320d9a8e8a
Summary: The patch replaces `std::map` with a sorted `std::vector` for `VersionStorageInfo::blob_files_` and preallocates the space for the `vector` before saving the `BlobFileMetaData` into the new `VersionStorageInfo` in `VersionBuilder::Rep::SaveBlobFilesTo`. These changes reduce the time the DB mutex is held while saving new `Version`s, and using a sorted `vector` also makes lookups faster thanks to better memory locality. In addition, the patch introduces helper methods `VersionStorageInfo::GetBlobFileMetaData` and `VersionStorageInfo::GetBlobFileMetaDataLB` that can be used by clients to perform lookups in the `vector`, and does some general cleanup in the parts of code where blob file metadata are used. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9526 Test Plan: Ran `make check` and the crash test script for a while. Performance was tested using a load-optimized benchmark (`fillseq` with vector memtable, no WAL) and small file sizes so that a significant number of files are produced: ``` numactl --interleave=all ./db_bench --benchmarks=fillseq --allow_concurrent_memtable_write=false --level0_file_num_compaction_trigger=4 --level0_slowdown_writes_trigger=20 --level0_stop_writes_trigger=30 --max_background_jobs=8 --max_write_buffer_number=8 --db=/data/ltamasi-dbbench --wal_dir=/data/ltamasi-dbbench --num=800000000 --num_levels=8 --key_size=20 --value_size=400 --block_size=8192 --cache_size=51539607552 --cache_numshardbits=6 --compression_max_dict_bytes=0 --compression_ratio=0.5 --compression_type=lz4 --bytes_per_sync=8388608 --cache_index_and_filter_blocks=1 --cache_high_pri_pool_ratio=0.5 --benchmark_write_rate_limit=0 --write_buffer_size=16777216 --target_file_size_base=16777216 --max_bytes_for_level_base=67108864 --verify_checksum=1 --delete_obsolete_files_period_micros=62914560 --max_bytes_for_level_multiplier=8 --statistics=0 --stats_per_interval=1 --stats_interval_seconds=20 --histogram=1 --memtablerep=skip_list --bloom_bits=10 --open_files=-1 --subcompactions=1 --compaction_style=0 --min_level_to_compress=3 --level_compaction_dynamic_level_bytes=true --pin_l0_filter_and_index_blocks_in_cache=1 --soft_pending_compaction_bytes_limit=167503724544 --hard_pending_compaction_bytes_limit=335007449088 --min_level_to_compress=0 --use_existing_db=0 --sync=0 --threads=1 --memtablerep=vector --allow_concurrent_memtable_write=false --disable_wal=1 --enable_blob_files=1 --blob_file_size=16777216 --min_blob_size=0 --blob_compression_type=lz4 --enable_blob_garbage_collection=1 --seed=<some value> ``` Final statistics before the patch: ``` Cumulative writes: 0 writes, 700M keys, 0 commit groups, 0.0 writes per commit group, ingest: 284.62 GB, 121.27 MB/s Interval writes: 0 writes, 334K keys, 0 commit groups, 0.0 writes per commit group, ingest: 139.28 MB, 72.46 MB/s ``` With the patch: ``` Cumulative writes: 0 writes, 760M keys, 0 commit groups, 0.0 writes per commit group, ingest: 308.66 GB, 131.52 MB/s Interval writes: 0 writes, 445K keys, 0 commit groups, 0.0 writes per commit group, ingest: 185.35 MB, 93.15 MB/s ``` Total time to complete the benchmark is 2611 seconds with the patch, down from 2986 secs. Reviewed By: riversand963 Differential Revision: D34082728 Pulled By: ltamasi fbshipit-source-id: fc598abf676dce436734d06bb9d2d99a26a004fc
1219 lines
48 KiB
C++
1219 lines
48 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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#include "db/compaction/compaction_iterator.h"
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#include <iterator>
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#include <limits>
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#include "db/blob/blob_fetcher.h"
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#include "db/blob/blob_file_builder.h"
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#include "db/blob/blob_index.h"
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#include "db/blob/prefetch_buffer_collection.h"
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#include "db/snapshot_checker.h"
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#include "logging/logging.h"
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#include "port/likely.h"
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#include "rocksdb/listener.h"
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#include "table/internal_iterator.h"
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#include "test_util/sync_point.h"
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namespace ROCKSDB_NAMESPACE {
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CompactionIterator::CompactionIterator(
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InternalIterator* input, const Comparator* cmp, MergeHelper* merge_helper,
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SequenceNumber last_sequence, std::vector<SequenceNumber>* snapshots,
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SequenceNumber earliest_write_conflict_snapshot,
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const SnapshotChecker* snapshot_checker, Env* env,
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bool report_detailed_time, bool expect_valid_internal_key,
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CompactionRangeDelAggregator* range_del_agg,
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BlobFileBuilder* blob_file_builder, bool allow_data_in_errors,
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const Compaction* compaction, const CompactionFilter* compaction_filter,
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const std::atomic<bool>* shutting_down,
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const SequenceNumber preserve_deletes_seqnum,
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const std::atomic<int>* manual_compaction_paused,
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const std::atomic<bool>* manual_compaction_canceled,
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const std::shared_ptr<Logger> info_log,
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const std::string* full_history_ts_low)
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: CompactionIterator(
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input, cmp, merge_helper, last_sequence, snapshots,
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earliest_write_conflict_snapshot, snapshot_checker, env,
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report_detailed_time, expect_valid_internal_key, range_del_agg,
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blob_file_builder, allow_data_in_errors,
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std::unique_ptr<CompactionProxy>(
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compaction ? new RealCompaction(compaction) : nullptr),
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compaction_filter, shutting_down, preserve_deletes_seqnum,
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manual_compaction_paused, manual_compaction_canceled, info_log,
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full_history_ts_low) {}
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CompactionIterator::CompactionIterator(
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InternalIterator* input, const Comparator* cmp, MergeHelper* merge_helper,
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SequenceNumber /*last_sequence*/, std::vector<SequenceNumber>* snapshots,
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SequenceNumber earliest_write_conflict_snapshot,
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const SnapshotChecker* snapshot_checker, Env* env,
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bool report_detailed_time, bool expect_valid_internal_key,
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CompactionRangeDelAggregator* range_del_agg,
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BlobFileBuilder* blob_file_builder, bool allow_data_in_errors,
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std::unique_ptr<CompactionProxy> compaction,
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const CompactionFilter* compaction_filter,
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const std::atomic<bool>* shutting_down,
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const SequenceNumber preserve_deletes_seqnum,
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const std::atomic<int>* manual_compaction_paused,
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const std::atomic<bool>* manual_compaction_canceled,
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const std::shared_ptr<Logger> info_log,
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const std::string* full_history_ts_low)
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: input_(input, cmp,
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!compaction || compaction->DoesInputReferenceBlobFiles()),
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cmp_(cmp),
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merge_helper_(merge_helper),
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snapshots_(snapshots),
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earliest_write_conflict_snapshot_(earliest_write_conflict_snapshot),
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snapshot_checker_(snapshot_checker),
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env_(env),
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clock_(env_->GetSystemClock().get()),
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report_detailed_time_(report_detailed_time),
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expect_valid_internal_key_(expect_valid_internal_key),
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range_del_agg_(range_del_agg),
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blob_file_builder_(blob_file_builder),
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compaction_(std::move(compaction)),
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compaction_filter_(compaction_filter),
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shutting_down_(shutting_down),
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manual_compaction_paused_(manual_compaction_paused),
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manual_compaction_canceled_(manual_compaction_canceled),
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preserve_deletes_seqnum_(preserve_deletes_seqnum),
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info_log_(info_log),
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allow_data_in_errors_(allow_data_in_errors),
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timestamp_size_(cmp_ ? cmp_->timestamp_size() : 0),
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full_history_ts_low_(full_history_ts_low),
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current_user_key_sequence_(0),
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current_user_key_snapshot_(0),
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merge_out_iter_(merge_helper_),
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blob_garbage_collection_cutoff_file_number_(
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ComputeBlobGarbageCollectionCutoffFileNumber(compaction_.get())),
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blob_fetcher_(CreateBlobFetcherIfNeeded(compaction_.get())),
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prefetch_buffers_(
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CreatePrefetchBufferCollectionIfNeeded(compaction_.get())),
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current_key_committed_(false),
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cmp_with_history_ts_low_(0),
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level_(compaction_ == nullptr ? 0 : compaction_->level()) {
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assert(snapshots_ != nullptr);
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bottommost_level_ = compaction_ == nullptr
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? false
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: compaction_->bottommost_level() &&
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!compaction_->allow_ingest_behind();
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if (compaction_ != nullptr) {
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level_ptrs_ = std::vector<size_t>(compaction_->number_levels(), 0);
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}
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if (snapshots_->size() == 0) {
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// optimize for fast path if there are no snapshots
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visible_at_tip_ = true;
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earliest_snapshot_iter_ = snapshots_->end();
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earliest_snapshot_ = kMaxSequenceNumber;
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latest_snapshot_ = 0;
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} else {
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visible_at_tip_ = false;
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earliest_snapshot_iter_ = snapshots_->begin();
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earliest_snapshot_ = snapshots_->at(0);
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latest_snapshot_ = snapshots_->back();
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}
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#ifndef NDEBUG
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// findEarliestVisibleSnapshot assumes this ordering.
