使用内存映射来对文件排序

#include"stdafx.h"
#include <windows.h>

#define DATALEN 56
#define KEY_SIZE 8

typedef struct _RECORD {
   TCHAR key[KEY_SIZE];
   TCHAR data[DATALEN];
} RECORD;

#define RECSIZE sizeof (RECORD)

int Comp(const void *p1,const void *p2)
{
　　return _tcsncmp ((LPCSTR)p1, (LPCTSTR)p2, KEY_SIZE);
}

int _tmain (int argc, LPTSTR argv[])
{
   HANDLE hFile=INVALID_HANDLE_VALUE,hMap=NULL;
   LPVOID pFile=NULL;
   LARGE_INTEGER fileSize;
   TCHAR tempFile[MAX_PATH];
   LPTSTR pTFile;

   CopyFileA("e:\\large.txt",tempFile,TRUE);

   hFile=CreateFile(tempFile,GENERIC_READ|GENERIC_WRITE,
                   0,NULL,OPEN_EXISTING,0,NULL);
   GetFileSizeEx(hFile,&fileSize);
   fileSize.QuadPart+=2;
   hMap=CreateFileMapping(hFile,NULL,PAGE_READWRITE,fileSize.HighPart,fileSize.LowPart,NULL);
   pFile=MapViewOfFile(hMap,FILE_MAP_ALL_ACCESS,0,0,0);

   qsort(pFile,(SIZE_T)fileSize.QuadPart / RECSIZE,RECSIZE,Comp);

   pTFile=(LPTSTR)pFile;
   pTFile[fileSize.QuadPart]='\0';
   _tprintf(_T("%s"),pFile);
   UnmapViewOfFile(pFile);
   CloseHandle(hMap);
   DeleteFile(tempFile);

   system("pause");
   return 0;
}

待排序内容格式如下：

部分排序结果如下：

使用内存映射来对文件排序

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