系列文章目录:C++ asio网络编程-CSDN博客
本教程使用的是jsoncpp,安装方式网上有很多,可以自己下载源码编译,也可以使用vcpkg一键安装,我比较推荐使用vcpkg,感觉这个就像 visual studio 的 maven,使用这种方式安装后就不需要自己配置项目的包含目录和库目录了,直接使用。
1、消息头完善
前面我们的消息头其实是一种简化的方式去构造的,从本小节开始将使用完整的 tlv 格式
2、json数据格式
json中将id和data分开存放:
cpp
{
"data" : "hello",
"id" : 1001
}
3、MsgNode修改
现在,我们修改一下MsgNode
cpp
#pragma once
#include <string>
#include <iostream>
#include <boost/asio.hpp>
#include "const.h"
class MsgNode
{
public:
MsgNode(short max_len);
~MsgNode();
void clearData(); // 清空数据
public:
short _cur_len; // 当前收发数据的长度
short _total_len; // 数据总长度
char* _data; // 数据起始地址
};
class RecvNode : public MsgNode
{
public:
RecvNode(short max_len, short msg_id);
private:
short _msg_id;
};
class SendNode : public MsgNode
{
public:
SendNode(const char* msg, short max_len, short msg_id);
private:
short _msg_id;
};
cpp
#include "MsgNode.h"
MsgNode::MsgNode(short max_len) : _total_len(max_len), _cur_len(0)
{
_data = new char[_total_len + 1]();
_data[_total_len] = '\0';
}
MsgNode::~MsgNode() {
std::cout << "destruct MsgNode" << std::endl;
delete[] _data;
}
void MsgNode::clearData()
{
memset(_data, 0, _total_len);
_cur_len = 0;
}
RecvNode::RecvNode(short max_len, short msg_id)
: MsgNode(max_len), _msg_id(msg_id)
{
}
SendNode::SendNode(const char* msg, short max_len, short msg_id)
: MsgNode(max_len + HEAD_TOTAL_LEN), _msg_id(msg_id)
{
// 先拼接id
short msg_id_host = boost::asio::detail::socket_ops::host_to_network_short(msg_id);
memcpy(_data, &msg_id_host, HEAD_ID_LEN);
// 再拼接长度
short msg_len_host = boost::asio::detail::socket_ops::host_to_network_short(max_len);
memcpy(_data + HEAD_ID_LEN, &msg_len_host, HEAD_DATA_LEN);
// 最后拼接消息
memcpy(_data + HEAD_TOTAL_LEN, msg, max_len);
}
const.h的内容如下
cpp
#pragma once
#define MAX_LENGTH 1024*2
#define MAX_SENDQUE 1000
#define MAX_RECVQUE 10000
#define HEAD_TOTAL_LEN 4
#define HEAD_ID_LEN 2
#define HEAD_DATA_LEN 2
4、Session类修改
cpp
#pragma once
#include <iostream>
#include <boost/asio.hpp>
#include <map>
#include "Server.h"
#include <queue>
#include <mutex>
#include "MsgNode.h"
class Server;
class Session : public std::enable_shared_from_this<Session>
{
public:
Session(boost::asio::io_context& ioc, Server* server);
~Session();
void start();
void close();
void send(char* msg, int max_length, short msg_id);
void send(std::string msg, short msg_id);
boost::asio::ip::tcp::socket& getSocket();
std::string& getUuid();
std::shared_ptr<Session> getSelfShared();
private:
void handle_read(const boost::system::error_code& ec,
std::size_t bytes_transferred,
std::shared_ptr<Session> self_share);
void handle_write(const boost::system::error_code& ec,
std::shared_ptr<Session> self_share);
boost::asio::ip::tcp::socket _socket;
std::string _uuid;
Server* _server;
bool _b_close;
char _data[MAX_LENGTH];
// 收到的消息头
std::shared_ptr<MsgNode> _recv_head_node;
// 消息头是否处理完成
bool _b_head_parse;
// 收到的消息
std::shared_ptr<RecvNode> _recv_msg_node;
// 发送的消息
std::queue<std::shared_ptr<SendNode>> _send_que;
std::mutex _send_lock;
};
cpp
#include "Session.h"
#include <boost/uuid/uuid_generators.hpp>
#include <boost/uuid/uuid_io.hpp>
#include <json/json.h>
#include <json/value.h>
#include <json/reader.h>
Session::Session(boost::asio::io_context& ioc, Server* server)
