// Copyright (c) 2011-present, Facebook, Inc. All rights reserved. // This source code is licensed under both the GPLv2 (found in the // COPYING file in the root directory) and Apache 2.0 License // (found in the LICENSE.Apache file in the root directory). // // Copyright (c) 2011 The LevelDB Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. See the AUTHORS file for names of contributors. #include "db/table_cache.h" #include "db/dbformat.h" #include "db/range_tombstone_fragmenter.h" #include "db/snapshot_impl.h" #include "db/version_edit.h" #include "file/filename.h" #include "file/random_access_file_reader.h" #include "monitoring/perf_context_imp.h" #include "rocksdb/statistics.h" #include "table/block_based/block_based_table_reader.h" #include "table/get_context.h" #include "table/internal_iterator.h" #include "table/iterator_wrapper.h" #include "table/multiget_context.h" #include "table/table_builder.h" #include "table/table_reader.h" #include "test_util/sync_point.h" #include "util/cast_util.h" #include "util/coding.h" #include "util/stop_watch.h" namespace rocksdb { namespace { template static void DeleteEntry(const Slice& /*key*/, void* value) { T* typed_value = reinterpret_cast(value); delete typed_value; } static void UnrefEntry(void* arg1, void* arg2) { Cache* cache = reinterpret_cast(arg1); Cache::Handle* h = reinterpret_cast(arg2); cache->Release(h); } static Slice GetSliceForFileNumber(const uint64_t* file_number) { return Slice(reinterpret_cast(file_number), sizeof(*file_number)); } #ifndef ROCKSDB_LITE void AppendVarint64(IterKey* key, uint64_t v) { char buf[10]; auto ptr = EncodeVarint64(buf, v); key->TrimAppend(key->Size(), buf, ptr - buf); } #endif // ROCKSDB_LITE } // namespace TableCache::TableCache(const ImmutableCFOptions& ioptions, const FileOptions& file_options, Cache* const cache, BlockCacheTracer* const block_cache_tracer) : ioptions_(ioptions), file_options_(file_options), cache_(cache), immortal_tables_(false), block_cache_tracer_(block_cache_tracer) { if (ioptions_.row_cache) { // If the same cache is shared by multiple instances, we need to // disambiguate its entries. PutVarint64(&row_cache_id_, ioptions_.row_cache->NewId()); } } TableCache::~TableCache() { } TableReader* TableCache::GetTableReaderFromHandle(Cache::Handle* handle) { return reinterpret_cast(cache_->Value(handle)); } void TableCache::ReleaseHandle(Cache::Handle* handle) { cache_->Release(handle); } Status TableCache::GetTableReader( const FileOptions& file_options, const InternalKeyComparator& internal_comparator, const FileDescriptor& fd, bool sequential_mode, bool record_read_stats, HistogramImpl* file_read_hist, std::unique_ptr* table_reader, const SliceTransform* prefix_extractor, bool skip_filters, int level, bool prefetch_index_and_filter_in_cache) { std::string fname = TableFileName(ioptions_.cf_paths, fd.GetNumber(), fd.GetPathId()); std::unique_ptr file; Status s = ioptions_.fs->NewRandomAccessFile(fname, file_options, &file, nullptr); RecordTick(ioptions_.statistics, NO_FILE_OPENS); if (s.ok()) { if (!sequential_mode && ioptions_.advise_random_on_open) { file->Hint(FSRandomAccessFile::kRandom); } StopWatch sw(ioptions_.env, ioptions_.statistics, TABLE_OPEN_IO_MICROS); std::unique_ptr file_reader( new RandomAccessFileReader( std::move(file), fname, ioptions_.env, record_read_stats ? ioptions_.statistics : nullptr, SST_READ_MICROS, file_read_hist, ioptions_.rate_limiter, ioptions_.listeners)); s = ioptions_.table_factory->NewTableReader( TableReaderOptions(ioptions_, prefix_extractor, file_options, internal_comparator, skip_filters, immortal_tables_, level, fd.largest_seqno, block_cache_tracer_), std::move(file_reader), fd.GetFileSize(), table_reader, prefetch_index_and_filter_in_cache); TEST_SYNC_POINT("TableCache::GetTableReader:0"); } return s; } void TableCache::EraseHandle(const FileDescriptor& fd, Cache::Handle* handle) { ReleaseHandle(handle); uint64_t number = fd.GetNumber(); Slice key = GetSliceForFileNumber(&number); cache_->Erase(key); } Status TableCache::FindTable(const FileOptions& file_options, const InternalKeyComparator& internal_comparator, const