestamp of each key (including start
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// key, and end key). This API is only used by flush when user-defined
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// timestamps in MemTable only feature is enabled.
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FragmentedRangeTombstoneIterator* NewTimestampStrippingRangeTombstoneIterator(
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const ReadOptions& read_options, SequenceNumber read_seq, size_t ts_sz);
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Status VerifyEncodedEntry(Slice encoded,
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const ProtectionInfoKVOS64& kv_prot_info);
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// Add an entry into memtable that maps key to value at the
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// specified sequence number and with the specified type.
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// Typically value will be empty if type==kTypeDeletion.
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//
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// REQUIRES: if allow_concurrent = false, external synchronization to prevent
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// simultaneous operations on the same MemTable.
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//
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// Returns `Status::TryAgain` if the `seq`, `key` combination already exists
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// in the memtable and `MemTableRepFactory::CanHandleDuplicatedKey()` is true.
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// The next attempt should try a larger value for `seq`.
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Status Add(SequenceNumber seq, ValueType type, const Slice& key,
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const Slice& value, const ProtectionInfoKVOS64* kv_prot_info,
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bool allow_concurrent = false,
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MemTablePostProcessInfo* post_process_info = nullptr,
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void** hint = nullptr);
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// Used to Get value associated with key or Get Merge Operands associated
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// with key.
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// If do_merge = true the default behavior which is Get value for key is
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// executed. Expected behavior is described right below.
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// If memtable contains a value for key, store it in *value and return true.
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// If memtable contains a deletion for key, store NotFound() in *status and
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// return true.
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// If memtable contains Merge operation as the most recent entry for a key,
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// and the merge process does not stop (not reaching a value or delete),
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// prepend the current merge operand to *operands.
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// store MergeInProgress in s, and return false.
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// If an unexpected error or corruption occurs, store Corruption() or other
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// error in *status and return true.
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// Else, return false.
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// If any operation was found, its most recent sequence number
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// will be stored in *seq on success (regardless of whether true/false is
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// returned). Otherwise, *seq will be set to kMaxSequenceNumber.
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// On success, *s may be set to OK, NotFound, or MergeInProgress. Any other
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// status returned indicates a corruption or other unexpected error.
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// If do_merge = false then any Merge Operands encountered for key are simply
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// stored in merge_context.operands_list and never actually merged to get a
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// final value. The raw Merge Operands are eventually returned to the user.
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// @param value If not null and memtable contains a value for key, `value`
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// will be set to the result value.
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// @param column If not null and memtable contains a value/WideColumn for key,
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// `column` will be set to the result value/WideColumn.
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// Note: only one of `value` and `column` can be non-nullptr.
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// @param immutable_memtable Whether this memtable is immutable. Used
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// internally by NewRangeTombstoneIterator(). See comment above
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// NewRangeTombstoneIterator() for more detail.
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bool Get(const LookupKey& key, std::string* value,
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PinnableWideColumns* columns, std::string* timestamp, Status* s,
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MergeContext* merge_context,
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SequenceNumber* max_covering_tombstone_seq, SequenceNumber* seq,
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const ReadOptions& read_opts, bool immutable_memtable,
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ReadCallback* callback = nullptr, bool* is_blob_index = nullptr,
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bool do_merge = true);
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bool Get(const LookupKey& key, std::string* value,
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PinnableWideColumns* columns, std::string* timestamp, Status* s,
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MergeContext* merge_context,
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SequenceNumber* max_covering_tombstone_seq,
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const ReadOptions& read_opts, bool immutable_memtable,
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ReadCallback* callback = nullptr, bool* is_blob_index = nullptr,
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bool do_merge = true) {
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SequenceNumber seq;
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return Get(key, value, columns, timestamp, s, merge_context,
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max_covering_tombstone_seq, &seq, read_opts, immutable_memtable,
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callback, is_blob_index, do_merge);
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}
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// @param immutable_memtable Whether this memtable is immutable. Used
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// internally by NewRangeTombstoneIterator(). See comment above
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// NewRangeTombstoneIterator() for more detail.
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void MultiGet(const ReadOptions& read_options, MultiGetRange* range,
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ReadCallback* callback, bool immutable_memtable);
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// If `key` exists in current memtable with type value_type and the existing
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// value is at least as large as the new value, updates it in-place. Otherwise
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// adds the new value to the memtable out-of-place.
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//
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// Returns `Status::TryAgain` if the `seq`, `key` combination already exists
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// in the memtable and `MemTableRepFactory::CanHandleDuplicatedKey()` is true.
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// The next attempt should try a larger value for `seq`.
