yiguolei commented on code in PR #14480: URL: https://github.com/apache/doris/pull/14480#discussion_r1028972966
########## be/src/vec/common/hash_table/partitioned_hash_table.h: ########## @@ -0,0 +1,666 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. +// This file is copied from +// https://github.com/ClickHouse/ClickHouse/blob/master/src/Common/HashTable/TwoLevelHashTable.h +// and modified by Doris +#pragma once + +#include "vec/common/hash_table/hash_table.h" + +/** Partitioned hash table. + * Represents 16 (or 1ULL << BITS_FOR_SUB_TABLE) small hash tables (sub table count of the first level). + * To determine which one to use, one of the bytes of the hash function is taken. + * + * Usually works a little slower than a simple hash table. + * However, it has advantages in some cases: + * - if you need to merge two hash tables together, then you can easily parallelize it by sub tables; + * - delay during resizes is amortized, since the small hash tables will be resized separately; + * - in theory, resizes are cache-local in a larger range of sizes. + */ + +template <size_t initial_size_degree = 8> +struct PartitionedHashTableGrower : public HashTableGrowerWithPrecalculation<initial_size_degree> { + /// Increase the size of the hash table. + void increase_size() { this->increase_size_degree(this->size_degree() >= 15 ? 1 : 2); } +}; + +template <typename Key, typename Cell, typename Hash, typename Grower, typename Allocator, + typename ImplTable = HashTable<Key, Cell, Hash, Grower, Allocator>, + bool ENABLE_PARTITIONED = false, size_t BITS_FOR_SUB_TABLE = 4> +class PartitionedHashTable : private boost::noncopyable, + protected Hash /// empty base optimization +{ +public: + using Impl = ImplTable; + + using key_type = typename Impl::key_type; + using mapped_type = typename Impl::mapped_type; + using value_type = typename Impl::value_type; + using cell_type = typename Impl::cell_type; + + using LookupResult = typename Impl::LookupResult; + using ConstLookupResult = typename Impl::ConstLookupResult; + +protected: + friend class const_iterator; + friend class iterator; + + using HashValue = size_t; + using Self = PartitionedHashTable; + +private: + static constexpr size_t NUM_LEVEL1_SUB_TABLES = 1ULL << BITS_FOR_SUB_TABLE; + static constexpr size_t MAX_SUB_TABLE = NUM_LEVEL1_SUB_TABLES - 1; + + //factor that will trigger growing the hash table on insert. + static constexpr float MAX_SUB_TABLE_OCCUPANCY_FRACTION = 0.5f; + + static const int PARTITIONED_BUCKET_THRESHOLD = 8388608; + + Impl level0_sub_table; + Impl level1_sub_tables[NUM_LEVEL1_SUB_TABLES]; + + bool _is_partitioned = false; + + // if ENABLE_PARTITIONED, the threshold of bucket count of level0 hash table above + // which the hash table is converted to partioned hash table + int _partitioned_threshold = PARTITIONED_BUCKET_THRESHOLD; + +public: + PartitionedHashTable() { + if constexpr (ENABLE_PARTITIONED) { + level0_sub_table.set_partitioned_threshold(PARTITIONED_BUCKET_THRESHOLD); + } + } + + explicit PartitionedHashTable(size_t size_hint) { + if constexpr (ENABLE_PARTITIONED) { + level0_sub_table.set_partitioned_threshold(PARTITIONED_BUCKET_THRESHOLD); + if (level0_sub_table.check_if_need_partition(size_hint)) { + _is_partitioned = true; + + for (size_t i = 0; i < NUM_LEVEL1_SUB_TABLES; ++i) { + level1_sub_tables[i] = std::move(Impl(size_hint / NUM_LEVEL1_SUB_TABLES)); + } + } else { + level0_sub_table = std::move(Impl(size_hint)); + } + } else { + level0_sub_table = std::move(Impl(size_hint)); + } + } + + PartitionedHashTable(PartitionedHashTable&& rhs) { *this = std::move(rhs); } + + PartitionedHashTable& operator=(PartitionedHashTable&& rhs) { + std::swap(_is_partitioned, rhs._is_partitioned); + std::swap(_partitioned_threshold, rhs._partitioned_threshold); + + level0_sub_table = std::move(rhs.level0_sub_table); + for (size_t i = 0; i < NUM_LEVEL1_SUB_TABLES; ++i) { + level1_sub_tables[i] = std::move(rhs.level1_sub_tables[i]); + } + return *this; + } + + size_t hash(const Key& x) const { return Hash::operator()(x); } + + float get_factor() const { return MAX_SUB_TABLE_OCCUPANCY_FRACTION; } + + bool should_be_shrink(int64_t