If i have a dat file some roms with only crc32, some with md5 and some with sha1, does clrmame choose which to hash if you select all three? or does it always do all 3?

Is the speed even worth considering contemplating a "smart hash"? ie. sha1 then md5 then crc32?

EgotisticalElf

> If i have a dat file some roms with only crc32, some with md5 and some with
> sha1, does clrmame choose which to hash if you select all three? or does it
> always do all 3?
>
> Is the speed even worth considering contemplating a "smart hash"? ie. sha1 then
> md5 then crc32?
>
> EgotisticalElf
>


CRC32 is a must, SHA1/MD5 are optional parameters. You can enable or disable any used hashalgorithm in scanner->checksums. Of course a sha1/md5 check means you have to unzip packed files to memory to calculate the checksums. This is of course time-intensive.
Normally you don't have to enable sha1/md5 if you used the rebuilder or fixmissing to add new files. Both routines got a sha1/md5 check enabled, so only valid files can be added.



Roman Scherzer

I was referring to if you had both MD5 & SHA1 selected if clrmame processed both hashes.

I'm assuming it does.

EgotisticalElf

> > If i have a dat file some roms with only crc32, some with md5 and some with
> > sha1, does clrmame choose which to hash if you select all three? or does it
> > always do all 3?
> >
> > Is the speed even worth considering contemplating a "smart hash"? ie. sha1
> then
> > md5 then crc32?
> >
> > EgotisticalElf
> >
>
>
> CRC32 is a must, SHA1/MD5 are optional parameters. You can enable or disable any
> used hashalgorithm in scanner->checksums. Of course a sha1/md5 check means you
> have to unzip packed files to memory to calculate the checksums. This is of
> course time-intensive.
> Normally you don't have to enable sha1/md5 if you used the rebuilder or
> fixmissing to add new files. Both routines got a sha1/md5 check enabled, so only
> valid files can be added.
>
>
>
> Roman Scherzer
>

if you enabled the check option sha1, md5, crc32, it will check the hash if it is available in the datfile.
If one file got only a crc32 listed it will only check the crc32, if another file got crc32 and sha1 entries, it will check both.


Roman Scherzer