VoxelEngine/src/data/StructLayout.hpp
2024-08-29 18:56:26 +03:00

149 lines
5.2 KiB
C++

#pragma once
#include <vector>
#include <string>
#include <unordered_map>
#include "typedefs.hpp"
namespace data {
enum class FieldType {
I8=0, I16, I32, I64, F32, F64, CHAR,
COUNT
};
inline constexpr int sizeof_type(FieldType type) {
const int sizes[static_cast<int>(FieldType::COUNT)] = {
1, 2, 4, 8, 4, 8, 1
};
return sizes[static_cast<int>(type)];
}
struct Field {
FieldType type;
std::string name;
/// @brief Number of field elements (array size)
int elements;
/// @brief Byte offset of the field
int offset;
/// @brief Byte size of the field
int size;
};
class StructLayout {
int totalSize;
std::vector<Field> fields;
std::unordered_map<std::string, int> indices;
public:
StructLayout(
int totalSize,
std::vector<Field> fields,
std::unordered_map<std::string, int> indices
) : totalSize(totalSize),
fields(std::move(fields)),
indices(std::move(indices))
{}
/// @brief Get field by name. Returns nullptr if field not found.
/// @param name field name
/// @return nullable field pointer
[[nodiscard]]
const Field* getField(const std::string& name) const {
auto found = indices.find(name);
if (found == indices.end()) {
return nullptr;
}
return &fields.at(found->second);
}
/// @brief Get field by name
/// @throws std::runtime_exception - field not found
/// @param name field name
/// @return read-only field reference
const Field& requreField(const std::string& name) const;
/// @brief Get integer from specified field.
/// Types: (i8, i16, i32, i64, char)
/// @throws std::runtime_exception - field not found
/// @throws std::out_of_range - index is out of range [0, elements-1]
/// @param src source buffer
/// @param name field name
/// @param index array index
/// @return field value
[[nodiscard]]
integer_t getInteger(const ubyte* src, const std::string& name, int index=0) const;
/// @brief Get floating-point number from specified field.
/// Types: (f32, f64, i8, i16, i32, i64, char)
/// @throws std::runtime_exception - field not found
/// @throws std::out_of_range - index is out of range [0, elements-1]
/// @param src source buffer
/// @param name field name
/// @param index array index
/// @return field value
[[nodiscard]]
number_t getNumber(const ubyte* src, const std::string& name, int index=0) const;
/// @brief Get read-only chars array as string_view.
/// @param src source buffer
/// @param name field name
[[nodiscard]]
std::string_view getChars(const ubyte* src, const std::string& name) const;
/// @brief Set field integer value.
/// Types: (i8, i16, i32, i64, f32, f64, char)
/// @throws std::runtime_exception - field not found
/// @throws std::out_of_range - index is out of range [0, elements-1]
/// @param dst destination buffer
/// @param value value
/// @param name field name
/// @param index array index
void setInteger(ubyte* dst, integer_t value, const std::string& name, int index=0);
/// @brief Set field numeric value.
/// Types: (f32, f64)
/// @throws std::runtime_exception - field not found
/// @throws std::out_of_range - index is out of range [0, elements-1]
/// @param dst destination buffer
/// @param value value
/// @param name field name
/// @param index array index
void setNumber(ubyte* dst, number_t value, const std::string& name, int index=0);
/// @brief Replace chars array to given ASCII string
/// @throws std::runtime_exception - field not found
/// @see StructMapper::setUnicode - utf-8 version of setChars
/// @param dst destination buffer
/// @param value ASCII string
/// @param name field name
/// @return number of written string chars
size_t setChars(ubyte* dst, std::string_view value, const std::string& name);
/// @brief Unicode-safe version of setChars
/// @throws std::runtime_exception - field not found
/// @param dst destination buffer
/// @param value utf-8 string
/// @param name field name
/// @return number of written string chars
size_t setUnicode(ubyte* dst, std::string_view value, const std::string& name);
/// @return total structure size (bytes)
[[nodiscard]] size_t size() const {
return totalSize;
}
[[nodiscard]]
static StructLayout create(const std::vector<Field>& fields);
};
class StructAccess {
const StructLayout& mapping;
uint8_t* buffer;
public:
StructAccess(const StructLayout& mapping, uint8_t* buffer)
: mapping(mapping), buffer(buffer) {
}
};
}