mapleFU commented on code in PR #2524: URL: https://github.com/apache/kvrocks/pull/2524#discussion_r1759613349
########## src/types/cms.cc: ########## @@ -0,0 +1,128 @@ +/* + * 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. + * + */ + +#include "cms.h" + +#include <algorithm> +#include <cmath> +#include <cstdint> +#include <vector> + +CMSketch::CMSketchDimensions CMSketch::CMSDimFromProb(double error, double delta) { + CMSketchDimensions dims; + dims.width = std::ceil(2 / error); + dims.depth = std::ceil(std::log10(delta) / std::log10(0.5)); + return dims; +} + +size_t CMSketch::IncrBy(std::string_view item, uint32_t value) { + size_t min_count = std::numeric_limits<size_t>::max(); + + for (size_t i = 0; i < depth_; ++i) { + uint64_t hash = HllMurMurHash64A(item.data(), static_cast<int>(item.size()), i); + size_t loc = GetLocation(hash, i); + if (array_[loc] > UINT32_MAX - value) { + array_[loc] = UINT32_MAX; + } else { + array_[loc] += value; + } + min_count = std::min(min_count, static_cast<size_t>(array_[loc])); + } + counter_ += value; + return min_count; +} + +size_t CMSketch::Query(std::string_view item) const { + size_t min_count = std::numeric_limits<size_t>::max(); + + for (size_t i = 0; i < depth_; ++i) { + uint64_t hash = HllMurMurHash64A(item.data(), static_cast<int>(item.size()), i); + min_count = std::min(min_count, static_cast<size_t>(array_[(hash % width_) + (i * width_)])); Review Comment: Why didn't `GetLocation` used here? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
