60 lines
1.9 KiB
JavaScript
60 lines
1.9 KiB
JavaScript
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"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.CachedUtf8Decoder = void 0;
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const tslib_1 = require("tslib");
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const v10_1 = tslib_1.__importDefault(require("./decodeUtf8/v10"));
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let x = 1 + Math.round(Math.random() * ((-1 >>> 0) - 1));
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function randomU32(min, max) {
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x ^= x << 13;
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x ^= x >>> 17;
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x ^= x << 5;
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return ((x >>> 0) % (max - min + 1)) + min;
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}
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class CacheItem {
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constructor(bytes, value) {
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this.bytes = bytes;
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this.value = value;
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}
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}
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class CachedUtf8Decoder {
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constructor() {
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this.caches = [];
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for (let i = 0; i < 31; i++)
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this.caches.push([]);
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}
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get(bytes, offset, size) {
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const records = this.caches[size - 1];
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const len = records.length;
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FIND_CHUNK: for (let i = 0; i < len; i++) {
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const record = records[i];
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const recordBytes = record.bytes;
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for (let j = 0; j < size; j++)
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if (recordBytes[j] !== bytes[offset + j])
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continue FIND_CHUNK;
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return record.value;
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}
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return null;
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}
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store(bytes, value) {
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const records = this.caches[bytes.length - 1];
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const record = new CacheItem(bytes, value);
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const length = records.length;
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if (length >= 16)
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records[randomU32(0, 16 - 1)] = record;
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else
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records.push(record);
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}
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decode(bytes, offset, size) {
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if (!size)
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return '';
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const cachedValue = this.get(bytes, offset, size);
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if (cachedValue !== null)
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return cachedValue;
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const value = (0, v10_1.default)(bytes, offset, size);
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const copy = Uint8Array.prototype.slice.call(bytes, offset, offset + size);
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this.store(copy, value);
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return value;
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}
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}
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exports.CachedUtf8Decoder = CachedUtf8Decoder;
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//# sourceMappingURL=CachedUtf8Decoder.js.map
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