minetest/src/metadata.h

123 lines
3.8 KiB
C++

/*
Minetest
Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#pragma once
#include "irr_v3d.h"
#include <iostream>
#include <vector>
#include "util/string.h"
// Basic metadata interface
class IMetadata
{
public:
virtual ~IMetadata() = default;
virtual void clear() = 0;
bool operator==(const IMetadata &other) const;
inline bool operator!=(const IMetadata &other) const
{
return !(*this == other);
}
//
// Key-value related
//
virtual bool contains(const std::string &name) const = 0;
// May (not must!) put a string in `place` and return a reference to that string.
const std::string &getString(const std::string &name, std::string *place,
u16 recursion = 0) const;
// If the entry is present, puts the value in str and returns true;
// otherwise just returns false.
bool getStringToRef(const std::string &name, std::string &str, u16 recursion = 0) const;
// Returns whether the metadata was (potentially) changed.
virtual bool setString(const std::string &name, const std::string &var) = 0;
inline bool removeString(const std::string &name) { return setString(name, ""); }
// May (not must!) put strings in `place` and return a reference to these strings.
virtual const StringMap &getStrings(StringMap *place) const = 0;
// May (not must!) put keys in `place` and return a reference to these keys.
virtual const std::vector<std::string> &getKeys(std::vector<std::string> *place) const = 0;
// Add support for variable names in values. Uses place like getString.
const std::string &resolveString(const std::string &str, std::string *place,
u16 recursion = 0, bool deprecated = false) const;
protected:
// Returns nullptr to indicate absence of value. Uses place like getString.
virtual const std::string *getStringRaw(const std::string &name,
std::string *place) const = 0;
};
// Simple metadata parent class (in-memory storage)
class SimpleMetadata: public virtual IMetadata
{
bool m_modified = false;
public:
virtual ~SimpleMetadata() = default;
virtual void clear() override;
virtual bool empty() const;
//
// Key-value related
//
size_t size() const;
bool contains(const std::string &name) const override;
virtual bool setString(const std::string &name, const std::string &var) override;
const StringMap &getStrings(StringMap *) const override final;
const std::vector<std::string> &getKeys(std::vector<std::string> *place)
const override final;
// Simple version of getters, possible due to in-memory storage:
inline const std::string &getString(const std::string &name, u16 recursion = 0) const
{
return IMetadata::getString(name, nullptr, recursion);
}
inline const std::string &resolveString(const std::string &str, u16 recursion = 0) const
{
return IMetadata::resolveString(str, nullptr, recursion);
}
inline const StringMap &getStrings() const
{
return SimpleMetadata::getStrings(nullptr);
}
inline bool isModified() const { return m_modified; }
inline void setModified(bool v) { m_modified = v; }
protected:
StringMap m_stringvars;
const std::string *getStringRaw(const std::string &name,
std::string *) const override final;
};