diff options
Diffstat (limited to 'lib/concepts/Hash.ml')
| -rw-r--r-- | lib/concepts/Hash.ml | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/lib/concepts/Hash.ml b/lib/concepts/Hash.ml index f467ee7..aac7428 100644 --- a/lib/concepts/Hash.ml +++ b/lib/concepts/Hash.ml @@ -2,8 +2,31 @@ type hash = Digestif.SHA256.t +let size = 256/8 + +let compare h1 h2 = Digestif.SHA256.unsafe_compare h1 h2 + |> Ordering.of_int + let hash_of_value (v : Value.value) = Representation.(blob_of_value v |> bytes_of_blob) |> Digestif.SHA256.digest_bytes +let hash_of_bytes bytes = Digestif.SHA256.digest_bytes bytes + +let hash_of_blob blob = Representation.bytes_of_blob blob |> Digestif.SHA256.digest_bytes + +let to_raw_string hash = Digestif.SHA256.to_raw_string hash + +let of_raw_string str = Digestif.SHA256.of_raw_string str + let hash_equals = Digestif.SHA256.equal let bytes_of_hash (h : hash) = Bytes.of_string (Digestif.SHA256.to_raw_string h) + +let power_of_two p = + let b = Bytes.make 32 '\x00' in + let byte = 31 - (p / 8) in + Bytes.set b byte (Char.chr (1 lsl (p mod 8))); + Bytes.unsafe_to_string b + +let pick n hash = + let threshold = Digestif.SHA256.of_raw_string (power_of_two (256 - n)) in + compare hash threshold = Ordering.Smaller |