That's wonderful. For non-cryptographic uses, this could speed-up a lot of things, e.g. even git, replacing the SHA1 with a e.g. a 128 bit hash made from a xxHa

That's wonderful. For non-cryptographic uses, this could speed-up a lot of things, e.g. even git, replacing the SHA1 with a e.g. a 128 bit hash made from a xxHash64(file_content)) plus the size of the file (64 + 64 bit). In fact, replacing SHA1 with xxHash64 + file size, and replacing zlib with LZ4, could allow git reduce "repack" times to the minimum. BTW, both xxHash and LZ4 are developments from Yann Collet, a very talented programmer (also author of Zstandard -most of the "magic" of both LZ4 an Zstandard comes from the hash function, which is a huge breakthrough-).