valid_row) const { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + return false; + } else { + return level0_sub_table.should_be_shrink(valid_row); + } + } else { + return level0_sub_table.should_be_shrink(valid_row); + } + } + + template <typename Func> + void ALWAYS_INLINE for_each_value(Func&& func) { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + for (auto i = 0u; i < NUM_LEVEL1_SUB_TABLES; ++i) { + level1_sub_tables[i].for_each_value(func); + } + } else { + level0_sub_table.for_each_value(func); + } + } else { + level0_sub_table.for_each_value(func); + } + } + + size_t get_size() { + size_t count = 0; + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + for (auto i = 0u; i < this->NUM_LEVEL1_SUB_TABLES; ++i) { + for (auto& v : this->level1_sub_tables[i]) { + count += v.get_second().get_row_count(); + } + } + } else { + count = level0_sub_table.get_size(); + } + } else { + count = level0_sub_table.get_size(); + } + return count; + } + + void init_buf_size(size_t reserve_for_num_elements) { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + for (auto& impl : level1_sub_tables) { + impl.init_buf_size(reserve_for_num_elements / NUM_LEVEL1_SUB_TABLES); + } + } else { + if (level0_sub_table.check_if_need_partition(reserve_for_num_elements)) { + level0_sub_table.clear_and_shrink(); + _is_partitioned = true; + + for (size_t i = 0; i < NUM_LEVEL1_SUB_TABLES; ++i) { + level1_sub_tables[i].init_buf_size(reserve_for_num_elements / + NUM_LEVEL1_SUB_TABLES); + } + } else { + level0_sub_table.init_buf_size(reserve_for_num_elements); + } + } + } else { + level0_sub_table.init_buf_size(reserve_for_num_elements); + } + } + + void delete_zero_key(Key key) { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + const auto key_hash = hash(key); + size_t bucket = get_sub_table_from_hash(key_hash); + level1_sub_tables[bucket].delete_zero_key(key); + } else { + level0_sub_table.delete_zero_key(key); + } + } else { + level0_sub_table.delete_zero_key(key); + } + } + + size_t get_buffer_size_in_bytes() const { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + size_t buff_size = 0; + for (const auto& impl : level1_sub_tables) + buff_size += impl.get_buffer_size_in_bytes(); + return buff_size; + } else { + return level0_sub_table.get_buffer_size_in_bytes(); + } + } else { + return level0_sub_table.get_buffer_size_in_bytes(); + } + } + + size_t get_buffer_size_in_cells() const { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + size_t buff_size = 0; + for (const auto& impl : level1_sub_tables) + buff_size += impl.get_buffer_size_in_cells(); + return buff_size; + } else { + return level0_sub_table.get_buffer_size_in_cells(); + } + } else { + return level0_sub_table.get_buffer_size_in_cells(); + } + } + + std::vector<size_t> get_buffer_sizes_in_cells() const { + std::vector<size_t> sizes; + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + for (size_t i = 0; i < NUM_LEVEL1_SUB_TABLES; ++i) { + sizes.push_back(level1_sub_tables[i].get_buffer_size_in_cells()); + } + } else { + sizes.push_back(level0_sub_table.get_buffer_size_in_cells()); + } + } else { + sizes.push_back(level0_sub_table.get_buffer_size_in_cells()); + } + return sizes; + } + + void reset_resize_timer() { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + for (auto& impl : level1_sub_tables) { + impl.reset_resize_timer(); + } + } else { + level0_sub_table.reset_resize_timer(); + } + } else { + level0_sub_table.reset_resize_timer(); + } + } + int64_t get_resize_timer_value() const { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + int64_t resize_timer_ns = 0; + for (const auto& impl : level1_sub_tables) { + resize_timer_ns += impl.get_resize_timer_value(); + } + return resize_timer_ns; + } else { + return level0_sub_table.get_resize_timer_value(); + } + } else { + return level0_sub_table.get_resize_timer_value(); + } + } + +protected: + typename Impl::iterator begin_of_next_non_empty_bucket(size_t& bucket) { + while (bucket != NUM_LEVEL1_SUB_TABLES && level1_sub_tables[bucket].empty()) ++bucket; + + if (bucket != NUM_LEVEL1_SUB_TABLES) return level1_sub_tables[bucket].begin(); + + --bucket; + return