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e633983cf1
Summary: Leverage existing `FlushJob` to implement atomic flush of multiple column families. This PR depends on other PRs and is a subset of #3752 . This PR itself is not sufficient in fulfilling atomic flush. Pull Request resolved: https://github.com/facebook/rocksdb/pull/4262 Differential Revision: D9283109 Pulled By: riversand963 fbshipit-source-id: 65401f913e4160b0a61c0be6cd02adc15dad28ed
981 lines
35 KiB
C++
981 lines
35 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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#include "db/memtable.h"
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#include <algorithm>
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#include <limits>
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#include <memory>
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#include "db/dbformat.h"
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#include "db/merge_context.h"
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#include "db/merge_helper.h"
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#include "db/pinned_iterators_manager.h"
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#include "db/read_callback.h"
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#include "monitoring/perf_context_imp.h"
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#include "monitoring/statistics.h"
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#include "port/port.h"
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#include "rocksdb/comparator.h"
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#include "rocksdb/env.h"
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#include "rocksdb/iterator.h"
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#include "rocksdb/merge_operator.h"
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#include "rocksdb/slice_transform.h"
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#include "rocksdb/write_buffer_manager.h"
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#include "table/internal_iterator.h"
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#include "table/iterator_wrapper.h"
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#include "table/merging_iterator.h"
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#include "util/arena.h"
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#include "util/autovector.h"
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#include "util/coding.h"
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#include "util/memory_usage.h"
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#include "util/murmurhash.h"
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#include "util/mutexlock.h"
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#include "util/util.h"
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namespace rocksdb {
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ImmutableMemTableOptions::ImmutableMemTableOptions(
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const ImmutableCFOptions& ioptions,
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const MutableCFOptions& mutable_cf_options)
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: arena_block_size(mutable_cf_options.arena_block_size),
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memtable_prefix_bloom_bits(
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static_cast<uint32_t>(
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static_cast<double>(mutable_cf_options.write_buffer_size) *
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mutable_cf_options.memtable_prefix_bloom_size_ratio) *
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8u),
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memtable_huge_page_size(mutable_cf_options.memtable_huge_page_size),
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inplace_update_support(ioptions.inplace_update_support),
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inplace_update_num_locks(mutable_cf_options.inplace_update_num_locks),
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inplace_callback(ioptions.inplace_callback),
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max_successive_merges(mutable_cf_options.max_successive_merges),
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statistics(ioptions.statistics),
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merge_operator(ioptions.merge_operator),
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info_log(ioptions.info_log) {}
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MemTable::MemTable(const InternalKeyComparator& cmp,
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const ImmutableCFOptions& ioptions,
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const MutableCFOptions& mutable_cf_options,
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WriteBufferManager* write_buffer_manager,
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SequenceNumber latest_seq, uint32_t column_family_id)
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: comparator_(cmp),
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moptions_(ioptions, mutable_cf_options),
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refs_(0),
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kArenaBlockSize(OptimizeBlockSize(moptions_.arena_block_size)),
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mem_tracker_(write_buffer_manager),
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arena_(
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moptions_.arena_block_size,
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(write_buffer_manager != nullptr && write_buffer_manager->enabled())
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? &mem_tracker_
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: nullptr,
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mutable_cf_options.memtable_huge_page_size),
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table_(ioptions.memtable_factory->CreateMemTableRep(
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comparator_, &arena_, mutable_cf_options.prefix_extractor.get(),
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ioptions.info_log, column_family_id)),
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range_del_table_(SkipListFactory().CreateMemTableRep(
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comparator_, &arena_, nullptr /* transform */, ioptions.info_log,
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column_family_id)),
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is_range_del_table_empty_(true),
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data_size_(0),
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num_entries_(0),
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num_deletes_(0),
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write_buffer_size_(mutable_cf_options.write_buffer_size),
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flush_in_progress_(false),
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flush_completed_(false),
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file_number_(0),
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first_seqno_(0),
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earliest_seqno_(latest_seq),
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creation_seq_(latest_seq),
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mem_next_logfile_number_(0),
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min_prep_log_referenced_(0),
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locks_(moptions_.inplace_update_support
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? moptions_.inplace_update_num_locks
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: 0),
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prefix_extractor_(mutable_cf_options.prefix_extractor.get()),
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flush_state_(FLUSH_NOT_REQUESTED),
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env_(ioptions.env),
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insert_with_hint_prefix_extractor_(
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ioptions.memtable_insert_with_hint_prefix_extractor),
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oldest_key_time_(std::numeric_limits<uint64_t>::max()),
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atomic_flush_seqno_(kMaxSequenceNumber) {
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UpdateFlushState();
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// something went wrong if we need to flush before inserting anything
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assert(!ShouldScheduleFlush());
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if (prefix_extractor_ && moptions_.memtable_prefix_bloom_bits > 0) {
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prefix_bloom_.reset(new DynamicBloom(
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&arena_, moptions_.memtable_prefix_bloom_bits, ioptions.bloom_locality,
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6 /* hard coded 6 probes */, nullptr, moptions_.memtable_huge_page_size,
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ioptions.info_log));
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}
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}
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MemTable::~MemTable() {
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mem_tracker_.FreeMem();
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assert(refs_ == 0);
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}
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size_t MemTable::ApproximateMemoryUsage() {
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autovector<size_t> usages = {arena_.ApproximateMemoryUsage(),
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table_->ApproximateMemoryUsage(),
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range_del_table_->ApproximateMemoryUsage(),
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rocksdb::ApproximateMemoryUsage(insert_hints_)};
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size_t total_usage = 0;
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for (size_t usage : usages) {
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// If usage + total_usage >= kMaxSizet, return kMaxSizet.