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for (size_t i = 1; i < snapshots_->size(); ++i) {
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assert(snapshots_->at(i - 1) < snapshots_->at(i));
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}
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assert(timestamp_size_ == 0 || !full_history_ts_low_ ||
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timestamp_size_ == full_history_ts_low_->size());
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#endif
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input_.SetPinnedItersMgr(&pinned_iters_mgr_);
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TEST_SYNC_POINT_CALLBACK("CompactionIterator:AfterInit", compaction_.get());
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}
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CompactionIterator::~CompactionIterator() {
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// input_ Iterator lifetime is longer than pinned_iters_mgr_ lifetime
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input_.SetPinnedItersMgr(nullptr);
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}
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void CompactionIterator::ResetRecordCounts() {
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iter_stats_.num_record_drop_user = 0;
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iter_stats_.num_record_drop_hidden = 0;
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iter_stats_.num_record_drop_obsolete = 0;
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iter_stats_.num_record_drop_range_del = 0;
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iter_stats_.num_range_del_drop_obsolete = 0;
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iter_stats_.num_optimized_del_drop_obsolete = 0;
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}
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void CompactionIterator::SeekToFirst() {
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NextFromInput();
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PrepareOutput();
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}
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void CompactionIterator::Next() {
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// If there is a merge output, return it before continuing to process the
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// input.
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if (merge_out_iter_.Valid()) {
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merge_out_iter_.Next();
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// Check if we returned all records of the merge output.
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if (merge_out_iter_.Valid()) {
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key_ = merge_out_iter_.key();
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value_ = merge_out_iter_.value();
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Status s = ParseInternalKey(key_, &ikey_, allow_data_in_errors_);
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// MergeUntil stops when it encounters a corrupt key and does not
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// include them in the result, so we expect the keys here to be valid.
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assert(s.ok());
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if (!s.ok()) {
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ROCKS_LOG_FATAL(info_log_, "Invalid key in compaction. %s",
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s.getState());
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}
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// Keep current_key_ in sync.
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current_key_.UpdateInternalKey(ikey_.sequence, ikey_.type);
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key_ = current_key_.GetInternalKey();
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ikey_.user_key = current_key_.GetUserKey();
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valid_ = true;
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} else {
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// We consumed all pinned merge operands, release pinned iterators
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pinned_iters_mgr_.ReleasePinnedData();
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// MergeHelper moves the iterator to the first record after the merged
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// records, so even though we reached the end of the merge output, we do
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// not want to advance the iterator.
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NextFromInput();
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}
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} else {
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// Only advance the input iterator if there is no merge output and the
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// iterator is not already at the next record.
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if (!at_next_) {
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AdvanceInputIter();
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}
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NextFromInput();
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}
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if (valid_) {
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// Record that we've outputted a record for the current key.
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has_outputted_key_ = true;
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}
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PrepareOutput();
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}
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bool CompactionIterator::InvokeFilterIfNeeded(bool* need_skip,
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Slice* skip_until) {
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if (!compaction_filter_ ||
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(ikey_.type != kTypeValue && ikey_.type != kTypeBlobIndex)) {
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return true;
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}
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bool error = false;
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// If the user has specified a compaction filter and the sequence
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// number is greater than any external snapshot, then invoke the
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// filter. If the return value of the compaction filter is true,
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// replace the entry with a deletion marker.
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CompactionFilter::Decision filter = CompactionFilter::Decision::kUndetermined;
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compaction_filter_value_.clear();
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compaction_filter_skip_until_.Clear();
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CompactionFilter::ValueType value_type =
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ikey_.type == kTypeValue ? CompactionFilter::ValueType::kValue
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: CompactionFilter::ValueType::kBlobIndex;
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// Hack: pass internal key to BlobIndexCompactionFilter since it needs
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// to get sequence number.
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assert(compaction_filter_);
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Slice& filter_key =
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(ikey_.type == kTypeValue ||
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!compaction_filter_->IsStackedBlobDbInternalCompactionFilter())
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? ikey_.user_key
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: key_;
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{
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StopWatchNano timer(clock_, report_detailed_time_);
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if (kTypeBlobIndex == ikey_.type) {
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blob_value_.Reset();
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filter = compaction_filter_->FilterBlobByKey(
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level_, filter_key, &compaction_filter_value_,
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compaction_filter_skip_until_.rep());
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if (CompactionFilter::Decision::kUndetermined == filter &&
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!compaction_filter_->IsStackedBlobDbInternalCompactionFilter()) {
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if (compaction_ == nullptr) {
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status_ =
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Status::Corruption("Unexpected blob index outside of compaction");
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valid_ = false;
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return false;
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}
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// For integrated BlobDB impl, CompactionIterator reads blob value.
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// For Stacked BlobDB impl, the corresponding CompactionFilter's
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// FilterV2 method should read the blob value.
