Bug#566275: srcpkgcache.bin maintained even though no deb-src lines in sources.list

[David Kalnischkies <kalnischkies+debian@gmail.com>]

package apt
retitle 566275 difference between src- and pkgcache.bin isn't documented
thanks

2010/1/22  <jidanni@jidanni.org>:
> deb-src lines in sources.list files. However this is a wasteful
> assumption... possibly doubling startup times!
Nope. It even lower the startup time, because:

> Or maybe srcpkgcache.bin has a totally different meaning.
It has. srcpkgcache.bin includes the information containing in the files
in /var/lib/apt/lists - aka all informations you get from the internet
by deb and deb-src lines -- these information are changed only on
apt-get update.

pkgcache.bin on the other hand caches the information in srcpkgcache.bin +
the informations extracted from the apt and dpkg status files. These change
on every install/remove done by apt or directly by dpkg.

So if only the status files are changed apt doesn't need to reparse the
other informations again - and if no file was changed in between yet and
the last call apt can directly load the pkgcache.bin file into memory.

> If so, this man page should say what it is.
> Say what the two files track anyway here in any case.
I am unsure if this should really be done. The manpages are already verbose
(if not too verbose) on various topics and these options are rather lowlevel
and not really commonly used, nor that i would expect that it would be widely
used if it would be described to full extend. Such descriptions are in my eyes
better suited for a manual, guide or other extra material...


Best regards / Mit freundlichen Grüßen,

David "DonKult" Kalnischkies