port downloads file when livecheck.check = moddate

[Paul Guyot]

On Jul 16, 2007, at 3:26 AM, Ryan Schmidt wrote:

> For ImageMagick I had this livecheck defined:
>
> livecheck.check     moddate
> livecheck.url       ftp://ftp.imagemagick.net/pub/${name}/$ 
> {name}.tar.bz2
>
> When the portfile was up to date, "sudo port livecheck ImageMagick"  
> returned quickly. However, when a new version of ImageMagick was  
> available, that command took awhile, and I could see from my  
> network traffic meter that it seemed to be downloading the entire  
> archive before telling me the port was outdated.
>
> Why is MacPorts downloading the file I specified, when I only  
> wanted it to check its modification date -- a check which MacPorts  
> is obviously already doing correctly, else if would be downloading  
> the archive every time I check. But it's not; it's only downloading  
> it when its modification date has in fact changed.

This livecheck is based on Pextlib "curl isnewer" command, which  
fetches a file with libcurl by saying please do not fetch it if what  
you have is older than this date, which is something that only exists  
with HTTP If-Modified-Since header and there is no FTP equivalent. At  
least nothing is saved on disk there because the target file is /dev/ 
null. Using additional libcurl APIs, we might be able to improve this  
and avoid an FTP fetch (or even a full HTTP fetch when the resource  
is newer).

Paul
-- 
http://paul-guyot.com/