c++ - ENet c++ 库的最大数据包大小

Question

我正在尝试使用 ENet库，它用于使用可靠的 UDP 套接字进行编程。在官方网站的 Feature 选项卡上，它说:

ENet will send and deliver packets regardless of size. Large packets are fragmented into many smaller packets of suitable size, and reassembled on the foreign host to recover the original packet for delivery. The process is entirely transparent to the developer.

我用一个简单的服务器/客户端测试，向服务器发送1k数据是可以的，但是当数据增长到2k时，服务器似乎没有接收到。

我的代码:

//服务器

#include <string>
#include <iostream>
#include <enet/enet.h>
using namespace std;

void main()
{
    // initialize
    if(enet_initialize()) {
        cout << "fail init" << endl;
        return;
    }

    ENetAddress address;
    address.host = ENET_HOST_ANY;
    address.port = 9000;

    ENetHost* server;
    server = enet_host_create(&address,
                  512,
                  2,
                  0,
                  0);
    if(server == NULL) {
        cout << "fail create host" << endl;
        enet_deinitialize();
        return;
    }


    ENetEvent event;
    while(enet_host_service(server, &event, 5000) >= 0) {
        if(event.type == ENET_EVENT_TYPE_CONNECT) { // client connected
            static unsigned int num = 0;
            ENetAddress remote = event.peer->address; // peer address
            char ip[256];
            enet_address_get_host_ip(&remote, ip, 256);
            cout << "ip:" << ip << " connected, id: " << num << endl;
            event.peer->data = (void*)num++;
        } else if(event.type == ENET_EVENT_TYPE_RECEIVE) {    // recv data
            cout << "received data at channel: " << event.channelID << endl;
            cout << "data length: " << event.packet->dataLength << endl;
            cout << "data: " << string((char*)event.packet->data, event.packet->dataLength) << endl;
            enet_packet_destroy(event.packet); // free
            cout << endl;
        } else if(event.type == ENET_EVENT_TYPE_DISCONNECT) {     // disconnect
            cout << "id " << event.peer->data << " disconnected" << endl;
        }
    }

    enet_deinitialize();
}

//客户端

#include <string>
#include <iostream>
#include <enet/enet.h>
using namespace std;

void main()
{
    if(enet_initialize()) {
        cout << "fail init" << endl;
        return;
    }

    ENetHost* client = enet_host_create(NULL,
                        1,
                        2,
                        0,
                        0);
    if(client == NULL) {
        cout << "fail create client" << endl;
        return;
    }


    ENetAddress svraddr;
    enet_address_set_host(&svraddr, "127.0.0.1");
    svraddr.port = 9000;

    ENetPeer* server = enet_host_connect(client, &svraddr, 2, 0);

    if(server == NULL) {
        cout << "fail connect" << endl;
        return;
    }

    ENetEvent event;
    if(enet_host_service (client, &event, 5000) > 0 &&
       event.type == ENET_EVENT_TYPE_CONNECT) {
        cout << "connected successfully" << endl;
    } else {
        enet_peer_reset (server);
        cout << "failed to connect" << endl;
        return;
    }


    string data(1024, 'a'); // <--------------- ok
    string data(2 * 1024, 'a'); // <--------------- fail
    ENetPacket* packet1 = enet_packet_create(data.c_str(), data.length(), ENET_PACKET_FLAG_RELIABLE);
    if(!packet1) {
        cout << "create packet fail" << endl;
        return;
    }
    if(enet_peer_send(server, 0, packet1) < 0) {
        cout << "send fail" << endl;
        return;
    }

    enet_host_flush (client);


    enet_peer_disconnect (server, 0);
    while(enet_host_service (client, &event, 5000) > 0) {
        switch(event.type) {
          case ENET_EVENT_TYPE_RECEIVE:
            enet_packet_destroy (event.packet);
            break;

          case ENET_EVENT_TYPE_DISCONNECT:
            cout << "disconnected" << endl;
            enet_deinitialize();
            return;
        }
    }

    enet_peer_reset(server);
    cout << "force reset" << endl;

    enet_deinitialize();
}

代码有问题吗？

Answer 1

我找到了 enet_peer_disconnect_later，这似乎是有效的 API。不知道为什么官方的例子要用enet_peer_disconnect..