byte-helpers.js
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"use strict";
var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.reverseBytes = exports.sliceBytes = exports.bytesMatch = exports.concatTypedArrays = exports.stringToBytes = exports.bytesToString = exports.numberToBytes = exports.bytesToNumber = exports.IS_LITTLE_ENDIAN = exports.IS_BIG_ENDIAN = exports.ENDIANNESS = exports.toBinaryString = exports.toHexString = exports.toUint8 = exports.isTypedArray = exports.padStart = exports.countBytes = exports.countBits = void 0;
var _window = _interopRequireDefault(require("global/window"));
// const log2 = Math.log2 ? Math.log2 : (x) => (Math.log(x) / Math.log(2));
var repeat = function repeat(str, len) {
var acc = '';
while (len--) {
acc += str;
}
return acc;
}; // count the number of bits it would take to represent a number
// we used to do this with log2 but BigInt does not support builtin math
// Math.ceil(log2(x));
var countBits = function countBits(x) {
return x.toString(2).length;
}; // count the number of whole bytes it would take to represent a number
exports.countBits = countBits;
var countBytes = function countBytes(x) {
return Math.ceil(countBits(x) / 8);
};
exports.countBytes = countBytes;
var padStart = function padStart(b, len, str) {
if (str === void 0) {
str = ' ';
}
return (repeat(str, len) + b.toString()).slice(-len);
};
exports.padStart = padStart;
var isTypedArray = function isTypedArray(obj) {
return ArrayBuffer.isView(obj);
};
exports.isTypedArray = isTypedArray;
var toUint8 = function toUint8(bytes) {
if (bytes instanceof Uint8Array) {
return bytes;
}
if (!Array.isArray(bytes) && !isTypedArray(bytes) && !(bytes instanceof ArrayBuffer)) {
// any non-number or NaN leads to empty uint8array
// eslint-disable-next-line
if (typeof bytes !== 'number' || typeof bytes === 'number' && bytes !== bytes) {
bytes = 0;
} else {
bytes = [bytes];
}
}
return new Uint8Array(bytes && bytes.buffer || bytes, bytes && bytes.byteOffset || 0, bytes && bytes.byteLength || 0);
};
exports.toUint8 = toUint8;
var toHexString = function toHexString(bytes) {
bytes = toUint8(bytes);
var str = '';
for (var i = 0; i < bytes.length; i++) {
str += padStart(bytes[i].toString(16), 2, '0');
}
return str;
};
exports.toHexString = toHexString;
var toBinaryString = function toBinaryString(bytes) {
bytes = toUint8(bytes);
var str = '';
for (var i = 0; i < bytes.length; i++) {
str += padStart(bytes[i].toString(2), 8, '0');
}
return str;
};
exports.toBinaryString = toBinaryString;
var BigInt = _window.default.BigInt || Number;
var BYTE_TABLE = [BigInt('0x1'), BigInt('0x100'), BigInt('0x10000'), BigInt('0x1000000'), BigInt('0x100000000'), BigInt('0x10000000000'), BigInt('0x1000000000000'), BigInt('0x100000000000000'), BigInt('0x10000000000000000')];
var ENDIANNESS = function () {
var a = new Uint16Array([0xFFCC]);
var b = new Uint8Array(a.buffer, a.byteOffset, a.byteLength);
if (b[0] === 0xFF) {
return 'big';
}
if (b[0] === 0xCC) {
return 'little';
}
return 'unknown';
}();
exports.ENDIANNESS = ENDIANNESS;
var IS_BIG_ENDIAN = ENDIANNESS === 'big';
exports.IS_BIG_ENDIAN = IS_BIG_ENDIAN;
var IS_LITTLE_ENDIAN = ENDIANNESS === 'little';
exports.IS_LITTLE_ENDIAN = IS_LITTLE_ENDIAN;
var bytesToNumber = function bytesToNumber(bytes, _temp) {
var _ref = _temp === void 0 ? {} : _temp,
_ref$signed = _ref.signed,
signed = _ref$signed === void 0 ? false : _ref$signed,
_ref$le = _ref.le,
le = _ref$le === void 0 ? false : _ref$le;
bytes = toUint8(bytes);
var fn = le ? 'reduce' : 'reduceRight';
var obj = bytes[fn] ? bytes[fn] : Array.prototype[fn];
var number = obj.call(bytes, function (total, byte, i) {
var exponent = le ? i : Math.abs(i + 1 - bytes.length);
return total + BigInt(byte) * BYTE_TABLE[exponent];
}, BigInt(0));
if (signed) {
var max = BYTE_TABLE[bytes.length] / BigInt(2) - BigInt(1);
number = BigInt(number);
if (number > max) {
number -= max;
number -= max;
number -= BigInt(2);
}
}
return Number(number);
};
exports.bytesToNumber = bytesToNumber;
var numberToBytes = function numberToBytes(number, _temp2) {
var _ref2 = _temp2 === void 0 ? {} : _temp2,
_ref2$le = _ref2.le,
le = _ref2$le === void 0 ? false : _ref2$le;
// eslint-disable-next-line
if (typeof number !== 'bigint' && typeof number !== 'number' || typeof number === 'number' && number !== number) {
number = 0;
}
number = BigInt(number);
var byteCount = countBytes(number);
var bytes = new Uint8Array(new ArrayBuffer(byteCount));
for (var i = 0; i < byteCount; i++) {
var byteIndex = le ? i : Math.abs(i + 1 - bytes.length);
bytes[byteIndex] = Number(number / BYTE_TABLE[i] & BigInt(0xFF));
if (number < 0) {
bytes[byteIndex] = Math.abs(~bytes[byteIndex]);
bytes[byteIndex] -= i === 0 ? 1 : 2;
}
}
return bytes;
};
exports.numberToBytes = numberToBytes;
var bytesToString = function bytesToString(bytes) {
if (!bytes) {
return '';
} // TODO: should toUint8 handle cases where we only have 8 bytes
// but report more since this is a Uint16+ Array?
