6d977fcf88
Detects type of reduction if it is possible. Separate case for `COUNT(*)` is left for compatibility reason. By now only single selection is supported.
121 lines
4.2 KiB
C++
121 lines
4.2 KiB
C++
/*
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* Modified by ScyllaDB
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* Copyright (C) 2015-present ScyllaDB
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*/
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/*
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* SPDX-License-Identifier: (AGPL-3.0-or-later and Apache-2.0)
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*/
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#include "abstract_function_selector.hh"
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#include "aggregate_function_selector.hh"
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#include "scalar_function_selector.hh"
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#include "to_string.hh"
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#include "cql3/selection/selector_factories.hh"
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#include "cql3/functions/abstract_function.hh"
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namespace cql3 {
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namespace selection {
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bool abstract_function_selector::requires_thread() const {
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return _requires_thread;
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}
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shared_ptr<selector::factory>
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abstract_function_selector::new_factory(shared_ptr<functions::function> fun, shared_ptr<selector_factories> factories) {
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if (fun->is_aggregate()) {
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if (factories->does_aggregation()) {
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throw exceptions::invalid_request_exception("aggregate functions cannot be used as arguments of aggregate functions");
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}
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} else {
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if (factories->does_aggregation() && !factories->contains_only_aggregate_functions()) {
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throw exceptions::invalid_request_exception(format("the {} function arguments must be either all aggregates or all none aggregates",
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fun->name()));
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}
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}
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struct fun_selector_factory : public factory {
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shared_ptr<functions::function> _fun;
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shared_ptr<selector_factories> _factories;
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fun_selector_factory(shared_ptr<functions::function> fun,
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shared_ptr<selector_factories> factories)
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: _fun(std::move(fun)), _factories(std::move(factories)) {
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}
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virtual sstring column_name() const override {
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return _fun->column_name(_factories->get_column_names());
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}
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virtual data_type get_return_type() const override {
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return _fun->return_type();
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}
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virtual shared_ptr<selector> new_instance() const override {
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using ret_type = shared_ptr<selector>;
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return _fun->is_aggregate() ? ret_type(::make_shared<aggregate_function_selector>(_fun, _factories->new_instances()))
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: ret_type(::make_shared<scalar_function_selector>(_fun, _factories->new_instances()));
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}
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virtual bool is_write_time_selector_factory() const override {
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return _factories->contains_write_time_selector_factory();
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}
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virtual bool is_ttl_selector_factory() const override {
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return _factories->contains_ttl_selector_factory();
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}
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virtual bool is_aggregate_selector_factory() const override {
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return _fun->is_aggregate() || _factories->contains_only_aggregate_functions();
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}
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virtual bool contains_only_simple_arguments() const override {
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return _factories->contains_only_simple_selection();
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}
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virtual bool is_count_selector_factory() const override {
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auto p = dynamic_cast<functions::abstract_function*>(_fun.get());
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if (!p) {
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return false;
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}
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return p->name().name == "countRows";
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}
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virtual bool is_reducible_selector_factory() const override {
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auto p = dynamic_cast<functions::aggregate_function*>(_fun.get());
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if (!p) {
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return false;
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}
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return p->is_reducible();
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}
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virtual std::optional<std::pair<query::forward_request::reduction_type, query::forward_request::aggregation_info>>
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get_reduction() const override {
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auto p = dynamic_cast<functions::aggregate_function*>(_fun.get());
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if (!p) {
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return std::nullopt;
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}
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auto type = (p->name().name == "countRows") ? query::forward_request::reduction_type::count : query::forward_request::reduction_type::aggregate;
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auto info = query::forward_request::aggregation_info {
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.name = p->name(),
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.column_names = _factories->get_column_names()
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};
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return {{type, info}};
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}
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};
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return make_shared<fun_selector_factory>(std::move(fun), std::move(factories));
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}
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bool scalar_function_selector::requires_thread() const {
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return fun()->requires_thread();
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}
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}
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}
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