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// the following variation is to avoid numeric overflow.
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if (usage >= port::kMaxSizet - total_usage) {
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return port::kMaxSizet;
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}
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total_usage += usage;
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}
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// otherwise, return the actual usage
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return total_usage;
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}
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bool MemTable::ShouldFlushNow() const {
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size_t write_buffer_size = write_buffer_size_.load(std::memory_order_relaxed);
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// In a lot of times, we cannot allocate arena blocks that exactly matches the
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// buffer size. Thus we have to decide if we should over-allocate or
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// under-allocate.
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// This constant variable can be interpreted as: if we still have more than
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// "kAllowOverAllocationRatio * kArenaBlockSize" space left, we'd try to over
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// allocate one more block.
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const double kAllowOverAllocationRatio = 0.6;
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// If arena still have room for new block allocation, we can safely say it
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// shouldn't flush.
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auto allocated_memory = table_->ApproximateMemoryUsage() +
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range_del_table_->ApproximateMemoryUsage() +
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arena_.MemoryAllocatedBytes();
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// if we can still allocate one more block without exceeding the
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// over-allocation ratio, then we should not flush.
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if (allocated_memory + kArenaBlockSize <
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write_buffer_size + kArenaBlockSize * kAllowOverAllocationRatio) {
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return false;
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}
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// if user keeps adding entries that exceeds write_buffer_size, we need to
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// flush earlier even though we still have much available memory left.
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if (allocated_memory >
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write_buffer_size + kArenaBlockSize * kAllowOverAllocationRatio) {
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return true;
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}
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// In this code path, Arena has already allocated its "last block", which
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// means the total allocatedmemory size is either:
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// (1) "moderately" over allocated the memory (no more than `0.6 * arena
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// block size`. Or,
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// (2) the allocated memory is less than write buffer size, but we'll stop
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// here since if we allocate a new arena block, we'll over allocate too much
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// more (half of the arena block size) memory.
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//
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// In either case, to avoid over-allocate, the last block will stop allocation
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// when its usage reaches a certain ratio, which we carefully choose "0.75
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// full" as the stop condition because it addresses the following issue with
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// great simplicity: What if the next inserted entry's size is
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// bigger than AllocatedAndUnused()?
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//
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// The answer is: if the entry size is also bigger than 0.25 *
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// kArenaBlockSize, a dedicated block will be allocated for it; otherwise
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// arena will anyway skip the AllocatedAndUnused() and allocate a new, empty
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// and regular block. In either case, we *overly* over-allocated.
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//
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// Therefore, setting the last block to be at most "0.75 full" avoids both
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// cases.
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//
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// NOTE: the average percentage of waste space of this approach can be counted
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// as: "arena block size * 0.25 / write buffer size". User who specify a small
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// write buffer size and/or big arena block size may suffer.
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return arena_.AllocatedAndUnused() < kArenaBlockSize / 4;
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}
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void MemTable::UpdateFlushState() {
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auto state = flush_state_.load(std::memory_order_relaxed);
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if (state == FLUSH_NOT_REQUESTED && ShouldFlushNow()) {
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// ignore CAS failure, because that means somebody else requested
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// a flush
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flush_state_.compare_exchange_strong(state, FLUSH_REQUESTED,
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std::memory_order_relaxed,
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std::memory_order_relaxed);
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}
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}
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void MemTable::UpdateOldestKeyTime() {
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uint64_t oldest_key_time = oldest_key_time_.load(std::memory_order_relaxed);
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if (oldest_key_time == std::numeric_limits<uint64_t>::max()) {
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int64_t current_time = 0;
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auto s = env_->GetCurrentTime(¤t_time);
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if (s.ok()) {
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assert(current_time >= 0);
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// If fail, the timestamp is already set.
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oldest_key_time_.compare_exchange_strong(
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oldest_key_time, static_cast<uint64_t>(current_time),
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std::memory_order_relaxed, std::memory_order_relaxed);
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}
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}
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}
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int MemTable::KeyComparator::operator()(const char* prefix_len_key1,
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const char* prefix_len_key2) const {
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// Internal keys are encoded as length-prefixed strings.
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Slice k1 = GetLengthPrefixedSlice(prefix_len_key1);
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Slice k2 = GetLengthPrefixedSlice(prefix_len_key2);
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return comparator.CompareKeySeq(k1, k2);
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}
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int MemTable::KeyComparator::operator()(const char* prefix_len_key,
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const KeyComparator::DecodedType& key)
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const {
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// Internal keys are encoded as length-prefixed strings.
