twonly-app-dependencies/hashlib/lib/src/algorithms/xxh3/xxh3_64_64bit.dart
2025-12-07 16:10:41 +01:00

391 lines
12 KiB
Dart

// Copyright (c) 2023, Sudipto Chandra
// All rights reserved. Check LICENSE file for details.
import 'dart:collection';
import 'dart:typed_data';
import 'package:hashlib/src/core/block_hash.dart';
const int _mask32 = 0xFFFFFFFF;
const int _stripeLen = 64;
const int _midsizeMax = 240;
const int _minSecretSize = 136;
// Pseudorandom secret taken directly from FARSH (little-endian)
const List<int> _kSecret = <int>[
0xb8, 0xfe, 0x6c, 0x39, 0x23, 0xa4, 0x4b, 0xbe, 0x7c, 0x01, 0x81, 0x2c, //
0xf7, 0x21, 0xad, 0x1c, 0xde, 0xd4, 0x6d, 0xe9, 0x83, 0x90, 0x97, 0xdb,
0x72, 0x40, 0xa4, 0xa4, 0xb7, 0xb3, 0x67, 0x1f, 0xcb, 0x79, 0xe6, 0x4e,
0xcc, 0xc0, 0xe5, 0x78, 0x82, 0x5a, 0xd0, 0x7d, 0xcc, 0xff, 0x72, 0x21,
0xb8, 0x08, 0x46, 0x74, 0xf7, 0x43, 0x24, 0x8e, 0xe0, 0x35, 0x90, 0xe6,
0x81, 0x3a, 0x26, 0x4c, 0x3c, 0x28, 0x52, 0xbb, 0x91, 0xc3, 0x00, 0xcb,
0x88, 0xd0, 0x65, 0x8b, 0x1b, 0x53, 0x2e, 0xa3, 0x71, 0x64, 0x48, 0x97,
0xa2, 0x0d, 0xf9, 0x4e, 0x38, 0x19, 0xef, 0x46, 0xa9, 0xde, 0xac, 0xd8,
0xa8, 0xfa, 0x76, 0x3f, 0xe3, 0x9c, 0x34, 0x3f, 0xf9, 0xdc, 0xbb, 0xc7,
0xc7, 0x0b, 0x4f, 0x1d, 0x8a, 0x51, 0xe0, 0x4b, 0xcd, 0xb4, 0x59, 0x31,
0xc8, 0x9f, 0x7e, 0xc9, 0xd9, 0x78, 0x73, 0x64, 0xea, 0xc5, 0xac, 0x83,
0x34, 0xd3, 0xeb, 0xc3, 0xc5, 0x81, 0xa0, 0xff, 0xfa, 0x13, 0x63, 0xeb,
0x17, 0x0d, 0xdd, 0x51, 0xb7, 0xf0, 0xda, 0x49, 0xd3, 0x16, 0x55, 0x26,
0x29, 0xd4, 0x68, 0x9e, 0x2b, 0x16, 0xbe, 0x58, 0x7d, 0x47, 0xa1, 0xfc,
0x8f, 0xf8, 0xb8, 0xd1, 0x7a, 0xd0, 0x31, 0xce, 0x45, 0xcb, 0x3a, 0x8f,
0x95, 0x16, 0x04, 0x28, 0xaf, 0xd7, 0xfb, 0xca, 0xbb, 0x4b, 0x40, 0x7e,
];
/// This implementation is derived from
/// https://github.com/RedSpah/xxhash_cpp/blob/master/include/xxhash.hpp
class XXH3Sink64bit extends BlockHashSink {
final int seed;
final int rounds;
final Uint8List secret;
final Uint64List acc = Uint64List(8);
final ListQueue<int> last = ListQueue<int>(_midsizeMax);
late final Uint64List qbuffer = Uint64List.view(buffer.buffer);
late final Uint64List secret64 = Uint64List.view(secret.buffer);
late final ByteData secretBD = secret.buffer.asByteData();
@override
final int hashLength = 8;
static const int prime32_1 = 0x9E3779B1;
static const int prime32_2 = 0x85EBCA77;
static const int prime32_3 = 0xC2B2AE3D;
static const int prime64_1 = 0x9E3779B185EBCA87;
static const int prime64_2 = 0xC2B2AE3D27D4EB4F;
static const int prime64_3 = 0x165667B19E3779F9;
static const int prime64_4 = 0x85EBCA77C2B2AE63;
static const int prime64_5 = 0x27D4EB2F165667C5;
factory XXH3Sink64bit.withSeed(int seed) {
if (seed == 0) {
return XXH3Sink64bit.withSecret();
}
var secret = Uint8List.fromList(_kSecret);
var secret64 = Uint64List.view(secret.buffer);
for (int i = 0; i < secret64.length; i += 2) {
secret64[i] += seed;
}
for (int i = 1; i < secret64.length; i += 2) {
secret64[i] -= seed;
}
return XXH3Sink64bit._(
seed: seed,
secret: secret,
rounds: (secret.lengthInBytes - _stripeLen) >>> 3,
);
}
factory XXH3Sink64bit.withSecret([List<int>? secret]) {
var key = Uint8List.fromList(secret ?? _kSecret);
if (key.lengthInBytes < _minSecretSize) {
throw ArgumentError('The secret length must be at least $_minSecretSize');
}
return XXH3Sink64bit._(
seed: 0,
secret: key,
rounds: (key.lengthInBytes - _stripeLen) >>> 3,
);
}
XXH3Sink64bit._({
required this.seed,
required this.secret,
required this.rounds,
}) : super(rounds << 6) {
reset();
}
