#include "initsock.h"
#include <stdio.h>
#include <windows.h>

// 初始化Winsock库
CInitSock theSock;

#define BUFFER_SIZE 1024

typedef struct _PER_HANDLE_DATA        // per-handle数据
{
    SOCKET s;            // 对应的套节字句柄
    sockaddr_in addr;    // 客户方地址
} PER_HANDLE_DATA, *PPER_HANDLE_DATA;


typedef struct _PER_IO_DATA            // per-I/O数据
{
    OVERLAPPED ol;            // 重叠结构
    char buf[BUFFER_SIZE];    // 数据缓冲区
    int nOperationType;        // 操作类型
#define OP_READ   1
#define OP_WRITE  2
#define OP_ACCEPT 3
} PER_IO_DATA, *PPER_IO_DATA;


DWORD WINAPI ServerThread(LPVOID lpParam)
{
    // 得到完成端口对象句柄
    HANDLE hCompletion = (HANDLE)lpParam;

    DWORD dwTrans;
    PPER_HANDLE_DATA pPerHandle;
    PPER_IO_DATA pPerIO;
    while(TRUE)
    {
        // 在关联到此完成端口的所有套节字上等待I/O完成
        BOOL bOK = ::GetQueuedCompletionStatus(hCompletion, 
            &dwTrans, (LPDWORD)&pPerHandle, (LPOVERLAPPED*)&pPerIO, WSA_INFINITE);
        if(!bOK)                        // 在此套节字上有错误发生
        {
            ::closesocket(pPerHandle->s);
            ::GlobalFree(pPerHandle);
            ::GlobalFree(pPerIO);
            continue;
        }
        
        if(dwTrans == 0 &&                // 套节字被对方关闭
            (pPerIO->nOperationType == OP_READ || pPerIO->nOperationType == OP_WRITE))    
            
        {
            ::closesocket(pPerHandle->s);
            ::GlobalFree(pPerHandle);
            ::GlobalFree(pPerIO);
            continue;
        }

        switch(pPerIO->nOperationType)    // 通过per-I/O数据中的nOperationType域查看什么I/O请求完成了
        {
        case OP_READ:    // 完成一个接收请求
            {
                pPerIO->buf[dwTrans] = '\0';
                printf(pPerIO -> buf);
                
                // 继续投递接收I/O请求
                WSABUF buf;
                buf.buf = pPerIO->buf ;
                buf.len = BUFFER_SIZE;
                pPerIO->nOperationType = OP_READ;

                DWORD nFlags = 0;
                ::WSARecv(pPerHandle->s, &buf, 1, &dwTrans, &nFlags, &pPerIO->ol, NULL);
            }
            break;
        case OP_WRITE: // 本例中没有投递这些类型的I/O请求
        case OP_ACCEPT:
            break;
        }
    }
    return 0;
}


void main()
{
    int nPort = 4567;
    // 创建完成端口对象，创建工作线程处理完成端口对象中事件
    HANDLE hCompletion = ::CreateIoCompletionPort(INVALID_HANDLE_VALUE, 0, 0, 0);
    ::CreateThread(NULL, 0, ServerThread, (LPVOID)hCompletion, 0, 0);

    // 创建监听套节字，绑定到本地地址，开始监听
    SOCKET sListen = ::socket(AF_INET, SOCK_STREAM, 0);
    SOCKADDR_IN si;
    si.sin_family = AF_INET;
    si.sin_port = ::ntohs(nPort);
    si.sin_addr.S_un.S_addr = INADDR_ANY;
    ::bind(sListen, (sockaddr*)&si, sizeof(si));
    ::listen(sListen, 5);

    // 循环处理到来的连接
    while(TRUE)
    {
        // 等待接受未决的连接请求
        SOCKADDR_IN saRemote;
        int nRemoteLen = sizeof(saRemote);
        SOCKET sNew = ::accept(sListen, (sockaddr*)&saRemote, &nRemoteLen);

        // 接受到新连接之后，为它创建一个per-handle数据，并将它们关联到完成端口对象。
        PPER_HANDLE_DATA pPerHandle = 
                            (PPER_HANDLE_DATA)::GlobalAlloc(GPTR, sizeof(PER_HANDLE_DATA));
        pPerHandle->s = sNew;
        memcpy(&pPerHandle->addr, &saRemote, nRemoteLen);
        ::CreateIoCompletionPort((HANDLE)pPerHandle->s, hCompletion, (DWORD)pPerHandle, 0);
    
        // 投递一个接收请求
        PPER_IO_DATA pPerIO = (PPER_IO_DATA)::GlobalAlloc(GPTR, sizeof(PER_IO_DATA));
        pPerIO->nOperationType = OP_READ;
        WSABUF buf;
        buf.buf = pPerIO->buf;
        buf.len = BUFFER_SIZE;    
        DWORD dwRecv;
        DWORD dwFlags = 0;
        ::WSARecv(pPerHandle->s, &buf, 1, &dwRecv, &dwFlags, &pPerIO->ol, NULL);
    }
}

// 在关联到此完成端口的所有套节字上等待I/O完成
        BOOL bOK = ::GetQueuedCompletionStatus(hCompletion, 
            &dwTrans, (LPDWORD)&pPerHandle, (LPOVERLAPPED*)&pPerIO, WSA_INFINITE);