To home page

Source code. Composite files

 Home page

Nowadays it is very funny to look at a program made up of thousands of files scattered over different directories, even logos and icons, what is clearly unprofessional because

  • it is untidy
  • easy access to all files (it is easy to change a logo, e.g.)
  • speed (it is much faster to open a single file than many files)
  • loss of one of thousands files is more probable
    •  If you have many files of different types, you may wish to gather them in a single file and get programmatic access to each of them.
    This source contains two main classes and some accompanying functions. The classes are
  • CFile - analog of MFC CFile
  • CCompFile - very useful thing, a composite file.
    •  The compfils.exe (a supplied utility) gathers many files into a single composite file. You run it specifying a file mask (wildcard) to select files :

    >COMPFILS file_header file_mask output_file

    where

    - file_header is a string (the first bytes in the new file) with no spaces used to identify if this is a right file when loaded
    - file_mask is a file mask to place into the new composite file, this routine is very old, so please use only 8.3 DOS filenames.
    IMPORTANT : it is recommended to name files to be collected like 0000.ext, 0001.ext ... because files before collection will be sorted by names and the entry number in the composite file will be equal to its place in the sorted order. No internal checks are performed. Just sorted and placed inside the file one by one.
    - output_file is a filename for the new composite file (also 8.3).

    For example, if in the current directory you have five files

    000.BMP
    001.BMP
    002.BMP
    003.BMP
    004.BMP

    >compfils MY_BITMAPS *.bmp pbitmaps.cmp

    will generate a new composite file pbitmaps.cmp with header "MY_BITMAPS" with 5 entries, entry 0 - for file 000.BMP, entry 1 - for file 001.BMP etc.

    But, if, for example, you have files named as

    000.BMP
    001.BMP
    003.BMP
    004.BMP
    005.BMP

    entry 0 will correspond to 000.BMP, 1 - to 001.BMP, 2 - to 002.BMP, 3 - to 004.BMP, and 4 - to 005.BMP.

    Now we have the composite file.

    Get access to its components using a class CCompFile derived from CFile. You seek file position by SetEntryPos(int index) and load data for this entry (see cadlectures.dsw VC++ project for working samples).

    © Copyright 2007..2009 MI Simulators