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BlobIndex blob_index;
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Status s = blob_index.DecodeFrom(value_);
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if (!s.ok()) {
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status_ = s;
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valid_ = false;
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return false;
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}
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FilePrefetchBuffer* prefetch_buffer =
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prefetch_buffers_ ? prefetch_buffers_->GetOrCreatePrefetchBuffer(
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blob_index.file_number())
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: nullptr;
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uint64_t bytes_read = 0;
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assert(blob_fetcher_);
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s = blob_fetcher_->FetchBlob(ikey_.user_key, blob_index,
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prefetch_buffer, &blob_value_,
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&bytes_read);
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if (!s.ok()) {
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status_ = s;
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valid_ = false;
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return false;
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}
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++iter_stats_.num_blobs_read;
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iter_stats_.total_blob_bytes_read += bytes_read;
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value_type = CompactionFilter::ValueType::kValue;
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}
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}
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if (CompactionFilter::Decision::kUndetermined == filter) {
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filter = compaction_filter_->FilterV2(
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level_, filter_key, value_type,
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blob_value_.empty() ? value_ : blob_value_, &compaction_filter_value_,
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compaction_filter_skip_until_.rep());
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}
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iter_stats_.total_filter_time +=
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env_ != nullptr && report_detailed_time_ ? timer.ElapsedNanos() : 0;
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}
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if (CompactionFilter::Decision::kUndetermined == filter) {
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// Should not reach here, since FilterV2 should never return kUndetermined.
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status_ =
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Status::NotSupported("FilterV2() should never return kUndetermined");
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valid_ = false;
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return false;
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}
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if (filter == CompactionFilter::Decision::kRemoveAndSkipUntil &&
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cmp_->Compare(*compaction_filter_skip_until_.rep(), ikey_.user_key) <=
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0) {
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// Can't skip to a key smaller than the current one.
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// Keep the key as per FilterV2 documentation.
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filter = CompactionFilter::Decision::kKeep;
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}
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if (filter == CompactionFilter::Decision::kRemove) {
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// convert the current key to a delete; key_ is pointing into
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// current_key_ at this point, so updating current_key_ updates key()
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ikey_.type = kTypeDeletion;
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current_key_.UpdateInternalKey(ikey_.sequence, kTypeDeletion);
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// no value associated with delete
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value_.clear();
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iter_stats_.num_record_drop_user++;
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} else if (filter == CompactionFilter::Decision::kChangeValue) {
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if (ikey_.type == kTypeBlobIndex) {
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// value transfer from blob file to inlined data
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ikey_.type = kTypeValue;
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current_key_.UpdateInternalKey(ikey_.sequence, ikey_.type);
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}
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value_ = compaction_filter_value_;
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} else if (filter == CompactionFilter::Decision::kRemoveAndSkipUntil) {
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*need_skip = true;
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compaction_filter_skip_until_.ConvertFromUserKey(kMaxSequenceNumber,
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kValueTypeForSeek);
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*skip_until = compaction_filter_skip_until_.Encode();
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} else if (filter == CompactionFilter::Decision::kChangeBlobIndex) {
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// Only the StackableDB-based BlobDB impl's compaction filter should return
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// kChangeBlobIndex. Decision about rewriting blob and changing blob index
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// in the integrated BlobDB impl is made in subsequent call to
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// PrepareOutput() and its callees.
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if (!compaction_filter_->IsStackedBlobDbInternalCompactionFilter()) {
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status_ = Status::NotSupported(
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"Only stacked BlobDB's internal compaction filter can return "
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"kChangeBlobIndex.");
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valid_ = false;
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return false;
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}
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if (ikey_.type == kTypeValue) {
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// value transfer from inlined data to blob file
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ikey_.type = kTypeBlobIndex;
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current_key_.UpdateInternalKey(ikey_.sequence, ikey_.type);
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}
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value_ = compaction_filter_value_;
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} else if (filter == CompactionFilter::Decision::kIOError) {
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if (!compaction_filter_->IsStackedBlobDbInternalCompactionFilter()) {
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status_ = Status::NotSupported(
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"CompactionFilter for integrated BlobDB should not return kIOError");
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valid_ = false;
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return false;
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}
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status_ = Status::IOError("Failed to access blob during compaction filter");
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error = true;
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}
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return !error;
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}
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void CompactionIterator::NextFromInput() {
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at_next_ = false;
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valid_ = false;
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while (!valid_ && input_.Valid() && !IsPausingManualCompaction() &&
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!IsShuttingDown()) {
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key_ = input_.key();
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value_ = input_.value();
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iter_stats_.num_input_records++;
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Status pik_status = ParseInternalKey(key_, &ikey_, allow_data_in_errors_);
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if (!pik_status.ok()) {
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iter_stats_.num_input_corrupt_records++;
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// If `expect_valid_internal_key_` is false, return the corrupted key
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// and let the caller decide what to do with it.
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if (expect_valid_internal_key_) {
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status_ = pik_status;
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return;
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}
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key_ = current_key_.SetInternalKey(key_);
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has_current_user_key_ = false;
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current_user_key_sequence_ = kMaxSequenceNumber;
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current_user_key_snapshot_ = 0;
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valid_ = true;
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break;
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}
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TEST_SYNC_POINT_CALLBACK("CompactionIterator:ProcessKV", &ikey_);
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// Update input statistics
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if (ikey_.type == kTypeDeletion || ikey_.type == kTypeSingleDeletion ||
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ikey_.type == kTypeDeletionWithTimestamp) {
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iter_stats_.num_input_deletion_records++;
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}
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iter_stats_.total_input_raw_key_bytes += key_.size();
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iter_stats_.total_input_raw_value_bytes += value_.size();
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// If need_skip is true, we should seek the input iterator
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// to internal key skip_until and continue from there.
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bool need_skip = false;
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// Points either into compaction_filter_skip_until_ or into
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// merge_helper_->compaction_filter_skip_until_.
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Slice skip_until;
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bool user_key_equal_without_ts = false;
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int cmp_ts = 0;
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|
if (has_current_user_key_) {
|
|
user_key_equal_without_ts =
|
|
cmp_->EqualWithoutTimestamp(ikey_.user_key, current_user_key_);
|
|
// if timestamp_size_ > 0, then curr_ts_ has been initialized by a
|
|
// previous key.
|
|
cmp_ts = timestamp_size_ ? cmp_->CompareTimestamp(
|
|
ExtractTimestampFromUserKey(
|
|
ikey_.user_key, timestamp_size_),
|
|
curr_ts_)
|
|
: 0;
|
|
}
|
|
|
|
// Check whether the user key changed. After this if statement current_key_
|
|
// is a copy of the current input key (maybe converted to a delete by the
|
|
// compaction filter). ikey_.user_key is pointing to the copy.
|
|
if (!has_current_user_key_ || !user_key_equal_without_ts || cmp_ts != 0) {
|
|
// First occurrence of this user key
|
|
// Copy key for output
|
|
key_ = current_key_.SetInternalKey(key_, &ikey_);
|
|
|
|
int prev_cmp_with_ts_low =
|
|
!full_history_ts_low_ ? 0
|
|
: curr_ts_.empty()
|
|
? 0
|
|
: cmp_->CompareTimestamp(curr_ts_, *full_history_ts_low_);
|
|
|
|
// If timestamp_size_ > 0, then copy from ikey_ to curr_ts_ for the use
|
|
// in next iteration to compare with the timestamp of next key.
