loopfile.c

循环日志读写,用于嵌入式系统记载日志文件

/*************************************************************************************************
 * 文件名称:LoopFile.c
 * 功能:循环文件访问
 *      底层函数需要PackageFileSystem.c
 * 日期:2007-11-30
 *
 *
 *
 *
 *************************************************************************************************
 */
#include <stdio.h>
#include "LoopFile.h"


/*=================================================================================================
 * 函数名称：InitLoopFile()
 * 输入参数：int number 循环文件最高容纳记录数
 * 输出参数：void
 *
 *
 *=================================================================================================
 */
void InitLoopFile(int number,char *path)
{
 FILE  *lf_fd;
struct LF_ctrl lfc;
 
       
       memset(&lfc, 0x00, sizeof(struct LF_ctrl));
       lfc.sum = number;
       
       if (( lf_fd = Fopen(path,"w")) == NULL ){
#if DEBUG_ALL || DEBUG_MIX
          DEBUG_printf("OpenOSFile() failed\r\n");
#endif
          Fclose(lf_fd);
          return;
	   }
       /*=======写入循环文件头结构=====================================*/
       if ( !Fwrite((void *)&lfc, sizeof(struct LF_ctrl), 1, lf_fd)) {
#if DEBUG_ALL || DEBUG_MIX
            DEBUG_printf("WriteOSFile() failed \r\n");
#endif
            return;
		}
            
        Fclose(lf_fd);
#if DEBUG_ALL || DEBUG_MIX
      DEBUG_printf("InitLoopFile OK!\r\n");
#endif 
       return;	
} 
    

/*===================================================================================
 * 函数名称：AppendLoopFile()
 * 输入描述: 
             unsigned char    *ptr      //数据，
             int              len       //数据长度，
             char             * path    //文件路径
 * 输出描述：>= 0 成功; < 0 失败
 *
 *
 *====================================================================================
 */
int AppendLoopFile(
                   unsigned char  *ptr, int len,
                   char     *path)
{
 FILE  *lf_fd;
 struct LF_ctrl lfc;
 int ilfc;
 
       ilfc = sizeof(struct LF_ctrl);

       if (( lf_fd = Fopen(path, "r")) == NULL ) 
       	   return(-1);
       
       if ( Fread((unsigned char *)&lfc,ilfc , 1 , lf_fd) != ilfc ) {
#if DEBUG_ALL || DEBUG_MIX
          DEBUG_printf("AppendLoopFile: ReadOSFile() failed \r\n");
#endif
          Fclose(lf_fd);
          return(-1);
		}
       
       Fclose(lf_fd);
#if DEBUG_ALL || DEBUG_MIX
             DEBUG_printf("APPENDLOOPFILE startpos = [%d] ",lfc.startpos);
             DEBUG_printf(" endpos = [%d] ",lfc.endpos);
             DEBUG_printf(" total = [%d] ",lfc.total);
             DEBUG_printf(" sum = [%d] ",lfc.sum);
             DEBUG_printf(" synflag = [%d] ",lfc.synflag);
             DEBUG_printf(" nouse1 = [%d] ",lfc.nouse1);
             DEBUG_printf(" nouse2 = [%d] \r\n",lfc.nouse2);
             
#endif
       
       
       if (( lf_fd = Fopen(path, "ab+")) == NULL )
          return(-1);
          
       if ( lfc.total < lfc.sum ) {
       	    if ( !Fwrite(ptr, len, 1 , lf_fd) ) {
                Fclose(lf_fd);
       	        return(-1);
             }
            if (lfc.endpos == 0 ) lfc.endpos = 1;
       	    lfc.startpos++;
       	    lfc.total++;
       }
       else {
#if DEBUG_ALL || DEBUG_MIX
       //DEBUG_printf("1111111111111111111\r\n");
#endif

       	    if ( Fseek(lf_fd,i (sizeof(struct LF_ctrl) + len * (lfc.endpos - 1)), SEEK_SET) < 0 ) {
                 Fclose(lf_fd);
       	         return(-1);
            }
#if DEBUG_ALL || DEBUG_MIX
       //DEBUG_printf("22222221111111\r\n");
#endif

       	    if ( !Fwrite(ptr, len, 1 ,lf_fd) ) {
                Fclose(lf_fd);
       	        return(-1);
            }
#if DEBUG_ALL || DEBUG_MIX
       //DEBUG_printf("3333333333331111\r\n");
#endif

