将多个 boost::asio::const_buffer 组合成一个缓冲区

Question

我的程序以std::vector<boost::asio::const_buffer> buf_vect的形式接收数据。我需要将向量中的 const_buffer 组合成一个缓冲区，然后将其转换为 std::string 以供进一步处理。

第一次尝试：

size_t total_size = 0;
for (auto e : buf_vect) {
    total_size += e.size();
}
char* char_buf = new char[total_size];

for (auto e : buf_vect) {
    strncpy(char_buf, static_cast<const char*>(e.data()), e.size());
}
std::string data(char_buf, total_size);
delete char_buf;

// process data string

这种尝试在数据字符串中产生了无意义。这是正确的方法还是我完全误解了缓冲区的行为...？

Answer 1

std::vector<boost::asio::const_buffer> buf_vect

满足 ConstBufferSequence

的标准

[I need to combine the const_buffer in the vector into a single buffer which will then be converted to] a std::string [for further processing]

让我们跳过中间人？

std::string const for_further_processing(asio::buffers_begin(buf_vect),
                                         asio::buffers_end(buf_vect));

Live Demo

#include <boost/asio.hpp>
#include <iomanip>
#include <iostream>
#include <string>

namespace asio = boost::asio;

int main() {
    float f[]{42057036,      1.9603e-19, 1.9348831e-19,
              1.7440063e+28, 10268.8545, 10.027938,
              2.7560551e+12, 10265.352,  9.592293e-39};
    int  ints[]{1819043144, 1867980911, 174353522}; // "Hello World\n"
    char arr[]{" aaaaaa bbbbb ccccc ddddd "};
    std::string_view msg{"Earth To Mars Do You Read\n"};

    std::vector<asio::const_buffer> buf_vect{
        asio::buffer(ints),
        asio::buffer(arr),
        asio::buffer(msg),
        asio::buffer(f),
    };

    std::string const for_further_processing(asio::buffers_begin(buf_vect),
                                             asio::buffers_end(buf_vect));

    std::cout << std::quoted(for_further_processing) << "\n";
}

版画

"Hello World
 aaaaaa bbbbb ccccc ddddd Earth To Mars Do You Read
So Long And Thanks For All The Fish"

将多个 boost::asio::const_buffer 组合成一个缓冲区

Combine multiple boost::asio::const_buffer into a single buffer

c++

buffer

boost-asio

strncpy