Hashing and Checksums

hash(seed:) computes a fast 64-bit UInt64 hash of the content, with an optional seed.

let h = "the quick brown fox".hash()
let seeded = "the quick brown fox".hash(seed: 42)
assert(h != seeded)  // a different seed yields a different hash

For data arriving in chunks, StringZillaHasher hashes incrementally. update(_:) is chainable, finalize() and its alias digest() return the UInt64 without consuming the state, and reset(seed:) restarts it.

let hasher = StringZillaHasher(seed: 0)
hasher.update("the quick ").update("brown fox")
let digest = hasher.finalize()
assert(digest == "the quick brown fox".hash())

sha256() returns the SHA-256 digest of the content as a 32-byte [UInt8].

let sum = "hello".sha256()  // [UInt8] of length 32
assert(sum.count == 32)

The streaming StringZillaSha256 mirrors the incremental hasher. update(_:) accepts either a string view or a [UInt8], finalize() and its alias digest() return the 32-byte digest, hexdigest() returns the 64-character lowercase hex string, and reset() restarts it.

let sha = StringZillaSha256()
sha.update("hello, ").update("world")
let hex = sha.hexdigest()  // 64-char hex string
assert(hex.count == 64)