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| -rw-r--r-- | wsrep-lib/include/wsrep/provider_options.hpp | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/wsrep-lib/include/wsrep/provider_options.hpp b/wsrep-lib/include/wsrep/provider_options.hpp new file mode 100644 index 00000000..022e159e --- /dev/null +++ b/wsrep-lib/include/wsrep/provider_options.hpp @@ -0,0 +1,271 @@ +/* + * Copyright (C) 2021 Codership Oy <info@codership.com> + * + * This file is part of wsrep-lib. + * + * Wsrep-lib is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + * + * Wsrep-lib 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 wsrep-lib. If not, see <https://www.gnu.org/licenses/>. + */ + +/** @file provider_options.hpp + * + * A proxy interface to control provider configuration options. + */ + +#ifndef WSREP_PROVIDER_OPTIONS_HPP +#define WSREP_PROVIDER_OPTIONS_HPP + +#include "provider.hpp" + +#include <functional> +#include <map> +#include <memory> +#include <string> + +namespace wsrep +{ + /** + * Proxy class for managing provider options. + * Options are strings by default, or flagged with corresponding + * provider_options::flag as either bool, integer or double. + */ + class provider_options + { + public: + struct flag + { + static const int deprecated = (1 << 0); + static const int readonly = (1 << 1); + static const int type_bool = (1 << 2); + static const int type_integer = (1 << 3); + static const int type_double = (1 << 4); + }; + + static const int flag_type_mask + = flag::type_bool | flag::type_integer | flag::type_double; + + class option_value + { + public: + virtual ~option_value() {} + virtual const char* as_string() const = 0; + virtual const void* get_ptr() const = 0; + }; + + class option_value_string : public option_value + { + public: + option_value_string(const std::string& value) + : value_(value) + { + } + ~option_value_string() WSREP_OVERRIDE {} + const char* as_string() const WSREP_OVERRIDE + { + return value_.c_str(); + } + const void* get_ptr() const WSREP_OVERRIDE + { + return value_.c_str(); + } + + private: + std::string value_; + }; + + class option_value_bool : public option_value + { + public: + option_value_bool(bool value) + : value_(value) + { + } + ~option_value_bool() WSREP_OVERRIDE {} + const char* as_string() const WSREP_OVERRIDE + { + if (value_) + { + return "yes"; + } + else + { + return "no"; + } + } + const void* get_ptr() const WSREP_OVERRIDE { return &value_; } + + private: + bool value_; + }; + + class option_value_int : public option_value + { + public: + option_value_int(int64_t value) + : value_(value) + , value_str_(std::to_string(value)) + { + } + ~option_value_int() WSREP_OVERRIDE {} + const char* as_string() const WSREP_OVERRIDE + { + return value_str_.c_str(); + } + const void* get_ptr() const WSREP_OVERRIDE { return &value_; } + + private: + int64_t value_; + std::string value_str_; + }; + + class option_value_double : public option_value + { + public: + option_value_double(double value) + : value_(value) + , value_str_(std::to_string(value)) + { + } + ~option_value_double() WSREP_OVERRIDE {} + const char* as_string() const WSREP_OVERRIDE + { + return value_str_.c_str(); + } + const void* get_ptr() const WSREP_OVERRIDE { return &value_; } + + private: + double value_; + std::string value_str_; + }; + + class option + { + public: + option(); + /** Construct option with given values. Allocates + * memory. */ + option(const std::string& name, std::unique_ptr<option_value> value, + std::unique_ptr<option_value> default_value, int flags); + /** Non copy-constructible. */ + option(const option&) = delete; + /** Non copy-assignable. */ + option& operator=(const option&) = delete; + option(option&&) = delete; + option& operator=(option&&) = delete; + ~option(); + + /** + * Get name of the option. + * + * @return Name of the option. + */ + const char* name() const { return name_.c_str(); } + + /** + * Get the real name of the option. This displays the + * option name as it is visible in provider options. + */ + const char* real_name() const { return real_name_.c_str(); } + + /** + * Get value of the option. + * + * @return Value of the option. + */ + option_value* value() const { return value_.get(); } + + /** + * Get default value of the option. + * + * @return Default value of the option. + */ + option_value* default_value() const { return default_value_.get(); } + + /** + * Get flags of the option + * + * @return Flag of the option + */ + int flags() const { return flags_; } + + /** + * Update the value of the option with new_value. The old + * value is freed. + */ + void update_value(std::unique_ptr<option_value> new_value); + + private: + /** Sanitized name with dots replaced with underscores */ + std::string name_; + /** Real name in provider */ + std::string real_name_; + std::unique_ptr<option_value> value_; + std::unique_ptr<option_value> default_value_; + int flags_; + }; + + provider_options(wsrep::provider&); + provider_options(const provider_options&) = delete; + provider_options& operator=(const provider_options&) = delete; + + /** + * Set initial options. This should be used to initialize + * provider options after the provider has been loaded. + * Individual options should be accessed through set()/get(). + * + * @return Provider status code. + */ + enum wsrep::provider::status initial_options(); + + /** + * Get the option with the given name + * + * @param name Name of the option to retrieve + */ + const option* get_option(const std::string& name) const; + + /** + * Set a value for the option. + * + * @return Wsrep provider status code. + * @return wsrep::provider::error_size_exceeded if memory could + * not be allocated for the new value. + */ + enum wsrep::provider::status set(const std::string& name, + std::unique_ptr<option_value> value); + + /** + * Create a new option with default value. + */ + enum wsrep::provider::status + set_default(const std::string& name, + std::unique_ptr<option_value> value, + std::unique_ptr<option_value> default_value, int flags); + + void for_each(const std::function<void(option*)>& fn); + + private: + provider& provider_; + using options_map = std::map<std::string, std::unique_ptr<option>>; + options_map options_; + }; + + /** + * Equality operator for provider option. Returns true if + * the name part is equal. + */ + bool operator==(const wsrep::provider_options::option&, + const wsrep::provider_options::option&); +} // namespace wsrep + +#endif // WSREP_PROVIDER_OPTIONS_HPP |