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Slice a = GetLengthPrefixedSlice(prefix_len_key);
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return comparator.CompareKeySeq(a, key);
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}
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void MemTableRep::InsertConcurrently(KeyHandle /*handle*/) {
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#ifndef ROCKSDB_LITE
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throw std::runtime_error("concurrent insert not supported");
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#else
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abort();
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#endif
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}
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Slice MemTableRep::UserKey(const char* key) const {
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Slice slice = GetLengthPrefixedSlice(key);
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return Slice(slice.data(), slice.size() - 8);
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}
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KeyHandle MemTableRep::Allocate(const size_t len, char** buf) {
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*buf = allocator_->Allocate(len);
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return static_cast<KeyHandle>(*buf);
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}
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// Encode a suitable internal key target for "target" and return it.
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// Uses *scratch as scratch space, and the returned pointer will point
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// into this scratch space.
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const char* EncodeKey(std::string* scratch, const Slice& target) {
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scratch->clear();
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PutVarint32(scratch, static_cast<uint32_t>(target.size()));
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scratch->append(target.data(), target.size());
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return scratch->data();
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}
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class MemTableIterator : public InternalIterator {
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public:
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MemTableIterator(const MemTable& mem, const ReadOptions& read_options,
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Arena* arena, bool use_range_del_table = false)
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: bloom_(nullptr),
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prefix_extractor_(mem.prefix_extractor_),
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comparator_(mem.comparator_),
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valid_(false),
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arena_mode_(arena != nullptr),
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value_pinned_(
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!mem.GetImmutableMemTableOptions()->inplace_update_support) {
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if (use_range_del_table) {
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iter_ = mem.range_del_table_->GetIterator(arena);
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} else if (prefix_extractor_ != nullptr && !read_options.total_order_seek) {
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bloom_ = mem.prefix_bloom_.get();
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iter_ = mem.table_->GetDynamicPrefixIterator(arena);
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} else {
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iter_ = mem.table_->GetIterator(arena);
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}
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}
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~MemTableIterator() {
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#ifndef NDEBUG
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// Assert that the MemTableIterator is never deleted while
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// Pinning is Enabled.
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assert(!pinned_iters_mgr_ || !pinned_iters_mgr_->PinningEnabled());
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#endif
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if (arena_mode_) {
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iter_->~Iterator();
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} else {
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delete iter_;
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}
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}
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#ifndef NDEBUG
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virtual void SetPinnedItersMgr(
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PinnedIteratorsManager* pinned_iters_mgr) override {
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pinned_iters_mgr_ = pinned_iters_mgr;
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}
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PinnedIteratorsManager* pinned_iters_mgr_ = nullptr;
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#endif
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virtual bool Valid() const override { return valid_; }
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virtual void Seek(const Slice& k) override {
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PERF_TIMER_GUARD(seek_on_memtable_time);
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PERF_COUNTER_ADD(seek_on_memtable_count, 1);
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if (bloom_ != nullptr) {
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if (!bloom_->MayContain(
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prefix_extractor_->Transform(ExtractUserKey(k)))) {
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PERF_COUNTER_ADD(bloom_memtable_miss_count, 1);
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valid_ = false;
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return;
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} else {
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PERF_COUNTER_ADD(bloom_memtable_hit_count, 1);
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}
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}
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iter_->Seek(k, nullptr);
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valid_ = iter_->Valid();
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}
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virtual void SeekForPrev(const Slice& k) override {
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PERF_TIMER_GUARD(seek_on_memtable_time);
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PERF_COUNTER_ADD(seek_on_memtable_count, 1);
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if (bloom_ != nullptr) {
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if (!bloom_->MayContain(
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prefix_extractor_->Transform(ExtractUserKey(k)))) {
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PERF_COUNTER_ADD(bloom_memtable_miss_count, 1);
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valid_ = false;
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return;
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} else {
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PERF_COUNTER_ADD(bloom_memtable_hit_count, 1);
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}
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}
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iter_->Seek(k, nullptr);
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valid_ = iter_->Valid();
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if (!Valid()) {
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SeekToLast();
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}
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while (Valid() && comparator_.comparator.Compare(k, key()) < 0) {
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Prev();
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}
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}
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virtual void SeekToFirst() override {
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iter_->SeekToFirst();
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valid_ = iter_->Valid();
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}
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virtual void SeekToLast() override {
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iter_->SeekToLast();
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valid_ = iter_->Valid();
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}
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virtual void Next() override {
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PERF_COUNTER_ADD(next_on_memtable_count, 1);
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assert(Valid());
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iter_->Next();
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valid_ = iter_->Valid();
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}
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virtual void Prev() override {
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PERF_COUNTER_ADD(prev_on_memtable_count, 1);
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assert(Valid());
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iter_->Prev();
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valid_ = iter_->Valid();
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}
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virtual Slice key() const override {
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assert(Valid());
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return GetLengthPrefixedSlice(iter_->key());
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}
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virtual Slice value() const override {
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assert(Valid());
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Slice key_slice = GetLengthPrefixedSlice(iter_->key());
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return GetLengthPrefixedSlice(key_slice.data() + key_slice.size());
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}
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virtual Status status() const override { return Status::OK(); }
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virtual bool IsKeyPinned() const override {
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// memtable data is always pinned
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return true;
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}
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virtual bool IsValuePinned() const override {
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// memtable value is always pinned, except if we allow inplace update.