@override
void reset() {
acc[0] = prime32_3;
acc[1] = prime64_1;
acc[2] = prime64_2;
acc[3] = prime64_3;
acc[4] = prime64_4;
acc[5] = prime32_2;
acc[6] = prime64_5;
acc[7] = prime32_1;
super.reset();
}
@override
void $process(List<int> chunk, int start, int end) {
messageLength += end - start;
for (; start < end; start++, pos++) {
if (pos == blockLength) {
$update();
pos = 0;
}
buffer[pos] = chunk[start];
if (last.length == _midsizeMax) {
last.removeFirst();
}
last.add(chunk[start]);
}
}
@pragma('vm:prefer-inline')
static int _crossSwap(int x) => (x & _mask32) * (x >>> 32);
@override
void $update([List<int>? block, int offset = 0, bool last = false]) {
int n, i, v, l, k;
// accumulate
for (n = 0; n < rounds; n++) {
l = n << 3;
for (i = 0; i < acc.length; i++) {
v = qbuffer[l + i];
acc[i ^ 1] += v;
v ^= secret64[n + i];
acc[i] += _crossSwap(v);
}
}
// scramble
k = secret.lengthInBytes - _stripeLen;
for (i = 0; i < 8; ++i) {
acc[i] ^= acc[i] >>> 47;
acc[i] ^= secretBD.getUint64(k + (i << 3), Endian.little);
acc[i] *= prime32_1;
}
}
@pragma('vm:prefer-inline')
static int _avalanche(int hash) {
hash ^= hash >>> 37;
hash *= 0x165667919E3779F9;
hash ^= hash >>> 32;
return hash;
}
@pragma('vm:prefer-inline')
static int _midsizeAvalanche(int hash) {
hash ^= hash >>> 33;
hash *= prime64_2;
hash ^= hash >>> 29;
hash *= prime64_3;
hash ^= hash >>> 32;
return hash;
}
@pragma('vm:prefer-inline')
static int _rrmxmx(int hash, int length) {
hash ^= _rotl64(hash, 49) ^ _rotl64(hash, 24);
hash *= 0x9FB21C651E98DF25;
hash ^= (hash >>> 35) + length;
hash *= 0x9FB21C651E98DF25;
hash ^= hash >>> 28;
return hash;
}
int _finalizeLong(Uint64List stripe) {
// void hash_long_internal_loop
int hash;
int t, n, i, v, l, a, b;
const int lastAccStart = 7;
const int mergeAccStart = 11;
// last partial block
for (t = n = 0; t + _stripeLen < pos; n++, t += _stripeLen) {
l = n << 3;
for (i = 0; i < acc.length; i++) {
v = qbuffer[l + i];
acc[i ^ 1] += v;
v ^= secret64[n + i];
acc[i] += _crossSwap(v);
}
}
// last stripe
t = secret.lengthInBytes - _stripeLen - lastAccStart;
for (i = 0; i < acc.length; i++, t += 8) {
v = stripe[i];
acc[i ^ 1] += v;
v ^= secretBD.getUint64(t, Endian.little);
acc[i] += _crossSwap(v);
}
// converge into final hash: uint64_t merge_accs
hash = messageLength * prime64_1;
t = mergeAccStart;
for (i = 0; i < 8; i += 2, t += 16) {
a = acc[i] ^ secretBD.getUint64(t, Endian.little);
b = acc[i + 1] ^ secretBD.getUint64(t + 8, Endian.little);
hash += _mul128fold64(a, b);
}
// avalanche
return _avalanche(hash);
}
@pragma('vm:prefer-inline')
static int _swap32(int x) =>
((x << 24) & 0xff000000) |
((x << 8) & 0x00ff0000) |
((x >>> 8) & 0x0000ff00) |
((x >>> 24) & 0x000000ff);
@pragma('vm:prefer-inline')
static int _swap64(int x) =>
((x << 56) & 0xff00000000000000) |
((x << 40) & 0x00ff000000000000) |
((x << 24) & 0x0000ff0000000000) |
((x << 8) & 0x000000ff00000000) |
((x >>> 8) & 0x00000000ff000000) |
((x >>> 24) & 0x0000000000ff0000) |
((x >>> 40) & 0x000000000000ff00) |
((x >>> 56) & 0x00000000000000ff);
@pragma('vm:prefer-inline')
static int _rotl64(int x, int n) => (x << n) | (x >>> (64 - n));
// Multiply two 64-bit numbers to get 128-bit number and
// xor the low bits of the product with the high bits
static int _mul128fold64(int a, int b) {
int al, ah, bl, bh, ll, hl, lh, hh, cross, upper, lower;
al = a & _mask32;
ah = a >>> 32;
bl = b & _mask32;
bh = b >>> 32;
ll = al * bl;
hl = ah * bl;
lh = al * bh;
hh = ah * bh;
