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| author | Jeroen van Rijn <Kelimion@users.noreply.github.com> | 2021-03-25 13:48:34 +0100 |
|---|---|---|
| committer | Jeroen van Rijn <Kelimion@users.noreply.github.com> | 2021-03-25 13:48:34 +0100 |
| commit | f4d0f74dbbe0cc1dca7a5c40fea8e3f683cf5b38 (patch) | |
| tree | c0025ae5d75ce19418d49c4bf4b8bd7cfd99f750 /core/hash | |
| parent | 7a045bd95770d5c9624963dd9b8bb8a614940841 (diff) | |
Allow seeding CRC32, CRC64 & Adler32 with previous partial hash.
Foo := []u8{'F', 'o','o', '3', 'F', 'o', 'o', '4'};
crc := hash.crc32(Foo[0:4]);
crc = hash.crc32(Foo[4:], crc);
crc_all := hash.crc32(Foo);
fmt.printf("%8x %8x\n", crc, crc_all);
d6285ff7 d6285ff7
a32 := hash.adler32(Foo[0:4]);
a32 = hash.adler32(Foo[4:], a32);
a32_all := hash.adler32(Foo);
fmt.printf("%8x %8x\n", a32, a32_all);
0c5102b0 0c5102b0
Diffstat (limited to 'core/hash')
| -rw-r--r-- | core/hash/crc.odin | 8 | ||||
| -rw-r--r-- | core/hash/hash.odin | 4 |
2 files changed, 6 insertions, 6 deletions
diff --git a/core/hash/crc.odin b/core/hash/crc.odin index 008310408..bb31669d0 100644 --- a/core/hash/crc.odin +++ b/core/hash/crc.odin @@ -1,14 +1,14 @@ package hash -crc32 :: proc(data: []byte) -> u32 #no_bounds_check { - result := ~u32(0); +crc32 :: proc(data: []byte, seed := u32(0)) -> u32 #no_bounds_check { + result := ~u32(seed); for b in data { result = result>>8 ~ _crc32_table[(result ~ u32(b)) & 0xff]; } return ~result; } -crc64 :: proc(data: []byte) -> u64 #no_bounds_check { - result := ~u64(0); +crc64 :: proc(data: []byte, seed := u32(0)) -> u64 #no_bounds_check { + result := ~u64(seed); for b in data { result = result>>8 ~ _crc64_table[(result ~ u64(b)) & 0xff]; } diff --git a/core/hash/hash.odin b/core/hash/hash.odin index 391fc09f7..5bd2f6e10 100644 --- a/core/hash/hash.odin +++ b/core/hash/hash.odin @@ -2,9 +2,9 @@ package hash import "core:mem" -adler32 :: proc(data: []byte) -> u32 { +adler32 :: proc(data: []byte, seed := u32(1)) -> u32 { ADLER_CONST :: 65521; - a, b: u32 = 1, 0; + a, b: u32 = seed & 0xFFFF, seed >> 16; for x in data { a = (a + u32(x)) % ADLER_CONST; b = (b + a) % ADLER_CONST; |