#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>

#define MAXLINE 10
#define OPEN_MAX 100
#define LISTENQ 20
#define SERV_PORT 5555
#define INFTIM 1000

void setnonblocking(int sock)
{
	int opts;
	opts = fcntl(sock, F_GETFL);
	if (opts < 0)
	{
		perror("fcntl(sock, GETFL)");
		exit(1);
	}
	opts = opts|O_NONBLOCK;
	if (fcntl(sock, F_SETFL, opts) < 0)
	{
		perror("fcntl(sock, SETFL, opts)");
		exit(1);
	}
}

// 發(fā)送數(shù)據(jù)
ssize_t socket_send(int sockfd, const char* buffer, size_t buflen)
{
	ssize_t tmp;
	size_t total = buflen;
	const char *p = buffer;

	while(1)
	{
		tmp = send(sockfd, p, total, 0);
		if(tmp < 0)
		{
			// 當(dāng)send收到信號時,可以繼續(xù)寫,但這里返回-1.
			if(errno == EINTR)
			{
				return -1;
			}

			// 當(dāng)socket是非阻塞時,如返回此錯誤,表示寫緩沖隊列已滿,
			// 在這里做延時后再重試.
			if(errno == EAGAIN)
			{
				usleep(1000);
				continue;
			}

			return -1;
		}

		if((size_t)tmp == total)
		{
			return buflen;
		}

		total -= tmp;
		p += tmp;
	}

	return tmp;
}

int main()
{
	int i, maxi, listenfd, connfd, sockfd, epfd, nfds;
	ssize_t rs, n = 0;
	char line[MAXLINE];
	int l_sinSize = 0;
	l_sinSize = sizeof(struct sockaddr);

	// 聲明epoll_event結(jié)構(gòu)體的變量,ev用于注冊事件,數(shù)組用于回傳要處理的事件
	struct epoll_event ev, events[20];
	// 生成用于處理accept的epoll專用的文件描述符
	epfd = epoll_create(256);

	struct sockaddr_in clientaddr;
	struct sockaddr_in serveraddr;
	listenfd = socket(AF_INET, SOCK_STREAM, 0);

	// 把socket設(shè)置為非阻塞方式
	setnonblocking(listenfd);

	// 設(shè)置與要處理的事件相關(guān)的文件描述符
	ev.data.fd = listenfd;
	// 設(shè)置要處理的事件類型
	ev.events = EPOLLIN|EPOLLET;
	// 注冊epoll事件
	epoll_ctl(epfd, EPOLL_CTL_ADD, listenfd, &ev);


	bzero(&serveraddr, sizeof(struct sockaddr_in));
	serveraddr.sin_family = AF_INET;
	serveraddr.sin_addr.s_addr = htonl(INADDR_ANY);
	serveraddr.sin_port = htons(SERV_PORT);
	bind(listenfd, (struct sockaddr *)(&serveraddr), sizeof(struct sockaddr));
	listen(listenfd, LISTENQ);
	maxi = 0;
	for ( ; ; ) 
	{
		// 等待epoll事件的發(fā)生
		nfds=epoll_wait(epfd,events,20,500);
		// 處理所發(fā)生的所有事件
		for (i = 0; i < nfds; ++i)
		{
			if (events[i].data.fd == listenfd)
			{
				connfd = accept(listenfd, (struct sockaddr *)(&clientaddr), (socklen_t *)&l_sinSize);
				if (connfd < 0)
				{
					perror("connfd < 0");
					exit(1);
				}
				setnonblocking(connfd);
				char* str = inet_ntoa(clientaddr.sin_addr);
				std::cout<<"connect from "<<str<<std::endl;
				// 設(shè)置用于讀操作的文件描述符
				ev.data.fd = connfd;
				// 設(shè)置用于注測的讀操作事件
				ev.events = EPOLLIN|EPOLLET;
				// 注冊ev
				epoll_ctl(epfd, EPOLL_CTL_ADD, connfd, &ev);
			}
			else if (events[i].events&EPOLLIN)
			{
				if ((sockfd = events[i].data.fd) < 0)
				{
					continue;
				}
/*
				if ((n = read(sockfd, line, MAXLINE)) < 0)
				{
					if (errno == ECONNRESET)
					{
						close(sockfd);
						events[i].data.fd = -1;
					}
					else
					{
						std::cout<<"readline error"<<std::endl;
					}
				}
				else if (n == 0)
				{
					close(sockfd);
					events[i].data.fd = -1;
				}

*/				
				while(rs)
				{
					n = recv(sockfd, line, MAXLINE, 0);
					if(n < 0)
					{
						// 由于是非阻塞的模式,所以當(dāng)errno為EAGAIN時,表示當(dāng)前緩沖區(qū)已無數(shù)據(jù)可讀
						// 在這里就當(dāng)作是該次事件已處理處.
						if(errno == EAGAIN)
						{
							break;
						}
						else
						{
							return;
						}
					}
					else if(n == 0)
					{
						// 這里表示對端的socket已正常關(guān)閉.
					}

					if(n == sizeof(line))
					{
						rs = 1;   // 未讀完 需要再次讀取
					}
					else
					{
						rs = 0;
					}
				}

				//設(shè)置用于寫操作的文件描述符
				ev.data.fd = sockfd;
				//設(shè)置用于注測的寫操作事件
				ev.events = EPOLLOUT|EPOLLET;
				//修改sockfd上要處理的事件為EPOLLOUT
				epoll_ctl(epfd, EPOLL_CTL_MOD, sockfd, &ev);
			}
			else if(events[i].events&EPOLLOUT)
			{
				sockfd = events[i].data.fd;
				ssize_t l_writeSize = write(sockfd, line, n);
				std::cout<<"write "<<l_writeSize<<std::endl;
				//設(shè)置用于讀操作的文件描述符
				ev.data.fd = sockfd;
				//設(shè)置用于注測的讀操作事件
				ev.events = EPOLLIN|EPOLLET;
				//修改sockfd上要處理的事件為EPOLIN
				epoll_ctl(epfd, EPOLL_CTL_MOD, sockfd, &ev);
			}
		}
	}
}