debugedit: switch to xxhash for buildid recomputation
When debugedit recomputes build-id (due to -i), it previously used md5
or sha1 (depending on length of incoming buildid). This patch
replaces both those (including the code that does all the hashing)
with a 128-bit xxhash. The 128-bit hash is truncated or padded to
whatever the incoming ELF note width was.
xxhash is much faster (8x over sha1) than either of those
crypto-flavoured hashes, and still produces fairly collision-free
values. This was confirmed informally with a bulk build-id
recomputation of a few million binaries in the debuginfod server
corpus, yielding zero unexpected collisions.
git://sourceware.org / debugedit.git / commit