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//
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable.
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Status Update(SequenceNumber seq, ValueType value_type, const Slice& key,
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const Slice& value, const ProtectionInfoKVOS64* kv_prot_info);
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// If `key` exists in current memtable with type `kTypeValue` and the existing
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// value is at least as large as the new value, updates it in-place. Otherwise
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// if `key` exists in current memtable with type `kTypeValue`, adds the new
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// value to the memtable out-of-place.
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//
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// Returns `Status::NotFound` if `key` does not exist in current memtable or
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// the latest version of `key` does not have `kTypeValue`.
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//
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// Returns `Status::TryAgain` if the `seq`, `key` combination already exists
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// in the memtable and `MemTableRepFactory::CanHandleDuplicatedKey()` is true.
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// The next attempt should try a larger value for `seq`.
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//
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable.
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Status UpdateCallback(SequenceNumber seq, const Slice& key,
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const Slice& delta,
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const ProtectionInfoKVOS64* kv_prot_info);
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// Returns the number of successive merge entries starting from the newest
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// entry for the key. The count ends when the oldest entry in the memtable
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// with which the newest entry would be merged is reached, or the count
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// reaches `limit`.
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size_t CountSuccessiveMergeEntries(const LookupKey& key, size_t limit);
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// Update counters and flush status after inserting a whole write batch
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// Used in concurrent memtable inserts.
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void BatchPostProcess(const MemTablePostProcessInfo& update_counters) {
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num_entries_.fetch_add(update_counters.num_entries,
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std::memory_order_relaxed);
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data_size_.fetch_add(update_counters.data_size, std::memory_order_relaxed);
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if (update_counters.num_deletes != 0) {
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num_deletes_.fetch_add(update_counters.num_deletes,
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std::memory_order_relaxed);
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}
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if (update_counters.num_range_deletes > 0) {
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num_range_deletes_.fetch_add(update_counters.num_range_deletes,
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std::memory_order_relaxed);
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}
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UpdateFlushState();
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}
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// Get total number of entries in the mem table.
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable (unless this Memtable is immutable).
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uint64_t num_entries() const {
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return num_entries_.load(std::memory_order_relaxed);
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}
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// Get total number of deletes in the mem table.
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable (unless this Memtable is immutable).
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uint64_t num_deletes() const {
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return num_deletes_.load(std::memory_order_relaxed);
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}
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// Get total number of range deletions in the mem table.
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable (unless this Memtable is immutable).
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uint64_t num_range_deletes() const {
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return num_range_deletes_.load(std::memory_order_relaxed);
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}
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uint64_t get_data_size() const {
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return data_size_.load(std::memory_order_relaxed);
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}
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size_t write_buffer_size() const {
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return write_buffer_size_.load(std::memory_order_relaxed);
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}
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// Dynamically change the memtable's capacity. If set below the current usage,
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// the next key added will trigger a flush. Can only increase size when
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// memtable prefix bloom is disabled, since we can't easily allocate more
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// space.
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void UpdateWriteBufferSize(size_t new_write_buffer_size) {
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if (bloom_filter_ == nullptr ||
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new_write_buffer_size < write_buffer_size_) {
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write_buffer_size_.store(new_write_buffer_size,
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std::memory_order_relaxed);
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}
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}
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// Returns the edits area that is needed for flushing the memtable
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VersionEdit* GetEdits() { return &edit_; }
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// Returns if there is no entry inserted to the mem table.
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable (unless this Memtable is immutable).
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bool IsEmpty() const { return first_seqno_ == 0; }
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// Returns the sequence number of the first element that was inserted
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// into the memtable.
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable (unless this Memtable is immutable).
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SequenceNumber GetFirstSequenceNumber() {
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return first_seqno_.load(std::memory_order_relaxed);
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}
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// Returns the sequence number of the first element that was inserted
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// into the memtable.
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// REQUIRES: external synchronization to prevent simultaneous
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// operations on the same MemTable (unless this Memtable is immutable).