       	    
       	    lfc.startpos = (++lfc.startpos > lfc.sum)?(lfc.startpos - lfc.sum):lfc.startpos;
       	    lfc.endpos   = (++lfc.endpos > lfc.sum)? (lfc.endpos - lfc.sum) : lfc.endpos;
       	    	
       }   /* end if */
      // lfc->synflag = 1;
       if ( Fseek(lf_fd,0,SEEK_SET) < 0 ) {
            Fclose(lf_fd);
       	    return(-1);
       }
#if DEBUG_ALL || DEBUG_MIX
       //DEBUG_printf("444444444444444441\r\n");
#endif

       if ( !Fwrite((unsigned char *)&lfc,ilfc, 1 , lf_fd) ) {
            Fclose(lf_fd);
            return(-1);
       }
#if DEBUG_ALL || DEBUG_MIX
       DEBUG_printf("AppendLoopFile: lfc.endpos = %d\r\n",lfc.endpos);
#endif
       Fclose(lf_fd);
	   return(lfc.startpos);
}   /* end function */
 
 
/***************************************************************************************
 * 模块名称:ReadLoopFile()
 * 输入参数: char *ptr
             int   len
             int   offset //记录号,从1~
             char *path
 * 输出参数:读到的字节数
            <=0 读失败
 *
 ***************************************************************************************
*/
int ReadLoopFile(char *ptr,int len,int offset,
                 char *path)
{
FILE *fd;
struct LF_ctrl lfc;
int  ilfc,curpos;
int  ans;

  if ( mainfilename == NULL )
       return(-1);
  if ( offset < 1 ) return(-1);

  if (( fd = Fopen(path, "r")) == NULL ) 

       return(-1);

  ilfc = sizeof(struct LF_ctrl);     
  if ( Fread((unsigned char *)&lfc,ilfc, 1 , fd) != ilfc ) {
       Fclose(fd);
       return(-1);
   }
#if DEBUG_ALL || DEBUG_MIX
             DEBUG_printf("startpos = [%d] \r\n",lfc.startpos);
             DEBUG_printf("endpos = [%d] \r\n",lfc.endpos);
             DEBUG_printf("total = [%d] \r\n",lfc.total);
             DEBUG_printf("sum = [%d] \r\n",lfc.sum);
             DEBUG_printf("synflag = [%d] \r\n",lfc.synflag);
             DEBUG_printf("nouse1 = [%d] \r\n",lfc.nouse1);
             DEBUG_printf("nouse2 = [%d] \r\n",lfc.nouse2);
             
#endif
  
  if ( offset > lfc.total ) return(-1);

                       //计算记录位置
/*
  if ( lfc.endpos > offset )
       curpos = lfc.endpos - offset;
  else
       curpos = lfc.sum - (offset - lfc.endpos + 1);
*/
  curpos = lfc.startpos - (offset -1);
  if (curpos < 1 ) curpos = lfc.sum + curpos;

  if ( Fseek(fd,(curpos -1)*len,SEEK_CUR) < 0 )
      return(-1);
  ans = Fread( ptr, len, 1, fd);
  
  Fclose(fd);
  return(ans);
}


/***********************************************************************************************
 * 模块名称:UpdateLoopFile()
 * 输入参数:char *ptr
            int   len
			int   offset  //记录号
			char  *path
 * 输出描述: 修改的字节数
             <= 0 失败
 *
 ************************************************************************************************
*/

int UpdateLoopFile(char *ptr, int len, int offset,
                   char *path)
{
FILE *fd;
struct LF_ctrl lfc;
int  ilfc,curpos;
int  ans;

  if ( mainfilename == NULL )
       return(-1);
  if (( fd = Fopen(path, "r")) == NULL ) 
       return(-1);

  ilfc = sizeof(struct LF_ctrl);     
  if ( Fread((unsigned char *)&lfc,ilfc,1,fd) != ilfc ) {
       Fclose(fd);
       return(-1);
  }
  Fclose(fd);

  offset = offset % lfc.total;

                       //计算记录位置
  if ( lfc.endpos > offset )
       curpos = lfc.endpos - offset;
  else
       curpos = lfc.sum - (offset - lfc.endpos + 1);

  if (( fd = Fwrite(path, "ab+")) == NULL ) {
       Fclose(fd);
       return(-1);
  }
  if ( Fseek(fd,((curpos -1)*len + sizeof(struct LF_ctrl)),SEEK_SET) < 0 ) {
      Fclose(fd);
      return(-1);
  }
  ans = Fwrite( ptr, len , 1 ,fd);
  
  Fclose(fd);
  return(ans);
}