| /* |
| * 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 THETA_HELPERS_HPP_ |
| #define THETA_HELPERS_HPP_ |
| |
| #include <stdexcept> |
| #include <string> |
| |
| #include "theta_constants.hpp" |
| |
| namespace datasketches { |
| |
| template<typename T> |
| static void check_value(T actual, T expected, const char* description) { |
| if (actual != expected) { |
| throw std::invalid_argument(std::string(description) + " mismatch: expected " + std::to_string(expected) + ", actual " + std::to_string(actual)); |
| } |
| } |
| |
| template<bool dummy> |
| class checker { |
| public: |
| static void check_serial_version(uint8_t actual, uint8_t expected) { |
| check_value(actual, expected, "serial version"); |
| } |
| static void check_sketch_family(uint8_t actual, uint8_t expected) { |
| check_value(actual, expected, "sketch family"); |
| } |
| static void check_sketch_type(uint8_t actual, uint8_t expected) { |
| check_value(actual, expected, "sketch type"); |
| } |
| static void check_seed_hash(uint16_t actual, uint16_t expected) { |
| check_value(actual, expected, "seed hash"); |
| } |
| }; |
| |
| template<bool dummy> |
| class theta_build_helper{ |
| public: |
| // consistent way of initializing theta from p |
| // avoids multiplication if p == 1 since it might not yield MAX_THETA exactly |
| static uint64_t starting_theta_from_p(float p) { |
| if (p < 1) return static_cast<uint64_t>(theta_constants::MAX_THETA * p); |
| return theta_constants::MAX_THETA; |
| } |
| |
| static uint8_t starting_sub_multiple(uint8_t lg_tgt, uint8_t lg_min, uint8_t lg_rf) { |
| return (lg_tgt <= lg_min) ? lg_min : (lg_rf == 0) ? lg_tgt : ((lg_tgt - lg_min) % lg_rf) + lg_min; |
| } |
| }; |
| |
| } /* namespace datasketches */ |
| |
| #endif |