fdi_file.c

FDI Intel开发的FLASH文件系统,功能很强大

 *###  stream            file stream identifier
 *###
 *### OUTPUTS:
 *###
 *### RETURNS:
 *###  Returns EOF if an error is detected; otherwise, it returns zero.
 *###*/
int
FDI_fclose(FILE_ID stream)
{
   COMMAND_CONTROL cmd_cntrl;          /* command control structure for APIS */
   ERR_CODE        status = ERR_NONE;  /* define ERROR_CODE variable */
   STREAM_INFO     *stream_info_ptr;   /* pointer to table entry */

   /* make sure file init function has been called */
   if (FileInitComplete == FALSE)
   {
      FDI_errno = ERR_INIT;
      return EOF;
   }

   /* make sure stream is valid */
   if ((stream == 0) || (stream > NUM_OPEN_FILES))
   {
      FDI_errno = ERR_PARAM;

      return EOF;
   }

   /* lock the File Manager API semaphore */
   SEM_MTX_WAIT(FileAPIMutexSemaphore);

   /* make sure stream is open */
   if (StreamInfoTable[stream].mode_flag == MODE_INVALID)
   {
      FDI_errno = ERR_NOTOPEN;

      /* unlock the File Manager API semaphore */
      SEM_MTX_POST(FileAPIMutexSemaphore);

      return EOF;
   }

   /* initialize STREAM_INFO pointer to reduce array math */
   stream_info_ptr = &(StreamInfoTable[stream]);

   cmd_cntrl.type = FILE_SUPPORT_DATA_TYPE;
   cmd_cntrl.priority = FDI_MIN_PRIORITY;

   /* check if file data stream is valid */
   if (stream_info_ptr->open_file_info.data_id != FILE_INVALID)
   {
      /* prepare to call FDI_Close for the open file data stream */
      cmd_cntrl.identifier = stream_info_ptr->open_file_info.data_id;

      /* call FDI_Close to close the actual file data stream */
      status = FDI_Close(&cmd_cntrl);

      /* ignore return value incase file was never opened */
   }

   /* if the file size is zero, remove the file, no action was taken */
   if (stream_info_ptr->open_file_info.size == 0)
   {
      status = FileDelete(stream_info_ptr->file_info_id,
                          stream_info_ptr->open_file_info.data_id, FALSE);
   }
   /* clear STREAM_INFO of all the file's information */
   INIT_STREAM_INFO(stream_info_ptr);

   if (status != ERR_NONE)
   {
      FDI_errno = status;              /* log error for use by ferror */

      /* unlock the File Manager API semaphore */
      SEM_MTX_POST(FileAPIMutexSemaphore);

      return EOF;
   }
   else
   {
      /* unlock the File Manager API semaphore */
      SEM_MTX_POST(FileAPIMutexSemaphore);

      return FILE_NOERR;
   }
}                                      /* ENDOF FDI_fclose */


/*############################################################################
 *### FDI_fseek
 *###
 *### DESCRIPTION:
 *###    The function FDI_fseek allows random access within a file.  The first
 *###    argument must be an open stream.  The second two arguments specify a
 *###    file position.  The stream is positioned as requested and fseek
 *###    returns zero if successful.
 *###
 *### USAGE:
 *###    status = FDI_fseek(stream, offset, SEEK_SET);
 *###
 *### PARAMETERS:
 *###
 *### INPUTS:
 *###  stream            file stream identifier
 *###  offset            a signed integer specifying a number of characters
 *###  wherefrom         a "seek code" indicating from what point in the file
 *###                    offset should be measured; modes supported:
 *###                    SEEK_SET = set file offset to offset
 *###                    SEEK_CUR = set file offset to current plus offset
 *###                    SEEK_END = set file offset to end plus offset (offset
 *###                               must be <= 0 since seeking beyond current
 *###                               end of file is not supported and returns
 *###                               error)
 *### OUTPUTS:
 *###
 *### RETURNS:
 *###  Returns zero if successful or EOF if an error occurs.
 *###*/
int
FDI_fseek(FILE_ID stream, long offset, int wherefrom)
{
   COMMAND_CONTROL cmd_cntrl;          /* command control structure for APIS */
   ERR_CODE        status;             /* define ERROR_CODE variable */
   BYTE            data_byte;          /* used by FDI_Read call */
   STREAM_INFO     *stream_info_ptr;   /* pointer to table entry */

