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scylladb/db/extensions.hh

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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Modified by ScyllaDB
* Copyright (C) 2017-present 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 <set>
#include <stdexcept>
#include <functional>
#include <map>
#include <variant>
#include <vector>
#include <seastar/core/sstring.hh>
#include "bytes.hh"
#include "schema_fwd.hh"
namespace sstables {
class file_io_extension;
}
namespace db {
class commitlog_file_extension;
class extensions {
public:
extensions();
~extensions();
using map_type = std::map<sstring, sstring>;
using schema_ext_config = std::variant<sstring, map_type, bytes>;
using schema_ext_create_func = std::function<seastar::shared_ptr<schema_extension>(schema_ext_config)>;
using sstable_file_io_extension = std::unique_ptr<sstables::file_io_extension>;
using commitlog_file_extension_ptr = std::unique_ptr<db::commitlog_file_extension>;
/**
* Registered extensions
*/
const std::map<sstring, schema_ext_create_func>& schema_extensions() const {
return _schema_extensions;
}
/**
* Returns iterable range of registered sstable IO extensions (see sstable.hh#sstable_file_io_extension)
* For any sstables wanting to call these on file open...
*/
std::vector<sstables::file_io_extension*> sstable_file_io_extensions() const;
/**
* Returns iterable range of registered commitlog IO extensions (see commitlog_extensions.hh#commitlog_file_extension)
* For any commitlogs wanting to call these on file open or descriptor scan...
*/
std::vector<db::commitlog_file_extension*> commitlog_file_extensions() const;
/**
* Registered extensions keywords, i.e. custom properties/propery sets
* for schema extensions
*/
std::set<sstring> schema_extension_keywords() const;
/**
* Init time method to add schema extension.
*/
void add_schema_extension(sstring w, schema_ext_create_func f) {
_schema_extensions.emplace(std::move(w), std::move(f));
}
/**
* A shorthand for the add_schema_extension. Adds a function that adds
* the extension to a schema with appropriate constructor overload.
*/
template<typename Extension>
void add_schema_extension(sstring w) {
add_schema_extension(std::move(w), [] (db::extensions::schema_ext_config cfg) {
return std::visit([] (auto v) {
return ::make_shared<Extension>(v);
}, cfg);
});
}
/**
* Init time method to add sstable extension
*/
void add_sstable_file_io_extension(sstring n, sstable_file_io_extension);
/**
* Init time method to add sstable extension
*/
void add_commitlog_file_extension(sstring n, commitlog_file_extension_ptr);
/**
* Allows forcible modification of schema extensions of a schema. This should
* not be done lightly however. In fact, it should only be done on startup
* at most, and thus this method is non-const, i.e. you can only use it on
* config apply.
*/
void add_extension_to_schema(schema_ptr, const sstring&, shared_ptr<schema_extension>);
private:
std::map<sstring, schema_ext_create_func> _schema_extensions;
std::map<sstring, sstable_file_io_extension> _sstable_file_io_extensions;
std::map<sstring, commitlog_file_extension_ptr> _commitlog_file_extensions;
};
}