Hello, Jonathan!
> Is a one-way hash such as MD5 really superior to a CRC here? I believe that
> CRC's are substantially cheaper to compute, which could be relevant in the
> case of large projects. The nonrepudiability and resistance to forgery that
> recommend one-way hashes for cryptographic protocols seem kind of
> irrelevant here.
I agree that MD5 is an overkill here, and a simple CRC should be Ok.
However, timestamps are already used by "make".
Although it's often not the right thing to do, makefiles may contain rules
involving "touch". Files are touched so that the dependent files are
rebuilt. There is no intention to confuse CVS. The intention is only to
affect the behaviour of make.
Linux kernel uses this technique. Also automake-generated makefiles may
want to rebuild files under the source control. Again, this is not
perfect, but even CVS itself has "configure" under the source control.
If a file is rebuilt and is equal to the original version except the
timestamp, why send it to the server for comparison? Slow connections do
exist. Big files exist too.
Regards,
Pavel Roskin
