Files
scylladb/atomic_cell_or_collection.hh
Avi Kivity fcb8d040e8 treewide: use Software Package Data Exchange (SPDX) license identifiers
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.

Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.

The changes we applied mechanically with a script, except to
licenses/README.md.

Closes #9937
2022-01-18 12:15:18 +01:00

61 lines
2.6 KiB
C++

/*
* Copyright (C) 2015-present ScyllaDB
*/
/*
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
#pragma once
#include "atomic_cell.hh"
#include "collection_mutation.hh"
#include "schema.hh"
// A variant type that can hold either an atomic_cell, or a serialized collection.
// Which type is stored is determined by the schema.
// Has an "empty" state.
// Objects moved-from are left in an empty state.
class atomic_cell_or_collection final {
managed_bytes _data;
private:
atomic_cell_or_collection(managed_bytes&& data) : _data(std::move(data)) {}
public:
atomic_cell_or_collection() = default;
atomic_cell_or_collection(atomic_cell_or_collection&&) = default;
atomic_cell_or_collection(const atomic_cell_or_collection&) = delete;
atomic_cell_or_collection& operator=(atomic_cell_or_collection&&) = default;
atomic_cell_or_collection& operator=(const atomic_cell_or_collection&) = delete;
atomic_cell_or_collection(atomic_cell ac) : _data(std::move(ac._data)) {}
atomic_cell_or_collection(const abstract_type& at, atomic_cell_view acv);
static atomic_cell_or_collection from_atomic_cell(atomic_cell data) { return { std::move(data._data) }; }
atomic_cell_view as_atomic_cell(const column_definition& cdef) const { return atomic_cell_view::from_bytes(*cdef.type, _data); }
atomic_cell_mutable_view as_mutable_atomic_cell(const column_definition& cdef) { return atomic_cell_mutable_view::from_bytes(*cdef.type, _data); }
atomic_cell_or_collection(collection_mutation cm) : _data(std::move(cm._data)) { }
atomic_cell_or_collection copy(const abstract_type&) const;
explicit operator bool() const {
return !_data.empty();
}
static constexpr bool can_use_mutable_view() {
return true;
}
static atomic_cell_or_collection from_collection_mutation(collection_mutation data) { return std::move(data._data); }
collection_mutation_view as_collection_mutation() const;
bytes_view serialize() const;
bool equals(const abstract_type& type, const atomic_cell_or_collection& other) const;
size_t external_memory_usage(const abstract_type&) const;
class printer {
const column_definition& _cdef;
const atomic_cell_or_collection& _cell;
public:
printer(const column_definition& cdef, const atomic_cell_or_collection& cell)
: _cdef(cdef), _cell(cell) { }
printer(const printer&) = delete;
printer(printer&&) = delete;
friend std::ostream& operator<<(std::ostream&, const printer&);
};
friend std::ostream& operator<<(std::ostream&, const printer&);
};