|
|
UpdateTimestampAndCompareWithFullHistoryLow();
|
|
|
|
// If
|
|
// (1) !has_current_user_key_, OR
|
|
// (2) timestamp is disabled, OR
|
|
// (3) all history will be preserved, OR
|
|
// (4) user key (excluding timestamp) is different from previous key, OR
|
|
// (5) timestamp is NO older than *full_history_ts_low_, OR
|
|
// (6) timestamp is the largest one older than full_history_ts_low_,
|
|
// then current_user_key_ must be treated as a different user key.
|
|
// This means, if a user key (excluding ts) is the same as the previous
|
|
// user key, and its ts is older than *full_history_ts_low_, then we
|
|
// consider this key for GC, e.g. it may be dropped if certain conditions
|
|
// match.
|
|
if (!has_current_user_key_ || !timestamp_size_ || !full_history_ts_low_ ||
|
|
!user_key_equal_without_ts || cmp_with_history_ts_low_ >= 0 ||
|
|
prev_cmp_with_ts_low >= 0) {
|
|
// Initialize for future comparison for rule (A) and etc.
|
|
current_user_key_sequence_ = kMaxSequenceNumber;
|
|
current_user_key_snapshot_ = 0;
|
|
has_current_user_key_ = true;
|
|
}
|
|
current_user_key_ = ikey_.user_key;
|
|
|
|
has_outputted_key_ = false;
|
|
|
|
last_key_seq_zeroed_ = false;
|
|
|
|
current_key_committed_ = KeyCommitted(ikey_.sequence);
|
|
|
|
// Apply the compaction filter to the first committed version of the user
|
|
// key.
|
|
if (current_key_committed_ &&
|
|
!InvokeFilterIfNeeded(&need_skip, &skip_until)) {
|
|
break;
|
|
}
|
|
} else {
|
|
// Update the current key to reflect the new sequence number/type without
|
|
// copying the user key.
|
|
// TODO(rven): Compaction filter does not process keys in this path
|
|
// Need to have the compaction filter process multiple versions
|
|
// if we have versions on both sides of a snapshot
|
|
current_key_.UpdateInternalKey(ikey_.sequence, ikey_.type);
|
|
key_ = current_key_.GetInternalKey();
|
|
ikey_.user_key = current_key_.GetUserKey();
|
|
|
|
// Note that newer version of a key is ordered before older versions. If a
|
|
// newer version of a key is committed, so as the older version. No need
|
|
// to query snapshot_checker_ in that case.
|
|
if (UNLIKELY(!current_key_committed_)) {
|
|
assert(snapshot_checker_ != nullptr);
|
|
current_key_committed_ = KeyCommitted(ikey_.sequence);
|
|
// Apply the compaction filter to the first committed version of the
|
|
// user key.
|
|
if (current_key_committed_ &&
|
|
!InvokeFilterIfNeeded(&need_skip, &skip_until)) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (UNLIKELY(!current_key_committed_)) {
|
|
assert(snapshot_checker_ != nullptr);
|
|
valid_ = true;
|
|
break;
|
|
}
|
|
|
|
// If there are no snapshots, then this kv affect visibility at tip.
|
|
// Otherwise, search though all existing snapshots to find the earliest
|
|
// snapshot that is affected by this kv.
|
|
SequenceNumber last_sequence = current_user_key_sequence_;
|
|
current_user_key_sequence_ = ikey_.sequence;
|
|
SequenceNumber last_snapshot = current_user_key_snapshot_;
|
|
SequenceNumber prev_snapshot = 0; // 0 means no previous snapshot
|
|
current_user_key_snapshot_ =
|
|
visible_at_tip_
|
|
? earliest_snapshot_
|
|
: findEarliestVisibleSnapshot(ikey_.sequence, &prev_snapshot);
|
|
|
|
if (need_skip) {
|
|
// This case is handled below.
|
|
} else if (clear_and_output_next_key_) {
|
|
// In the previous iteration we encountered a single delete that we could
|
|
// not compact out. We will keep this Put, but can drop it's data.
|
|
// (See Optimization 3, below.)
|
|
assert(ikey_.type == kTypeValue || ikey_.type == kTypeBlobIndex);
|
|
if (ikey_.type != kTypeValue && ikey_.type != kTypeBlobIndex) {
|
|
ROCKS_LOG_FATAL(info_log_,
|
|
"Unexpected key type %d for compaction output",
|
|
ikey_.type);
|
|
}
|
|
assert(current_user_key_snapshot_ >= last_snapshot);
|
|
if (current_user_key_snapshot_ < last_snapshot) {
|
|
ROCKS_LOG_FATAL(info_log_,
|
|
"current_user_key_snapshot_ (%" PRIu64
|
|
") < last_snapshot (%" PRIu64 ")",
|
|
current_user_key_snapshot_, last_snapshot);
|
|
}
|
|
|
|
if (ikey_.type == kTypeBlobIndex) {
|
|
ikey_.type = kTypeValue;
|
|
current_key_.UpdateInternalKey(ikey_.sequence, ikey_.type);
|
|
}
|
|
|
|
value_.clear();
|
|
valid_ = true;
|
|
clear_and_output_next_key_ = false;
|
|
} else if (ikey_.type == kTypeSingleDeletion) {
|
|
// We can compact out a SingleDelete if:
|
|
// 1) We encounter the corresponding PUT -OR- we know that this key
|
|
// doesn't appear past this output level
|
|
// =AND=
|
|
// 2) We've already returned a record in this snapshot -OR-
|
|
// there are no earlier earliest_write_conflict_snapshot.
|
|
//
|
|
// A note about 2) above:
|
|
// we try to determine whether there is any earlier write conflict
|
|
// checking snapshot by calling DefinitelyInSnapshot() with seq and
|
|
// earliest_write_conflict_snapshot as arguments. For write-prepared
|
|
// and write-unprepared transactions, if earliest_write_conflict_snapshot
|
|
// is evicted from WritePreparedTxnDB::commit_cache, then
|
|
// DefinitelyInSnapshot(seq, earliest_write_conflict_snapshot) returns
|
|
// false, even if the seq is actually visible within
|
|
// earliest_write_conflict_snapshot. Consequently, CompactionIterator
|
|
// may try to zero out its sequence number, thus hitting assertion error
|
|
// in debug mode or cause incorrect DBIter return result.
|
|
// We observe that earliest_write_conflict_snapshot >= earliest_snapshot,
|
|
// and the seq zeroing logic depends on
|
|
// DefinitelyInSnapshot(seq, earliest_snapshot). Therefore, if we cannot
|
|
// determine whether seq is **definitely** in
|
|
// earliest_write_conflict_snapshot, then we can additionally check if
|
|
// seq is definitely in earliest_snapshot. If the latter holds, then the
|
|
// former holds too.
|
|
//
|
|
// Rule 1 is needed for SingleDelete correctness. Rule 2 is needed to
|
|
// allow Transactions to do write-conflict checking (if we compacted away
|
|
// all keys, then we wouldn't know that a write happened in this
|
|
// snapshot). If there is no earlier snapshot, then we know that there
|
|
// are no active transactions that need to know about any writes.
|
|
//
|
|
// Optimization 3:
|
|
// If we encounter a SingleDelete followed by a PUT and Rule 2 is NOT
|
|
// true, then we must output a SingleDelete. In this case, we will decide
|
|
// to also output the PUT. While we are compacting less by outputting the
|
|
// PUT now, hopefully this will lead to better compaction in the future
|
|
// when Rule 2 is later true (Ie, We are hoping we can later compact out
|
|
// both the SingleDelete and the Put, while we couldn't if we only
|
|
// outputted the SingleDelete now).