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return value_pinned_;
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}
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private:
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DynamicBloom* bloom_;
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const SliceTransform* const prefix_extractor_;
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const MemTable::KeyComparator comparator_;
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MemTableRep::Iterator* iter_;
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bool valid_;
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bool arena_mode_;
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bool value_pinned_;
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// No copying allowed
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MemTableIterator(const MemTableIterator&);
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void operator=(const MemTableIterator&);
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};
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InternalIterator* MemTable::NewIterator(const ReadOptions& read_options,
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Arena* arena) {
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assert(arena != nullptr);
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auto mem = arena->AllocateAligned(sizeof(MemTableIterator));
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return new (mem) MemTableIterator(*this, read_options, arena);
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}
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InternalIterator* MemTable::NewRangeTombstoneIterator(
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const ReadOptions& read_options) {
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if (read_options.ignore_range_deletions || is_range_del_table_empty_) {
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return nullptr;
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}
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return new MemTableIterator(*this, read_options, nullptr /* arena */,
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true /* use_range_del_table */);
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}
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port::RWMutex* MemTable::GetLock(const Slice& key) {
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static murmur_hash hash;
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return &locks_[hash(key) % locks_.size()];
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}
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MemTable::MemTableStats MemTable::ApproximateStats(const Slice& start_ikey,
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const Slice& end_ikey) {
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uint64_t entry_count = table_->ApproximateNumEntries(start_ikey, end_ikey);
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entry_count += range_del_table_->ApproximateNumEntries(start_ikey, end_ikey);
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if (entry_count == 0) {
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return {0, 0};
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}
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uint64_t n = num_entries_.load(std::memory_order_relaxed);
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if (n == 0) {
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return {0, 0};
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}
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if (entry_count > n) {
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// (range_del_)table_->ApproximateNumEntries() is just an estimate so it can
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// be larger than actual entries we have. Cap it to entries we have to limit
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// the inaccuracy.
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entry_count = n;
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}
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uint64_t data_size = data_size_.load(std::memory_order_relaxed);
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return {entry_count * (data_size / n), entry_count};
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}
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bool MemTable::Add(SequenceNumber s, ValueType type,
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const Slice& key, /* user key */
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const Slice& value, bool allow_concurrent,
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MemTablePostProcessInfo* post_process_info) {
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// Format of an entry is concatenation of:
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// key_size : varint32 of internal_key.size()
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// key bytes : char[internal_key.size()]
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// value_size : varint32 of value.size()
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// value bytes : char[value.size()]
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uint32_t key_size = static_cast<uint32_t>(key.size());
|
|
uint32_t val_size = static_cast<uint32_t>(value.size());
|
|
uint32_t internal_key_size = key_size + 8;
|
|
const uint32_t encoded_len = VarintLength(internal_key_size) +
|
|
internal_key_size + VarintLength(val_size) +
|
|
val_size;
|
|
char* buf = nullptr;
|
|
std::unique_ptr<MemTableRep>& table =
|
|
type == kTypeRangeDeletion ? range_del_table_ : table_;
|
|
KeyHandle handle = table->Allocate(encoded_len, &buf);
|
|
|
|
char* p = EncodeVarint32(buf, internal_key_size);
|
|
memcpy(p, key.data(), key_size);
|
|
Slice key_slice(p, key_size);
|
|
p += key_size;
|
|
uint64_t packed = PackSequenceAndType(s, type);
|
|
EncodeFixed64(p, packed);
|
|
p += 8;
|
|
p = EncodeVarint32(p, val_size);
|
|
memcpy(p, value.data(), val_size);
|
|
assert((unsigned)(p + val_size - buf) == (unsigned)encoded_len);
|
|
if (!allow_concurrent) {
|
|
// Extract prefix for insert with hint.