level1_sub_tables[MAX_SUB_TABLE].end(); + } + + typename Impl::const_iterator begin_of_next_non_empty_bucket(size_t& bucket) const { + while (bucket != NUM_LEVEL1_SUB_TABLES && level1_sub_tables[bucket].empty()) ++bucket; + + if (bucket != NUM_LEVEL1_SUB_TABLES) return level1_sub_tables[bucket].begin(); + + --bucket; + return level1_sub_tables[MAX_SUB_TABLE].end(); + } + +public: + void set_partitioned_threshold(int threshold) { + _partitioned_threshold = threshold; + if constexpr (ENABLE_PARTITIONED) { + level0_sub_table.set_partitioned_threshold(threshold); + } + } + + bool is_partitioned() const { + if constexpr (ENABLE_PARTITIONED) { + return _is_partitioned; + } else { + return false; + } + } + + class iterator /// NOLINT + { + Self* container {}; + size_t bucket {}; + typename Impl::iterator current_it {}; + + friend class PartitionedHashTable; + + iterator(Self* container_, size_t bucket_, typename Impl::iterator current_it_) + : container(container_), bucket(bucket_), current_it(current_it_) {} + + public: + iterator() = default; + + bool operator==(const iterator& rhs) const { + return bucket == rhs.bucket && current_it == rhs.current_it; + } + bool operator!=(const iterator& rhs) const { return !(*this == rhs); } + + iterator& operator++() { + ++current_it; + if constexpr (ENABLE_PARTITIONED) { + if (current_it == container->level1_sub_tables[bucket].end()) { + ++bucket; + current_it = container->begin_of_next_non_empty_bucket(bucket); + } + } + + return *this; + } + + Cell& operator*() const { return *current_it; } + Cell* operator->() const { return current_it.get_ptr(); } + + Cell* get_ptr() const { return current_it.get_ptr(); } + size_t get_hash() const { return current_it.get_hash(); } + }; + + class const_iterator /// NOLINT + { + Self* container {}; + size_t bucket {}; + typename Impl::const_iterator current_it {}; + + friend class PartitionedHashTable; + + const_iterator(Self* container_, size_t bucket_, typename Impl::const_iterator current_it_) + : container(container_), bucket(bucket_), current_it(current_it_) {} + + public: + const_iterator() = default; + const_iterator(const iterator& rhs) + : container(rhs.container), + bucket(rhs.bucket), + current_it(rhs.current_it) {} /// NOLINT + + bool operator==(const const_iterator& rhs) const { + return bucket == rhs.bucket && current_it == rhs.current_it; + } + bool operator!=(const const_iterator& rhs) const { return !(*this == rhs); } + + const_iterator& operator++() { + ++current_it; + if constexpr (ENABLE_PARTITIONED) { + if (current_it == container->level1_sub_tables[bucket].end()) { + ++bucket; + current_it = container->begin_of_next_non_empty_bucket(bucket); + } + } + + return *this; + } + + const Cell& operator*() const { return *current_it; } + const Cell* operator->() const { return current_it->get_ptr(); } + + const Cell* get_ptr() const { return current_it.get_ptr(); } + size_t get_hash() const { return current_it.get_hash(); } + }; + + const_iterator begin() const { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + size_t buck = 0; + typename Impl::const_iterator impl_it = begin_of_next_non_empty_bucket(buck); + return {this, buck, impl_it}; + } else { + return {this, NUM_LEVEL1_SUB_TABLES, level0_sub_table.begin()}; + } + } else { + return {this, NUM_LEVEL1_SUB_TABLES, level0_sub_table.begin()}; + } + } + + iterator begin() { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + size_t buck = 0; + typename Impl::iterator impl_it = begin_of_next_non_empty_bucket(buck); + return {this, buck, impl_it}; + } else { + return {this, NUM_LEVEL1_SUB_TABLES, level0_sub_table.begin()}; + } + } else { + return {this, NUM_LEVEL1_SUB_TABLES, level0_sub_table.begin()}; + } + } + + const_iterator end() const { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + return {this, MAX_SUB_TABLE, level1_sub_tables[MAX_SUB_TABLE].end()}; + } else { + return {this, NUM_LEVEL1_SUB_TABLES, level0_sub_table.end()}; + } + } else { + return {this, NUM_LEVEL1_SUB_TABLES, level0_sub_table.end()}; + } + } + iterator end() { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + return {this, MAX_SUB_TABLE, level1_sub_tables[MAX_SUB_TABLE].end()}; + } else { + return {this, NUM_LEVEL1_SUB_TABLES, level0_sub_table.end()}; + } + } else { + return {this, NUM_LEVEL1_SUB_TABLES, level0_sub_table.end()}; + } + } + + /// Insert a value. In the case of any more complex values, it is better to use the `emplace` function. + std::pair<LookupResult, bool> ALWAYS_INLINE insert(const value_type& x) { + size_t hash_value = hash(Cell::get_key(x)); + + std::pair<LookupResult, bool> res; + emplace(Cell::get_key(x), res.first, res.second, hash_value); + + if (res.second) insert_set_mapped(lookup_result_get_mapped(res.first), x); + + return res; + } + + void expanse_for_add_elem(size_t num_elem) { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + size_t num_elem_per_bucket = + (num_elem + NUM_LEVEL1_SUB_TABLES - 1) / NUM_LEVEL1_SUB_TABLES; + for (size_t i = 0; i < NUM_LEVEL1_SUB_TABLES; ++i) { + level1_sub_tables[i].expanse_for_add_elem(num_elem_per_bucket); + } + } else { + level0_sub_table.expanse_for_add_elem(num_elem); + if (UNLIKELY(level0_sub_table.need_partition())) { + convert_to_partitioned(); + } + } + } else { + level0_sub_table.expanse_for_add_elem(num_elem); + } + } + + template <typename KeyHolder> + void ALWAYS_INLINE prefetch(KeyHolder& key_holder) { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + const auto& key = key_holder_get_key(key_holder); + const auto key_hash = hash(key); + const auto bucket = get_sub_table_from_hash(key_hash); + level1_sub_tables[bucket].prefetch(key_holder); + } else { + level0_sub_table.prefetch(key_holder); + } + } else { + level0_sub_table.prefetch(key_holder); + } + } + + template <bool READ> + void ALWAYS_INLINE prefetch_by_hash(size_t hash_value) { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + const auto bucket = get_sub_table_from_hash(hash_value); + level1_sub_tables[bucket].template prefetch_by_hash<READ>(hash_value); + } else { + level0_sub_table.template prefetch_by_hash<READ>(hash_value); + } + } else { + level0_sub_table.template prefetch_by_hash<READ>(hash_value); + } + } + + template <bool READ, typename KeyHolder> + void ALWAYS_INLINE prefetch(KeyHolder& key_holder) { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + const auto& key = key_holder_get_key(key_holder); + const auto key_hash = hash(key); + const auto bucket = get_sub_table_from_hash(key_hash); + level1_sub_tables[bucket].template prefetch<READ>(key_holder); + } else { + level0_sub_table.template prefetch<READ>(key_holder); + } + } else { + level0_sub_table.template prefetch<READ>(key_holder); + } + } + + /** Insert the key, + * return an iterator to a position that can be used for `placement new` of value, + * as well as the flag - whether a new key was inserted. + * + * You have to make `placement new` values if you inserted a new key, + * since when destroying a hash table, the destructor will be invoked for it! + * + * Example usage: + * + * Map::iterator it; + * bool inserted; + * map.emplace(key, it, inserted); + * if (inserted) + * new(&it->second) Mapped(value); + */ + template <typename KeyHolder> + void ALWAYS_INLINE emplace(KeyHolder&& key_holder, LookupResult& it, bool& inserted) { + size_t hash_value = hash(key_holder_get_key(key_holder)); + emplace(key_holder, it, inserted, hash_value); + } + + /// Same, but with a precalculated values of hash function. + template <typename KeyHolder> + void ALWAYS_INLINE emplace(KeyHolder&& key_holder, LookupResult& it, bool& inserted, + size_t hash_value) { + if constexpr (ENABLE_PARTITIONED) { + if (_is_partitioned) { + size_t buck = get_sub_table_from_hash(hash_value); + level1_sub_tables[buck].emplace(key_holder, it, inserted, hash_value); + } else { + level0_sub_table.emplace(key_holder, it, inserted, hash_value); + if (UNLIKELY(level0_sub_table.need_partition())) { + convert_to_partitioned(); + + // The hash table was converted to partitioned, so we have to re-find the key. + size_t buck = get_sub_table_from_hash(hash_value); Review Comment: In this case, the “it” should be changed, in your code, it is still the it in old level0 hash table. -- This is an automated message from the Apache Git Service. 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