如何优化C++大数据开发中的磁盘读写速度?

#include <iostream>
#include <fstream>
#include <vector>

void writeData(const std::vector<int>& data, const std::string& filename) {
    std::ofstream file(filename, std::ios::out | std::ios::binary);
    if (!file) {
        std::cout << "Failed to open file for writing." << std::endl;
        return;
    }

    // 缓冲区大小为4KB
    const int bufferSize = 4 * 1024;
    char buffer[bufferSize];

    for (int i = 0; i < data.size(); i++) {
        const char* ptr = reinterpret_cast<const char*>(&data[i]);
        std::memcpy(&buffer[i % bufferSize], ptr, sizeof(int));

        // 将缓冲区中的数据写入磁盘
        if ((i + 1) % bufferSize == 0) {
            file.write(buffer, bufferSize);
            file.flush(); // 确保数据实际写入磁盘
        }
    }

    // 将剩下的数据写入磁盘
    int remaining = data.size() % bufferSize;
    file.write(buffer, remaining);
    file.flush(); // 确保数据实际写入磁盘

    file.close();
    std::cout << "Data has been written to file successfully." << std::endl;
}

int main() {
    std::vector<int> data(1000000, 123); // 假设要写入100万个int型数据

    writeData(data, "data.bin");

    return 0;
}

#include <iostream>
#include <fstream>
#include <vector>
#include <thread>

void readData(const std::string& filename, std::vector<int>& data) {
    std::ifstream file(filename, std::ios::in | std::ios::binary);
    if (!file) {
        std::cout << "Failed to open file for reading." << std::endl;
        return;
    }

    while (file) {
        int value;
        file.read(reinterpret_cast<char*>(&value), sizeof(int));

        if (file) {
            data.push_back(value);
        }
    }

    file.close();
    std::cout << "Data has been read from file successfully." << std::endl;
}

void writeToDisk(const std::vector<int>& data, const std::string& filename) {
    std::ofstream file(filename, std::ios::out | std::ios::binary);
    if (!file) {
        std::cout << "Failed to open file for writing." << std::endl;
        return;
    }

    for (int i = 0; i < data.size(); i++) {
        file.write(reinterpret_cast<const char*>(&data[i]), sizeof(int));
    }

    file.close();
    std::cout << "Data has been written to file successfully." << std::endl;
}

int main() {
    std::vector<int> data(1000000, 123);

    std::thread readThread(readData, "data.bin", std::ref(data));
    std::thread writeThread(writeToDisk, std::ref(data), "data_new.bin");

    readThread.join();
    writeThread.join();

    return 0;
}