: _socket(ioc), _server(server), _b_close(false), _b_head_parse(false)
{
// 生成唯一id,可以了解一下雪花算法
// 这里直接使用boost自带的方法
boost::uuids::uuid a_uuid = boost::uuids::random_generator()();
_uuid = boost::uuids::to_string(a_uuid);
_recv_head_node = std::make_shared<MsgNode>(HEAD_TOTAL_LEN);
}
Session::~Session()
{
std::cout << "~Session destruct" << std::endl;
}
boost::asio::ip::tcp::socket& Session::getSocket()
{
return _socket;
}
void Session::start()
{
memset(_data, 0, MAX_LENGTH);
_socket.async_read_some(boost::asio::buffer(_data, MAX_LENGTH),
std::bind(&Session::handle_read, this,
std::placeholders::_1, std::placeholders::_2,
getSelfShared()));
}
void Session::send(char* msg, int max_length, short msg_id)
{
std::lock_guard<std::mutex> lock(_send_lock);
if (_send_que.size() > MAX_SENDQUE) {
std::cout << "session: " << _uuid << " send que fulled, size is " << MAX_SENDQUE << std::endl;
return;
}
_send_que.push(std::make_shared<SendNode>(msg, max_length, msg_id));
if (_send_que.size() > 1) { // 因为push了一次,判断条件为大于1
return;
}
auto& msgnode = _send_que.front();
boost::asio::async_write(_socket, boost::asio::buffer(msgnode->_data, msgnode->_total_len),
std::bind(&Session::handle_write, this, std::placeholders::_1, getSelfShared()));
}
void Session::send(std::string msg, short msg_id)
{
std::lock_guard<std::mutex> lock(_send_lock);
if (_send_que.size() > MAX_SENDQUE) {
std::cout << "session: " << _uuid << " send que fulled, size is " << MAX_SENDQUE << std::endl;
return;
}
_send_que.push(std::make_shared<SendNode>(msg.c_str(), msg.length(), msg_id));
if (_send_que.size() > 1) { // 因为push了一次,判断条件为大于1
return;
}
auto& msgnode = _send_que.front();
boost::asio::async_write(_socket, boost::asio::buffer(msgnode->_data, msgnode->_total_len),
std::bind(&Session::handle_write, this, std::placeholders::_1, getSelfShared()));
}
void Session::close()
{
_socket.close();
_b_close = true;
}
std::string& Session::getUuid()
{
return _uuid;
}
std::shared_ptr<Session> Session::getSelfShared()
{
return shared_from_this();
}
void Session::handle_read(const boost::system::error_code& ec,
std::size_t bytes_transferred, std::shared_ptr<Session> self_share)
{
try {
if (!ec) {
int copy_len = 0; // 已经处理的字符数
while (bytes_transferred > 0) {
// 头部未处理完成
if (!_b_head_parse) {
// 接收到的数据长度比头部长度小
if (bytes_transferred + _recv_head_node->_cur_len < HEAD_TOTAL_LEN) {
// 将接收到的存起来
memcpy(_recv_head_node->_data + _recv_head_node->_cur_len, _data + copy_len, bytes_transferred);
_recv_head_node->_cur_len += bytes_transferred;
// 继续接收数据
memset(_data, 0, MAX_LENGTH);
_socket.async_read_some(boost::asio::buffer(_data, MAX_LENGTH),
std::bind(&Session::handle_read, this, std::placeholders::_1, std::placeholders::_2, self_share));
return;
}
// 接收到的长度大于等于头部长度
// 只存头部剩余部分
int head_remain = HEAD_TOTAL_LEN - _recv_head_node->_cur_len;
memcpy(_recv_head_node->_data + _recv_head_node->_cur_len, _data + copy_len, head_remain);
// 更新已处理的data长度和接收到但未处理的长度
copy_len += head_remain;
bytes_transferred -= head_remain;
// 获取头部 msg_id 数据
short msg_id = 0;
memcpy(&msg_id, _recv_head_node->_data, HEAD_ID_LEN);
// 网络字节序转本地字节序
msg_id = boost::asio::detail::socket_ops::network_to_host_short(msg_id);
std::cout << "msg id: " << msg_id << std::endl;
// id 校验
if (msg_id > MAX_LENGTH) {