|
|
if (insert_with_hint_prefix_extractor_ != nullptr &&
|
|
insert_with_hint_prefix_extractor_->InDomain(key_slice)) {
|
|
Slice prefix = insert_with_hint_prefix_extractor_->Transform(key_slice);
|
|
bool res = table->InsertKeyWithHint(handle, &insert_hints_[prefix]);
|
|
if (UNLIKELY(!res)) {
|
|
return res;
|
|
}
|
|
} else {
|
|
bool res = table->InsertKey(handle);
|
|
if (UNLIKELY(!res)) {
|
|
return res;
|
|
}
|
|
}
|
|
|
|
// this is a bit ugly, but is the way to avoid locked instructions
|
|
// when incrementing an atomic
|
|
num_entries_.store(num_entries_.load(std::memory_order_relaxed) + 1,
|
|
std::memory_order_relaxed);
|
|
data_size_.store(data_size_.load(std::memory_order_relaxed) + encoded_len,
|
|
std::memory_order_relaxed);
|
|
if (type == kTypeDeletion) {
|
|
num_deletes_.store(num_deletes_.load(std::memory_order_relaxed) + 1,
|
|
std::memory_order_relaxed);
|
|
}
|
|
|
|
if (prefix_bloom_) {
|
|
assert(prefix_extractor_);
|
|
prefix_bloom_->Add(prefix_extractor_->Transform(key));
|
|
}
|
|
|
|
// The first sequence number inserted into the memtable
|
|
assert(first_seqno_ == 0 || s >= first_seqno_);
|
|
if (first_seqno_ == 0) {
|
|
first_seqno_.store(s, std::memory_order_relaxed);
|
|
|
|
if (earliest_seqno_ == kMaxSequenceNumber) {
|
|
earliest_seqno_.store(GetFirstSequenceNumber(),
|
|
std::memory_order_relaxed);
|
|
}
|
|
assert(first_seqno_.load() >= earliest_seqno_.load());
|
|
}
|
|
assert(post_process_info == nullptr);
|
|
UpdateFlushState();
|
|
} else {
|
|
bool res = table->InsertKeyConcurrently(handle);
|
|
if (UNLIKELY(!res)) {
|
|
return res;
|
|
}
|
|
|
|
assert(post_process_info != nullptr);
|
|
post_process_info->num_entries++;
|
|
post_process_info->data_size += encoded_len;
|
|
if (type == kTypeDeletion) {
|
|
post_process_info->num_deletes++;
|
|
}
|
|
|
|
if (prefix_bloom_) {
|
|
assert(prefix_extractor_);
|
|
prefix_bloom_->AddConcurrently(prefix_extractor_->Transform(key));
|
|
}
|
|
|
|
// atomically update first_seqno_ and earliest_seqno_.
|
|
uint64_t cur_seq_num = first_seqno_.load(std::memory_order_relaxed);
|
|
while ((cur_seq_num == 0 || s < cur_seq_num) &&
|
|
!first_seqno_.compare_exchange_weak(cur_seq_num, s)) {
|
|
}
|
|
uint64_t cur_earliest_seqno =
|
|
earliest_seqno_.load(std::memory_order_relaxed);
|
|
while (
|
|
(cur_earliest_seqno == kMaxSequenceNumber || s < cur_earliest_seqno) &&
|
|
!first_seqno_.compare_exchange_weak(cur_earliest_seqno, s)) {
|
|
}
|
|
}
|
|
if (is_range_del_table_empty_ && type == kTypeRangeDeletion) {
|
|
is_range_del_table_empty_ = false;
|
|
}
|
|
UpdateOldestKeyTime();
|
|
return true;
|
|
}
|
|
|
|
// Callback from MemTable::Get()
|
|
namespace {
|
|
|
|
struct Saver {
|
|
Status* status;
|
|
const LookupKey* key;
|
|
bool* found_final_value; // Is value set correctly? Used by KeyMayExist
|
|
bool* merge_in_progress;
|
|
std::string* value;
|
|
SequenceNumber seq;
|
|
const MergeOperator* merge_operator;
|
|
// the merge operations encountered;
|
|
MergeContext* merge_context;
|
|
RangeDelAggregator* range_del_agg;
|
|
MemTable* mem;
|
|
Logger* logger;
|
|
Statistics* statistics;
|
|
bool inplace_update_support;
|
|
Env* env_;
|
|
ReadCallback* callback_;
|
|
bool* is_blob_index;
|
|
|
|
bool CheckCallback(SequenceNumber _seq) {
|
|
if (callback_) {
|
|
return callback_->IsVisible(_seq);
|
|
}
|
|
return true;
|
|
}
|
|
};
|
|
} // namespace
|
|
|
|
static bool SaveValue(void* arg, const char* entry) {
|
|
Saver* s = reinterpret_cast<Saver*>(arg);
|
|
assert(s != nullptr);
|
|
MergeContext* merge_context = s->merge_context;
|
|
RangeDelAggregator* range_del_agg = s->range_del_agg;
|
|
const MergeOperator* merge_operator = s->merge_operator;
|
|
|
|
assert(merge_context != nullptr && range_del_agg != nullptr);
|
|
|
|
// entry format is:
|
|
// klength varint32
|
|
// userkey char[klength-8]
|
|
// tag uint64
|
|
// vlength varint32
|
|
// value char[vlength]
|
|
// Check that it belongs to same user key. We do not check the
|
|
// sequence number since the Seek() call above should have skipped
|
|
// all entries with overly large sequence numbers.