   /* make sure file init function has been called */
   if (FileInitComplete == FALSE)
   {
      FDI_errno = ERR_INIT;
      return EOF;
   }

   /* make sure stream is valid */
   if ((stream == 0) || (stream > NUM_OPEN_FILES))
   {
      FDI_errno = ERR_PARAM;

      return EOF;
   }

   /* lock the File Manager API semaphore */
   SEM_MTX_WAIT(FileAPIMutexSemaphore);

   /* make sure stream is open */
   if (StreamInfoTable[stream].mode_flag == MODE_INVALID)
   {
      FDI_errno = ERR_NOTOPEN;

      /* unlock the File Manager API semaphore */
      SEM_MTX_POST(FileAPIMutexSemaphore);

      return EOF;
   }

   /* initialize STREAM_INFO pointer to reduce array math */
   stream_info_ptr = &(StreamInfoTable[stream]);

   /* test if wherefrom is SEEK_SET */
   if (wherefrom == SEEK_SET)
   {
      /*
       * test parameter offset is less than file stream field file info
       * field size, and greater than -1.
       */
      if ((offset <= (long)stream_info_ptr->open_file_info.size) &&
          (offset >= 0))
      {
         /* assign command control field offset to parameter offset */
         cmd_cntrl.offset = (DWORD)offset;
      }
      /* input parameter error */
      else
      {
         FDI_errno = ERR_PARAM;

         /* unlock the File Manager API semaphore */
         SEM_MTX_POST(FileAPIMutexSemaphore);

         return EOF;
      }
   }
   else if (wherefrom == SEEK_CUR) /* else if wherefrom is SEEK_CUR */
   {
      /*
       * test parameter offset plus file stream field file_pointer is less
       * than file stream field file info field size and greater than -1.
       */
      if ((((long)stream_info_ptr->file_pointer + offset) <=
           (long)stream_info_ptr->open_file_info.size) &&
          (((long)stream_info_ptr->file_pointer + offset) >= 0))
      {
         /*
          * assign command control field offset to parameter offset plus file
          * stream field file_pointer
          */
         cmd_cntrl.offset = (DWORD)((long)stream_info_ptr->file_pointer +
                                    offset);
      }
      else  /* input parameter error */
      {
         FDI_errno = ERR_PARAM;

         /* unlock the File Manager API semaphore */
         SEM_MTX_POST(FileAPIMutexSemaphore);

         return EOF;
      }
   }
   else if (wherefrom == SEEK_END) /* else if wherefrom is SEEK_END */
   {
      /*
       * test parameter offset plus file stream field file info field
       * size is less than file stream field file info field size and
       * greater than -1.
       */
      if ((((long)stream_info_ptr->open_file_info.size + offset) <=
           (long)stream_info_ptr->open_file_info.size) &&
          (((long)stream_info_ptr->open_file_info.size + offset) >= 0))
      {
         /*
          * assign command control field offset to parameter offset plus file
          * stream field file info field size
          */
         cmd_cntrl.offset = (DWORD)((long)stream_info_ptr->open_file_info.size +
                                    offset);
      }
      else  /* input parameter error */
      {
         FDI_errno = ERR_PARAM;

         /* unlock the File Manager API semaphore */
         SEM_MTX_POST(FileAPIMutexSemaphore);

         return EOF;
      }
   }
   else  /* wherefrom is not SEEK_SET, SEEK_CUR or SEEK_END return an error */
   {
      FDI_errno = ERR_PARAM;

      /* unlock the File Manager API semaphore */
      SEM_MTX_POST(FileAPIMutexSemaphore);

      return EOF;
   }

   /* prepare to use read to setup the internal FDI_OpenStream structure */
   cmd_cntrl.buffer_ptr = &data_byte;
   cmd_cntrl.count = 0;
   cmd_cntrl.identifier = stream_info_ptr->open_file_info.data_id;
   cmd_cntrl.type = FILE_SUPPORT_DATA_TYPE;
   cmd_cntrl.priority = FDI_MIN_PRIORITY;

