87 lines
3.3 KiB
JavaScript
87 lines
3.3 KiB
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.createFromBase64Bin = void 0;
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const constants_1 = require("./constants");
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const createFromBase64Bin = (chars = constants_1.alphabet, pad = '=') => {
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if (chars.length !== 64)
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throw new Error('chars must be 64 characters long');
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let max = 0;
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for (let i = 0; i < chars.length; i++)
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max = Math.max(max, chars.charCodeAt(i));
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const table = [];
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for (let i = 0; i <= max; i += 1)
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table[i] = -1;
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for (let i = 0; i < chars.length; i++)
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table[chars.charCodeAt(i)] = i;
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const doExpectPadding = pad.length === 1;
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const PAD = doExpectPadding ? pad.charCodeAt(0) : 0;
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return (view, offset, length) => {
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if (!length)
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return new Uint8Array(0);
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let padding = 0;
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if (length % 4 !== 0) {
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padding = 4 - (length % 4);
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length += padding;
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}
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else {
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const end = offset + length;
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const last = end - 1;
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if (view.getUint8(last) === PAD) {
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padding = 1;
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if (length > 1 && view.getUint8(last - 1) === PAD)
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padding = 2;
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}
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}
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if (length % 4 !== 0)
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throw new Error('Base64 string length must be a multiple of 4');
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const mainEnd = offset + length - (padding ? 4 : 0);
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const bufferLength = (length >> 2) * 3 - padding;
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const buf = new Uint8Array(bufferLength);
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let j = 0;
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let i = offset;
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for (; i < mainEnd; i += 4) {
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const word = view.getUint32(i);
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const octet0 = word >>> 24;
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const octet1 = (word >>> 16) & 0xff;
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const octet2 = (word >>> 8) & 0xff;
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const octet3 = word & 0xff;
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const sextet0 = table[octet0];
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const sextet1 = table[octet1];
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const sextet2 = table[octet2];
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const sextet3 = table[octet3];
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if (sextet0 < 0 || sextet1 < 0 || sextet2 < 0 || sextet3 < 0)
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throw new Error('INVALID_BASE64_SEQ');
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buf[j] = (sextet0 << 2) | (sextet1 >> 4);
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buf[j + 1] = (sextet1 << 4) | (sextet2 >> 2);
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buf[j + 2] = (sextet2 << 6) | sextet3;
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j += 3;
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}
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if (!padding)
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return buf;
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if (padding === 1) {
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const word = view.getUint16(mainEnd);
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const octet0 = word >> 8;
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const octet1 = word & 0xff;
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const octet2 = view.getUint8(mainEnd + 2);
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const sextet0 = table[octet0];
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const sextet1 = table[octet1];
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const sextet2 = table[octet2];
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if (sextet0 < 0 || sextet1 < 0 || sextet2 < 0)
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throw new Error('INVALID_BASE64_SEQ');
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buf[j] = (sextet0 << 2) | (sextet1 >> 4);
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buf[j + 1] = (sextet1 << 4) | (sextet2 >> 2);
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return buf;
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}
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const word = view.getUint16(mainEnd);
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const octet0 = word >> 8;
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const octet1 = word & 0xff;
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const sextet0 = table[octet0];
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const sextet1 = table[octet1];
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if (sextet0 < 0 || sextet1 < 0)
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throw new Error('INVALID_BASE64_SEQ');
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buf[j] = (sextet0 << 2) | (sextet1 >> 4);
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return buf;
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};
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};
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exports.createFromBase64Bin = createFromBase64Bin;
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//# sourceMappingURL=createFromBase64Bin.js.map
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