|
|
// In this case, we can save space by removing the PUT's value as it will
|
|
// never be read.
|
|
//
|
|
// Deletes and Merges are not supported on the same key that has a
|
|
// SingleDelete as it is not possible to correctly do any partial
|
|
// compaction of such a combination of operations. The result of mixing
|
|
// those operations for a given key is documented as being undefined. So
|
|
// we can choose how to handle such a combinations of operations. We will
|
|
// try to compact out as much as we can in these cases.
|
|
// We will report counts on these anomalous cases.
|
|
//
|
|
// Note: If timestamp is enabled, then record will be eligible for
|
|
// deletion, only if, along with above conditions (Rule 1 and Rule 2)
|
|
// full_history_ts_low_ is specified and timestamp for that key is less
|
|
// than *full_history_ts_low_. If it's not eligible for deletion, then we
|
|
// will output the SingleDelete. For Optimization 3 also, if
|
|
// full_history_ts_low_ is specified and timestamp for the key is less
|
|
// than *full_history_ts_low_ then only optimization will be applied.
|
|
|
|
// The easiest way to process a SingleDelete during iteration is to peek
|
|
// ahead at the next key.
|
|
const bool is_timestamp_eligible_for_gc =
|
|
(timestamp_size_ == 0 ||
|
|
(full_history_ts_low_ && cmp_with_history_ts_low_ < 0));
|
|
|
|
ParsedInternalKey next_ikey;
|
|
AdvanceInputIter();
|
|
|
|
// Check whether the next key exists, is not corrupt, and is the same key
|
|
// as the single delete.
|
|
if (input_.Valid() &&
|
|
ParseInternalKey(input_.key(), &next_ikey, allow_data_in_errors_)
|
|
.ok() &&
|
|
cmp_->EqualWithoutTimestamp(ikey_.user_key, next_ikey.user_key)) {
|
|
#ifndef NDEBUG
|
|
const Compaction* c =
|
|
compaction_ ? compaction_->real_compaction() : nullptr;
|
|
#endif
|
|
TEST_SYNC_POINT_CALLBACK(
|
|
"CompactionIterator::NextFromInput:SingleDelete:1",
|
|
const_cast<Compaction*>(c));
|
|
if (last_key_seq_zeroed_) {
|
|
++iter_stats_.num_record_drop_hidden;
|
|
++iter_stats_.num_record_drop_obsolete;
|
|
assert(bottommost_level_);
|
|
AdvanceInputIter();
|
|
} else if (prev_snapshot == 0 ||
|
|
DefinitelyNotInSnapshot(next_ikey.sequence, prev_snapshot)) {
|
|
// Check whether the next key belongs to the same snapshot as the
|
|
// SingleDelete.
|
|
|
|
TEST_SYNC_POINT_CALLBACK(
|
|
"CompactionIterator::NextFromInput:SingleDelete:2", nullptr);
|
|
if (next_ikey.type == kTypeSingleDeletion ||
|
|
next_ikey.type == kTypeDeletion) {
|
|
// We encountered two SingleDeletes for same key in a row. This
|
|
// could be due to unexpected user input. If write-(un)prepared
|
|
// transaction is used, this could also be due to releasing an old
|
|
// snapshot between a Put and its matching SingleDelete.
|
|
// Furthermore, if write-(un)prepared transaction is rolled back
|
|
// after prepare, we will write a Delete to cancel a prior Put. If
|
|
// old snapshot is released between a later Put and its matching
|
|
// SingleDelete, we will end up with a Delete followed by
|
|
// SingleDelete.
|
|
// Skip the first SingleDelete and let the next iteration decide
|
|
// how to handle the second SingleDelete or Delete.
|
|
|
|
// First SingleDelete has been skipped since we already called
|
|
// input_.Next().
|
|
++iter_stats_.num_record_drop_obsolete;
|
|
++iter_stats_.num_single_del_mismatch;
|
|
} else if (!is_timestamp_eligible_for_gc) {
|
|
// We cannot drop the SingleDelete as timestamp is enabled, and
|
|
// timestamp of this key is greater than or equal to
|
|
// *full_history_ts_low_. We will output the SingleDelete.
|
|
valid_ = true;
|
|
} else if (has_outputted_key_ ||
|
|
DefinitelyInSnapshot(ikey_.sequence,
|
|
earliest_write_conflict_snapshot_) ||
|
|
(earliest_snapshot_ < earliest_write_conflict_snapshot_ &&
|
|
DefinitelyInSnapshot(ikey_.sequence,
|
|
earliest_snapshot_))) {
|
|
// Found a matching value, we can drop the single delete and the
|
|
// value. It is safe to drop both records since we've already
|
|
// outputted a key in this snapshot, or there is no earlier
|
|
// snapshot (Rule 2 above).
|
|
|
|
// Note: it doesn't matter whether the second key is a Put or if it
|
|
// is an unexpected Merge or Delete. We will compact it out
|
|
// either way. We will maintain counts of how many mismatches
|
|
// happened
|
|
if (next_ikey.type != kTypeValue &&
|
|
next_ikey.type != kTypeBlobIndex) {
|
|
++iter_stats_.num_single_del_mismatch;
|
|
}
|
|
|
|
++iter_stats_.num_record_drop_hidden;
|
|
++iter_stats_.num_record_drop_obsolete;
|
|
// Already called input_.Next() once. Call it a second time to
|
|
// skip past the second key.
|
|
AdvanceInputIter();
|
|
} else {
|
|
// Found a matching value, but we cannot drop both keys since
|
|
// there is an earlier snapshot and we need to leave behind a record
|
|
// to know that a write happened in this snapshot (Rule 2 above).
|
|
// Clear the value and output the SingleDelete. (The value will be
|
|
// outputted on the next iteration.)
|
|
|
|
// Setting valid_ to true will output the current SingleDelete
|
|
valid_ = true;
|
|
|
|
// Set up the Put to be outputted in the next iteration.
|
|
// (Optimization 3).
|
|
clear_and_output_next_key_ = true;
|
|
TEST_SYNC_POINT_CALLBACK(
|
|
"CompactionIterator::NextFromInput:KeepSDForWW",
|
|
/*arg=*/nullptr);
|
|
}
|
|
} else {
|
|
// We hit the next snapshot without hitting a put, so the iterator
|
|
// returns the single delete.
|
|
valid_ = true;
|
|
TEST_SYNC_POINT_CALLBACK(
|
|
"CompactionIterator::NextFromInput:SingleDelete:3",
|
|
const_cast<Compaction*>(c));
|
|
}
|
|
} else {
|
|
// We are at the end of the input, could not parse the next key, or hit
|
|
// a different key. The iterator returns the single delete if the key
|
|
// possibly exists beyond the current output level. We set
|
|
// has_current_user_key to false so that if the iterator is at the next
|
|
// key, we do not compare it again against the previous key at the next
|
|
// iteration. If the next key is corrupt, we return before the
|
|
// comparison, so the value of has_current_user_key does not matter.
