| /* |
| * 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. |
| */ |
| |
| // author Kevin Lang, Oath Research |
| |
| #ifndef U32_TABLE_HPP_ |
| #define U32_TABLE_HPP_ |
| |
| // This is a highly specialized hash table that was designed |
| // to be a part of the library's CPC sketch implementation |
| |
| #include "cpc_common.hpp" |
| |
| namespace datasketches { |
| |
| static const uint64_t U32_TABLE_UPSIZE_NUMER = 3LL; |
| static const uint64_t U32_TABLE_UPSIZE_DENOM = 4LL; |
| |
| static const uint64_t U32_TABLE_DOWNSIZE_NUMER = 1LL; |
| static const uint64_t U32_TABLE_DOWNSIZE_DENOM = 4LL; |
| |
| template<typename A> |
| class u32_table { |
| public: |
| |
| u32_table(const A& allocator); |
| u32_table(uint8_t lg_size, uint8_t num_valid_bits, const A& allocator); |
| |
| inline size_t get_num_items() const; |
| inline const uint32_t* get_slots() const; |
| inline uint8_t get_lg_size() const; |
| inline void clear(); |
| |
| // returns true iff the item was new and was therefore added to the table |
| inline bool maybe_insert(uint32_t item); |
| // returns true iff the item was present and was therefore removed from the table |
| inline bool maybe_delete(uint32_t item); |
| |
| static u32_table make_from_pairs(const uint32_t* pairs, size_t num_pairs, uint8_t lg_k, const A& allocator); |
| |
| vector_u32<A> unwrapping_get_items() const; |
| |
| static void merge( |
| const uint32_t* arr_a, size_t start_a, size_t length_a, // input |
| const uint32_t* arr_b, size_t start_b, size_t length_b, // input |
| uint32_t* arr_c, size_t start_c // output |
| ); |
| |
| static void introspective_insertion_sort(uint32_t* a, size_t l, size_t r); |
| static void knuth_shell_sort3(uint32_t* a, size_t l, size_t r); |
| |
| private: |
| |
| uint8_t lg_size; // log2 of number of slots |
| uint8_t num_valid_bits; |
| size_t num_items; |
| vector_u32<A> slots; |
| |
| inline size_t lookup(uint32_t item) const; |
| inline void must_insert(uint32_t item); |
| inline void rebuild(uint8_t new_lg_size); |
| }; |
| |
| } /* namespace datasketches */ |
| |
| #include "u32_table_impl.hpp" |
| |
| #endif |