FileDescriptor& fd, Cache::Handle** handle, const SliceTransform* prefix_extractor, const bool no_io, bool record_read_stats, HistogramImpl* file_read_hist, bool skip_filters, int level, bool prefetch_index_and_filter_in_cache) { PERF_TIMER_GUARD_WITH_ENV(find_table_nanos, ioptions_.env); Status s; uint64_t number = fd.GetNumber(); Slice key = GetSliceForFileNumber(&number); *handle = cache_->Lookup(key); TEST_SYNC_POINT_CALLBACK("TableCache::FindTable:0", const_cast(&no_io)); if (*handle == nullptr) { if (no_io) { // Don't do IO and return a not-found status return Status::Incomplete("Table not found in table_cache, no_io is set"); } std::unique_ptr table_reader; s = GetTableReader(file_options, internal_comparator, fd, false /* sequential mode */, record_read_stats, file_read_hist, &table_reader, prefix_extractor, skip_filters, level, prefetch_index_and_filter_in_cache); if (!s.ok()) { assert(table_reader == nullptr); RecordTick(ioptions_.statistics, NO_FILE_ERRORS); // We do not cache error results so that if the error is transient, // or somebody repairs the file, we recover automatically. } else { s = cache_->Insert(key, table_reader.get(), 1, &DeleteEntry, handle); if (s.ok()) { // Release ownership of table reader. table_reader.release(); } } } return s; } InternalIterator* TableCache::NewIterator( const ReadOptions& options, const FileOptions& file_options, const InternalKeyComparator& icomparator, const FileMetaData& file_meta, RangeDelAggregator* range_del_agg, const SliceTransform* prefix_extractor, TableReader** table_reader_ptr, HistogramImpl* file_read_hist, TableReaderCaller caller, Arena* arena, bool skip_filters, int level, const InternalKey* smallest_compaction_key, const InternalKey* largest_compaction_key) { PERF_TIMER_GUARD(new_table_iterator_nanos); Status s; TableReader* table_reader = nullptr; Cache::Handle* handle = nullptr; if (table_reader_ptr != nullptr) { *table_reader_ptr = nullptr; } bool for_compaction = caller == TableReaderCaller::kCompaction; auto& fd = file_meta.fd; table_reader = fd.table_reader; if (table_reader == nullptr) { s = FindTable(file_options, icomparator, fd, &handle, prefix_extractor, options.read_tier == kBlockCacheTier /* no_io */, !for_compaction /* record_read_stats */, file_read_hist, skip_filters, level); if (s.ok()) { table_reader = GetTableReaderFromHandle(handle); } } InternalIterator* result = nullptr; if (s.ok()) { if (options.table_filter && !options.table_filter(*table_reader->GetTableProperties())) { result = NewEmptyInternalIterator(arena); } else { result = table_reader->NewIterator(options, prefix_extractor, arena, skip_filters, caller, file_options.compaction_readahead_size); } if (handle != nullptr) { result->RegisterCleanup(&UnrefEntry, cache_, handle); handle = nullptr; // prevent from releasing below } if (for_compaction) { table_reader->SetupForCompaction(); } if (table_reader_ptr != nullptr) { *table_reader_ptr = table_reader; } } if (s.ok() && range_del_agg != nullptr && !options.ignore_range_deletions) { if (range_del_agg->AddFile(fd.GetNumber())) { std::unique_ptr range_del_iter( static_cast( table_reader->NewRangeTombstoneIterator(options))); if (range_del_iter != nullptr) { s = range_del_iter->status(); } if (s.ok()) { const InternalKey* smallest = &file_meta.smallest; const InternalKey* largest = &file_meta.largest; if (smallest_compaction_key != nullptr) { smallest = smallest_compaction_key; } if (largest_compaction_key != nullptr) { largest = largest_compaction_key; } range_del_agg->AddTombstones(std::move(range_del_iter), smallest, largest); } } } if (handle != nullptr) { ReleaseHandle(handle); } if (!s.ok()) { assert(result == nullptr); result = NewErrorInternalIterator(s, arena); } return result; } Status TableCache::GetRangeTombstoneIterator( const ReadOptions& options, const InternalKeyComparator& internal_comparator, const FileMetaData& file_meta, std::unique_ptr* out_iter) { const FileDescriptor& fd = file_meta.fd; Status s; TableReader* t = fd.table_reader; Cache::Handle* handle = nullptr; if (t == nullptr) { s = FindTable(file_options_, internal_comparator, fd, &handle); if (s.ok()) { t = GetTableReaderFromHandle(handle); } } if (s.ok()) { out_iter->reset(t->NewRangeTombstoneIterator(options)); assert(out_iter); } return s; } #ifndef ROCKSDB_LITE void TableCache::CreateRowCacheKeyPrefix(const ReadOptions& options, const FileDescriptor& fd, const Slice& internal_key, GetContext* get_context, IterKey& row_cache_key) { uint64_t fd_number = fd.GetNumber(); // We use the user key as cache key instead of the internal key, // otherwise the whole cache would be invalidated every time the // sequence key increases. However, to support caching snapshot // reads, we append the sequence number (incremented by 1 to // distinguish from 0) only in this case. // If the snapshot is larger than the largest seqno in the file, // all data should be exposed to the snapshot, so we treat it // the same as there is no snapshot. The exception is that if // a seq-checking callback is registered, some internal keys // may still be filtered out. uint64_t seq_no = 0; // Maybe we can include the whole file ifsnapshot == fd.largest_seqno. if (options.snapshot != nullptr && (get_context->has_callback() || static_cast_with_check( options.snapshot) ->GetSequenceNumber() <= fd.largest_seqno)) { // We should consider to use options.snapshot->GetSequenceNumber() // instead of GetInternalKeySeqno(k), which will make the code // easier to understand. seq_no = 1 + GetInternalKeySeqno(internal_key); } // Compute row cache key. row_cache_key.TrimAppend(row_cache_key.Size(), row_cache_id_.data(), row_cache_id_.size()); AppendVarint64(&row_cache_key, fd_number); AppendVarint64(&row_cache_key, seq_no); } bool TableCache::GetFromRowCache(const Slice& user_key, IterKey& row_cache_key, size_t prefix_size, GetContext* get_context) { bool found = false; row_cache_key.TrimAppend(prefix_size, user_key.data(), user_key.size()); if (auto row_handle = ioptions_.row_cache->Lookup(row_cache_key.GetUserKey())) { // Cleanable routine to release the cache entry Cleanable value_pinner; auto release_cache_entry_func = [](void* cache_to_clean, void* cache_handle) { ((Cache*)cache_to_clean)->Release((Cache::Handle*)cache_handle); }; auto found_row_cache_entry = static_cast(ioptions_.row_cache->Value(row_handle)); // If it comes here value is located on the cache. // found_row_cache_entry points to the value on cache, // and value_pinner has cleanup procedure for the cached entry. // After replayGetContextLog() returns, get_context.pinnable_slice_ // will point to cache entry buffer (or a copy based on that) and // cleanup routine under value_pinner will be delegated to // get_context.pinnable_slice_. Cache entry is released when // get_context.pinnable_slice_ is reset. value_pinner.RegisterCleanup(release_cache_entry_func, ioptions_.row_cache.get(), row_handle); replayGetContextLog(*found_row_cache_entry, user_key, get_context, &value_pinner); RecordTick(ioptions_.statistics, ROW_CACHE_HIT); found = true; } else { RecordTick(ioptions_.statistics, ROW_CACHE_MISS); } return found; } #endif // ROCKSDB_LITE Status TableCache::Get(const ReadOptions& options, const InternalKeyComparator& internal_comparator, const FileMetaData& file_meta, const Slice& k, GetContext* get_context, const SliceTransform* prefix_extractor, HistogramImpl* file_read_hist, bool skip_filters, int level) { auto& fd = file_meta.fd; std::string* row_cache_entry = nullptr; bool done = false; #ifndef ROCKSDB_LITE IterKey row_cache_key; std::string row_cache_entry_buffer; // Check row cache if enabled. Since row cache does not currently store // sequence numbers, we cannot use it if we need to fetch the sequence. if (ioptions_.row_cache && !get_context->NeedToReadSequence()) { auto user_key = ExtractUserKey(k); CreateRowCacheKeyPrefix(options, fd, k, get_context, row_cache_key); done = GetFromRowCache(user_key, row_cache_key, row_cache_key.Size(), get_context); if (!done) { row_cache_entry = &row_cache_entry_buffer; } } #endif // ROCKSDB_LITE Status s; TableReader* t = fd.table_reader; Cache::Handle* handle = nullptr; if (!done && s.ok()) { if (t == nullptr) { s = FindTable( file_options_, internal_comparator, fd, &handle, prefix_extractor, options.read_tier == kBlockCacheTier /* no_io */, true /* record_read_stats */, file_read_hist, skip_filters, level); if (s.ok()) { t = GetTableReaderFromHandle(handle); } } SequenceNumber* max_covering_tombstone_seq = get_context->max_covering_tombstone_seq(); if (s.ok() && max_covering_tombstone_seq != nullptr && !options.ignore_range_deletions) { std::unique_ptr range_del_iter( t->NewRangeTombstoneIterator(options)); if (range_del_iter != nullptr) { *max_covering_tombstone_seq = std::max( *max_covering_tombstone_seq, range_del_iter->MaxCoveringTombstoneSeqnum(ExtractUserKey(k))); } } if (s.ok()) { get_context->SetReplayLog(row_cache_entry); // nullptr if no cache. s = t->Get(options, k, get_context, prefix_extractor, skip_filters); get_context->SetReplayLog(nullptr); } else if (options.read_tier == kBlockCacheTier && s.IsIncomplete()) { // Couldn't find Table in cache but treat as kFound if no_io set get_context->MarkKeyMayExist(); s = Status::OK(); done = true; } } #ifndef ROCKSDB_LITE // Put the replay log in row cache only if something was found. if (!done && s.ok() && row_cache_entry && !row_cache_entry->empty()) { size_t charge = row_cache_key.Size() + row_cache_entry->size() + sizeof(std::string); void* row_ptr = new std::string(std::move(*row_cache_entry)); ioptions_.row_cache->Insert(row_cache_key.GetUserKey(), row_ptr, charge, &DeleteEntry); } #endif // ROCKSDB_LITE if (handle != nullptr) { ReleaseHandle(handle); } return s; } // Batched version of TableCache::MultiGet. Status TableCache::MultiGet(const ReadOptions& options, const InternalKeyComparator& internal_comparator, const FileMetaData& file_meta, const MultiGetContext::Range* mget_range, const SliceTransform* prefix_extractor, HistogramImpl* file_read_hist, bool skip_filters, int level) { auto& fd = file_meta.fd; Status s; TableReader* t = fd.table_reader; Cache::Handle* handle = nullptr; MultiGetRange table_range(*mget_range, mget_range->begin(), mget_range->end()); #ifndef ROCKSDB_LITE autovector row_cache_entries; IterKey row_cache_key; size_t row_cache_key_prefix_size = 0; KeyContext& first_key = *table_range.begin(); bool lookup_row_cache = ioptions_.row_cache && !first_key.get_context->NeedToReadSequence(); // Check row cache if enabled. Since row cache does not currently store // sequence numbers, we cannot use it if we need to fetch the sequence. if (lookup_row_cache) { GetContext* first_context = first_key.get_context; CreateRowCacheKeyPrefix(options, fd, first_key.ikey, first_context, row_cache_key); row_cache_key_prefix_size = row_cache_key.Size(); for (auto miter = table_range.begin(); miter != table_range.end(); ++miter) { const Slice& user_key = miter->ukey; ; GetContext* get_context = miter->get_context; if (GetFromRowCache(user_key, row_cache_key, row_cache_key_prefix_size, get_context)) { table_range.SkipKey(miter); } else { row_cache_entries.emplace_back(); get_context->SetReplayLog(&(row_cache_entries.back())); } } } #endif // ROCKSDB_LITE // Check that table_range is not empty. Its possible all keys may have been // found in the row cache and thus the range may now be empty if (s.ok() && !table_range.empty()) { if (t == nullptr) { s = FindTable( file_options_, internal_comparator, fd, &handle, prefix_extractor, options.read_tier == kBlockCacheTier /* no_io */, true /* record_read_stats */, file_read_hist, skip_filters, level); if (s.ok()) { t = GetTableReaderFromHandle(handle); assert(t); } } if (s.ok() && !options.ignore_range_deletions) { std::unique_ptr range_del_iter( t->NewRangeTombstoneIterator(options)); if (range_del_iter != nullptr) { for (auto iter = table_range.begin(); iter != table_range.end(); ++iter) { SequenceNumber* max_covering_tombstone_seq = iter->get_context->max_covering_tombstone_seq(); *max_covering_tombstone_seq = std::max(*max_covering_tombstone_seq, range_del_iter->MaxCoveringTombstoneSeqnum(iter->ukey)); } } } if (s.ok()) { t->MultiGet(options, &table_range, prefix_extractor, skip_filters); } else if (options.read_tier == kBlockCacheTier && s.IsIncomplete()) { for (auto iter = table_range.begin(); iter != table_range.end(); ++iter) { Status* status = iter->s; if (status->IsIncomplete()) { // Couldn't