cross = (ll >>> 32) + (hl & _mask32) + lh;
upper = (hl >>> 32) + (cross >>> 32) + hh;
lower = (cross << 32) | (ll & _mask32);
return upper ^ lower;
}
static int _mix16B(ByteData input, int i, ByteData key, int j, int seed) {
int lhs, rhs;
lhs = input.getUint64(i, Endian.little);
rhs = input.getUint64(i + 8, Endian.little);
lhs ^= key.getUint64(j, Endian.little) + seed;
rhs ^= key.getUint64(j + 8, Endian.little) - seed;
return _mul128fold64(lhs, rhs);
}
int _finalizeShort(ByteData input, int length, ByteData key) {
int hash, lhs, rhs, a, b, c, i;
if (length == 0) {
// hash_t<N> len_0to16
hash = seed;
hash ^= key.getUint64(56, Endian.little);
hash ^= key.getUint64(64, Endian.little);
return _midsizeAvalanche(hash);
} else if (length <= 3) {
// hash_t<N> len_1to3
a = input.getUint8(0);
b = input.getUint8(length >>> 1);
c = input.getUint8(length - 1);
hash = key.getUint32(0, Endian.little);
hash ^= key.getUint32(4, Endian.little);
hash += seed;
hash ^= (a << 16) | (b << 24) | (c) | (length << 8);
return _midsizeAvalanche(hash);
} else if (length <= 8) {
// hash_t<N> len_4to8
lhs = input.getUint32(0, Endian.little);
rhs = input.getUint32(length - 4, Endian.little);
hash = key.getUint64(8, Endian.little);
hash ^= key.getUint64(16, Endian.little);
hash -= seed ^ ((_swap32(seed) & _mask32) << 32);
hash ^= (lhs << 32) | rhs;
return _rrmxmx(hash, length);
} else if (length <= 16) {
// hash_t<N> len_9to16
lhs = key.getUint64(24, Endian.little);
lhs ^= key.getUint64(32, Endian.little);
lhs += seed;
rhs = key.getUint64(40, Endian.little);
rhs ^= key.getUint64(48, Endian.little);
rhs -= seed;
lhs ^= input.getUint64(0, Endian.little);
rhs ^= input.getUint64(length - 8, Endian.little);
hash = length + _swap64(lhs) + rhs + _mul128fold64(lhs, rhs);
return _avalanche(hash);
} else if (length <= 128) {
// hash_t<N> len_17to128
hash = length * prime64_1;
if (length > 32) {
if (length > 64) {
if (length > 96) {
hash += _mix16B(input, 48, key, 96, seed);
hash += _mix16B(input, length - 64, key, 112, seed);
}
hash += _mix16B(input, 32, key, 64, seed);
hash += _mix16B(input, length - 48, key, 80, seed);
}
hash += _mix16B(input, 16, key, 32, seed);
hash += _mix16B(input, length - 32, key, 48, seed);
}
hash += _mix16B(input, 0, key, 0, seed);
hash += _mix16B(input, length - 16, key, 16, seed);
return _avalanche(hash);
} else {
// hash_t<N> len_129to240
const int startOffset = 3;
const int lastOffset = 17;
hash = length * prime64_1;
// first 128 bytes
for (i = 0; i < 128; i += 16) {
hash += _mix16B(input, i, key, i, seed);
}
hash = _avalanche(hash);
// remaining bytes
for (i = 128; i + 16 <= length; i += 16) {
c = startOffset + i - 128;
hash += _mix16B(input, i, key, c, seed);
}
// last byte
c = _minSecretSize - lastOffset;
hash += _mix16B(input, length - 16, key, c, seed);
return _avalanche(hash);
}
}
@override
Uint8List $finalize() {
int i;
int hash;
ByteData key;
Uint64List input = Uint64List(_midsizeMax >>> 3);
Uint8List input8 = Uint8List.view(input.buffer);
if (messageLength <= _midsizeMax) {
var it = last.iterator;
for (i = 0; it.moveNext(); ++i) {
input8[i] = it.current;
}
if (seed == 0) {
key = secretBD;
} else {
key = Uint8List.fromList(_kSecret).buffer.asByteData();
}
hash = _finalizeShort(input.buffer.asByteData(), i, key);
} else {
for (i = 63; i >= 0; --i) {
input8[i] = last.removeLast();
}
hash = _finalizeLong(input);
}
return Uint8List.fromList([
hash >>> 56,
hash >>> 48,
hash >>> 40,
hash >>> 32,
hash >>> 24,
hash >>> 16,
hash >>> 8,
hash,
]);
}
}