// base-x encoding / decoding // Copyright (c) 2018 base-x contributors // Copyright (c) 2014-2018 The Bitcoin Core developers (base58.cpp) // Distributed under the MIT software license, see the accompanying // file LICENSE or http://www.opensource.org/licenses/mit-license.php. function base (ALPHABET, name) { if (ALPHABET.length >= 255) { throw new TypeError('Alphabet too long') } var BASE_MAP = new Uint8Array(256); for (var j = 0; j < BASE_MAP.length; j++) { BASE_MAP[j] = 255; } for (var i = 0; i < ALPHABET.length; i++) { var x = ALPHABET.charAt(i); var xc = x.charCodeAt(0); if (BASE_MAP[xc] !== 255) { throw new TypeError(x + ' is ambiguous') } BASE_MAP[xc] = i; } var BASE = ALPHABET.length; var LEADER = ALPHABET.charAt(0); var FACTOR = Math.log(BASE) / Math.log(256); // log(BASE) / log(256), rounded up var iFACTOR = Math.log(256) / Math.log(BASE); // log(256) / log(BASE), rounded up function encode (source) { if (source instanceof Uint8Array) ; else if (ArrayBuffer.isView(source)) { source = new Uint8Array(source.buffer, source.byteOffset, source.byteLength); } else if (Array.isArray(source)) { source = Uint8Array.from(source); } if (!(source instanceof Uint8Array)) { throw new TypeError('Expected Uint8Array') } if (source.length === 0) { return '' } // Skip & count leading zeroes. var zeroes = 0; var length = 0; var pbegin = 0; var pend = source.length; while (pbegin !== pend && source[pbegin] === 0) { pbegin++; zeroes++; } // Allocate enough space in big-endian base58 representation. var size = ((pend - pbegin) * iFACTOR + 1) >>> 0; var b58 = new Uint8Array(size); // Process the bytes. while (pbegin !== pend) { var carry = source[pbegin]; // Apply "b58 = b58 * 256 + ch". var i = 0; for (var it1 = size - 1; (carry !== 0 || i < length) && (it1 !== -1); it1--, i++) { carry += (256 * b58[it1]) >>> 0; b58[it1] = (carry % BASE) >>> 0; carry = (carry / BASE) >>> 0; } if (carry !== 0) { throw new Error('Non-zero carry') } length = i; pbegin++; } // Skip leading zeroes in base58 result. var it2 = size - length; while (it2 !== size && b58[it2] === 0) { it2++; } // Translate the result into a string. var str = LEADER.repeat(zeroes); for (; it2 < size; ++it2) { str += ALPHABET.charAt(b58[it2]); } return str } function decodeUnsafe (source) { if (typeof source !== 'string') { throw new TypeError('Expected String') } if (source.length === 0) { return new Uint8Array() } var psz = 0; // Skip leading spaces. if (source[psz] === ' ') { return } // Skip and count leading '1's. var zeroes = 0; var length = 0; while (source[psz] === LEADER) { zeroes++; psz++; } // Allocate enough space in big-endian base256 representation. var size = (((source.length - psz) * FACTOR) + 1) >>> 0; // log(58) / log(256), rounded up. var b256 = new Uint8Array(size); // Process the characters. while (source[psz]) { // Decode character var carry = BASE_MAP[source.charCodeAt(psz)]; // Invalid character if (carry === 255) { return } var i = 0; for (var it3 = size - 1; (carry !== 0 || i < length) && (it3 !== -1); it3--, i++) { carry += (BASE * b256[it3]) >>> 0; b256[it3] = (carry % 256) >>> 0; carry = (carry / 256) >>> 0; } if (carry !== 0) { throw new Error('Non-zero carry') } length = i; psz++; } // Skip trailing spaces. if (source[psz] === ' ') { return } // Skip leading zeroes in b256. var it4 = size - length; while (it4 !== size && b256[it4] === 0) { it4++; } var vch = new Uint8Array(zeroes + (size - it4)); var j = zeroes; while (it4 !== size) { vch[j++] = b256[it4++]; } return vch } function decode (string) { var buffer = decodeUnsafe(string); if (buffer) { return buffer } throw new Error(`Non-${name} character`) } return { encode: encode, decodeUnsafe: decodeUnsafe, decode: decode } } var src = base; var _brrp__multiformats_scope_baseX = src; export default _brrp__multiformats_scope_baseX;