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44 lines
1.4 KiB
JavaScript
44 lines
1.4 KiB
JavaScript
8 months ago
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"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.ByteLengthParser = void 0;
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const stream_1 = require("stream");
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/**
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* Emit data every number of bytes
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*
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* A transform stream that emits data as a buffer after a specific number of bytes are received. Runs in O(n) time.
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*/
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class ByteLengthParser extends stream_1.Transform {
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constructor(options) {
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super(options);
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if (typeof options.length !== 'number') {
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throw new TypeError('"length" is not a number');
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}
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if (options.length < 1) {
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throw new TypeError('"length" is not greater than 0');
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}
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this.length = options.length;
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this.position = 0;
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this.buffer = Buffer.alloc(this.length);
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}
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_transform(chunk, _encoding, cb) {
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let cursor = 0;
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while (cursor < chunk.length) {
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this.buffer[this.position] = chunk[cursor];
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cursor++;
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this.position++;
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if (this.position === this.length) {
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this.push(this.buffer);
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this.buffer = Buffer.alloc(this.length);
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this.position = 0;
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}
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}
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cb();
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}
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_flush(cb) {
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this.push(this.buffer.slice(0, this.position));
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this.buffer = Buffer.alloc(this.length);
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cb();
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}
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}
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exports.ByteLengthParser = ByteLengthParser;
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