Files
scylladb/utils/updateable_value.cc
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

110 lines
2.5 KiB
C++

/*
* Copyright (C) 2019-present ScyllaDB
*/
/*
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
#include "updateable_value.hh"
#include <seastar/core/seastar.hh>
namespace utils {
updateable_value_base::updateable_value_base(const updateable_value_source_base& source) {
source.add_ref(this);
_source = &source;
}
updateable_value_base::~updateable_value_base() {
if (_source) {
_source->del_ref(this);
}
}
updateable_value_base::updateable_value_base(const updateable_value_base& v) {
if (v._source) {
v._source->add_ref(this);
_source = v._source;
}
}
updateable_value_base&
updateable_value_base::updateable_value_base::operator=(const updateable_value_base& v) {
if (this != &v) {
// If both sources are null, or non-null and equal, nothing needs to be done
if (_source != v._source) {
if (v._source) {
v._source->add_ref(this);
}
if (_source) {
_source->del_ref(this);
}
_source = v._source;
}
}
return *this;
}
updateable_value_base::updateable_value_base(updateable_value_base&& v) noexcept
: _source(std::exchange(v._source, nullptr)) {
if (_source) {
_source->update_ref(&v, this);
}
}
updateable_value_base&
updateable_value_base::operator=(updateable_value_base&& v) noexcept {
if (this != &v) {
if (_source) {
_source->del_ref(this);
}
_source = std::exchange(v._source, nullptr);
if (_source) {
_source->update_ref(&v, this);
}
}
return *this;
}
updateable_value_base&
updateable_value_base::updateable_value_base::operator=(std::nullptr_t) {
if (_source) {
_source->del_ref(this);
_source = nullptr;
}
return *this;
}
void
updateable_value_source_base::for_each_ref(std::function<void (updateable_value_base* ref)> func) {
for (auto ref : _refs) {
func(ref);
}
}
updateable_value_source_base::~updateable_value_source_base() {
for (auto ref : _refs) {
ref->_source = nullptr;
}
}
void
updateable_value_source_base::add_ref(updateable_value_base* ref) const {
_refs.push_back(ref);
}
void
updateable_value_source_base::del_ref(updateable_value_base* ref) const {
_refs.erase(std::remove(_refs.begin(), _refs.end(), ref), _refs.end());
}
void
updateable_value_source_base::update_ref(updateable_value_base* old_ref, updateable_value_base* new_ref) const {
std::replace(_refs.begin(), _refs.end(), old_ref, new_ref);
}
}