GetqueueStatus

最新推荐文章于 2020-08-02 00:00:16 发布

转载最新推荐文章于 2020-08-02 00:00:16 发布 · 225 阅读

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CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/qq76211822/p/4712074.html

文章标签：

#数据库

本文介绍了一种使用异步IO和多线程进行高效文件复制的方法，通过创建IO完成端口（IOCP）来实现跨文件系统的快速复制任务。此方法能够充分利用系统资源，减少等待时间和提高复制速度。

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#include "stdafx.h"
#include <Windows.h>
#include <process.h>
#include <iostream>
using namespace std;

//完成键
#define CK_READ 1
#define CK_WRITE 2

void ShowErrMsg(LPCSTR lpMsg);

//传给线程函数的参数
typedef struct _tagThreadParam
{
HANDLE hIOCP; //IOCP
LPVOID lpAddr; //读入的内存地址
LARGE_INTEGER liFileSize; //源文件大小
size_t nDataBlockSize; //每次读写的数据块大小
HANDLE hSrc; //源文件
HANDLE hDest; //目的文件
LPOVERLAPPED lpOLPSrc; //源文件的OVERLAPPED结构指针
LPOVERLAPPED lpOLPDest; //目的文件的OVERLAPPED结构指针
}ThreadParam, *LPTHREADPARAM;

int _tmain(int argc, _TCHAR* argv[])
{
/*LPCTSTR lpSrc = TEXT("D:\\SourceSoftware\\myeclipse-8.5.0.rar");
LPCTSTR lpDest = TEXT("D:\\SourceSoftware\\myeclipse-8.5.0_copy.rar");*/

/*LPCTSTR lpSrc = TEXT("D:\\SourceSoftware\\VS2010\\cn_visual_studio_2010_ultimate_x86_dvd_532347.iso");
LPCTSTR lpDest = TEXT("D:\\SourceSoftware\\VS2010\\cn_visual_studio_2010_ultimate_x86_dvd_532347_copy.iso");*/

/*LPCTSTR lpSrc = TEXT("D:\\SourceSoftware\\SQLServer2008\\cn_sql_server_2008_r2_developer_x86_x64_ia64_dvd_522724.iso");
LPCTSTR lpDest = TEXT("D:\\SourceSoftware\\SQLServer2008\\cn_sql_server_2008_r2_developer_x86_x64_ia64_dvd_522724_copy.iso");
*/
/*LPCTSTR lpSrc = TEXT("D:\\SourceSoftware\\SQLServer2008\\cn_sql_server_2008_r2_developer_x86_x64_ia64_dvd_522724.rar");
LPCTSTR lpDest = TEXT("D:\\SourceSoftware\\SQLServer2008\\cn_sql_server_2008_r2_developer_x86_x64_ia64_dvd_522724_copy.rar");*/



LPCTSTR lpSrc = TEXT("D:\\SourceSoftware\\VS2012旗舰版\\VS2012_ULT_chs.iso");
LPCTSTR lpDest = TEXT("D:\\SourceSoftware\\VS2012旗舰版\\VS2012_ULT_chs_copy.iso");

HANDLE hSrcFile = INVALID_HANDLE_VALUE; //源文件句柄
HANDLE hDestFile = INVALID_HANDLE_VALUE; //目标文件句柄
HANDLE hIOCP = NULL; //IOCP
LPVOID lpAddr = NULL; //申请内存地址

__try
{
cout << endl << "开始打开源文件" <<endl;
//源文件
hSrcFile = CreateFile(
lpSrc, //源文件
GENERIC_READ, //读模式
FILE_SHARE_READ, //读共享
NULL, //安全属性
OPEN_EXISTING, //必须存在
FILE_FLAG_OVERLAPPED | FILE_FLAG_NO_BUFFERING,//异步 | 不用缓存
NULL //文件模板为空
);
if(INVALID_HANDLE_VALUE == hSrcFile)
{
ShowErrMsg("源文件打开错误");
return -1;
}

cout << endl << "开始打开目的文件" << endl;

