Files
scylladb/query-request.hh
2015-09-20 10:43:39 +03:00

125 lines
4.1 KiB
C++

/*
* Copyright 2015 Cloudius Systems
*/
/*
* 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 <experimental/optional>
#include "keys.hh"
#include "dht/i_partitioner.hh"
#include "enum_set.hh"
#include "range.hh"
namespace query {
template <typename T>
using range = ::range<T>;
using ring_position = dht::ring_position;
using partition_range = range<ring_position>;
using clustering_range = range<clustering_key_prefix>;
extern const partition_range full_partition_range;
// FIXME: Move this to i_partitioner.hh after query::range<> is moved to utils/range.hh
query::partition_range to_partition_range(query::range<dht::token>);
inline
bool is_wrap_around(const query::partition_range& range, const schema& s) {
return range.is_wrap_around(dht::ring_position_comparator(s));
}
inline
bool is_single_partition(const query::partition_range& range) {
return range.is_singular() && range.start()->value().has_key();
}
// Specifies subset of rows, columns and cell attributes to be returned in a query.
// Can be accessed across cores.
class partition_slice {
public:
enum class option { send_clustering_key, send_partition_key, send_timestamp_and_expiry, reversed, distinct };
using option_set = enum_set<super_enum<option,
option::send_clustering_key,
option::send_partition_key,
option::send_timestamp_and_expiry,
option::reversed,
option::distinct>>;
public:
std::vector<clustering_range> row_ranges;
std::vector<column_id> static_columns; // TODO: consider using bitmap
std::vector<column_id> regular_columns; // TODO: consider using bitmap
option_set options;
public:
partition_slice(std::vector<clustering_range> row_ranges, std::vector<column_id> static_columns,
std::vector<column_id> regular_columns, option_set options)
: row_ranges(std::move(row_ranges))
, static_columns(std::move(static_columns))
, regular_columns(std::move(regular_columns))
, options(options)
{ }
friend std::ostream& operator<<(std::ostream& out, const partition_slice& ps);
};
constexpr auto max_rows = std::numeric_limits<uint32_t>::max();
// Full specification of a query to the database.
// Intended for passing across replicas.
// Can be accessed across cores.
class read_command {
public:
utils::UUID cf_id;
partition_slice slice;
uint32_t row_limit;
gc_clock::time_point timestamp;
public:
read_command(const utils::UUID& cf_id, partition_slice slice, uint32_t row_limit = max_rows, gc_clock::time_point now = gc_clock::now())
: cf_id(cf_id)
, slice(std::move(slice))
, row_limit(row_limit)
, timestamp(now)
{ }
size_t serialized_size() const;
void serialize(bytes::iterator& out) const;
static read_command deserialize(bytes_view& v);
friend std::ostream& operator<<(std::ostream& out, const read_command& r);
};
}
// Allow using query::range<T> in a hash table. The hash function 31 * left +
// right is the same one used by Cassandra's AbstractBounds.hashCode().
namespace std {
template<typename T>
struct hash<query::range<T>> {
using argument_type = query::range<T>;
using result_type = decltype(std::hash<T>()(std::declval<T>()));
result_type operator()(argument_type const& s) const {
auto hash = std::hash<T>();
auto left = s.start() ? hash(s.start()->value()) : 0;
auto right = s.end() ? hash(s.end()->value()) : 0;
return 31 * left + right;
}
};
}