SuKi2cn commented on code in PR #335: URL: https://github.com/apache/iceberg-cpp/pull/335#discussion_r2564057809
########## src/iceberg/expression/aggregate.cc: ########## @@ -0,0 +1,398 @@ +/* + * 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 "iceberg/expression/aggregate.h" + +#include <format> +#include <optional> +#include <vector> + +#include "iceberg/exception.h" +#include "iceberg/expression/binder.h" +#include "iceberg/row/struct_like.h" +#include "iceberg/type.h" +#include "iceberg/util/checked_cast.h" +#include "iceberg/util/macros.h" + +namespace iceberg { + +namespace { + +Result<std::shared_ptr<PrimitiveType>> GetPrimitiveType(const BoundTerm& term) { + if (!term.type()->is_primitive()) { + return InvalidExpression("Aggregate requires primitive type, got {}", + term.type()->ToString()); + } + return internal::checked_pointer_cast<PrimitiveType>(term.type()); +} + +class CountNonNullAggregator : public BoundAggregate::Aggregator { + public: + explicit CountNonNullAggregator(std::shared_ptr<BoundTerm> term) + : term_(std::move(term)) {} + + Status Update(const StructLike& row) override { + ICEBERG_ASSIGN_OR_RAISE(auto literal, term_->Evaluate(row)); + if (!literal.IsNull()) { + ++count_; + } + return {}; + } + + Result<Literal> ResultLiteral() const override { return Literal::Long(count_); } + + private: + std::shared_ptr<BoundTerm> term_; + int64_t count_ = 0; +}; + +class CountNullAggregator : public BoundAggregate::Aggregator { + public: + explicit CountNullAggregator(std::shared_ptr<BoundTerm> term) + : term_(std::move(term)) {} + + Status Update(const StructLike& row) override { + ICEBERG_ASSIGN_OR_RAISE(auto literal, term_->Evaluate(row)); + if (literal.IsNull()) { + ++count_; + } + return {}; + } + + Result<Literal> ResultLiteral() const override { return Literal::Long(count_); } + + private: + std::shared_ptr<BoundTerm> term_; + int64_t count_ = 0; +}; + +class CountStarAggregator : public BoundAggregate::Aggregator { + public: + Status Update(const StructLike& /*row*/) override { + ++count_; + return {}; + } + + Result<Literal> ResultLiteral() const override { return Literal::Long(count_); } + + private: + int64_t count_ = 0; +}; + +class ValueAggregatorImpl : public BoundAggregate::Aggregator { + public: + ValueAggregatorImpl(bool is_max, std::shared_ptr<BoundTerm> term) + : is_max_(is_max), term_(std::move(term)) {} + + Status Update(const StructLike& row) override { + ICEBERG_ASSIGN_OR_RAISE(auto val_literal, term_->Evaluate(row)); + if (val_literal.IsNull()) { + return {}; + } + if (!current_) { + current_ = std::move(val_literal); + return {}; + } + + auto ordering = val_literal <=> *current_; + if (ordering == std::partial_ordering::unordered) { + return InvalidExpression("Cannot compare literals of type {}", + val_literal.type()->ToString()); + } + + if (is_max_) { + if (ordering == std::partial_ordering::greater) { + current_ = std::move(val_literal); + } + } else { + if (ordering == std::partial_ordering::less) { + current_ = std::move(val_literal); + } + } + return {}; + } + + Result<Literal> ResultLiteral() const override { + if (current_) { + return *current_; + } + ICEBERG_ASSIGN_OR_RAISE(auto type, GetPrimitiveType(*term_)); + return Literal::Null(type); + } + + private: + bool is_max_; + std::shared_ptr<BoundTerm> term_; + std::optional<Literal> current_; +}; + +} // namespace + +// -------------------- Bound aggregates -------------------- + +CountNonNullAggregate::CountNonNullAggregate(std::shared_ptr<BoundTerm> term) + : CountAggregate(Expression::Operation::kCount, std::move(term)) {} + +Result<std::shared_ptr<CountNonNullAggregate>> CountNonNullAggregate::Make( + std::shared_ptr<BoundTerm> term) { + if (!term) { + return InvalidExpression("Bound count aggregate requires non-null term"); + } + return std::shared_ptr<CountNonNullAggregate>( + new CountNonNullAggregate(std::move(term))); +} + +std::string CountNonNullAggregate::ToString() const { + ICEBERG_DCHECK(term() != nullptr, "Bound count aggregate should have term"); + return std::format("count({})", term()->reference()->name()); +} + +Result<Literal> CountNonNullAggregate::Evaluate(const StructLike& data) const { + ICEBERG_ASSIGN_OR_RAISE(auto literal, term()->Evaluate(data)); + return Literal::Long(literal.IsNull() ? 