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charSet.js
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166 lines (139 loc) · 4.79 KB
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'use strict';
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.charSet2 = exports.charSet4 = exports.charSet8 = exports.charSet16 = exports.charSet32 = exports.charSet64 = undefined;
var _log = require('babel-runtime/core-js/math/log2');
var _log2 = _interopRequireDefault(_log);
var _classCallCheck2 = require('babel-runtime/helpers/classCallCheck');
var _classCallCheck3 = _interopRequireDefault(_classCallCheck2);
var _createClass2 = require('babel-runtime/helpers/createClass');
var _createClass3 = _interopRequireDefault(_createClass2);
var _lcm = require('./lcm');
var _lcm2 = _interopRequireDefault(_lcm);
var _weakMap = require('weak-map');
var _weakMap2 = _interopRequireDefault(_weakMap);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
var propMap = new _weakMap2.default();
var BITS_PER_BYTE = 8;
var CharSet = function () {
function CharSet(chars) {
(0, _classCallCheck3.default)(this, CharSet);
if (!(typeof chars === 'string' || chars instanceof String)) {
throw new Error('Invalid chars: Must be string');
}
var length = chars.length;
if (![2, 4, 8, 16, 32, 64].includes(length)) {
throw new Error('Invalid char count: must be one of 2,4,8,16,32,64');
}
var bitsPerChar = Math.floor((0, _log2.default)(length));
// Ensure no repeated characters
for (var i = 0; i < length; i++) {
var c = chars.charAt(i);
for (var j = i + 1; j < length; j++) {
if (c === chars.charAt(j)) {
throw new Error('Characters not unique');
}
}
}
var privProps = {
chars: chars,
bitsPerChar: bitsPerChar,
length: length,
ndxFn: _ndxFn(bitsPerChar),
charsPerChunk: (0, _lcm2.default)(bitsPerChar, BITS_PER_BYTE) / bitsPerChar
};
propMap.set(this, privProps);
}
(0, _createClass3.default)(CharSet, [{
key: 'getChars',
value: function getChars() {
return propMap.get(this).chars;
}
}, {
key: 'getBitsPerChar',
value: function getBitsPerChar() {
return propMap.get(this).bitsPerChar;
}
}, {
key: 'getNdxFn',
value: function getNdxFn() {
return propMap.get(this).ndxFn;
}
}, {
key: 'getCharsPerChunk',
value: function getCharsPerChunk() {
return propMap.get(this).charsPerChunk;
}
}, {
key: 'length',
value: function length() {
return propMap.get(this).length;
}
}, {
key: 'getNdxFn',
value: function getNdxFn() {
return propMap.get(this).ndxFn;
}
}, {
key: 'bytesNeeded',
value: function bytesNeeded(entropyBits) {
var count = Math.ceil(entropyBits / this.bitsPerChar());
return Math.ceil(count * this.bitsPerChar() / BITS_PER_BYTE);
}
// Aliases
}, {
key: 'chars',
value: function chars() {
return this.getChars();
}
}, {
key: 'ndxFn',
value: function ndxFn() {
return this.getNdxFn();
}
}, {
key: 'bitsPerChar',
value: function bitsPerChar() {
return this.getBitsPerChar();
}
}]);
return CharSet;
}();
exports.default = CharSet;
var _ndxFn = function _ndxFn(bitsPerChar) {
// If BITS_PER_BYTEs is a multiple of bitsPerChar, we can slice off an integer number
// of chars per byte.
if ((0, _lcm2.default)(bitsPerChar, BITS_PER_BYTE) === BITS_PER_BYTE) {
return function (chunk, slice, bytes) {
var lShift = bitsPerChar;
var rShift = BITS_PER_BYTE - bitsPerChar;
return (bytes[chunk] << lShift * slice & 0xff) >> rShift;
};
}
// Otherwise, while slicing off bits per char, we will possibly straddle a couple
// of bytes, so a bit more work is involved
else {
var slicesPerChunk = (0, _lcm2.default)(bitsPerChar, BITS_PER_BYTE) / BITS_PER_BYTE;
return function (chunk, slice, bytes) {
var bNum = chunk * slicesPerChunk;
var offset = slice * bitsPerChar / BITS_PER_BYTE;
var lOffset = Math.floor(offset);
var rOffset = Math.ceil(offset);
var rShift = BITS_PER_BYTE - bitsPerChar;
var lShift = slice * bitsPerChar % BITS_PER_BYTE;
var ndx = (bytes[bNum + lOffset] << lShift & 0xff) >> rShift;
var rShiftIt = ((rOffset + 1) * BITS_PER_BYTE - (slice + 1) * bitsPerChar) % BITS_PER_BYTE;
if (rShift < rShiftIt) {
ndx += bytes[bNum + rOffset] >> rShiftIt;
}
return ndx;
};
}
};
var charSet64 = exports.charSet64 = new CharSet('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_');
var charSet32 = exports.charSet32 = new CharSet('2346789bdfghjmnpqrtBDFGHJLMNPQRT');
var charSet16 = exports.charSet16 = new CharSet('0123456789abcdef');
var charSet8 = exports.charSet8 = new CharSet('01234567');
var charSet4 = exports.charSet4 = new CharSet('ATCG');
var charSet2 = exports.charSet2 = new CharSet('01');