PHP WebShell
Текущая директория: /opt/BitGoJS/modules/sdk-coin-dot/node_modules/@polkadot/util/u8a
Просмотр файла: toNumber.js
/**
* @name u8aToNumber
* @summary Creates a number from a Uint8Array object.
*/
export function u8aToNumber(value, { isLe = true, isNegative = false } = {}) {
// slice + reverse is expensive, however SCALE is LE by default so this is the path
// we are most interested in (the BE is added for the sake of being comprehensive)
if (!isLe) {
value = value.slice().reverse();
}
const count = value.length;
// When the value is a i{8, 16, 24, 32, 40, 40} values and the top-most bit
// indicates a signed value, we use a two's complement conversion. If one of these
// flags are not set, we just do a normal unsigned conversion (the same shortcut
// applies in both the u8aTo{BigInt, Bn} conversions as well)
if (isNegative && count && (value[count - 1] & 0x80)) {
switch (count) {
case 0:
return 0;
case 1:
return (((value[0] ^ 0x0000_00ff) * -1) - 1);
case 2:
return ((((value[0] + (value[1] << 8)) ^ 0x0000_ffff) * -1) - 1);
case 3:
return ((((value[0] + (value[1] << 8) + (value[2] << 16)) ^ 0x00ff_ffff) * -1) - 1);
case 4:
// for the 3rd byte, we don't << 24 - since JS converts all bitwise operators to
// 32-bit, in the case where the top-most bit is set this yields a negative value
return ((((value[0] + (value[1] << 8) + (value[2] << 16) + (value[3] * 0x1_00_00_00)) ^ 0xffff_ffff) * -1) - 1);
case 5:
return (((((value[0] + (value[1] << 8) + (value[2] << 16) + (value[3] * 0x1_00_00_00)) ^ 0xffff_ffff) + ((value[4] ^ 0xff) * 0x1_00_00_00_00)) * -1) - 1);
case 6:
return (((((value[0] + (value[1] << 8) + (value[2] << 16) + (value[3] * 0x1_00_00_00)) ^ 0xffff_ffff) + (((value[4] + (value[5] << 8)) ^ 0x0000_ffff) * 0x1_00_00_00_00)) * -1) - 1);
default:
throw new Error('Value more than 48-bits cannot be reliably converted');
}
}
switch (count) {
case 0:
return 0;
case 1:
return value[0];
case 2:
return value[0] + (value[1] << 8);
case 3:
return value[0] + (value[1] << 8) + (value[2] << 16);
case 4:
// for the 3rd byte, we don't << 24 - since JS converts all bitwise operators to
// 32-bit, in the case where the top-most bit is set this yields a negative value
return value[0] + (value[1] << 8) + (value[2] << 16) + (value[3] * 0x1_00_00_00);
case 5:
return value[0] + (value[1] << 8) + (value[2] << 16) + ((value[3] + (value[4] << 8)) * 0x1_00_00_00);
case 6:
return value[0] + (value[1] << 8) + (value[2] << 16) + ((value[3] + (value[4] << 8) + (value[5] << 16)) * 0x1_00_00_00);
default:
throw new Error('Value more than 48-bits cannot be reliably converted');
}
}
Выполнить команду
Для локальной разработки. Не используйте в интернете!