Re: CVS and Binaries

[Sau Dan Lee]

>>>>> "Nils9" == Nils9  <address@hidden> writes:

    Nils9> Ok its clear, that CVS is not for merging binaries.. But
    Nils9> can I, theoretically, make my own wrapper which converts
    Nils9> the binary into some sort of mergeable text (uuencode for
    Nils9> example) which encodes binary before it gets into
    Nils9> repository, and reverts ir back when file is checked out?
    Nils9> I know it will take up more space, but less than keeping
    Nils9> exact copy of each binary version. Sometimes we need to
    Nils9> keep binaries in CVS.  I'm not into details how the CVS
    Nils9> internals work, but I'd like to.

The problem is: even change that are apparently minor, would result in
significant changes in the binary  (look at Word files!).  Even if you
convert these  binaries to  text using uuencode  (or base64,  which is
more compact), the changes are  still significant.  So, the diffs will
be very very large.

Try to encode  two text files which have  minor difference into base64
or uuencode,  and then  diff the result.   Are the diff  results still
minor?



For your  case, I think  you'll be better  of saving the  binary files
with names  containing version numbers (manually  assigned).  There is
no space lost with this method  (since there is no generic way to diff
two binary files to produce  a minimal diff result).  Moreover, one of
the most useful  function of CVS is to  diff arbitrary versions.  With
binary files, you don't have  this useful feature anyway.  If you want
be able to check out files by dates, then perhaps you could do this:

        1) Start a new file and save it as file-1.0.bin.
        2) cvs add file-1.0.bin
           cvs commit file-1.0.bin
        3) Work on this file and save it as file-1.1.bin
           cvs remove -f file-1.0.bin
           cvs add file-1.1.bin
           cvs commit file-1.1.bin
        and so on.

You can now check out by date.  Tags would also work.  But no diff, no
automatic version  numbering, no easy  way (a single command)  to read
all revision logs of the same file...




Anyway,  use the  right  tool to  do  the right  job!   CVS isn't  for
handling binary  files.  That's not  the right tool for  controlling a
large collection of large binary files.



-- 
Lee Sau Dan                     李守敦(Big5)                    address@hidden(HZ) 
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