|
|
uint32_t key_length;
|
|
const char* key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
|
|
if (s->mem->GetInternalKeyComparator().user_comparator()->Equal(
|
|
Slice(key_ptr, key_length - 8), s->key->user_key())) {
|
|
// Correct user key
|
|
const uint64_t tag = DecodeFixed64(key_ptr + key_length - 8);
|
|
ValueType type;
|
|
SequenceNumber seq;
|
|
UnPackSequenceAndType(tag, &seq, &type);
|
|
// If the value is not in the snapshot, skip it
|
|
if (!s->CheckCallback(seq)) {
|
|
return true; // to continue to the next seq
|
|
}
|
|
|
|
s->seq = seq;
|
|
|
|
if ((type == kTypeValue || type == kTypeMerge || type == kTypeBlobIndex) &&
|
|
range_del_agg->ShouldDelete(Slice(key_ptr, key_length))) {
|
|
type = kTypeRangeDeletion;
|
|
}
|
|
switch (type) {
|
|
case kTypeBlobIndex:
|
|
if (s->is_blob_index == nullptr) {
|
|
ROCKS_LOG_ERROR(s->logger, "Encounter unexpected blob index.");
|
|
*(s->status) = Status::NotSupported(
|
|
"Encounter unsupported blob value. Please open DB with "
|
|
"rocksdb::blob_db::BlobDB instead.");
|
|
} else if (*(s->merge_in_progress)) {
|
|
*(s->status) =
|
|
Status::NotSupported("Blob DB does not support merge operator.");
|
|
}
|
|
if (!s->status->ok()) {
|
|
*(s->found_final_value) = true;
|
|
return false;
|
|
}
|
|
FALLTHROUGH_INTENDED;
|
|
case kTypeValue: {
|
|
if (s->inplace_update_support) {
|
|
s->mem->GetLock(s->key->user_key())->ReadLock();
|
|
}
|
|
Slice v = GetLengthPrefixedSlice(key_ptr + key_length);
|
|
*(s->status) = Status::OK();
|
|
if (*(s->merge_in_progress)) {
|
|
if (s->value != nullptr) {
|
|
*(s->status) = MergeHelper::TimedFullMerge(
|
|
merge_operator, s->key->user_key(), &v,
|
|
merge_context->GetOperands(), s->value, s->logger,
|
|
s->statistics, s->env_, nullptr /* result_operand */, true);
|
|
}
|
|
} else if (s->value != nullptr) {
|
|
s->value->assign(v.data(), v.size());
|
|
}
|
|
if (s->inplace_update_support) {
|
|
s->mem->GetLock(s->key->user_key())->ReadUnlock();
|
|
}
|
|
*(s->found_final_value) = true;
|
|
if (s->is_blob_index != nullptr) {
|
|
*(s->is_blob_index) = (type == kTypeBlobIndex);
|
|
}
|
|
return false;
|
|
}
|
|
case kTypeDeletion:
|
|
case kTypeSingleDeletion:
|
|
case kTypeRangeDeletion: {
|
|
if (*(s->merge_in_progress)) {
|
|
if (s->value != nullptr) {
|
|
*(s->status) = MergeHelper::TimedFullMerge(
|
|
merge_operator, s->key->user_key(), nullptr,
|
|
merge_context->GetOperands(), s->value, s->logger,
|
|
s->statistics, s->env_, nullptr /* result_operand */, true);
|
|
}
|
|
} else {
|
|
*(s->status) = Status::NotFound();
|
|
}
|
|
*(s->found_final_value) = true;
|
|
return false;
|
|
}
|
|
case kTypeMerge: {
|
|
if (!merge_operator) {
|
|
*(s->status) = Status::InvalidArgument(
|
|
"merge_operator is not properly initialized.");
|
|
// Normally we continue the loop (return true) when we see a merge
|
|
// operand. But in case of an error, we should stop the loop
|
|
// immediately and pretend we have found the value to stop further
|
|
// seek. Otherwise, the later call will override this error status.
|
|
*(s->found_final_value) = true;
|
|
return false;
|
|
}
|
|
Slice v = GetLengthPrefixedSlice(key_ptr + key_length);
|
|
*(s->merge_in_progress) = true;
|
|
merge_context->PushOperand(
|
|
v, s->inplace_update_support == false /* operand_pinned */);
|
|
if (merge_operator->ShouldMerge(merge_context->GetOperandsDirectionBackward())) {
|
|
*(s->status) = MergeHelper::TimedFullMerge(
|
|
merge_operator, s->key->user_key(), nullptr,
|
|
merge_context->GetOperands(), s->value, s->logger, s->statistics,
|
|
s->env_, nullptr /* result_operand */, true);
|
|
*(s->found_final_value) = true;
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
default:
|
|
assert(false);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// s->state could be Corrupt, merge or notfound
|
|
return false;
|
|
}
|
|
|
|
bool MemTable::Get(const LookupKey& key, std::string* value, Status* s,
|
|
MergeContext* merge_context,
|
|
RangeDelAggregator* range_del_agg, SequenceNumber* seq,
|
|
const ReadOptions& read_opts, ReadCallback* callback,
|
|
bool* is_blob_index) {
|
|
// The sequence number is updated synchronously in version_set.h
|
|
if (IsEmpty()) {
|
|
// Avoiding recording stats for speed.