find Table in cache but treat as kFound if no_io set iter->get_context->MarkKeyMayExist(); s = Status::OK(); } } } } #ifndef ROCKSDB_LITE if (lookup_row_cache) { size_t row_idx = 0; for (auto miter = table_range.begin(); miter != table_range.end(); ++miter) { std::string& row_cache_entry = row_cache_entries[row_idx++]; const Slice& user_key = miter->ukey; ; GetContext* get_context = miter->get_context; get_context->SetReplayLog(nullptr); // Compute row cache key. row_cache_key.TrimAppend(row_cache_key_prefix_size, user_key.data(), user_key.size()); // Put the replay log in row cache only if something was found. if (s.ok() && !row_cache_entry.empty()) { size_t charge = row_cache_key.Size() + row_cache_entry.size() + sizeof(std::string); void* row_ptr = new std::string(std::move(row_cache_entry)); ioptions_.row_cache->Insert(row_cache_key.GetUserKey(), row_ptr, charge, &DeleteEntry); } } } #endif // ROCKSDB_LITE if (handle != nullptr) { ReleaseHandle(handle); } return s; } Status TableCache::GetTableProperties( const FileOptions& file_options, const InternalKeyComparator& internal_comparator, const FileDescriptor& fd, std::shared_ptr* properties, const SliceTransform* prefix_extractor, bool no_io) { Status s; auto table_reader = fd.table_reader; // table already been pre-loaded? if (table_reader) { *properties = table_reader->GetTableProperties(); return s; } Cache::Handle* table_handle = nullptr; s = FindTable(file_options, internal_comparator, fd, &table_handle, prefix_extractor, no_io); if (!s.ok()) { return s; } assert(table_handle); auto table = GetTableReaderFromHandle(table_handle); *properties = table->GetTableProperties(); ReleaseHandle(table_handle); return s; } size_t TableCache::GetMemoryUsageByTableReader( const FileOptions& file_options, const InternalKeyComparator& internal_comparator, const FileDescriptor& fd, const SliceTransform* prefix_extractor) { Status s; auto table_reader = fd.table_reader; // table already been pre-loaded? if (table_reader) { return table_reader->ApproximateMemoryUsage(); } Cache::Handle* table_handle = nullptr; s = FindTable(file_options, internal_comparator, fd, &table_handle, prefix_extractor, true); if (!s.ok()) { return 0; } assert(table_handle); auto table = GetTableReaderFromHandle(table_handle); auto ret = table->ApproximateMemoryUsage(); ReleaseHandle(table_handle); return ret; } void TableCache::Evict(Cache* cache, uint64_t file_number) { cache->Erase(GetSliceForFileNumber(&file_number)); } uint64_t TableCache::ApproximateOffsetOf( const Slice& key, const FileDescriptor& fd, TableReaderCaller caller, const InternalKeyComparator& internal_comparator, const SliceTransform* prefix_extractor) { uint64_t result = 0; TableReader* table_reader = fd.table_reader; Cache::Handle* table_handle = nullptr; if (table_reader == nullptr) { const bool for_compaction = (caller == TableReaderCaller::kCompaction); Status s = FindTable(file_options_, internal_comparator, fd, &table_handle, prefix_extractor, false /* no_io */, !for_compaction /* record_read_stats */); if (s.ok()) { table_reader = GetTableReaderFromHandle(table_handle); } } if (table_reader != nullptr) { result = table_reader->ApproximateOffsetOf(key, caller); } if (table_handle != nullptr) { ReleaseHandle(table_handle); } return result; } uint64_t TableCache::ApproximateSize( const Slice& start, const Slice& end, const FileDescriptor& fd, TableReaderCaller caller, const InternalKeyComparator& internal_comparator, const SliceTransform* prefix_extractor) { uint64_t result = 0; TableReader* table_reader = fd.table_reader; Cache::Handle* table_handle = nullptr; if (table_reader == nullptr) { const bool for_compaction = (caller == TableReaderCaller::kCompaction); Status s = FindTable(file_options_, internal_comparator, fd, &table_handle, prefix_extractor, false /* no_io */, !for_compaction /* record_read_stats */); if (s.ok()) { table_reader = GetTableReaderFromHandle(table_handle); } } if (table_reader != nullptr) { result = table_reader->ApproximateSize(start, end, caller); } if (table_handle != nullptr) { ReleaseHandle(table_handle); } return result; } } // namespace rocksdb