72 lines
2.2 KiB
JavaScript
72 lines
2.2 KiB
JavaScript
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"use strict";
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var __importDefault = (this && this.__importDefault) || function (mod) {
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return (mod && mod.__esModule) ? mod : { "default": mod };
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};
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Object.defineProperty(exports, "__esModule", { value: true });
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const match_1 = __importDefault(require("../match"));
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class Utf8 {
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name() {
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return 'UTF-8';
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}
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match(det) {
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let hasBOM = false, numValid = 0, numInvalid = 0, trailBytes = 0, confidence;
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const input = det.rawInput;
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if (det.rawLen >= 3 &&
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(input[0] & 0xff) == 0xef &&
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(input[1] & 0xff) == 0xbb &&
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(input[2] & 0xff) == 0xbf) {
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hasBOM = true;
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}
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for (let i = 0; i < det.rawLen; i++) {
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const b = input[i];
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if ((b & 0x80) == 0)
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continue;
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if ((b & 0x0e0) == 0x0c0) {
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trailBytes = 1;
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}
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else if ((b & 0x0f0) == 0x0e0) {
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trailBytes = 2;
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}
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else if ((b & 0x0f8) == 0xf0) {
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trailBytes = 3;
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}
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else {
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numInvalid++;
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if (numInvalid > 5)
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break;
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trailBytes = 0;
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}
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for (;;) {
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i++;
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if (i >= det.rawLen)
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break;
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if ((input[i] & 0xc0) != 0x080) {
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numInvalid++;
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break;
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}
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if (--trailBytes == 0) {
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numValid++;
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break;
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}
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}
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}
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confidence = 0;
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if (hasBOM && numInvalid == 0)
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confidence = 100;
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else if (hasBOM && numValid > numInvalid * 10)
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confidence = 80;
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else if (numValid > 3 && numInvalid == 0)
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confidence = 100;
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else if (numValid > 0 && numInvalid == 0)
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confidence = 80;
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else if (numValid == 0 && numInvalid == 0)
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confidence = 10;
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else if (numValid > numInvalid * 10)
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confidence = 25;
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else
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return null;
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return (0, match_1.default)(det, this, confidence);
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}
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}
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exports.default = Utf8;
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//# sourceMappingURL=utf8.js.map
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