OpenTTD-patches/src/command_aux.h

120 lines
3.8 KiB
C++

/*
* This file is part of OpenTTD.
* OpenTTD 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, version 2.
* OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file command_aux.h Command auxiliary data. */
#ifndef COMMAND_AUX_H
#define COMMAND_AUX_H
#include "command_type.h"
#include "command_func.h"
#include "string_type.h"
#include "core/serialisation.hpp"
#include "3rdparty/optional/ottd_optional.h"
struct CommandDeserialisationBuffer : public BufferDeserialisationHelper<CommandDeserialisationBuffer> {
const uint8 *buffer;
size_t size;
size_t pos = 0;
bool error = false;
CommandDeserialisationBuffer(const uint8 *buffer, size_t size) : buffer(buffer), size(size) {}
const byte *GetDeserialisationBuffer() const { return this->buffer; }
size_t GetDeserialisationBufferSize() const { return this->size; }
size_t &GetDeserialisationPosition() { return this->pos; }
bool CanDeserialiseBytes(size_t bytes_to_read, bool raise_error)
{
if (this->error) return false;
/* Check if variable is within packet-size */
if (this->pos + bytes_to_read > this->size) {
if (raise_error) this->error = true;
return false;
}
return true;
}
};
struct CommandSerialisationBuffer : public BufferSerialisationHelper<CommandSerialisationBuffer> {
std::vector<byte> &buffer;
size_t limit;
CommandSerialisationBuffer(std::vector<byte> &buffer, size_t limit) : buffer(buffer), limit(limit) {}
std::vector<byte> &GetSerialisationBuffer() { return this->buffer; }
size_t GetSerialisationLimit() const { return this->limit; }
};
struct CommandAuxiliarySerialised : public CommandAuxiliaryBase {
std::vector<byte> serialised_data;
CommandAuxiliaryBase *Clone() const override
{
return new CommandAuxiliarySerialised(*this);
}
virtual opt::optional<span<const uint8>> GetDeserialisationSrc() const override { return span<const uint8>(this->serialised_data.data(), this->serialised_data.size()); }
virtual void Serialise(CommandSerialisationBuffer &buffer) const override { buffer.Send_binary((const char *)this->serialised_data.data(), this->serialised_data.size()); }
};
template <typename T>
struct CommandAuxiliarySerialisable : public CommandAuxiliaryBase {
virtual opt::optional<span<const uint8>> GetDeserialisationSrc() const override { return {}; }
CommandAuxiliaryBase *Clone() const override
{
return new T(*static_cast<const T *>(this));
}
};
template <typename T>
struct CommandAuxData {
private:
opt::optional<T> store;
const T *data = nullptr;
public:
inline CommandCost Load(const CommandAuxiliaryBase *base)
{
if (base == nullptr) return CMD_ERROR;
opt::optional<span<const uint8>> deserialise_from = base->GetDeserialisationSrc();
if (deserialise_from.has_value()) {
this->store = T();
CommandDeserialisationBuffer buffer(deserialise_from->begin(), deserialise_from->size());
CommandCost res = this->store->Deserialise(buffer);
if (res.Failed()) return res;
if (buffer.error || buffer.pos != buffer.size) {
/* Other deserialisation error or wrong number of bytes read */
return CMD_ERROR;
}
this->data = &(*(this->store));
return res;
} else {
this->data = dynamic_cast<const T*>(base);
if (this->data == nullptr) return CMD_ERROR;
return CommandCost();
}
}
inline const T *operator->() const
{
return this->data;
}
inline const T &operator*() const
{
return *(this->data);
}
};
#endif /* COMMAND_AUX_H */