如何以比此代码更快的速度读取文件，通过更改可以使用类似的缓冲区技术或其他比此更快的速度.

问题描述

FILE* fp;
fp = fopen(strFilePath, "r");
char s1[651];
int iCount = 0;
bool stx_found = false;
while(!feof(fp))
{
  CASSImportRow structCASSImport;
  if(fgets(s1, 651, fp) != NULL)
  {
    if(s1[0] == ''\n'')
      continue;
    CString tempRecord = s1;

    if (address_seq_perfix.Compare("STX") != 0)
    {
      continue;
    }
    stx_found = true;
    structCASSImport.strRegNo   = CORBA::string_dup(tempRecord.Mid(3  , 12)); 
    structCASSImport.strADDR  = CORBA::string_dup((tempRecord.Mid(92 , 35)).TrimRight());
    structCASSImport.strCity    = CORBA::string_dup((tempRecord.Mid(127, 20)).TrimRight());
    structCASSImport.strCountry    = CORBA::string_dup((tempRecord.Mid(161, 20)).TrimRight());
    structCASSImport.strState = CORBA::string_dup((tempRecord.Mid(445, 2 )).TrimRight());
    structCASSImport.strReturnedZIP    = CORBA::string_dup(tempRecord.Mid(447, 5 ));
    structCASSImport.strReturnedZIPExt = CORBA::string_dup(tempRecord.Mid(452, 4 ));
    structCASSImport.strReturnedDPC    = CORBA::string_dup(tempRecord.Mid(456, 2 ));
    structCASSImport.strRCHK       = CORBA::string_dup(tempRecord.Mid(458, 1 ));
    iCount++;
    (*ptrCASSImportIn).length(iCount);
    (*ptrCASSImportIn)[iCount-1] = structCASSImport;
  }
}

fclose(fp);

推荐答案

FILE* fp = fopen(strFilePath, "r");
char *buffer = malloc(1048576); // Allocate a 1Mb buffer
int read = fread(buffer,1,1048576,fp);

然后扫描内存缓冲区中的换行符以逐行处理它.

and then scan the memory buffer for newline characters to process it line by line.

char sl[651];
int  slcounter = 0;
for(int i=0;i<read;i++){
    if(buffer[i] != ''\n''){
        sl[slcounter] = buffer[i];
        slcounter++;
    }
    else{
        sl[slcounter] = 0;
        slcounter = 0; // reset the character counter for the next string
        // do your regular processing of sl here
    }
}

如果您的文件大于1Mb，请调整缓冲区大小或进行更多次读取，直到到达文件末尾.

If your file is bigger than 1Mb, adjust the buffer size or do more freads until the end of file is reached.

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