|
|
has_current_user_key_ = false;
|
|
if (compaction_ != nullptr &&
|
|
DefinitelyInSnapshot(ikey_.sequence, earliest_snapshot_) &&
|
|
compaction_->KeyNotExistsBeyondOutputLevel(ikey_.user_key,
|
|
&level_ptrs_) &&
|
|
is_timestamp_eligible_for_gc) {
|
|
// Key doesn't exist outside of this range.
|
|
// Can compact out this SingleDelete.
|
|
++iter_stats_.num_record_drop_obsolete;
|
|
++iter_stats_.num_single_del_fallthru;
|
|
if (!bottommost_level_) {
|
|
++iter_stats_.num_optimized_del_drop_obsolete;
|
|
}
|
|
} else if (last_key_seq_zeroed_) {
|
|
// Skip.
|
|
++iter_stats_.num_record_drop_hidden;
|
|
++iter_stats_.num_record_drop_obsolete;
|
|
assert(bottommost_level_);
|
|
} else {
|
|
// Output SingleDelete
|
|
valid_ = true;
|
|
}
|
|
}
|
|
|
|
if (valid_) {
|
|
at_next_ = true;
|
|
}
|
|
} else if (last_snapshot == current_user_key_snapshot_ ||
|
|
(last_snapshot > 0 &&
|
|
last_snapshot < current_user_key_snapshot_)) {
|
|
// If the earliest snapshot is which this key is visible in
|
|
// is the same as the visibility of a previous instance of the
|
|
// same key, then this kv is not visible in any snapshot.
|
|
// Hidden by an newer entry for same user key
|
|
//
|
|
// Note: Dropping this key will not affect TransactionDB write-conflict
|
|
// checking since there has already been a record returned for this key
|
|
// in this snapshot.
|
|
assert(last_sequence >= current_user_key_sequence_);
|
|
if (last_sequence < current_user_key_sequence_) {
|
|
ROCKS_LOG_FATAL(info_log_,
|
|
"last_sequence (%" PRIu64
|
|
") < current_user_key_sequence_ (%" PRIu64 ")",
|
|
last_sequence, current_user_key_sequence_);
|
|
}
|
|
|
|
++iter_stats_.num_record_drop_hidden; // rule (A)
|
|
AdvanceInputIter();
|
|
} else if (compaction_ != nullptr &&
|
|
(ikey_.type == kTypeDeletion ||
|
|
(ikey_.type == kTypeDeletionWithTimestamp &&
|
|
cmp_with_history_ts_low_ < 0)) &&
|
|
DefinitelyInSnapshot(ikey_.sequence, earliest_snapshot_) &&
|
|
ikeyNotNeededForIncrementalSnapshot() &&
|
|
compaction_->KeyNotExistsBeyondOutputLevel(ikey_.user_key,
|
|
&level_ptrs_)) {
|
|
// TODO(noetzli): This is the only place where we use compaction_
|
|
// (besides the constructor). We should probably get rid of this
|
|
// dependency and find a way to do similar filtering during flushes.
|
|
//
|
|
// For this user key:
|
|
// (1) there is no data in higher levels
|
|
// (2) data in lower levels will have larger sequence numbers
|
|
// (3) data in layers that are being compacted here and have
|
|
// smaller sequence numbers will be dropped in the next
|
|
// few iterations of this loop (by rule (A) above).
|
|
// Therefore this deletion marker is obsolete and can be dropped.
|
|
//
|
|
// Note: Dropping this Delete will not affect TransactionDB
|
|
// write-conflict checking since it is earlier than any snapshot.
|
|
//
|
|
// It seems that we can also drop deletion later than earliest snapshot
|
|
// given that:
|
|
// (1) The deletion is earlier than earliest_write_conflict_snapshot, and
|
|
// (2) No value exist earlier than the deletion.
|
|
//
|
|
// Note also that a deletion marker of type kTypeDeletionWithTimestamp
|
|
// will be treated as a different user key unless the timestamp is older
|
|
// than *full_history_ts_low_.
|
|
++iter_stats_.num_record_drop_obsolete;
|
|
if (!bottommost_level_) {
|
|
++iter_stats_.num_optimized_del_drop_obsolete;
|
|
}
|
|
AdvanceInputIter();
|
|
} else if ((ikey_.type == kTypeDeletion ||
|
|
(ikey_.type == kTypeDeletionWithTimestamp &&
|
|
cmp_with_history_ts_low_ < 0)) &&
|
|
bottommost_level_ && ikeyNotNeededForIncrementalSnapshot()) {
|
|
// Handle the case where we have a delete key at the bottom most level
|
|
// We can skip outputting the key iff there are no subsequent puts for this
|
|
// key
|
|
assert(!compaction_ || compaction_->KeyNotExistsBeyondOutputLevel(
|
|
ikey_.user_key, &level_ptrs_));
|
|
ParsedInternalKey next_ikey;
|
|
AdvanceInputIter();
|
|
#ifndef NDEBUG
|
|
const Compaction* c =
|
|
compaction_ ? compaction_->real_compaction() : nullptr;
|
|
#endif
|
|
TEST_SYNC_POINT_CALLBACK(
|
|
"CompactionIterator::NextFromInput:BottommostDelete:1",
|
|
const_cast<Compaction*>(c));
|
|
// Skip over all versions of this key that happen to occur in the same
|
|
// snapshot range as the delete.
|
|
//
|
|
// Note that a deletion marker of type kTypeDeletionWithTimestamp will be
|
|
// considered to have a different user key unless the timestamp is older
|
|
// than *full_history_ts_low_.
|
|
while (!IsPausingManualCompaction() && !IsShuttingDown() &&
|
|
input_.Valid() &&
|
|
(ParseInternalKey(input_.key(), &next_ikey, allow_data_in_errors_)
|
|
.ok()) &&
|
|
cmp_->EqualWithoutTimestamp(ikey_.user_key, next_ikey.user_key) &&
|
|
(prev_snapshot == 0 ||
|
|
DefinitelyNotInSnapshot(next_ikey.sequence, prev_snapshot))) {
|
|
AdvanceInputIter();
|
|
}
|
|
// If you find you still need to output a row with this key, we need to output the
|
|
// delete too
|
|
if (input_.Valid() &&
|
|
(ParseInternalKey(input_.key(), &next_ikey, allow_data_in_errors_)
|
|
.ok()) &&
|
|
cmp_->EqualWithoutTimestamp(ikey_.user_key, next_ikey.user_key)) {
|
|
valid_ = true;
|
|
at_next_ = true;
|
|
}
|
|
} else if (ikey_.type == kTypeMerge) {
|
|
if (!merge_helper_->HasOperator()) {
|
|
status_ = Status::InvalidArgument(
|
|
"merge_operator is not properly initialized.");
|
|
return;
|
|
}
|
|
|
|
pinned_iters_mgr_.StartPinning();
|
|
|
|
// We know the merge type entry is not hidden, otherwise we would
|
|
// have hit (A)
|
|
// We encapsulate the merge related state machine in a different
|
|
// object to minimize change to the existing flow.
|
|
Status s = merge_helper_->MergeUntil(
|
|
&input_, range_del_agg_, prev_snapshot, bottommost_level_,
|
|
allow_data_in_errors_, blob_fetcher_.get(), prefetch_buffers_.get(),
|
|
&iter_stats_);
|
|
merge_out_iter_.SeekToFirst();
|
|
|
|
if (!s.ok() && !s.IsMergeInProgress()) {
|
|
status_ = s;
|
|
return;
|
|
} else if (merge_out_iter_.Valid()) {
|
|
// NOTE: key, value, and ikey_ refer to old entries.