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void SetFirstSequenceNumber(SequenceNumber first_seqno) {
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return first_seqno_.store(first_seqno, std::memory_order_relaxed);
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}
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// Returns the sequence number that is guaranteed to be smaller than or equal
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// to the sequence number of any key that could be inserted into this
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|
// memtable. It can then be assumed that any write with a larger(or equal)
|
|
// sequence number will be present in this memtable or a later memtable.
|
|
//
|
|
// If the earliest sequence number could not be determined,
|
|
// kMaxSequenceNumber will be returned.
|
|
SequenceNumber GetEarliestSequenceNumber() {
|
|
return earliest_seqno_.load(std::memory_order_relaxed);
|
|
}
|
|
|
|
// Sets the sequence number that is guaranteed to be smaller than or equal
|
|
// to the sequence number of any key that could be inserted into this
|
|
// memtable. It can then be assumed that any write with a larger(or equal)
|
|
// sequence number will be present in this memtable or a later memtable.
|
|
// Used only for MemPurge operation
|
|
void SetEarliestSequenceNumber(SequenceNumber earliest_seqno) {
|
|
return earliest_seqno_.store(earliest_seqno, std::memory_order_relaxed);
|
|
}
|
|
|
|
// DB's latest sequence ID when the memtable is created. This number
|
|
// may be updated to a more recent one before any key is inserted.
|
|
SequenceNumber GetCreationSeq() const { return creation_seq_; }
|
|
|
|
void SetCreationSeq(SequenceNumber sn) { creation_seq_ = sn; }
|
|
|
|
// Returns the next active logfile number when this memtable is about to
|
|
// be flushed to storage
|
|
// REQUIRES: external synchronization to prevent simultaneous
|
|
// operations on the same MemTable.
|
|
uint64_t GetNextLogNumber() { return mem_next_logfile_number_; }
|
|
|
|
// Sets the next active logfile number when this memtable is about to
|
|
// be flushed to storage
|
|
// REQUIRES: external synchronization to prevent simultaneous
|
|
// operations on the same MemTable.
|
|
void SetNextLogNumber(uint64_t num) { mem_next_logfile_number_ = num; }
|
|
|
|
// if this memtable contains data from a committed
|
|
// two phase transaction we must take note of the
|
|
// log which contains that data so we can know
|
|
// when to relese that log
|
|
void RefLogContainingPrepSection(uint64_t log);
|
|
uint64_t GetMinLogContainingPrepSection();
|
|
|
|
// Notify the underlying storage that no more items will be added.
|
|
// REQUIRES: external synchronization to prevent simultaneous
|
|
// operations on the same MemTable.
|
|
// After MarkImmutable() is called, you should not attempt to
|
|
// write anything to this MemTable(). (Ie. do not call Add() or Update()).
|
|
void MarkImmutable() {
|
|
table_->MarkReadOnly();
|
|
mem_tracker_.DoneAllocating();
|
|
}
|
|
|
|
// Notify the underlying storage that all data it contained has been
|
|
// persisted.
|
|
// REQUIRES: external synchronization to prevent simultaneous
|
|
// operations on the same MemTable.
|
|
void MarkFlushed() { table_->MarkFlushed(); }
|
|
|
|
// return true if the current MemTableRep supports merge operator.
|
|
bool IsMergeOperatorSupported() const {
|
|
return table_->IsMergeOperatorSupported();
|
|
}
|
|
|
|
// return true if the current MemTableRep supports snapshots.
|
|
// inplace update prevents snapshots,
|
|
bool IsSnapshotSupported() const {
|
|
return table_->IsSnapshotSupported() && !moptions_.inplace_update_support;
|
|
}
|
|
|
|
struct MemTableStats {
|
|
uint64_t size;
|
|
uint64_t count;
|
|
};
|
|
|
|
MemTableStats ApproximateStats(const Slice& start_ikey,
|
|
const Slice& end_ikey);
|
|
|
|
// Get the lock associated for the key
|
|
port::RWMutex* GetLock(const Slice& key);
|
|
|
|
const InternalKeyComparator& GetInternalKeyComparator() const {
|
|
return comparator_.comparator;
|
|
}
|
|
|
|
const ImmutableMemTableOptions* GetImmutableMemTableOptions() const {
|
|
return &moptions_;
|
|
}
|
|
|
|
uint64_t ApproximateOldestKeyTime() const {
|
|
return oldest_key_time_.load(std::memory_order_relaxed);
|
|
}
|
|
|
|
// REQUIRES: db_mutex held.
|
|
void SetID(uint64_t id) { id_ = id; }
|
|
|
|
uint64_t GetID() const { return id_; }
|
|
|
|
void SetFlushCompleted(bool completed) { flush_completed_ = completed; }
|
|
|
|
uint64_t GetFileNumber() const { return file_number_; }
|
|
|
|
void SetFileNumber(uint64_t file_num) { file_number_ = file_num; }
|
|
|
|
void SetFlushInProgress(bool in_progress) {
|
|
flush_in_progress_ = in_progress;
|
|
}
|
|
|
|
void SetFlushJobInfo(std::unique_ptr<FlushJobInfo>&& info) {
|
|
flush_job_info_ = std::move(info);
|
|
}
|
|
|
|
std::unique_ptr<FlushJobInfo> ReleaseFlushJobInfo() {
|
|
return std::move(flush_job_info_);
|
|
}
|
|
|
|
// Returns a heuristic flush decision
|
|
bool ShouldFlushNow();
|
|
|
|
// Updates `fragmented_range_tombstone_list_` that will be used to serve reads
|
|
// when this memtable becomes an immutable memtable (in some
|
|
// MemtableListVersion::memlist_). Should be called when this memtable is
|
|
// about to become immutable. May be called multiple times since
|
|
// SwitchMemtable() may fail.
