#include <iostream>

#include <sys/socket.h>

#include <sys/epoll.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <fcntl.h>

#include <unistd.h>

#include <stdio.h>

#include <errno.h>

#include <string.h>

using namespace std;

#define MAXLINE 5

#define OPEN_MAX 100

#define LISTENQ 20

#define SERV_PORT 5000

#define INFTIM 1000

void setnonblocking(int sock)

{

    int opts;

    opts=fcntl(sock,F_GETFL);

    if(opts<)

    {

        perror("fcntl(sock,GETFL)");

        return;

    }

    opts = opts|O_NONBLOCK;

    if(fcntl(sock,F_SETFL,opts)<)

    {

        perror("fcntl(sock,SETFL,opts)");

        return;

    }

}

void CloseAndDisable(int sockid, epoll_event ee)

{

    close(sockid);

    ee.data.fd = -;

}

ssize_t socket_send(int sockfd, const char* buffer, size_t buflen)

{

  ssize_t tmp;

  size_t total = buflen;

  const char *p = buffer;

  while()

  {

     tmp = send(sockfd, p, total, );

     if(tmp < )

     {

        if(errno == EINTR)

            return -;

        if(errno == EAGAIN)

        {

           usleep();

           continue;

        }

           return -;

     }

     if((size_t)tmp == total)

         return buflen;

     total -= tmp;

     p += tmp;

   }

   return tmp;

}

int main()

{

    int i, maxi, listenfd, connfd, sockfd,epfd,nfds, portnumber;

    char line[MAXLINE*];

    socklen_t clilen;

    portnumber = ;

    struct epoll_event ev,events[];

    epfd=epoll_create();

    struct sockaddr_in clientaddr;

    struct sockaddr_in serveraddr;

    listenfd = socket(AF_INET, SOCK_STREAM, );

    memset(&serveraddr, , sizeof(serveraddr));

    serveraddr.sin_family = AF_INET;

    serveraddr.sin_addr.s_addr = htonl(INADDR_ANY);

    serveraddr.sin_port=htons(portnumber);

    bind(listenfd,(sockaddr *)&serveraddr, sizeof(serveraddr));

    listen(listenfd, LISTENQ);

    ev.data.fd=listenfd;

    ev.events=EPOLLIN|EPOLLET;

    epoll_ctl(epfd,EPOLL_CTL_ADD,listenfd,&ev);

    maxi = ;

    int bOut = ;

    for ( ; ; )

    {

        if (bOut == )

            break;

        nfds=epoll_wait(epfd,events,,-);

        //printf("wait %d returns\n",nfds);

        for(i=;i<nfds;++i)

        {

            if(events[i].data.fd==listenfd)//如果新监测到一个SOCKET用户连接到了绑定的SOCKET端口

            {

                connfd = accept(listenfd,(sockaddr *)&clientaddr, &clilen);

                if(connfd<){

                    perror("connfd<0");

                    return ();

                }

                char *str = inet_ntoa(clientaddr.sin_addr);

                cout << "accapt a connection from " << str << endl;

                setnonblocking(connfd);

                ev.data.fd=connfd;

                ev.events=EPOLLIN | EPOLLET;

                //注册ev

                epoll_ctl(epfd,EPOLL_CTL_ADD,connfd,&ev);

            }

            else if(events[i].events & EPOLLIN)

            {

                cout << "EPOLLIN" << endl;

                if ( (sockfd = events[i].data.fd) < )

                    continue;

                cout << "START READ" << endl;

                char * head = line;

                int recvNum = ;

                int count = ;

                bool bReadOk = false;

                while()

                {

                    recvNum = recv(sockfd, head+count, MAXLINE-, );

                    if(recvNum < )

                    {

                        if(errno == EAGAIN)

                        {//已没数据 不阻塞等待

                            bReadOk = true;

                            break;

                        }

                        else if (errno == ECONNRESET)

                        {

                                CloseAndDisable(sockfd, events[i]);

                                cout << "counterpart send out RST\n";

                                break;

                         }

                        else if (errno == EINTR)

                        {//有数据但未读到断了，所以要接着读

                            continue;

                        }

                        else

                        {

                            CloseAndDisable(sockfd, events[i]);

                            cout << "unrecovable error\n";

                            break;

                        }

                   }

                   else if( recvNum == )

                   {

                        CloseAndDisable(sockfd, events[i]);

                        cout << "counterpart has shut off\n";

                        break;

                   }

                   count += recvNum;

                   if ( recvNum == MAXLINE-)

                   {

                   cout << "sleeping..."<<endl;

           sleep();

                       cout << "recvNum == MAXLINE-1\n"<<endl;

                       continue;

                   }

                   else // 0 < recvNum < MAXLINE-1

                   {

                       cout << "0 < recvNum < MAXLINE-1"<<endl;

                       bReadOk = true;

                       break; // 退出while(1),表示已经全部读完数据

                   }

                }

                if (bReadOk == true)

                {

                    line[count] = '\0';

                    cout << "we have read from the client : " << line;

                    ev.data.fd=sockfd;

                    ev.events = EPOLLOUT | EPOLLET;

                    epoll_ctl(epfd,EPOLL_CTL_MOD,sockfd,&ev);

                }

            }

            else if(events[i].events & EPOLLOUT) // 如果有数据发送

            {

                cout << "EPOLLOUT" << endl;

                const char str[] = "";

        //printf("%d\n",sizeof(str));

                memcpy(line, str, sizeof(str));

                //cout << line << endl;

        printf("d %d u %u lu %lu\n",i,i,i);

                sockfd = events[i].data.fd;

                int bWritten = ;

                int writenLen = ;

                int count = ;

                char * head = line;

        bWritten=socket_send(sockfd,head,strlen(head));

                if (bWritten == strlen(head))

                {

                    ev.data.fd=sockfd;

                    ev.events=EPOLLIN | EPOLLET;

                    epoll_ctl(epfd,EPOLL_CTL_MOD,sockfd,&ev);

                }

            }

        }

    }

    return ;

}