opt: IdUtils (#849)

This commit is contained in:
My-Responsitories
2025-05-11 12:11:10 +08:00
committed by GitHub
parent 17ea416c98
commit 5bff1747e6

View File

@@ -3,62 +3,49 @@
import 'dart:convert';
class IdUtils {
static final XOR_CODE = BigInt.parse('23442827791579');
static final MASK_CODE = BigInt.parse('2251799813685247');
static final MAX_AID = BigInt.one << (BigInt.from(51)).toInt();
static final BASE = BigInt.from(58);
static const XOR_CODE = 23442827791579;
static const MASK_CODE = 2251799813685247;
static const MAX_AID = 1 << 51;
static const BASE = 58;
static const data =
'FcwAPNKTMug3GV5Lj7EJnHpWsx4tb8haYeviqBz6rkCy12mUSDQX9RdoZf';
static final invData = {for (var (i, c) in data.codeUnits.indexed) c: i};
static final bvRegex = RegExp(r'bv(1[0-9A-Za-z]{9})', caseSensitive: false);
static final avRegex = RegExp(r'av(\d+)', caseSensitive: false);
static void swap<T>(List<T> list, int idx1, int idx2) {
final idx1Value = list[idx1];
list[idx1] = list[idx2];
list[idx2] = idx1Value;
}
/// av转bv
static String av2bv(int aid) {
List<String> bytes = [
'B',
'V',
'1',
'0',
'0',
'0',
'0',
'0',
'0',
'0',
'0',
'0'
];
final bytes = ['B', 'V', '1', '0', '0', '0', '0', '0', '0', '0', '0', '0'];
int bvIndex = bytes.length - 1;
BigInt tmp = (MAX_AID | BigInt.from(aid)) ^ XOR_CODE;
while (tmp > BigInt.zero) {
bytes[bvIndex] = data[(tmp % BASE).toInt()];
tmp = tmp ~/ BASE;
bvIndex -= 1;
int tmp = (MAX_AID | aid) ^ XOR_CODE;
while (tmp > 0) {
bytes[bvIndex--] = data[tmp % BASE];
tmp ~/= BASE;
}
String tmpSwap = bytes[3];
bytes[3] = bytes[9];
bytes[9] = tmpSwap;
tmpSwap = bytes[4];
bytes[4] = bytes[7];
bytes[7] = tmpSwap;
swap(bytes, 3, 9);
swap(bytes, 4, 7);
return bytes.join();
}
/// bv转av
static int bv2av(String bvid) {
List<String> bvidArr = bvid.split('');
final tmpValue = bvidArr[3];
bvidArr[3] = bvidArr[9];
bvidArr[9] = tmpValue;
final bvidArr = List.of(bvid.codeUnits);
final tmpValue2 = bvidArr[4];
bvidArr[4] = bvidArr[7];
bvidArr[7] = tmpValue2;
swap(bvidArr, 3, 9);
swap(bvidArr, 4, 7);
bvidArr.removeRange(0, 3);
BigInt tmp = bvidArr.fold(BigInt.zero,
(pre, bvidChar) => pre * BASE + BigInt.from(data.indexOf(bvidChar)));
int tmp = bvidArr.fold(0, (pre, char) => pre * BASE + invData[char]!);
return ((tmp & MASK_CODE) ^ XOR_CODE).toInt();
}
@@ -68,10 +55,8 @@ class IdUtils {
if (input == null || input.isEmpty) {
return result;
}
final RegExp bvRegex = RegExp(r'bv([0-9A-Za-z]{10})', caseSensitive: false);
String? bvid = bvRegex.firstMatch(input)?.group(1);
late final RegExp avRegex = RegExp(r'av(\d+)', caseSensitive: false);
late String? aid = avRegex.firstMatch(input)?.group(1);
if (bvid != null) {