augustoasilva commented on a change in pull request #11193: URL: https://github.com/apache/arrow/pull/11193#discussion_r732323838
########## File path: cpp/src/gandiva/expression_cache_key.h ########## @@ -0,0 +1,126 @@ +// 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. + +#pragma once + +#include <stddef.h> + +#include <thread> + +#include "arrow/util/hash_util.h" +#include "gandiva/arrow.h" +#include "gandiva/configuration.h" +#include "gandiva/expression.h" +#include "gandiva/selection_vector.h" +#include "gandiva/visibility.h" + +namespace gandiva { + +class ExpressionCacheKey { + public: + ExpressionCacheKey(SchemaPtr schema, std::shared_ptr<Configuration> configuration, + ExpressionVector expression_vector, SelectionVector::Mode mode, + std::string type) + : type_(type), + schema_(schema), + mode_(mode), + uniqifier_(0), + configuration_(configuration) { + static const int kSeedValue = 4; + size_t result = kSeedValue; + for (auto& expr : expression_vector) { + std::string expr_as_string = expr->ToString(); + expressions_as_strings_.push_back(expr_as_string); + arrow::internal::hash_combine(result, expr_as_string); + UpdateUniqifier(expr_as_string); + } + arrow::internal::hash_combine(result, static_cast<size_t>(mode)); + arrow::internal::hash_combine(result, configuration->Hash()); + arrow::internal::hash_combine(result, schema_->ToString()); + arrow::internal::hash_combine(result, uniqifier_); + hash_code_ = result; + } + + ExpressionCacheKey(SchemaPtr schema, std::shared_ptr<Configuration> configuration, + Expression& expression, std::string type) + : type_(type), schema_(schema), uniqifier_(0), configuration_(configuration) { + static const int kSeedValue = 4; + size_t result = kSeedValue; + expressions_as_strings_.push_back(expression.ToString()); + UpdateUniqifier(expression.ToString()); + + arrow::internal::hash_combine(result, configuration->Hash()); + arrow::internal::hash_combine(result, schema_->ToString()); + arrow::internal::hash_combine(result, uniqifier_); + hash_code_ = result; + } + + void UpdateUniqifier(const std::string& expr) { + if (uniqifier_ == 0) { + // caching of expressions with re2 patterns causes lock contention. So, use + // multiple instances to reduce contention. + if (expr.find(" like(") != std::string::npos) { + uniqifier_ = std::hash<std::thread::id>()(std::this_thread::get_id()) % 16; + } + } + } + + size_t Hash() const { return hash_code_; } + + std::string Type() const { return type_; } + + bool operator==(const ExpressionCacheKey& other) const { + if (type_ != other.type_) { + return false; + } + + if (hash_code_ != other.hash_code_) { + return false; + } + + if (!(schema_->Equals(*other.schema_, true))) { + return false; + } + + if (configuration_ != other.configuration_) { + return false; + } + + if (expressions_as_strings_ != other.expressions_as_strings_) { + return false; + } + + if (uniqifier_ != other.uniqifier_) { + return false; + } + + return true; + } + + bool operator!=(const ExpressionCacheKey& other) const { return !(*this == other); } + + private: + size_t hash_code_; + std::string type_; Review comment: Yes, my mistake, when I changed it to Expression Cache Key, I shoud have removed this type indicator. So I removed it now. -- 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]
