cocos_lib/cocos/editor-support/IOBuffer.h

/****************************************************************************
 Copyright (c) 2020-2023 Xiamen Yaji Software Co., Ltd.

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 of this software and associated documentation files (the "Software"), to deal
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#pragma once
#include <cmath>
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <functional>
#include <string>
#include <utility>
#include "MiddlewareMacro.h"
#include "base/Macros.h"

MIDDLEWARE_BEGIN
/**
 * Use for such as vertex buffer or index buffer,write bytes in it.
 * If write data out of range,will sign it in _outRange property.
 * User decide to enlarge it or not.
 */
class IOBuffer {
public:
    explicit IOBuffer(std::size_t defaultSize) {
        _bufferSize = defaultSize;
        _buffer = new uint8_t[_bufferSize];
        memset(_buffer, 0, _bufferSize);
    }

    IOBuffer() = default;

    virtual ~IOBuffer() {
        if (_buffer) {
            delete[] _buffer;
            _buffer = nullptr;
        }
    }

    inline void writeUint32(std::size_t pos, uint32_t val) {
        if (_bufferSize < pos + sizeof(val)) {
            _outRange = true;
            return;
        }
        auto *buffer = reinterpret_cast<uint32_t *>(_buffer + pos);
        *buffer = val;
    }

    inline void writeFloat32(std::size_t pos, float val) {
        if (_bufferSize < pos + sizeof(val)) {
            _outRange = true;
            return;
        }
        auto *buffer = reinterpret_cast<float *>(_buffer + pos);
        *buffer = val;
    }

    inline void writeBytes(const char *bytes, std::size_t bytesLen) {
        if (_bufferSize < _curPos + bytesLen) {
            _outRange = true;
            return;
        }
        memcpy(_buffer + _curPos, bytes, bytesLen);
        _curPos += bytesLen;
    }

    inline void writeUint32(uint32_t val) {
        if (_bufferSize < _curPos + sizeof(val)) {
            _outRange = true;
            return;
        }
        auto *buffer = reinterpret_cast<uint32_t *>(_buffer + _curPos);
        *buffer = val;
        _curPos += sizeof(val);
    }

    inline void writeFloat32(float val) {
        if (_bufferSize < _curPos + sizeof(val)) {
            _outRange = true;
            return;
        }
        auto *buffer = reinterpret_cast<float *>(_buffer + _curPos);
        *buffer = val;
        _curPos += sizeof(val);
    }

    inline void writeUint16(uint16_t val) {
        if (_bufferSize < _curPos + sizeof(val)) {
            _outRange = true;
            return;
        }
        auto *buffer = reinterpret_cast<uint16_t *>(_buffer + _curPos);
        *buffer = val;
        _curPos += sizeof(val);
    }

    inline uint32_t readUint32() {
        auto *buffer = reinterpret_cast<uint32_t *>(_buffer + _readPos);
        _readPos += sizeof(uint32_t);
        return *buffer;
    }

    inline uint16_t readUint16() {
        auto *buffer = reinterpret_cast<uint16_t *>(_buffer + _readPos);
        _readPos += sizeof(uint16_t);
        return *buffer;
    }

    inline float readFloat32() {
        auto *buffer = reinterpret_cast<float *>(_buffer + _readPos);
        _readPos += sizeof(float);
        return *buffer;
    }

    inline char readUint8() {
        char *buffer = reinterpret_cast<char *>(_buffer + _readPos);
        _readPos += sizeof(char);
        return *buffer;
    }

    inline void reset() {
        _curPos = 0;
        _readPos = 0;
    }

    inline void clear() {
        memset(_buffer, 0, _bufferSize);
    }

    inline void move(int pos) {
        if (_bufferSize < _curPos + pos) {
            _outRange = true;
            return;
        }
        _curPos += pos;
    }

    inline std::size_t length() const {
        return _curPos;
    }

    inline std::size_t getCurPos() const {
        return _curPos;
    }

    inline uint8_t *getCurBuffer() const {
        return _buffer + _curPos;
    }

    inline uint8_t *getBuffer() const {
        return _buffer;
    }

    inline std::size_t getCapacity() const {
        return _bufferSize;
    }

    inline bool isOutRange() const {
        return _outRange;
    }

    inline int checkSpace(std::size_t needSize, bool needCopy = false) {
        auto needLen = _curPos + needSize;
        auto isFull = 0;
        if (_maxSize > 0 && needLen > _maxSize) {
            isFull = 1;
            if (_fullCallback) {
                _fullCallback();
            }
        }
        if (!needCopy) {
            _curPos = 0;
        }
        if (_bufferSize < needLen) {
            int len = static_cast<int>(needLen);
            std::size_t fitSize = static_cast<std::size_t>(floorf(1.25F * len));
            resize(fitSize, needCopy);
            if (_resizeCallback) {
                _resizeCallback();
            }
        }

        return isFull;
    }

    void setMaxSize(std::size_t maxSize) {
        _maxSize = maxSize;
    }

    using fullCallback = std::function<void()>;
    void setFullCallback(fullCallback callback) {
        _fullCallback = std::move(callback);
    }

    using resizeCallback = std::function<void()>;
    void setResizeCallback(resizeCallback callback) {
        _resizeCallback = std::move(callback);
    }

    /**
     * @brief Resize buffer
     * @param[in] newLen New size you want to adjustment.
     * @param[in] needCopy If true,will copy old data to new buffer,default false.
     */
    virtual void resize(std::size_t newLen, bool needCopy);

protected:
    uint8_t *_buffer = nullptr;
    std::size_t _bufferSize = 0;
    std::size_t _curPos = 0;
    std::size_t _readPos = 0;
    bool _outRange = false;
    std::size_t _maxSize = 0;
    fullCallback _fullCallback = nullptr;
    resizeCallback _resizeCallback = nullptr;
};

MIDDLEWARE_END