|
|
return false;
|
|
}
|
|
PERF_TIMER_GUARD(get_from_memtable_time);
|
|
|
|
std::unique_ptr<InternalIterator> range_del_iter(
|
|
NewRangeTombstoneIterator(read_opts));
|
|
Status status = range_del_agg->AddTombstones(std::move(range_del_iter));
|
|
if (!status.ok()) {
|
|
*s = status;
|
|
return false;
|
|
}
|
|
|
|
Slice user_key = key.user_key();
|
|
bool found_final_value = false;
|
|
bool merge_in_progress = s->IsMergeInProgress();
|
|
bool const may_contain =
|
|
nullptr == prefix_bloom_
|
|
? false
|
|
: prefix_bloom_->MayContain(prefix_extractor_->Transform(user_key));
|
|
if (prefix_bloom_ && !may_contain) {
|
|
// iter is null if prefix bloom says the key does not exist
|
|
PERF_COUNTER_ADD(bloom_memtable_miss_count, 1);
|
|
*seq = kMaxSequenceNumber;
|
|
} else {
|
|
if (prefix_bloom_) {
|
|
PERF_COUNTER_ADD(bloom_memtable_hit_count, 1);
|
|
}
|
|
Saver saver;
|
|
saver.status = s;
|
|
saver.found_final_value = &found_final_value;
|
|
saver.merge_in_progress = &merge_in_progress;
|
|
saver.key = &key;
|
|
saver.value = value;
|
|
saver.seq = kMaxSequenceNumber;
|
|
saver.mem = this;
|
|
saver.merge_context = merge_context;
|
|
saver.range_del_agg = range_del_agg;
|
|
saver.merge_operator = moptions_.merge_operator;
|
|
saver.logger = moptions_.info_log;
|
|
saver.inplace_update_support = moptions_.inplace_update_support;
|
|
saver.statistics = moptions_.statistics;
|
|
saver.env_ = env_;
|
|
saver.callback_ = callback;
|
|
saver.is_blob_index = is_blob_index;
|
|
table_->Get(key, &saver, SaveValue);
|
|
|
|
*seq = saver.seq;
|
|
}
|
|
|
|
// No change to value, since we have not yet found a Put/Delete
|
|
if (!found_final_value && merge_in_progress) {
|
|
*s = Status::MergeInProgress();
|
|
}
|
|
PERF_COUNTER_ADD(get_from_memtable_count, 1);
|
|
return found_final_value;
|
|
}
|
|
|
|
void MemTable::Update(SequenceNumber seq,
|
|
const Slice& key,
|
|
const Slice& value) {
|
|
LookupKey lkey(key, seq);
|
|
Slice mem_key = lkey.memtable_key();
|
|
|
|
std::unique_ptr<MemTableRep::Iterator> iter(
|
|
table_->GetDynamicPrefixIterator());
|
|
iter->Seek(lkey.internal_key(), mem_key.data());
|
|
|
|
if (iter->Valid()) {
|
|
// entry format is:
|
|
// key_length varint32
|
|
// userkey char[klength-8]
|
|
// tag uint64
|
|
// vlength varint32
|
|
// value char[vlength]
|
|
// Check that it belongs to same user key. We do not check the
|
|
// sequence number since the Seek() call above should have skipped
|
|
// all entries with overly large sequence numbers.
|
|
const char* entry = iter->key();
|
|
uint32_t key_length = 0;
|
|
const char* key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
|
|
if (comparator_.comparator.user_comparator()->Equal(
|
|
Slice(key_ptr, key_length - 8), lkey.user_key())) {
|
|
// Correct user key
|
|
const uint64_t tag = DecodeFixed64(key_ptr + key_length - 8);
|
|
ValueType type;
|
|
SequenceNumber existing_seq;
|
|
UnPackSequenceAndType(tag, &existing_seq, &type);
|
|
assert(existing_seq != seq);
|
|
if (type == kTypeValue) {
|
|
Slice prev_value = GetLengthPrefixedSlice(key_ptr + key_length);
|
|
uint32_t prev_size = static_cast<uint32_t>(prev_value.size());
|
|
uint32_t new_size = static_cast<uint32_t>(value.size());
|
|
|
|
// Update value, if new value size <= previous value size
|
|
if (new_size <= prev_size) {
|
|
char* p =
|
|
EncodeVarint32(const_cast<char*>(key_ptr) + key_length, new_size);
|
|
WriteLock wl(GetLock(lkey.user_key()));
|
|
memcpy(p, value.data(), value.size());
|
|
assert((unsigned)((p + value.size()) - entry) ==
|
|
(unsigned)(VarintLength(key_length) + key_length +
|
|
VarintLength(value.size()) + value.size()));
|
|
RecordTick(moptions_.statistics, NUMBER_KEYS_UPDATED);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// key doesn't exist
|
|
bool add_res __attribute__((__unused__));
|
|
add_res = Add(seq, kTypeValue, key, value);
|
|
// We already checked unused != seq above. In that case, Add should not fail.
|
|
assert(add_res);
|
|
}
|
|
|
|
bool MemTable::UpdateCallback(SequenceNumber seq,
|
|
const Slice& key,
|
|
const Slice& delta) {
|
|
LookupKey lkey(key, seq);
|
|
Slice memkey = lkey.memtable_key();
|
|
|
|
std::unique_ptr<MemTableRep::Iterator> iter(
|
|
table_->GetDynamicPrefixIterator());
|
|
iter->Seek(lkey.internal_key(), memkey.data());
|
|
|
|
if (iter->Valid()) {
|
|
// entry format is:
|
|
// key_length varint32
|
|
// userkey char[klength-8]
|
|
// tag uint64
|
|
// vlength varint32
|
|
// value char[vlength]
|
|
// Check that it belongs to same user key. We do not check the
|
|
// sequence number since the Seek() call above should have skipped
|
|
// all entries with overly large sequence numbers.