bytes = Array.prototype.slice.call(bytes);
var string = String.fromCharCode.apply(null, toUint8(bytes));
try {
return decodeURIComponent(escape(string));
} catch (e) {// if decodeURIComponent/escape fails, we are dealing with partial
// or full non string data. Just return the potentially garbled string.
}
return string;
};
exports.bytesToString = bytesToString;
var stringToBytes = function stringToBytes(string, stringIsBytes) {
if (typeof string !== 'string' && string && typeof string.toString === 'function') {
string = string.toString();
}
if (typeof string !== 'string') {
return new Uint8Array();
} // If the string already is bytes, we don't have to do this
// otherwise we do this so that we split multi length characters
// into individual bytes
if (!stringIsBytes) {
string = unescape(encodeURIComponent(string));
}
var view = new Uint8Array(string.length);
for (var i = 0; i < string.length; i++) {
view[i] = string.charCodeAt(i);
}
return view;
};
exports.stringToBytes = stringToBytes;
var concatTypedArrays = function concatTypedArrays() {
for (var _len = arguments.length, buffers = new Array(_len), _key = 0; _key < _len; _key++) {
buffers[_key] = arguments[_key];
}
buffers = buffers.filter(function (b) {
return b && (b.byteLength || b.length) && typeof b !== 'string';
});
if (buffers.length <= 1) {
// for 0 length we will return empty uint8
// for 1 length we return the first uint8
return toUint8(buffers[0]);
}
var totalLen = buffers.reduce(function (total, buf, i) {
return total + (buf.byteLength || buf.length);
}, 0);
var tempBuffer = new Uint8Array(totalLen);
var offset = 0;
buffers.forEach(function (buf) {
buf = toUint8(buf);
tempBuffer.set(buf, offset);
offset += buf.byteLength;
});
return tempBuffer;
};
/**
* Check if the bytes "b" are contained within bytes "a".
*
* @param {Uint8Array|Array} a
* Bytes to check in
*
* @param {Uint8Array|Array} b
* Bytes to check for
*
* @param {Object} options
* options
*
* @param {Array|Uint8Array} [offset=0]
* offset to use when looking at bytes in a
*
* @param {Array|Uint8Array} [mask=[]]
* mask to use on bytes before comparison.
*
* @return {boolean}
* If all bytes in b are inside of a, taking into account
* bit masks.
*/
exports.concatTypedArrays = concatTypedArrays;
var bytesMatch = function bytesMatch(a, b, _temp3) {
var _ref3 = _temp3 === void 0 ? {} : _temp3,
_ref3$offset = _ref3.offset,
offset = _ref3$offset === void 0 ? 0 : _ref3$offset,
_ref3$mask = _ref3.mask,
mask = _ref3$mask === void 0 ? [] : _ref3$mask;
a = toUint8(a);
b = toUint8(b); // ie 11 does not support uint8 every
var fn = b.every ? b.every : Array.prototype.every;
return b.length && a.length - offset >= b.length && // ie 11 doesn't support every on uin8
fn.call(b, function (bByte, i) {
var aByte = mask[i] ? mask[i] & a[offset + i] : a[offset + i];
return bByte === aByte;
});
};
exports.bytesMatch = bytesMatch;
var sliceBytes = function sliceBytes(src, start, end) {
if (Uint8Array.prototype.slice) {
return Uint8Array.prototype.slice.call(src, start, end);
}
return new Uint8Array(Array.prototype.slice.call(src, start, end));
};
exports.sliceBytes = sliceBytes;
var reverseBytes = function reverseBytes(src) {
if (src.reverse) {
return src.reverse();
}
return Array.prototype.reverse.call(src);
};
exports.reverseBytes = reverseBytes;