86 lines
2.8 KiB
C++
86 lines
2.8 KiB
C++
/*
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* Copyright 2015 ScyllaDB
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*/
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/*
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* This file is part of Scylla.
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*
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* Scylla is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Scylla is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
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*/
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#pragma once
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#include "mutation_reader.hh"
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#include "schema.hh"
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#include "query-request.hh"
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#include "dht/i_partitioner.hh"
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class key_reader final {
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public:
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class impl {
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public:
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virtual ~impl() {}
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virtual future<dht::decorated_key_opt> operator()() = 0;
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};
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private:
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class null_impl final : public impl {
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public:
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virtual future<dht::decorated_key_opt> operator()() override { throw std::bad_function_call(); }
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};
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private:
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std::unique_ptr<impl> _impl;
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public:
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key_reader(std::unique_ptr<impl> impl) noexcept : _impl(std::move(impl)) {}
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key_reader() : key_reader(std::make_unique<null_impl>()) {}
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key_reader(key_reader&&) = default;
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key_reader(const key_reader&) = delete;
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key_reader& operator=(key_reader&&) = default;
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key_reader& operator=(const key_reader&) = delete;
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future<dht::decorated_key_opt> operator()() { return _impl->operator()(); }
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};
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template<typename Impl, typename... Args>
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inline key_reader make_key_reader(Args&&... args) {
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return key_reader(std::make_unique<Impl>(std::forward<Args>(args)...));
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}
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key_reader make_combined_reader(schema_ptr s, std::vector<key_reader>);
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key_reader make_key_from_mutation_reader(mutation_reader&&);
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template<typename Filter>
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class filtering_key_reader final : public key_reader::impl {
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key_reader _reader;
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Filter _filter;
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public:
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filtering_key_reader(key_reader&& reader, Filter&& filter)
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: _reader(std::move(reader)), _filter(std::move(filter))
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{ }
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virtual future<dht::decorated_key_opt> operator()() override {
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return _reader().then([this] (dht::decorated_key_opt&& dk) {
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if (!dk || _filter(*dk)) {
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return make_ready_future<dht::decorated_key_opt>(std::move(dk));
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}
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return operator()();
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});
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}
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};
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template<typename Filter>
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key_reader make_filtering_reader(key_reader&& reader, Filter&& filter) {
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return make_key_reader<filtering_key_reader<Filter>>(std::move(reader), std::forward<Filter>(filter));
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}
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using key_source = std::function<key_reader(const query::partition_range& range)>;
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