|
|
void ConstructFragmentedRangeTombstones();
|
|
|
|
// Returns whether a fragmented range tombstone list is already constructed
|
|
// for this memtable. It should be constructed right before a memtable is
|
|
// added to an immutable memtable list. Note that if a memtable does not have
|
|
// any range tombstone, then no range tombstone list will ever be constructed
|
|
// and true is returned in that case.
|
|
bool IsFragmentedRangeTombstonesConstructed() const {
|
|
return fragmented_range_tombstone_list_.get() != nullptr ||
|
|
is_range_del_table_empty_;
|
|
}
|
|
|
|
// Get the newest user-defined timestamp contained in this MemTable. Check
|
|
// `newest_udt_` for what newer means. This method should only be invoked for
|
|
// an MemTable that has enabled user-defined timestamp feature and set
|
|
// `persist_user_defined_timestamps` to false. The tracked newest UDT will be
|
|
// used by flush job in the background to help check the MemTable's
|
|
// eligibility for Flush.
|
|
const Slice& GetNewestUDT() const;
|
|
|
|
// Returns Corruption status if verification fails.
|
|
static Status VerifyEntryChecksum(const char* entry,
|
|
uint32_t protection_bytes_per_key,
|
|
bool allow_data_in_errors = false);
|
|
|
|
private:
|
|
enum FlushStateEnum { FLUSH_NOT_REQUESTED, FLUSH_REQUESTED, FLUSH_SCHEDULED };
|
|
|
|
friend class MemTableIterator;
|
|
friend class MemTableBackwardIterator;
|
|
friend class MemTableList;
|
|
|
|
KeyComparator comparator_;
|
|
const ImmutableMemTableOptions moptions_;
|
|
int refs_;
|
|
const size_t kArenaBlockSize;
|
|
AllocTracker mem_tracker_;
|
|
ConcurrentArena arena_;
|
|
std::unique_ptr<MemTableRep> table_;
|
|
std::unique_ptr<MemTableRep> range_del_table_;
|
|
std::atomic_bool is_range_del_table_empty_;
|
|
|
|
// Total data size of all data inserted
|
|
std::atomic<uint64_t> data_size_;
|
|
std::atomic<uint64_t> num_entries_;
|
|
std::atomic<uint64_t> num_deletes_;
|
|
std::atomic<uint64_t> num_range_deletes_;
|
|
|
|
// Dynamically changeable memtable option
|
|
std::atomic<size_t> write_buffer_size_;
|
|
|
|
// These are used to manage memtable flushes to storage
|
|
bool flush_in_progress_; // started the flush
|
|
bool flush_completed_; // finished the flush
|
|
uint64_t file_number_; // filled up after flush is complete
|
|
|
|
// The updates to be applied to the transaction log when this
|
|
// memtable is flushed to storage.
|
|
VersionEdit edit_;
|
|
|
|
// The sequence number of the kv that was inserted first
|
|
std::atomic<SequenceNumber> first_seqno_;
|
|
|
|
// The db sequence number at the time of creation or kMaxSequenceNumber
|
|
// if not set.
|
|
std::atomic<SequenceNumber> earliest_seqno_;
|
|
|
|
SequenceNumber creation_seq_;
|
|
|
|
// The log files earlier than this number can be deleted.
|
|
uint64_t mem_next_logfile_number_;
|
|
|
|
// the earliest log containing a prepared section
|
|
// which has been inserted into this memtable.
|
|
std::atomic<uint64_t> min_prep_log_referenced_;
|
|
|
|
// rw locks for inplace updates
|
|
std::vector<port::RWMutex> locks_;
|
|
|
|
const SliceTransform* const prefix_extractor_;
|
|
std::unique_ptr<DynamicBloom> bloom_filter_;
|
|
|
|
std::atomic<FlushStateEnum> flush_state_;
|
|
|
|
SystemClock* clock_;
|
|
|
|
// Extract sequential insert prefixes.
