apt/apt-pkg/deb/deblistparser.cc, branch 1.4.6

Do not package names representing .dsc/.deb/... files

2017-02-10T22:12:52Z

In the case of build-dep and other commands where a file can be passed we must make sure not to normalize the path name as that can have odd side effects, or well, cause the operation to do nothing. Test for build-dep-file is adjusted to perform the vcard check once as "vcard" and once as "VCard", thus testing that this solves the reported bug. We inline the std::transform() and optimize it a bit to not write anything in the common case (package names are defined to be lowercase, the whole transformation is just for names that should not exist...) to counter the performance hit of the added find() call (it's about 0.15% more instructions than with the existing transform, but we save about 0.67% in writes...). Closes: #854794

ParseDepends: Support passing the desired architecture

2017-01-02T13:27:52Z

This is useful for e.g. Britney, where the Build-Depends would have to be parsed for multiple architectures. With this change, the call can choose the architecture without having to mess with the config. Signed-off-by: Niels Thykier Closes: #845969 (jak@d.o: made the code compile)

Do not use MD5SumValue for Description_md5()

2016-11-22T21:58:33Z

Our profile says we spend about 5% of the time transforming the hex digits into the binary format used by HashsumValue, all for comparing them against the other strings. That makes no sense at all. According to callgrind, this reduces the overall instruction count from 5,3 billion to 5 billion in my example, which roughly matches the 5%.

debListParser: Micro-optimize AvailableDescriptionLanguages()

2016-11-22T21:58:19Z

Generating a string for each version we see is somewhat inefficient. The problem here is that the Description tag names are longer than 15 byte, and thus require an allocation on the heap, which we should avoid. It seems reasonable that 20 characters works for all languages codes used for archive descriptions, but if not, there's a warning, so we'll catch that. This should improve performance by about 2%.

Optimize VersionHash() to not need temporary copy of input

2016-11-22T21:58:18Z

Stop copying stuff, and just parse the bytes one by-one to the newly created AddCRC16Byte. This improves the instruction count for an update run from 720,850,121 to 455,801,749 according to callgrind.

Introduce tolower_ascii_unsafe() and use it for hashing

2016-11-22T21:58:18Z

This one has some obvious collisions for non-alphabetical characters, like some control characters also hashing to numbers, but we don't really have those, and these are hash functions which are not collision free to begin with.

debListParser: Convert to use pkgTagSection::Key-based lookup

2016-11-22T21:57:46Z

This basically gets rid of 40-50% of the hash table lookups, making things a bit faster that way, and the profiles look far cleaner.

add hidden config to set packages as Essential/Important

2016-11-11T22:40:39Z

You can pretty much achieve the same with a local dummy package if you want to, but libapt has an inbuilt setting for essential: "apt" which can be overridden with this option as well – it could be helpful in quick tests and what not so adding this alternative shouldn't really hurt much. We aren't going to document them much through as care must be taken in regards to the binary caches as they aren't invalidated by config options alone, so the effects of old settings could still be in them, similar to the other already existing pkgCacheGen option(s). Closes: 767891 Thanks: Anthony Towns for initial patch

VersionHash: Do not skip too long dependency lines

2016-09-18T12:17:17Z

If the dependency line does not contain spaces in the repository but does in the dpkg status file (because dpkg normalized the dependency list), the dpkg line might be longer than the line in the repository. If it now happens to be longer than 1024 characters, it would be skipped, causing the hashes to be out of date. Note that we have to bump the minor cache version again as this changes the format slightly, and we might get mismatches with an older src cache otherwise. Fixes Debian/apt#23

reinstalling local deb file is no downgrade

2016-07-01T11:36:40Z

If we have a (e.g. locally built) deb file installed and do try to install it again apt complained about this being a downgrade, but it wasn't as it is the very same version… it was just confused into not merging the versions together which looks like a downgrade then. The same size assumption is usually good, but given that volatile files are parsed last (even after the status file) the base assumption no longer holds, but is easy to adept without actually changing anything in practice.