| /* |
| * 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. |
| */ |
| |
| #ifndef KLL_QUANTILE_CALCULATOR_HPP_ |
| #define KLL_QUANTILE_CALCULATOR_HPP_ |
| |
| #include <memory> |
| |
| namespace datasketches { |
| |
| template <typename T, typename C, typename A> |
| class kll_quantile_calculator { |
| public: |
| // assumes that all levels are sorted including level 0 |
| kll_quantile_calculator(const T* items, const uint32_t* levels, uint8_t num_levels, uint64_t n, const A& allocator); |
| T get_quantile(double fraction) const; |
| |
| private: |
| using AllocU32 = typename std::allocator_traits<A>::template rebind_alloc<uint32_t>; |
| using vector_u32 = std::vector<uint32_t, AllocU32>; |
| using Entry = std::pair<T, uint64_t>; |
| using AllocEntry = typename std::allocator_traits<A>::template rebind_alloc<Entry>; |
| using Container = std::vector<Entry, AllocEntry>; |
| uint64_t n_; |
| vector_u32 levels_; |
| Container entries_; |
| |
| void populate_from_sketch(const T* items, const uint32_t* levels, uint8_t num_levels); |
| T approximately_answer_positional_query(uint64_t pos) const; |
| void convert_to_preceding_cummulative(); |
| uint32_t chunk_containing_pos(uint64_t pos) const; |
| uint32_t search_for_chunk_containing_pos(uint64_t pos, uint32_t l, uint32_t r) const; |
| static void merge_sorted_blocks(Container& entries, const uint32_t* levels, uint8_t num_levels, uint32_t num_items); |
| static void merge_sorted_blocks_direct(Container& orig, Container& temp, const uint32_t* levels, uint8_t starting_level, uint8_t num_levels); |
| static void merge_sorted_blocks_reversed(Container& orig, Container& temp, const uint32_t* levels, uint8_t starting_level, uint8_t num_levels); |
| static uint64_t pos_of_phi(double phi, uint64_t n); |
| |
| template<typename Comparator> |
| struct compare_pair_by_first { |
| template<typename Entry1, typename Entry2> |
| bool operator()(Entry1&& a, Entry2&& b) const { |
| return Comparator()(std::forward<Entry1>(a).first, std::forward<Entry2>(b).first); |
| } |
| }; |
| }; |
| |
| } /* namespace datasketches */ |
| |
| #include "kll_quantile_calculator_impl.hpp" |
| |
| #endif // KLL_QUANTILE_CALCULATOR_HPP_ |