efd035164b
Summary: Especially after updating to C++17, I don't see a compelling case for *requiring* any folly components in RocksDB. I was able to purge the existing hard dependencies, and it can be quite difficult to strip out non-trivial components from folly for use in RocksDB. (The prospect of doing that on F14 has changed my mind on the best approach here.) But this change creates an optional integration where we can plug in components from folly at compile time, starting here with F14FastMap to replace std::unordered_map when possible (probably no public APIs for example). I have replaced the biggest CPU users of std::unordered_map with compile-time pluggable UnorderedMap which will use F14FastMap when USE_FOLLY is set. USE_FOLLY is always set in the Meta-internal buck build, and a simulation of that is in the Makefile for public CI testing. A full folly build is not needed, but checking out the full folly repo is much simpler for getting the dependency, and anything else we might want to optionally integrate in the future. Some picky details: * I don't think the distributed mutex stuff is actually used, so it was easy to remove. * I implemented an alternative to `folly::constexpr_log2` (which is much easier in C++17 than C++11) so that I could pull out the hard dependencies on `ConstexprMath.h` * I had to add noexcept move constructors/operators to some types to make F14's complainUnlessNothrowMoveAndDestroy check happy, and I added a macro to make that easier in some common cases. * Updated Meta-internal buck build to use folly F14Map (always) No updates to HISTORY.md nor INSTALL.md as this is not (yet?) considered a production integration for open source users. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9546 Test Plan: CircleCI tests updated so that a couple of them use folly. Most internal unit & stress/crash tests updated to use Meta-internal latest folly. (Note: they should probably use buck but they currently use Makefile.) Example performance improvement: when filter partitions are pinned in cache, they are tracked by PartitionedFilterBlockReader::filter_map_ and we can build a test that exercises that heavily. Build DB with ``` TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=30000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -partition_index_and_filters ``` and test with (simultaneous runs with & without folly, ~20 times each to see convergence) ``` TEST_TMPDIR=/dev/shm/rocksdb ./db_bench_folly -readonly -use_existing_db -benchmarks=readrandom -num=10000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -partition_index_and_filters -duration=40 -pin_l0_filter_and_index_blocks_in_cache ``` Average ops/s no folly: 26229.2 Average ops/s with folly: 26853.3 (+2.4%) Reviewed By: ajkr Differential Revision: D34181736 Pulled By: pdillinger fbshipit-source-id: ffa6ad5104c2880321d8a1aa7187e00ab0d02e94
56 lines
2.4 KiB
C++
56 lines
2.4 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#pragma once
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#include "table/block_based/index_reader_common.h"
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#include "util/hash_containers.h"
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namespace ROCKSDB_NAMESPACE {
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// Index that allows binary search lookup in a two-level index structure.
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class PartitionIndexReader : public BlockBasedTable::IndexReaderCommon {
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public:
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// Read the partition index from the file and create an instance for
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// `PartitionIndexReader`.
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// On success, index_reader will be populated; otherwise it will remain
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// unmodified.
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static Status Create(const BlockBasedTable* table, const ReadOptions& ro,
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FilePrefetchBuffer* prefetch_buffer, bool use_cache,
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bool prefetch, bool pin,
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BlockCacheLookupContext* lookup_context,
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std::unique_ptr<IndexReader>* index_reader);
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// return a two-level iterator: first level is on the partition index
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InternalIteratorBase<IndexValue>* NewIterator(
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const ReadOptions& read_options, bool /* disable_prefix_seek */,
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IndexBlockIter* iter, GetContext* get_context,
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BlockCacheLookupContext* lookup_context) override;
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Status CacheDependencies(const ReadOptions& ro, bool pin) override;
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size_t ApproximateMemoryUsage() const override {
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size_t usage = ApproximateIndexBlockMemoryUsage();
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#ifdef ROCKSDB_MALLOC_USABLE_SIZE
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usage += malloc_usable_size(const_cast<PartitionIndexReader*>(this));
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#else
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usage += sizeof(*this);
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#endif // ROCKSDB_MALLOC_USABLE_SIZE
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// TODO(myabandeh): more accurate estimate of partition_map_ mem usage
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return usage;
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}
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private:
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PartitionIndexReader(const BlockBasedTable* t,
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CachableEntry<Block>&& index_block)
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: IndexReaderCommon(t, std::move(index_block)) {}
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// For partition blocks pinned in cache. This is expected to be "all or
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// none" so that !partition_map_.empty() can use an iterator expecting
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// all partitions to be saved here.
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UnorderedMap<uint64_t, CachableEntry<Block>> partition_map_;
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};
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} // namespace ROCKSDB_NAMESPACE
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