0 : 1); +} + +Result<std::unique_ptr<BoundAggregate::Aggregator>> CountNonNullAggregate::NewAggregator() + const { + return std::unique_ptr<BoundAggregate::Aggregator>(new CountNonNullAggregator(term())); +} + +CountNullAggregate::CountNullAggregate(std::shared_ptr<BoundTerm> term) + : CountAggregate(Expression::Operation::kCountNull, std::move(term)) {} + +Result<std::shared_ptr<CountNullAggregate>> CountNullAggregate::Make( + std::shared_ptr<BoundTerm> term) { + if (!term) { + return InvalidExpression("Bound count aggregate requires non-null term"); + } + return std::shared_ptr<CountNullAggregate>(new CountNullAggregate(std::move(term))); +} + +std::string CountNullAggregate::ToString() const { + ICEBERG_DCHECK(term() != nullptr, "Bound count aggregate should have term"); + return std::format("count_null({})", term()->reference()->name()); +} + +Result<Literal> CountNullAggregate::Evaluate(const StructLike& data) const { + ICEBERG_ASSIGN_OR_RAISE(auto literal, term()->Evaluate(data)); + return Literal::Long(literal.IsNull() ? 1 : 0); +} + +Result<std::unique_ptr<BoundAggregate::Aggregator>> CountNullAggregate::NewAggregator() + const { + return std::unique_ptr<BoundAggregate::Aggregator>(new CountNullAggregator(term())); +} + +CountStarAggregate::CountStarAggregate() + : CountAggregate(Expression::Operation::kCountStar, nullptr) {} + +Result<std::shared_ptr<CountStarAggregate>> CountStarAggregate::Make() { + return std::shared_ptr<CountStarAggregate>(new CountStarAggregate()); +} + +std::string CountStarAggregate::ToString() const { return "count(*)"; } + +Result<Literal> CountStarAggregate::Evaluate(const StructLike& data) const { + return Literal::Long(1); +} + +Result<std::unique_ptr<BoundAggregate::Aggregator>> CountStarAggregate::NewAggregator() + const { + return std::unique_ptr<BoundAggregate::Aggregator>(new CountStarAggregator()); +} + +ValueAggregate::ValueAggregate(Expression::Operation op, std::shared_ptr<BoundTerm> term) + : BoundAggregate(op, std::move(term)) {} + +std::string ValueAggregate::ToString() const { + ICEBERG_DCHECK(term() != nullptr, "Bound value aggregate should have term"); + auto prefix = op() == Expression::Operation::kMax ? "max" : "min"; + return std::format("{}({})", prefix, term()->reference()->name()); +} + +Result<Literal> ValueAggregate::Evaluate(const StructLike& data) const { + ICEBERG_ASSIGN_OR_RAISE(auto literal, term()->Evaluate(data)); + return literal; +} + +Result<std::unique_ptr<BoundAggregate::Aggregator>> ValueAggregate::NewAggregator() + const { + bool is_max = op() == Expression::Operation::kMax; + return std::unique_ptr<BoundAggregate::Aggregator>( + new ValueAggregatorImpl(is_max, term())); +} + +// -------------------- Unbound binding -------------------- + +template <typename B> +Result<std::shared_ptr<Expression>> UnboundAggregateImpl<B>::Bind( + const Schema& schema, bool case_sensitive) const { + ICEBERG_DCHECK(UnboundAggregateImpl<B>::IsSupportedOp(this->op()), + "Unexpected aggregate operation"); + + std::shared_ptr<B> bound_term; + if (this->term()) { + ICEBERG_ASSIGN_OR_THROW(bound_term, this->term()->Bind(schema, case_sensitive)); + } + + switch (this->op()) { + case Expression::Operation::kCountStar: { + ICEBERG_ASSIGN_OR_THROW(auto aggregate, CountStarAggregate::Make()); + return aggregate; + } + case Expression::Operation::kCount: { + if (!bound_term) { + return InvalidExpression("Aggregate requires a term"); + } + ICEBERG_ASSIGN_OR_THROW(auto aggregate, + CountNonNullAggregate::Make(std::move(bound_term))); + return aggregate; + } + case Expression::Operation::kCountNull: { + if (!bound_term) { + return InvalidExpression("Aggregate requires a term"); + } + ICEBERG_ASSIGN_OR_THROW(auto aggregate, + CountNullAggregate::Make(std::move(bound_term))); + return aggregate; + } + case Expression::Operation::kMax: + case Expression::Operation::kMin: { + if (!bound_term) { + return InvalidExpression("Aggregate requires a term"); + } + auto aggregate = + std::make_shared<ValueAggregate>(this->op(), std::move(bound_term)); + return aggregate; + } + default: + return NotSupported("Unsupported aggregate operation"); + } +} + +template <typename B> +Result<std::shared_ptr<UnboundAggregateImpl<B>>> UnboundAggregateImpl<B>::Make( + Expression::Operation op, std::shared_ptr<UnboundTerm<B>> term) { + if (!IsSupportedOp(op)) { + return NotSupported("Unsupported aggregate operation: {}", ::iceberg::ToString(op)); + } + if (op != Expression::Operation::kCountStar && !term) { + return InvalidExpression("Aggregate term cannot be null unless COUNT(*)"); + } + + return std::shared_ptr<UnboundAggregateImpl<B>>( + new UnboundAggregateImpl<B>(op, std::move(term))); +} + +template <typename B> +std::string UnboundAggregateImpl<B>::ToString() const { Review Comment: > Can we move this to `Aggregate::ToString()` so all other overrides can be removed. Thanks, that makes sense. I’ve moved the common `ToString()` implementation into Aggregate so all aggregates share the same formatting logic, and removed the redundant overrides from the concrete classes. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