|
|
const char* entry = iter->key();
|
|
uint32_t key_length = 0;
|
|
const char* key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
|
|
if (comparator_.comparator.user_comparator()->Equal(
|
|
Slice(key_ptr, key_length - 8), lkey.user_key())) {
|
|
// Correct user key
|
|
const uint64_t tag = DecodeFixed64(key_ptr + key_length - 8);
|
|
ValueType type;
|
|
uint64_t unused;
|
|
UnPackSequenceAndType(tag, &unused, &type);
|
|
switch (type) {
|
|
case kTypeValue: {
|
|
Slice prev_value = GetLengthPrefixedSlice(key_ptr + key_length);
|
|
uint32_t prev_size = static_cast<uint32_t>(prev_value.size());
|
|
|
|
char* prev_buffer = const_cast<char*>(prev_value.data());
|
|
uint32_t new_prev_size = prev_size;
|
|
|
|
std::string str_value;
|
|
WriteLock wl(GetLock(lkey.user_key()));
|
|
auto status = moptions_.inplace_callback(prev_buffer, &new_prev_size,
|
|
delta, &str_value);
|
|
if (status == UpdateStatus::UPDATED_INPLACE) {
|
|
// Value already updated by callback.
|
|
assert(new_prev_size <= prev_size);
|
|
if (new_prev_size < prev_size) {
|
|
// overwrite the new prev_size
|
|
char* p = EncodeVarint32(const_cast<char*>(key_ptr) + key_length,
|
|
new_prev_size);
|
|
if (VarintLength(new_prev_size) < VarintLength(prev_size)) {
|
|
// shift the value buffer as well.
|
|
memcpy(p, prev_buffer, new_prev_size);
|
|
}
|
|
}
|
|
RecordTick(moptions_.statistics, NUMBER_KEYS_UPDATED);
|
|
UpdateFlushState();
|
|
return true;
|
|
} else if (status == UpdateStatus::UPDATED) {
|
|
Add(seq, kTypeValue, key, Slice(str_value));
|
|
RecordTick(moptions_.statistics, NUMBER_KEYS_WRITTEN);
|
|
UpdateFlushState();
|
|
return true;
|
|
} else if (status == UpdateStatus::UPDATE_FAILED) {
|
|
// No action required. Return.
|
|
UpdateFlushState();
|
|
return true;
|
|
}
|
|
}
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
// If the latest value is not kTypeValue
|
|
// or key doesn't exist
|
|
return false;
|
|
}
|
|
|
|
size_t MemTable::CountSuccessiveMergeEntries(const LookupKey& key) {
|
|
Slice memkey = key.memtable_key();
|
|
|
|
// A total ordered iterator is costly for some memtablerep (prefix aware
|
|
// reps). By passing in the user key, we allow efficient iterator creation.
|
|
// The iterator only needs to be ordered within the same user key.
|
|
std::unique_ptr<MemTableRep::Iterator> iter(
|
|
table_->GetDynamicPrefixIterator());
|
|
iter->Seek(key.internal_key(), memkey.data());
|
|
|
|
size_t num_successive_merges = 0;
|
|
|
|
for (; iter->Valid(); iter->Next()) {
|
|
const char* entry = iter->key();
|
|
uint32_t key_length = 0;
|
|
const char* iter_key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
|
|
if (!comparator_.comparator.user_comparator()->Equal(
|
|
Slice(iter_key_ptr, key_length - 8), key.user_key())) {
|
|
break;
|
|
}
|
|
|
|
const uint64_t tag = DecodeFixed64(iter_key_ptr + key_length - 8);
|
|
ValueType type;
|
|
uint64_t unused;
|
|
UnPackSequenceAndType(tag, &unused, &type);
|
|
if (type != kTypeMerge) {
|
|
break;
|
|
}
|
|
|
|
++num_successive_merges;
|
|
}
|
|
|
|
return num_successive_merges;
|
|
}
|
|
|
|
void MemTableRep::Get(const LookupKey& k, void* callback_args,
|
|
bool (*callback_func)(void* arg, const char* entry)) {
|
|
auto iter = GetDynamicPrefixIterator();
|
|
for (iter->Seek(k.internal_key(), k.memtable_key().data());
|
|
iter->Valid() && callback_func(callback_args, iter->key());
|
|
iter->Next()) {
|
|
}
|
|
}
|
|
|
|
void MemTable::RefLogContainingPrepSection(uint64_t log) {
|
|
assert(log > 0);
|
|
auto cur = min_prep_log_referenced_.load();
|
|
while ((log < cur || cur == 0) &&
|
|
!min_prep_log_referenced_.compare_exchange_strong(cur, log)) {
|
|
cur = min_prep_log_referenced_.load();
|
|
}
|
|
}
|
|
|
|
uint64_t MemTable::GetMinLogContainingPrepSection() {
|
|
return min_prep_log_referenced_.load();
|
|
}
|
|
|
|
} // namespace rocksdb
|