f6cfb04d61
SSTables already have a priority argument wired to their read path. However, most of our reads do not call that interface directly, but employ the services of a mutation reader instead. Some of those readers will be used to read through a mutation_source, and those have to patched as well. Right now, whenever we need to pass a class, we pass Seastar's default priority class. Signed-off-by: Glauber Costa <glauber@scylladb.com>
100 lines
3.4 KiB
C++
100 lines
3.4 KiB
C++
/*
|
|
* Copyright 2015 ScyllaDB
|
|
*/
|
|
|
|
/*
|
|
* This file is part of Scylla.
|
|
*
|
|
* Scylla is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU Affero General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* Scylla is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include "mutation_reader.hh"
|
|
#include "schema.hh"
|
|
#include "query-request.hh"
|
|
|
|
#include "dht/i_partitioner.hh"
|
|
|
|
class key_reader final {
|
|
public:
|
|
class impl {
|
|
public:
|
|
virtual ~impl() {}
|
|
virtual future<dht::decorated_key_opt> operator()() = 0;
|
|
};
|
|
private:
|
|
class null_impl final : public impl {
|
|
public:
|
|
virtual future<dht::decorated_key_opt> operator()() override { throw std::bad_function_call(); }
|
|
};
|
|
private:
|
|
std::unique_ptr<impl> _impl;
|
|
public:
|
|
key_reader(std::unique_ptr<impl> impl) noexcept : _impl(std::move(impl)) {}
|
|
key_reader() : key_reader(std::make_unique<null_impl>()) {}
|
|
key_reader(key_reader&&) = default;
|
|
key_reader(const key_reader&) = delete;
|
|
key_reader& operator=(key_reader&&) = default;
|
|
key_reader& operator=(const key_reader&) = delete;
|
|
future<dht::decorated_key_opt> operator()() { return _impl->operator()(); }
|
|
};
|
|
|
|
template<typename Impl, typename... Args>
|
|
inline key_reader make_key_reader(Args&&... args) {
|
|
return key_reader(std::make_unique<Impl>(std::forward<Args>(args)...));
|
|
}
|
|
|
|
key_reader make_combined_reader(schema_ptr s, std::vector<key_reader>);
|
|
key_reader make_key_from_mutation_reader(mutation_reader&&);
|
|
|
|
template<typename Filter>
|
|
class filtering_key_reader final : public key_reader::impl {
|
|
key_reader _reader;
|
|
Filter _filter;
|
|
public:
|
|
filtering_key_reader(key_reader&& reader, Filter&& filter)
|
|
: _reader(std::move(reader)), _filter(std::move(filter))
|
|
{ }
|
|
virtual future<dht::decorated_key_opt> operator()() override {
|
|
return _reader().then([this] (dht::decorated_key_opt&& dk) {
|
|
if (!dk || _filter(*dk)) {
|
|
return make_ready_future<dht::decorated_key_opt>(std::move(dk));
|
|
}
|
|
return operator()();
|
|
});
|
|
}
|
|
};
|
|
|
|
template<typename Filter>
|
|
key_reader make_filtering_reader(key_reader&& reader, Filter&& filter) {
|
|
return make_key_reader<filtering_key_reader<Filter>>(std::move(reader), std::forward<Filter>(filter));
|
|
}
|
|
|
|
class key_source {
|
|
std::function<key_reader(const query::partition_range& range, const io_priority_class& pc)> _fn;
|
|
public:
|
|
key_source(std::function<key_reader(const query::partition_range& range, const io_priority_class& pc)> fn) : _fn(std::move(fn)) {}
|
|
key_source(std::function<key_reader(const query::partition_range& range)> fn)
|
|
: _fn([fn = std::move(fn)](const query::partition_range& range, const io_priority_class& pc) {
|
|
return fn(range);
|
|
}) {}
|
|
key_reader operator()(const query::partition_range& range, const io_priority_class& pc) {
|
|
return _fn(range, pc);
|
|
}
|
|
key_reader operator()(const query::partition_range& range) {
|
|
return _fn(range, default_priority_class());
|
|
}
|
|
};
|