63 lines
1.6 KiB
JavaScript
63 lines
1.6 KiB
JavaScript
import { Transform } from 'stream'
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import { Packr } from './pack.js'
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import { Unpackr } from './unpack.js'
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var DEFAULT_OPTIONS = {objectMode: true}
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export class PackrStream extends Transform {
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constructor(options) {
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if (!options)
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options = {}
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options.writableObjectMode = true
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super(options)
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options.sequential = true
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this.packr = options.packr || new Packr(options)
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}
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_transform(value, encoding, callback) {
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this.push(this.packr.pack(value))
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callback()
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}
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}
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export class UnpackrStream extends Transform {
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constructor(options) {
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if (!options)
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options = {}
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options.objectMode = true
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super(options)
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options.structures = []
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this.maxIncompleteBufferSize = options.maxIncompleteBufferSize !== undefined ? options.maxIncompleteBufferSize : 0x4000000
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this.unpackr = options.unpackr || new Unpackr(options)
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}
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_transform(chunk, encoding, callback) {
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if (this.incompleteBuffer) {
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chunk = Buffer.concat([this.incompleteBuffer, chunk])
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this.incompleteBuffer = null
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}
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let values
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try {
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values = this.unpackr.unpackMultiple(chunk)
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} catch(error) {
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if (error.incomplete) {
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let incompleteBuffer = chunk.slice(error.lastPosition)
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if (incompleteBuffer.length > this.maxIncompleteBufferSize) {
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this.incompleteBuffer = null
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return callback(new Error('Maximum incomplete buffer size exceeded'))
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}
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this.incompleteBuffer = incompleteBuffer
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values = error.values
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} else {
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return callback(error)
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}
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}
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for (let value of values || []) {
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if (value === null)
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value = this.getNullValue()
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this.push(value)
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}
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callback()
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}
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getNullValue() {
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return Symbol.for(null)
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}
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}
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