|
|
// These will be correctly set below.
|
|
key_ = merge_out_iter_.key();
|
|
value_ = merge_out_iter_.value();
|
|
pik_status = ParseInternalKey(key_, &ikey_, allow_data_in_errors_);
|
|
// MergeUntil stops when it encounters a corrupt key and does not
|
|
// include them in the result, so we expect the keys here to valid.
|
|
assert(pik_status.ok());
|
|
if (!pik_status.ok()) {
|
|
ROCKS_LOG_FATAL(info_log_, "Invalid key in compaction. %s",
|
|
pik_status.getState());
|
|
}
|
|
// Keep current_key_ in sync.
|
|
current_key_.UpdateInternalKey(ikey_.sequence, ikey_.type);
|
|
key_ = current_key_.GetInternalKey();
|
|
ikey_.user_key = current_key_.GetUserKey();
|
|
valid_ = true;
|
|
} else {
|
|
// all merge operands were filtered out. reset the user key, since the
|
|
// batch consumed by the merge operator should not shadow any keys
|
|
// coming after the merges
|
|
has_current_user_key_ = false;
|
|
pinned_iters_mgr_.ReleasePinnedData();
|
|
|
|
if (merge_helper_->FilteredUntil(&skip_until)) {
|
|
need_skip = true;
|
|
}
|
|
}
|
|
} else {
|
|
// 1. new user key -OR-
|
|
// 2. different snapshot stripe
|
|
bool should_delete = range_del_agg_->ShouldDelete(
|
|
key_, RangeDelPositioningMode::kForwardTraversal);
|
|
if (should_delete) {
|
|
++iter_stats_.num_record_drop_hidden;
|
|
++iter_stats_.num_record_drop_range_del;
|
|
AdvanceInputIter();
|
|
} else {
|
|
valid_ = true;
|
|
}
|
|
}
|
|
|
|
if (need_skip) {
|
|
SkipUntil(skip_until);
|
|
}
|
|
}
|
|
|
|
if (!valid_ && IsShuttingDown()) {
|
|
status_ = Status::ShutdownInProgress();
|
|
}
|
|
|
|
if (IsPausingManualCompaction()) {
|
|
status_ = Status::Incomplete(Status::SubCode::kManualCompactionPaused);
|
|
}
|
|
}
|
|
|
|
bool CompactionIterator::ExtractLargeValueIfNeededImpl() {
|
|
if (!blob_file_builder_) {
|
|
return false;
|
|
}
|
|
|
|
blob_index_.clear();
|
|
const Status s = blob_file_builder_->Add(user_key(), value_, &blob_index_);
|
|
|
|
if (!s.ok()) {
|
|
status_ = s;
|
|
valid_ = false;
|
|
|
|
return false;
|
|
}
|
|
|
|
if (blob_index_.empty()) {
|
|
return false;
|
|
}
|
|
|
|
value_ = blob_index_;
|
|
|
|
return true;
|
|
}
|
|
|
|
void CompactionIterator::ExtractLargeValueIfNeeded() {
|
|
assert(ikey_.type == kTypeValue);
|
|
|
|
if (!ExtractLargeValueIfNeededImpl()) {
|
|
return;
|
|
}
|
|
|
|
ikey_.type = kTypeBlobIndex;
|
|
current_key_.UpdateInternalKey(ikey_.sequence, ikey_.type);
|
|
}
|
|
|
|
void CompactionIterator::GarbageCollectBlobIfNeeded() {
|
|
assert(ikey_.type == kTypeBlobIndex);
|
|
|
|
if (!compaction_) {
|
|
return;
|
|
}
|
|
|
|
// GC for integrated BlobDB
|
|
if (compaction_->enable_blob_garbage_collection()) {
|
|
BlobIndex blob_index;
|
|
|
|
{
|
|
const Status s = blob_index.DecodeFrom(value_);
|
|
|
|
if (!s.ok()) {
|
|
status_ = s;
|
|
valid_ = false;
|
|
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (blob_index.file_number() >=
|
|
blob_garbage_collection_cutoff_file_number_) {
|
|
return;
|
|
}
|
|
|
|
FilePrefetchBuffer* prefetch_buffer =
|
|
prefetch_buffers_ ? prefetch_buffers_->GetOrCreatePrefetchBuffer(
|
|
blob_index.file_number())
|
|
: nullptr;
|
|
|
|
uint64_t bytes_read = 0;
|
|
|
|
{
|
|
assert(blob_fetcher_);
|
|
|
|
const Status s = blob_fetcher_->FetchBlob(
|
|
user_key(), blob_index, prefetch_buffer, &blob_value_, &bytes_read);
|
|
|
|
if (!s.ok()) {
|
|
status_ = s;
|
|
valid_ = false;
|
|
|
|
return;
|
|
}
|
|
}
|
|
|
|
++iter_stats_.num_blobs_read;
|
|
iter_stats_.total_blob_bytes_read += bytes_read;
|
|
|
|
++iter_stats_.num_blobs_relocated;
|
|
iter_stats_.total_blob_bytes_relocated += blob_index.size();
|
|
|
|
value_ = blob_value_;
|
|
|
|
if (ExtractLargeValueIfNeededImpl()) {
|
|
return;
|
|
}
|
|
|
|
ikey_.type = kTypeValue;
|
|
current_key_.UpdateInternalKey(ikey_.sequence, ikey_.type);
|
|
|
|
return;
|
|
}
|
|
|
|
// GC for stacked BlobDB
|
|
if (compaction_filter_ &&
|
|
compaction_filter_->IsStackedBlobDbInternalCompactionFilter()) {
|
|
const auto blob_decision = compaction_filter_->PrepareBlobOutput(
|
|
user_key(), value_, &compaction_filter_value_);
|
|
|
|
if (blob_decision == CompactionFilter::BlobDecision::kCorruption) {
|
|
status_ =
|
|
Status::Corruption("Corrupted blob reference encountered during GC");
|
|
valid_ = false;
|
|
|
|
return;
|
|
}
|
|
|
|
if (blob_decision == CompactionFilter::BlobDecision::kIOError) {
|
|
status_ = Status::IOError("Could not relocate blob during GC");
|
|
valid_ = false;
|
|
|
|
return;
|
|
}
|
|
|
|
if (blob_decision == CompactionFilter::BlobDecision::kChangeValue) {
|
|
value_ = compaction_filter_value_;
|
|
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
void CompactionIterator::PrepareOutput() {
|
|
if (valid_) {
|
|
if (ikey_.type == kTypeValue) {
|
|
ExtractLargeValueIfNeeded();
|
|
} else if (ikey_.type == kTypeBlobIndex) {
|
|
GarbageCollectBlobIfNeeded();
|
|
}
|
|
|
|
// Zeroing out the sequence number leads to better compression.
|
|
// If this is the bottommost level (no files in lower levels)
|
|
// and the earliest snapshot is larger than this seqno
|
|
// and the userkey differs from the last userkey in compaction
|
|
// then we can squash the seqno to zero.