std::cout << "invalid msd_id: " << msg_id << std::endl;
_server->clearSession(_uuid);
return;
}
// 获取数据长度
short msg_len = 0;
memcpy(&msg_len, _recv_head_node->_data + HEAD_ID_LEN, HEAD_DATA_LEN);
// 网络字节序转化为本地字节序
msg_len = boost::asio::detail::socket_ops::network_to_host_short(msg_len);
std::cout << "msg len: " << msg_len << std::endl;
// 头部长度非法
if (msg_len > MAX_LENGTH) {
std::cout << "invalid data length" << std::endl;
_server->clearSession(_uuid);
return;
}
// 头部处理完成
_b_head_parse = true;
// 头部处理完成后,还有剩余接收到的数据,就是正式数据
// 开始处理数据
_recv_msg_node = std::make_shared<RecvNode>(msg_len, msg_id);
// 有数据但不完整
if (bytes_transferred < msg_len) {
// 先存下已接收到的
memcpy(_recv_msg_node->_data + _recv_msg_node->_cur_len, _data + copy_len, bytes_transferred);
_recv_msg_node->_cur_len += bytes_transferred;
// 继续接收剩下的数据
memcpy(_data, 0, MAX_LENGTH);
_socket.async_read_some(boost::asio::buffer(_data, MAX_LENGTH),
std::bind(&Session::handle_read, this, std::placeholders::_1, std::placeholders::_2, self_share));
return;
}
// 数据齐全
memcpy(_recv_msg_node->_data + _recv_msg_node->_cur_len, _data + copy_len, msg_len);
_recv_msg_node->_cur_len += msg_len;
copy_len += msg_len;
bytes_transferred -= msg_len;
_recv_msg_node->_data[_recv_msg_node->_total_len] = '\0';
std::cout << "receive data: " << _recv_msg_node->_data << std::endl;
// 发过来的是json,解析数据测试是否正确
Json::Reader reader;
Json::Value root;
reader.parse(std::string(_recv_msg_node->_data, _recv_msg_node->_total_len), root);
std::cout << "receive msg id is " << root["id"].asInt() << " msg data is "
<< root["data"].asString() << std::endl;
// 发送测试
root["data"] = "server has received msg, msg data is " + root["data"].asString();
std::string return_str = root.toStyledString(); // 序列化后再发送
send(return_str, root["id"].asInt());
// 继续轮询剩余未处理的数据
_b_head_parse = false;
_recv_head_node->clearData();
if (bytes_transferred <= 0) {
memset(_data, 0, MAX_LENGTH);
_socket.async_read_some(boost::asio::buffer(_data, MAX_LENGTH),
std::bind(&Session::handle_read, this, std::placeholders::_1, std::placeholders::_2, self_share));
return;
}
continue;
}
// 已经处理完头部,继续处理未处理完的数据
int remain_msg = _recv_msg_node->_total_len - _recv_msg_node->_cur_len;
// 接收的数据仍不完整
if (bytes_transferred < remain_msg) {
memcpy(_recv_msg_node->_data + _recv_msg_node->_cur_len, _data + copy_len, bytes_transferred);
_recv_msg_node->_cur_len += bytes_transferred;
// 继续接收数据
memset(_data, 0, MAX_LENGTH);
_socket.async_read_some(boost::asio::buffer(_data, MAX_LENGTH),
std::bind(&Session::handle_read, this, std::placeholders::_1, std::placeholders::_2, self_share));
return;
}
// 接受的数据完整
memcpy(_recv_msg_node->_data + _recv_msg_node->_cur_len, _data + copy_len, remain_msg);
_recv_msg_node->_cur_len += remain_msg;
bytes_transferred -= remain_msg;
copy_len += remain_msg;
_recv_msg_node->_data[_recv_msg_node->_total_len] = '\0';
//std::cout << "receive data: " << _recv_msg_node->_data << std::endl;
// 发过来的是json,解析数据测试是否正确
Json::Reader reader;
Json::Value root;
reader.parse(std::string(_recv_msg_node->_data, _recv_msg_node->_total_len), root);
std::cout << "receive msg id is " << root["id"].asInt() << " msg data is "
<< root["data"].asString() << std::endl;
// 发送测试
root["data"] = "server has received msg, msg data is " + root["data"].asString();
