5、程序实现如下（非常简单、不再解释）：
// writeFileDemo.cpp : 定义控制台应用程序的入口点。
//
#include "stdafx.h"
#include <iostream>
#include <fstream>
using namespace std;
#include <windows.h>
#include <WinBase.h>
#include <ctime>
//目标写入文件
const char* g_psOutFile = "D:\\test_file\\1.txt";
//一次写入的Buffer大小
const long WRITE_BUFF_SIZE = 10*1024*1024; //300MB字节
//写入次数
#define MAX_WRITE_CNT 5
//buffer每个字节初始化为‘a‘字符
void initBuf(char* pszBuf, int iCnt)
{
for(int i = 0; i < iCnt; ++i)
{
pszBuf[i] = 97;
}
}
//循环写入文件
void writeFileFun(char* szBuf)
{
ofstream ofout(g_psOutFile);
int i = 0;
while(i < MAX_WRITE_CNT)
{
ofout << szBuf << endl;
++i;
}
}
//测试写磁盘速度
void writeFileTestFun()
{
//堆内存申请，显然栈内存不合适
char* szTenMBBuf = (char*)malloc(WRITE_BUFF_SIZE);
(void)initBuf(szTenMBBuf, WRITE_BUFF_SIZE);
size_t nBeginTicks = GetTickCount();
cout << "BeginTime = " << nBeginTicks << endl;
(void)writeFileFun(szTenMBBuf);
size_t nEndTicks = GetTickCount();
cout << "EndTime = " << nEndTicks << endl;
size_t nSpan = nEndTicks - nBeginTicks;
cout << "nSpanTime = " << nSpan << "ms" << endl; //ms
float nTotalBytes = WRITE_BUFF_SIZE*MAX_WRITE_CNT; //总写入字节数
float nTotalTimes = (float)(nSpan) / 1000.0f; //总耗费时间,单位s
cout << "nTotalWriteBytes = " << nTotalBytes << endl;
cout << "nTotalTimes = " << nTotalTimes << endl;
float fSpeed = nTotalBytes / nTotalTimes;
cout << "Speed = " << fSpeed << "Byte/s" << endl; //写入速度 Byte/s
cout << "Speed = " << fSpeed / 1024.0f / 1024.0f << "MB/s" << endl; //写入速度 MByte/s
if (NULL != szTenMBBuf)
{
free(szTenMBBuf);
szTenMBBuf = NULL;
}
}
int _tmain(int argc, _TCHAR* argv[])
{
(void)writeFileTestFun();
return 0;
}