42 lines
1.2 KiB
JavaScript
42 lines
1.2 KiB
JavaScript
'use strict';
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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var _stream = require('stream');
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class OverflowError extends Error {}
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class MeterSream extends _stream.Transform {
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constructor() {
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let maxSize = arguments.length <= 0 || arguments[0] === undefined ? Infinity : arguments[0];
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super();
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this.maxSize = maxSize;
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this.byteCount = 0;
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}
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_transform(chunk, encoding, cb) {
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// if this is called, _flush isn't called
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if (this.err) return cb(this.err);
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if (this.maxSize === Infinity) return cb(null, chunk);
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this.byteCount += chunk.length;
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if (this.byteCount > this.maxSize) {
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const remainingBytes = this.maxSize - this.byteCount;
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const lastChunk = chunk.slice(0, remainingBytes);
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this.err = new OverflowError(`Stream exceeded specified max of ${ this.maxSize } bytes.`);
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// flush remaining chunk and wait until next
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// _transform or _flush call to emit error
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return cb(null, lastChunk);
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}
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cb(null, chunk);
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}
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// if error detected on last call to _transform
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// flush will be called with the error
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_flush(cb) {
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cb(this.err);
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}
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}
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MeterSream.OverflowError = OverflowError;
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exports.default = MeterSream; |