This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
The purpose of testing with the crippled hash function is to cover
the otherwise very unlikely codepath in bucket_calculate_dib() where
it has to fall back to recomputing the hash value.
This unlikely path was not covered by test-hashmap anymore after
57217c8f "test: hashmap - cripple the hash function by truncating the
input rather than the output".
Restore the test coverage by increasing the number of entries in the test.
The number was determined empirically by checking with lcov.
All our hash functions are based on siphash24(), factor out
siphash_init() and siphash24_finalize() and pass the siphash
state to the hash functions rather than the hash key.
This simplifies the hash functions, and in particular makes
composition simpler as calling siphash24_compress() repeatedly
on separate chunks of input has the same effect as first
concatenating the input and then calling siphash23_compress()
on the result.
The reason for the crippled hash function is to reduce the distribution
of the hash function, do this by truncating the domain rather than the
range. This does introduce a change in behavoir as the range is no longer
contiguous, which greatly reduces collisions.
This is needed as a follow-up patch will no longer allow individual hash
functions to alter the output directly.
Currently, the HASHMAP iterators stop at the first NULL entry in a
hashmap. This is non-obvious and breaks users like sd-device, which
legitimately store NULL values in a hashmap.
Fix all the iterators by taking a pointer to the value storage, instead of
returning it. The iterators now return a boolean that tells whether the
end of the list was reached.
Current users of HASHMAP_FOREACH() are *NOT* changed to explicitly check
for NULL. If it turns out, there were users that inserted NULL into
hashmaps, but didn't properly check for it during iteration, then we
really want to find those and fix them.
It cannot fail in the current hashmap implementation, but it may fail in
alternative implementations (unless a sufficiently large reservation has
been placed beforehand).
Test more corner cases and error states in several tests.
Add new tests for:
hashmap_move
hashmap_remove
hashmap_remove2
hashmap_remove_value
hashmap_remove_and_replace
hashmap_get2
hashmap_first
In test_hashmap_many additionally test with an intentionally bad hash
function.
test-hashmap-ordered.c is generated from test-hashmap-plain.c simply by
substituting "ordered_hashmap" for "hashmap" etc.
In the cases where tests rely on the order of entries, a distinction
between plain and ordered hashmaps is made using the ORDERED macro,
which is defined only for test-hashmap-ordered.c.