//目的文件
hDestFile = CreateFile(
lpDest, //目的文件
GENERIC_WRITE, //写模式
0, //独占访问
NULL, //安全属性
CREATE_ALWAYS, //总是创建
FILE_FLAG_OVERLAPPED | FILE_FLAG_NO_BUFFERING, //异步 | 不用缓存
hSrcFile //文件属性同源文件
);
if (INVALID_HANDLE_VALUE == hDestFile)
{
ShowErrMsg("目的文件打开错误");
return -2;
}

cout << endl << "开始获取文件尺寸" << endl;
//源文件尺寸
LARGE_INTEGER liFileSize;
BOOL bRet = GetFileSizeEx(hSrcFile, &liFileSize);
if (FALSE == bRet)
{
ShowErrMsg("获取源文件尺寸失败");
return -3;
}

cout << endl << "开始用源文件尺寸设置目的文件大小" << endl;

//设置目的文件指针位置为源文件尺寸并设置文件尾
BOOL bRet2 = SetFilePointerEx(hDestFile, liFileSize, NULL, FILE_BEGIN);
BOOL bRet3 = SetEndOfFile(hDestFile);
if (FALSE == bRet2 || FALSE == bRet3)
{
ShowErrMsg("设置目的文件尺寸失败");
return -4;
}

cout << endl << "开始获取磁盘扇区大小和系统信息" << endl;
SYSTEM_INFO sysInfo = {0};
GetSystemInfo(&sysInfo);
DWORD dwBytesPerSector = 0UL;
bRet = GetDiskFreeSpace(TEXT("D:"), NULL, &dwBytesPerSector, NULL, NULL);
if (FALSE == bRet)
{
ShowErrMsg("开始获取磁盘扇区大小错误");
return -5;
}

//读
OVERLAPPED ovlpRead;
ovlpRead.Offset = 0;
ovlpRead.OffsetHigh = 0;
ovlpRead.hEvent = NULL;

//写
OVERLAPPED ovlpWrite;
ovlpWrite.Offset = 0;
ovlpWrite.OffsetHigh = 0;
ovlpWrite.hEvent = NULL;

//创建IOCP 并和文件关联
hIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, sysInfo.dwNumberOfProcessors);
if (NULL == hIOCP)
{
DWORD dwErr = GetLastError();
if (ERROR_ALREADY_EXISTS != dwErr)
{
ShowErrMsg("创建IOCP 失败");
return -6;
}
}

hIOCP = CreateIoCompletionPort(hSrcFile, hIOCP, CK_READ, sysInfo.dwNumberOfProcessors);
hIOCP = CreateIoCompletionPort(hDestFile, hIOCP, CK_WRITE, sysInfo.dwNumberOfProcessors);

//申请扇区大小的5倍的内存
size_t sizeMAX = dwBytesPerSector * 1024 * 64 * 2; //512K * 64 * 2
size_t sizeMIN = dwBytesPerSector * 1024 * 64 * 2;

//申请内存
lpAddr = VirtualAlloc(NULL, sizeMAX, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
if (NULL == lpAddr)
{
ShowErrMsg("申请内存错误");
return -7;
}

//先往IOCP的完成队列插入一个写完成项
//写0字节
PostQueuedCompletionStatus(
hIOCP, //IOCP
0, //GetQueuedCompletionStatus取到的传送字节为0
CK_WRITE, //写操作
&ovlpWrite //写OVERLAPPED
);

DWORD dwBytesTrans = 0; //传输字节数
ULONG_PTR ulCompleteKey = 0; //完成键
LPOVERLAPPED lpOverlapped = NULL; //OVERLAPPED结构
BOOL bLastTime = FALSE; //最后一个读操作
int i = 0;
int j = 0;
int nCountZero = 0; //计数