   /* call FDI_Read to setup the current_file_offset in FDI_OpenStream */
   status = FDI_Read(&cmd_cntrl);

   if (status != ERR_NONE)
   {
      FDI_errno = status;

      /* unlock the File Manager API semaphore */
      SEM_MTX_POST(FileAPIMutexSemaphore);

      return EOF;
   }
   /* set the new location of the file pointer */
   stream_info_ptr->file_pointer = cmd_cntrl.offset;

   /* clear end-of-file indicator */
   stream_info_ptr->read_eof = FILE_NOEOF;

   /* unlock the File Manager API semaphore */
   SEM_MTX_POST(FileAPIMutexSemaphore);

   return FILE_NOERR;
}                                      /* ENDOF FDI_seek */


/*############################################################################
 *### FDI_findfirst
 *###
 *### DESCRIPTION:
 *###    The function FDI_findfirst begins a search for files specified by
 *###    wildcards.  The parameter filename_ptr is a string specifying the
 *###    file name.  Wildcard match characters (* and ?) are supported.  The
 *###    parameter fileinfo_ptr is a pointer to the type FILE_INFO which is
 *###    filled with the file information.
 *###
 *### USAGE:
 *###    status = FDI_findfirst("*.ext", &the_file_info);
 *###
 *### PARAMETERS:
 *###
 *### INPUTS:
 *###  filename_ptr      const character string for file name specifier
 *###
 *### OUTPUTS:
 *###  fileinfo_ptr      pointer to type FILE_INFO structure filled with
 *###                    located file information
 *###
 *### RETURNS:
 *###  Returns zero if successful in finding a file matching the search of
 *###  filename_ptr, otherwise it returns EOF.
 *###*/
int
FDI_findfirst(const FDI_TCHAR *filename_ptr, FILE_INFO *fileinfo_ptr)
{
   ERR_CODE        status;             /* define ERROR_CODE variable */

   /* make sure file init function has been called */
   if (FileInitComplete == FALSE)
   {
      FDI_errno = ERR_INIT;
      return EOF;
   }

   /* make sure filename_ptr is valid length
    * can't call FileNameValid since filename_ptr can contain wild cards
    */
   if ((FM_GetStringLength(filename_ptr) == 0) ||
       (FM_GetStringLength(filename_ptr) > FILE_NAME_SIZE))
   {
      FDI_errno = ERR_PARAM;
      return EOF;
   }

   /* lock the File Manager API semaphore */
   SEM_MTX_WAIT(FileAPIMutexSemaphore);

   /* initialize or clear global STREAM_INFO structure search info */
   INIT_STREAM_INFO(SearchInfoPtr);

   /* save the file name to the global search name */
   FM_CopyString(FLTSearchName, filename_ptr, (FILE_NAME_SIZE + 1));

   /* look for an existing file matching file_name from wildcard search */
   status = FileNameSearch(FLTSearchName,
                           &(SearchInfoPtr->file_info_id),
                           &(SearchInfoPtr->open_file_info));

   if (status == ERR_NONE)
   {
      /* copy file info structure to parameter fileinfo_ptr */
      MemoryMove((BYTE_PTR)fileinfo_ptr,
                 (BYTE_PTR)&(SearchInfoPtr->open_file_info),
                 sizeof(FILE_INFO));

      /* save the info structure's identifier in data_id field of FILE_INFO */
      fileinfo_ptr->data_id = SearchInfoPtr->file_info_id;

      /* unlock the File Manager API semaphore */
      SEM_MTX_POST(FileAPIMutexSemaphore);

      return FILE_NOERR;
   }  /* ENDIF FileNameSearch successful */
   else
   {
      INIT_STREAM_INFO(SearchInfoPtr);
      MemorySet((BYTE_PTR)FLTSearchName, INIT_BYTE, sizeof(FLTSearchName));
      FDI_errno = status;

      /* unlock the File Manager API semaphore */
      SEM_MTX_POST(FileAPIMutexSemaphore);

      return EOF;
   }
}                                      /* ENDOF FDI_findfirst */


/*############################################################################
 *### FDI_findnext
 *###
 *### DESCRIPTION:
 *###    The function FDI_findnext fetches su