|
|
const SliceTransform* insert_with_hint_prefix_extractor_;
|
|
|
|
// Insert hints for each prefix.
|
|
UnorderedMapH<Slice, void*, SliceHasher32> insert_hints_;
|
|
|
|
// Timestamp of oldest key
|
|
std::atomic<uint64_t> oldest_key_time_;
|
|
|
|
// Memtable id to track flush.
|
|
uint64_t id_ = 0;
|
|
|
|
// Sequence number of the atomic flush that is responsible for this memtable.
|
|
// The sequence number of atomic flush is a seq, such that no writes with
|
|
// sequence numbers greater than or equal to seq are flushed, while all
|
|
// writes with sequence number smaller than seq are flushed.
|
|
SequenceNumber atomic_flush_seqno_;
|
|
|
|
// keep track of memory usage in table_, arena_, and range_del_table_.
|
|
// Gets refreshed inside `ApproximateMemoryUsage()` or `ShouldFlushNow`
|
|
std::atomic<uint64_t> approximate_memory_usage_;
|
|
|
|
// max range deletions in a memtable, before automatic flushing, 0 for
|
|
// unlimited.
|
|
uint32_t memtable_max_range_deletions_ = 0;
|
|
|
|
// Flush job info of the current memtable.
|
|
std::unique_ptr<FlushJobInfo> flush_job_info_;
|
|
|
|
// Size in bytes for the user-defined timestamps.
|
|
size_t ts_sz_;
|
|
|
|
// Whether to persist user-defined timestamps
|
|
bool persist_user_defined_timestamps_;
|
|
|
|
// Newest user-defined timestamp contained in this MemTable. For ts1, and ts2
|
|
// if Comparator::CompareTimestamp(ts1, ts2) > 0, ts1 is considered newer than
|
|
// ts2. We track this field for a MemTable if its column family has UDT
|
|
// feature enabled and the `persist_user_defined_timestamp` flag is false.
|
|
// Otherwise, this field just contains an empty Slice.
|
|
Slice newest_udt_;
|
|
|
|
// Updates flush_state_ using ShouldFlushNow()
|
|
void UpdateFlushState();
|
|
|
|
void UpdateOldestKeyTime();
|
|
|
|
void GetFromTable(const LookupKey& key,
|
|
SequenceNumber max_covering_tombstone_seq, bool do_merge,
|
|
ReadCallback* callback, bool* is_blob_index,
|
|
std::string* value, PinnableWideColumns* columns,
|
|
std::string* timestamp, Status* s,
|
|
MergeContext* merge_context, SequenceNumber* seq,
|
|
bool* found_final_value, bool* merge_in_progress);
|
|
|
|
// Always returns non-null and assumes certain pre-checks (e.g.,
|
|
// is_range_del_table_empty_) are done. This is only valid during the lifetime
|
|
// of the underlying memtable.
|
|
// read_seq and read_options.timestamp will be used as the upper bound
|
|
// for range tombstones.
|
|
FragmentedRangeTombstoneIterator* NewRangeTombstoneIteratorInternal(
|
|
const ReadOptions& read_options, SequenceNumber read_seq,
|
|
bool immutable_memtable);
|
|
|
|
// The fragmented range tombstones of this memtable.
|
|
// This is constructed when this memtable becomes immutable
|
|
// if !is_range_del_table_empty_.
|
|
std::unique_ptr<FragmentedRangeTombstoneList>
|
|
fragmented_range_tombstone_list_;
|
|
|
|
// The fragmented range tombstone of this memtable with all keys' user-defined
|
|
// timestamps logically stripped. This is constructed and used by flush when
|
|
// user-defined timestamps in memtable only feature is enabled.
|
|
std::unique_ptr<FragmentedRangeTombstoneList>
|
|
timestamp_stripping_fragmented_range_tombstone_list_;
|
|
|
|
// makes sure there is a single range tombstone writer to invalidate cache
|
|
std::mutex range_del_mutex_;
|
|
CoreLocalArray<std::shared_ptr<FragmentedRangeTombstoneListCache>>
|
|
cached_range_tombstone_;
|
|
|
|
void UpdateEntryChecksum(const ProtectionInfoKVOS64* kv_prot_info,
|
|
const Slice& key, const Slice& value, ValueType type,
|
|
SequenceNumber s, char* checksum_ptr);
|
|
|
|
void MaybeUpdateNewestUDT(const Slice& user_key);
|
|
};
|
|
|
|
const char* EncodeKey(std::string* scratch, const Slice& target);
|
|
|
|
} // namespace ROCKSDB_NAMESPACE
|