/************************************************************************/
/* 因为前一次只是往IOCP的完成队列插入了一项【写完成】，而并非真的写
只是让下面的代码从【读操作】开始，
执行序列为：读-写，读-写， ... ，读-写
当每个【读操作】完成时：把缓冲区中的数据写入【目的文件】，并更新【源文件】的偏移量

当每个【写操作】完成时：更新【目的文件】的偏移量，
同时，因为操作序列是写操作在后，因此写操作完成后，根据更新后的【源文件】的偏移量
和【源文件】大小做比较，如果大于等于源文件大小，则说明这是最后一次读取操作，则当下一次
写操作完成时退出循环。如果当前【源文件偏移量】没有达到【源文件大小】则再次从【源文件】
中读取数据进缓冲区，
/************************************************************************/
while(TRUE)
{
BOOL bRet = GetQueuedCompletionStatus(hIOCP, &dwBytesTrans, &ulCompleteKey, &lpOverlapped, INFINITE);
if (FALSE == bRet)
{
DWORD dwErr = GetLastError();
if (NULL != lpOverlapped)
{
ShowErrMsg("线程函数返回错误，错误原因:");
cout << dwErr <<endl;
break;
} //if
else
{
if (ERROR_TIMEOUT == dwErr)
{
ShowErrMsg("等待超时");
}
else
{
ShowErrMsg("线程函数返回错误，错误原因2:");
cout << dwErr <<endl;
}

continue;
} //else

} //if

//读操作完成
if (ulCompleteKey == CK_READ)
{
cout << endl << "-------------第 " << ++ i << " 次操作完成，开始写文件 ---------------- "<<endl;
WriteFile(hDestFile, lpAddr, sizeMIN, NULL, &ovlpWrite);

//读操作完成更新源文件的偏移量
LARGE_INTEGER liSrcFile;
liSrcFile.QuadPart = dwBytesTrans;

ovlpRead.Offset += liSrcFile.LowPart;
ovlpRead.OffsetHigh += liSrcFile.HighPart;
} //if

//写操作完成
else if (ulCompleteKey == CK_WRITE)
{
//写操作完成，更新目的文件的偏移量
LARGE_INTEGER liDestFile;
liDestFile.QuadPart = dwBytesTrans;
ovlpWrite.Offset += liDestFile.LowPart;
ovlpWrite.OffsetHigh += liDestFile.HighPart;

//当前源文件的偏移量
LARGE_INTEGER liTemp;
liTemp.LowPart = ovlpRead.Offset;
liTemp.HighPart = ovlpRead.OffsetHigh;
//当前文件偏移是超过文件大小
if (liTemp.QuadPart >= liFileSize.QuadPart)
{
break;
}
cout << endl << "*************第 " << ++ j << " 次读写操作完成，开始读文件 ***************"<<endl;
ReadFile(hSrcFile, lpAddr, sizeMIN, NULL, &ovlpRead);

} //else if

} //while

SetFilePointerEx(hDestFile, liFileSize, NULL, FILE_BEGIN);
SetEndOfFile(hDestFile);

cout << endl << " $$$$$$$$$$$$$$$$$$$$$ 操作完成 $$$$$$$$$$$$$$$$$" <<endl;

}
__finally
{
cout << endl << "清理资源" <<endl;
if (INVALID_HANDLE_VALUE != hSrcFile)
CloseHandle(hSrcFile);
hSrcFile = INVALID_HANDLE_VALUE;

if(INVALID_HANDLE_VALUE != hDestFile)
CloseHandle(hDestFile);
hDestFile = INVALID_HANDLE_VALUE;

if(NULL != lpAddr)
VirtualFree(lpAddr, 0, MEM_RELEASE | MEM_DECOMMIT);
lpAddr = NULL;
}


cout << endl << endl;
return 0;
}

void ShowErrMsg(LPCSTR lpMsg){ cout << endl << "Some error happened : " << lpMsg << "\n"; }