Wie können Lese- und Schreibvorgänge in der C++-Big-Data-Entwicklung optimiert werden?

#include <iostream>
#include <fstream>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>

#define FILE_SIZE 1024*1024*1024  // 1GB

int main() {
    int fd = open("data.bin", O_RDWR | O_CREAT | O_TRUNC, 0666);
    if (fd == -1) {
        std::cout << "Failed to open file!" << std::endl;
        return -1;
    }
    int res = lseek(fd, FILE_SIZE - 1, SEEK_SET);
    if (res == -1) {
        std::cout << "Failed to lseek!" << std::endl;
        close(fd);
        return -1;
    }
    res = write(fd, "", 1);
    if (res != 1) {
        std::cout << "Failed to write!" << std::endl;
        close(fd);
        return -1;
    }
    char* data = (char*) mmap(NULL, FILE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (data == MAP_FAILED) {
        std::cout << "Failed to mmap!" << std::endl;
        close(fd);
        return -1;
    }
    // 对于大数据文件进行读写操作
    strcpy(data, "Hello, World!");  // 写入数据
    std::cout << data << std::endl;  // 读取数据
    // 释放内存映射
    res = munmap(data, FILE_SIZE);
    if (res == -1) {
        std::cout << "Failed to munmap!" << std::endl;
        close(fd);
        return -1;
    }
    close(fd);
    return 0;
}

#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <aio.h>
#include <unistd.h>
#include <string.h>

#define BUFFER_SIZE 1024

void read_callback(sigval_t sigval) {
    aiocb* aio = (aiocb*)sigval.sival_ptr;
    int res = aio_error(aio);
    if (res != 0) {
        std::cout << "Failed to read!" << std::endl;
    } else {
        std::cout << aio->aio_buf << std::endl;  // 输出读取的数据
    }
    aio_result(aio);
    delete aio;
}

void write_callback(sigval_t sigval) {
    aiocb* aio = (aiocb*)sigval.sival_ptr;
    int res = aio_error(aio);
    if (res != 0) {
        std::cout << "Failed to write!" << std::endl;
    }
    aio_result(aio);
    delete aio;
}

void async_read_write(const char* from, const char* to) {
    int input_fd = open(from, O_RDONLY);
    int output_fd = open(to, O_WRONLY | O_CREAT | O_TRUNC, 0666);
    
    std::vector<char> buffer(BUFFER_SIZE);
    aiocb* aio_read = new aiocb{};
    aio_read->aio_fildes = input_fd;
    aio_read->aio_buf = buffer.data();
    aio_read->aio_nbytes = BUFFER_SIZE;
    aio_read->aio_offset = 0;
    aio_read->aio_lio_opcode = LIO_READ;
    aio_read->aio_sigevent.sigev_notify = SIGEV_THREAD;
    aio_read->aio_sigevent.sigev_notify_function = read_callback;
    aio_read->aio_sigevent.sigev_value.sival_ptr = aio_read;
    
    aiocb* aio_write = new aiocb{};
    aio_write->aio_fildes = output_fd;
    aio_write->aio_buf = buffer.data();
    aio_write->aio_nbytes = BUFFER_SIZE;
    aio_write->aio_offset = 0;
    aio_write->aio_lio_opcode = LIO_WRITE;
    aio_write->aio_sigevent.sigev_notify = SIGEV_THREAD;
    aio_write->aio_sigevent.sigev_notify_function = write_callback;
    aio_write->aio_sigevent.sigev_value.sival_ptr = aio_write;
    
    std::vector<aiocb*> aiocb_list = {aio_read, aio_write};
    lio_listio(LIO_WAIT, aiocb_list.data(), aiocb_list.size(), nullptr);
    
    close(input_fd);
    close(output_fd);
}

int main() {
    async_read_write("data.bin", "data_copy.bin");
    return 0;
}