问题可能在这里：

  char  data [MAX_BUFFER_SIZE]; 

 fileOpen.read（& data [ 0 ]，尺寸）; 

当文件大小大于

 MAX_BUFFER_SIZE< br /> 

时，这会导致缓冲区溢出。

为避免这种情况，请在堆使用 new 或 malloc ：

  char  data =  new   char  [size]; 
 fileOpen.read（& data [ 0 ]，size）; 
 //  在此处执行数据 
删除数据; 

Hi all,

I want to extract all 3 grams(each 3 gram contain 3 byte with 1 byte shift each time) of files in a directory and count frequency of each 3 gram in files. I have written a simple C++ program to extract 3 grams of binary files recursively and saved them in a hash table as a key.
before I add each key I find key. if it was in heap I did not add this key and just increase member value(frequency of presence 3gram).

The program runs but it stops with an error message saying "windows has triggered a break point in my program.This may be due to the corruption of the heap which indicated a bug in the program or the dlls that it loads"

I would appreciate it if somebody could help me ..

Thanks,

#include "hash_table.h"
#include <string>
#include <windows.h>
#include <fstream>
#include <stdio.h>
#include <iostream>

#define MAX_BUFFER_SIZE 256
typedef CHashTable<int> CLongHashT;

using namespace std;

void makeVocabHash(string dir, CLongHashT HashTperAll, int N) {
	/* N -> N-gram! */
	HANDLE		  hFindFile;
	WIN32_FIND_DATAA  Win32FindData;
	CHAR	        Directory[MAX_PATH];
	int counter;
        int countNgram;
	int  i;
	string tmp;

	fstream fileOpen;

	// copying path to directory
	sprintf(Directory,"%s\\*.*", &dir[0]);
      if((hFindFile = FindFirstFileA(Directory, &Win32FindData)) == INVALID_HANDLE_VALUE){ // if   directory not found (finding first file of directory)
		return ; // error, directory not found
	}

do{
if(strcmp(Win32FindData.cFileName, ".") != 0 && strcmp(Win32FindData.cFileName, "..") != 0){
sprintf(Directory, "%s\\%s", &dir[0], Win32FindData.cFileName);


        // if found a file
        if(! (Win32FindData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ) {
	// is a file
	fileOpen.open(Directory, ios::in | ios::binary | ios::ate);

	//size of file
	int end = fileOpen.tellg();
	fileOpen.seekg (0, ios::beg);
	int begin = fileOpen.tellg();
	int size = end - begin;
	char data[MAX_BUFFER_SIZE];

	fileOpen.read(&data[0], size);
	fileOpen.close();

	counter = 0;
	// reading data with N bytes, construct 3 grams and insert to hashT
    while(  (counter !=  ((size - N) + 1) ) ) {
	for( i=0; i!=N; ++i) 
		tmp += data[i+counter];

		// insert to hashT
		if (HashTperAll.GetMember(tmp))
		   countNgram = *(HashTperAll.GetMember(tmp)) + 1;
		else
		    countNgram = 1;
		
                HashTperAll.AddKey(tmp, &countNgram );
		tmp = "";
		counter++;
		}
			
	}
	else {
		// is a directory
		makeVocabHash(Directory, HashTperAll, N);
	}
		}
} while(FindNextFileA(hFindFile,&Win32FindData));//finding next file in directory

	// closing handles
	FindClose(hFindFile);
}
//---------------------------------------------------------------------
void main()
{
   CLongHashT HashTDocs;

   cout<< "enter a path";
   string dir;
   cin>> dir;
   makeVocabHash(dir,HashTDocs, 3);

}

The problem may be located here:

char data[MAX_BUFFER_SIZE];

fileOpen.read(&data[0], size);

This results in a buffer overflow when your file size is greater than

MAX_BUFFER_SIZE<br />

.
To avoid this, allocate the buffer on the heap using new or malloc:

char data = new char[size];
fileOpen.read(&data[0], size);
// Do something with data here
delete data;