|
|
//
|
|
// This is safe for TransactionDB write-conflict checking since transactions
|
|
// only care about sequence number larger than any active snapshots.
|
|
//
|
|
// Can we do the same for levels above bottom level as long as
|
|
// KeyNotExistsBeyondOutputLevel() return true?
|
|
if (valid_ && compaction_ != nullptr &&
|
|
!compaction_->allow_ingest_behind() &&
|
|
ikeyNotNeededForIncrementalSnapshot() && bottommost_level_ &&
|
|
DefinitelyInSnapshot(ikey_.sequence, earliest_snapshot_) &&
|
|
ikey_.type != kTypeMerge) {
|
|
assert(ikey_.type != kTypeDeletion);
|
|
assert(ikey_.type != kTypeSingleDeletion ||
|
|
(timestamp_size_ || full_history_ts_low_));
|
|
if (ikey_.type == kTypeDeletion ||
|
|
(ikey_.type == kTypeSingleDeletion &&
|
|
(!timestamp_size_ || !full_history_ts_low_))) {
|
|
ROCKS_LOG_FATAL(info_log_,
|
|
"Unexpected key type %d for seq-zero optimization",
|
|
ikey_.type);
|
|
}
|
|
ikey_.sequence = 0;
|
|
last_key_seq_zeroed_ = true;
|
|
TEST_SYNC_POINT_CALLBACK("CompactionIterator::PrepareOutput:ZeroingSeq",
|
|
&ikey_);
|
|
if (!timestamp_size_) {
|
|
current_key_.UpdateInternalKey(0, ikey_.type);
|
|
} else if (full_history_ts_low_ && cmp_with_history_ts_low_ < 0) {
|
|
// We can also zero out timestamp for better compression.
|
|
// For the same user key (excluding timestamp), the timestamp-based
|
|
// history can be collapsed to save some space if the timestamp is
|
|
// older than *full_history_ts_low_.
|
|
const std::string kTsMin(timestamp_size_, static_cast<char>(0));
|
|
const Slice ts_slice = kTsMin;
|
|
ikey_.SetTimestamp(ts_slice);
|
|
current_key_.UpdateInternalKey(0, ikey_.type, &ts_slice);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
inline SequenceNumber CompactionIterator::findEarliestVisibleSnapshot(
|
|
SequenceNumber in, SequenceNumber* prev_snapshot) {
|
|
assert(snapshots_->size());
|
|
if (snapshots_->size() == 0) {
|
|
ROCKS_LOG_FATAL(info_log_,
|
|
"No snapshot left in findEarliestVisibleSnapshot");
|
|
}
|
|
auto snapshots_iter = std::lower_bound(
|
|
snapshots_->begin(), snapshots_->end(), in);
|
|
if (snapshots_iter == snapshots_->begin()) {
|
|
*prev_snapshot = 0;
|
|
} else {
|
|
*prev_snapshot = *std::prev(snapshots_iter);
|
|
assert(*prev_snapshot < in);
|
|
if (*prev_snapshot >= in) {
|
|
ROCKS_LOG_FATAL(info_log_,
|
|
"*prev_snapshot >= in in findEarliestVisibleSnapshot");
|
|
}
|
|
}
|
|
if (snapshot_checker_ == nullptr) {
|
|
return snapshots_iter != snapshots_->end()
|
|
? *snapshots_iter : kMaxSequenceNumber;
|
|
}
|
|
bool has_released_snapshot = !released_snapshots_.empty();
|
|
for (; snapshots_iter != snapshots_->end(); ++snapshots_iter) {
|
|
auto cur = *snapshots_iter;
|
|
assert(in <= cur);
|
|
if (in > cur) {
|
|
ROCKS_LOG_FATAL(info_log_, "in > cur in findEarliestVisibleSnapshot");
|
|
}
|
|
// Skip if cur is in released_snapshots.
|
|
if (has_released_snapshot && released_snapshots_.count(cur) > 0) {
|
|
continue;
|
|
}
|
|
auto res = snapshot_checker_->CheckInSnapshot(in, cur);
|
|
if (res == SnapshotCheckerResult::kInSnapshot) {
|
|
return cur;
|
|
} else if (res == SnapshotCheckerResult::kSnapshotReleased) {
|
|
released_snapshots_.insert(cur);
|
|
}
|
|
*prev_snapshot = cur;
|
|
}
|
|
return kMaxSequenceNumber;
|
|
}
|
|
|
|
// used in 2 places - prevents deletion markers to be dropped if they may be
|
|
// needed and disables seqnum zero-out in PrepareOutput for recent keys.
|
|
inline bool CompactionIterator::ikeyNotNeededForIncrementalSnapshot() {
|
|
return (!compaction_->preserve_deletes()) ||
|
|
(ikey_.sequence < preserve_deletes_seqnum_);
|
|
}
|
|
|
|
uint64_t CompactionIterator::ComputeBlobGarbageCollectionCutoffFileNumber(
|
|
const CompactionProxy* compaction) {
|
|
if (!compaction) {
|
|
return 0;
|
|
}
|
|
|
|
if (!compaction->enable_blob_garbage_collection()) {
|
|
return 0;
|
|
}
|
|
|
|
const Version* const version = compaction->input_version();
|
|
assert(version);
|
|
|
|
const VersionStorageInfo* const storage_info = version->storage_info();
|
|
assert(storage_info);
|
|
|
|
const auto& blob_files = storage_info->GetBlobFiles();
|
|
|
|
const size_t cutoff_index = static_cast<size_t>(
|
|
compaction->blob_garbage_collection_age_cutoff() * blob_files.size());
|
|
|
|
if (cutoff_index >= blob_files.size()) {
|
|
return std::numeric_limits<uint64_t>::max();
|
|
}
|
|
|
|
const auto& meta = blob_files[cutoff_index];
|
|
assert(meta);
|
|
|
|
return meta->GetBlobFileNumber();
|
|
}
|
|
|
|
std::unique_ptr<BlobFetcher> CompactionIterator::CreateBlobFetcherIfNeeded(
|
|
const CompactionProxy* compaction) {
|
|
if (!compaction) {
|
|
return nullptr;
|
|
}
|
|
|
|
const Version* const version = compaction->input_version();
|
|
if (!version) {
|
|
return nullptr;
|
|
}
|
|
|
|
return std::unique_ptr<BlobFetcher>(new BlobFetcher(version, ReadOptions()));
|
|
}
|
|
|
|
std::unique_ptr<PrefetchBufferCollection>
|
|
CompactionIterator::CreatePrefetchBufferCollectionIfNeeded(
|
|
const CompactionProxy* compaction) {
|
|
if (!compaction) {
|
|
return nullptr;
|
|
}
|
|
|
|
if (!compaction->input_version()) {
|
|
return nullptr;
|
|
}
|
|
|
|
if (compaction->allow_mmap_reads()) {
|
|
return nullptr;
|
|
}
|
|
|
|
const uint64_t readahead_size = compaction->blob_compaction_readahead_size();
|
|
if (!readahead_size) {
|
|
return nullptr;
|
|
}
|
|
|
|
return std::unique_ptr<PrefetchBufferCollection>(
|
|
new PrefetchBufferCollection(readahead_size));
|
|
}
|
|
|
|
} // namespace ROCKSDB_NAMESPACE
|