std::string return_str = root.toStyledString(); // 序列化后再发送
send(return_str, root["id"].asInt());
// 继续轮询剩余未处理的数据
_b_head_parse = false;
_recv_head_node->clearData();
if (bytes_transferred <= 0) {
memset(_data, 0, MAX_LENGTH);
_socket.async_read_some(boost::asio::buffer(_data, MAX_LENGTH),
std::bind(&Session::handle_read, this, std::placeholders::_1, std::placeholders::_2, self_share));
return;
}
continue;
}
}
else {
std::cout << "read error" << std::endl;
close();
_server->clearSession(_uuid);
}
}
catch (std::exception& e) {
std::cout << "Exception: " << e.what() << std::endl;
}
}
void Session::handle_write(const boost::system::error_code& ec,
std::shared_ptr<Session> self_share)
{
try {
if (!ec) {
std::lock_guard<std::mutex> lock(_send_lock);
_send_que.pop();
if (!_send_que.empty()) {
auto& msgNode = _send_que.front();
boost::asio::async_write(_socket, boost::asio::buffer(msgNode->_data, msgNode->_total_len),
std::bind(&Session::handle_write, this, std::placeholders::_1, self_share));
}
}
else {
std::cout << "write error: " << ec.what() << std::endl;
close();
_server->clearSession(_uuid);
}
}
catch (std::exception& e) {
std::cerr << "Exception: " << e.what() << std::endl;
}
}
5、客户端修改
cpp
#include <boost/asio.hpp>
#include <iostream>
#include <thread>
#include <json/json.h>
#include <json/value.h>
#include <json/reader.h>
#define MAX_LENGTH 1024*2
#define HEAD_LENGTH 2
#define HEAD_TOTAL 4
int main() {
try {
// 创建上下文服务
boost::asio::io_context ioc;
// 构造endpoint
boost::asio::ip::tcp::endpoint remote_ep(boost::asio::ip::address::from_string("127.0.0.1"), 10086);
boost::asio::ip::tcp::socket sock(ioc);
boost::system::error_code error = boost::asio::error::host_not_found;
sock.connect(remote_ep, error);
if (error) {
std::cout << "连接失败,错误码:" << error.value()
<< "错误信息:" << error.message() << std::endl;
return 0;
}
Json::Value root;
root["id"] = 1001;
root["data"] = "hello";
std::string request = root.toStyledString();
std::size_t request_length = request.length();
char send_data[MAX_LENGTH] = { 0 };
int msgid = 1001;
int msgid_host = boost::asio::detail::socket_ops::host_to_network_short(msgid);
memcpy(send_data, &msgid_host, 2);
int request_host_length = boost::asio::detail::socket_ops::host_to_network_short(request_length);
memcpy(send_data + 2, &request_host_length, 2);
memcpy(send_data + 4, request.c_str(), request_length);
boost::asio::write(sock, boost::asio::buffer(send_data, request_length + 4));
std::cout << "begin to receive ..." << std::endl;
char reply_head[HEAD_TOTAL];
std::size_t reply_length = boost::asio::read(sock, boost::asio::buffer(reply_head, HEAD_TOTAL));
msgid = 0;
memcpy(&msgid, reply_head, 2);
short msglen = 0;
memcpy(&msglen, reply_head + 2, 2);
// 转换为本地字节序
msgid = boost::asio::detail::socket_ops::network_to_host_short(msgid);
msglen = boost::asio::detail::socket_ops::network_to_host_short(msglen);
char msg[MAX_LENGTH] = { 0 };
std::size_t msg_length = boost::asio::read(sock, boost::asio::buffer(msg, msglen));
Json::Reader reader;
reader.parse(std::string(msg, msg_length), root);
std::cout << "msg id: " << root["id"] << ", msg: " << root["data"] << std::endl;
getchar();
}
catch (std::exception& e) {
std::cout << "异常:" << e.what() << std::endl;
}
return 0;
}