1 | 'use strict'
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2 | const EE = require('events')
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3 | const Stream = require('stream')
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4 | const Yallist = require('yallist')
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5 | const SD = require('string_decoder').StringDecoder
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6 |
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7 | const EOF = Symbol('EOF')
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8 | const MAYBE_EMIT_END = Symbol('maybeEmitEnd')
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9 | const EMITTED_END = Symbol('emittedEnd')
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10 | const EMITTING_END = Symbol('emittingEnd')
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11 | const CLOSED = Symbol('closed')
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12 | const READ = Symbol('read')
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13 | const FLUSH = Symbol('flush')
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14 | const FLUSHCHUNK = Symbol('flushChunk')
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15 | const ENCODING = Symbol('encoding')
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16 | const DECODER = Symbol('decoder')
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17 | const FLOWING = Symbol('flowing')
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18 | const PAUSED = Symbol('paused')
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19 | const RESUME = Symbol('resume')
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20 | const BUFFERLENGTH = Symbol('bufferLength')
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21 | const BUFFERPUSH = Symbol('bufferPush')
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22 | const BUFFERSHIFT = Symbol('bufferShift')
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23 | const OBJECTMODE = Symbol('objectMode')
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24 | const DESTROYED = Symbol('destroyed')
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25 |
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26 |
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27 | const doIter = global._MP_NO_ITERATOR_SYMBOLS_ !== '1'
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28 | const ASYNCITERATOR = doIter && Symbol.asyncIterator
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29 | || Symbol('asyncIterator not implemented')
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30 | const ITERATOR = doIter && Symbol.iterator
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31 | || Symbol('iterator not implemented')
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32 |
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33 |
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34 |
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35 |
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36 | const isEndish = ev =>
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37 | ev === 'end' ||
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38 | ev === 'finish' ||
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39 | ev === 'prefinish'
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40 |
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41 | const isArrayBuffer = b => b instanceof ArrayBuffer ||
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42 | typeof b === 'object' &&
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43 | b.constructor &&
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44 | b.constructor.name === 'ArrayBuffer' &&
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45 | b.byteLength >= 0
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46 |
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47 | const isArrayBufferView = b => !Buffer.isBuffer(b) && ArrayBuffer.isView(b)
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48 |
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49 | module.exports = class Minipass extends Stream {
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50 | constructor (options) {
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51 | super()
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52 | this[FLOWING] = false
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53 |
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54 | this[PAUSED] = false
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55 | this.pipes = new Yallist()
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56 | this.buffer = new Yallist()
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57 | this[OBJECTMODE] = options && options.objectMode || false
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58 | if (this[OBJECTMODE])
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59 | this[ENCODING] = null
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60 | else
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61 | this[ENCODING] = options && options.encoding || null
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62 | if (this[ENCODING] === 'buffer')
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63 | this[ENCODING] = null
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64 | this[DECODER] = this[ENCODING] ? new SD(this[ENCODING]) : null
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65 | this[EOF] = false
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66 | this[EMITTED_END] = false
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67 | this[EMITTING_END] = false
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68 | this[CLOSED] = false
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69 | this.writable = true
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70 | this.readable = true
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71 | this[BUFFERLENGTH] = 0
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72 | this[DESTROYED] = false
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73 | }
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74 |
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75 | get bufferLength () { return this[BUFFERLENGTH] }
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76 |
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77 | get encoding () { return this[ENCODING] }
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78 | set encoding (enc) {
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79 | if (this[OBJECTMODE])
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80 | throw new Error('cannot set encoding in objectMode')
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81 |
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82 | if (this[ENCODING] && enc !== this[ENCODING] &&
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83 | (this[DECODER] && this[DECODER].lastNeed || this[BUFFERLENGTH]))
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84 | throw new Error('cannot change encoding')
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85 |
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86 | if (this[ENCODING] !== enc) {
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87 | this[DECODER] = enc ? new SD(enc) : null
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88 | if (this.buffer.length)
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89 | this.buffer = this.buffer.map(chunk => this[DECODER].write(chunk))
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90 | }
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91 |
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92 | this[ENCODING] = enc
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93 | }
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94 |
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95 | setEncoding (enc) {
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96 | this.encoding = enc
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97 | }
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98 |
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99 | get objectMode () { return this[OBJECTMODE] }
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100 | set objectMode (om) { this[OBJECTMODE] = this[OBJECTMODE] || !!om }
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101 |
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102 | write (chunk, encoding, cb) {
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103 | if (this[EOF])
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104 | throw new Error('write after end')
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105 |
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106 | if (this[DESTROYED]) {
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107 | this.emit('error', Object.assign(
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108 | new Error('Cannot call write after a stream was destroyed'),
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109 | { code: 'ERR_STREAM_DESTROYED' }
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110 | ))
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111 | return true
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112 | }
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113 |
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114 | if (typeof encoding === 'function')
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115 | cb = encoding, encoding = 'utf8'
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116 |
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117 | if (!encoding)
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118 | encoding = 'utf8'
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119 |
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120 |
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121 |
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122 |
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123 |
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124 | if (!this[OBJECTMODE] && !Buffer.isBuffer(chunk)) {
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125 | if (isArrayBufferView(chunk))
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126 | chunk = Buffer.from(chunk.buffer, chunk.byteOffset, chunk.byteLength)
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127 | else if (isArrayBuffer(chunk))
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128 | chunk = Buffer.from(chunk)
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129 | else if (typeof chunk !== 'string')
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130 |
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131 | this.objectMode = true
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132 | }
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133 |
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134 |
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135 |
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136 | if (!this.objectMode && !chunk.length) {
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137 | if (this[BUFFERLENGTH] !== 0)
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138 | this.emit('readable')
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139 | if (cb)
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140 | cb()
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141 | return this.flowing
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142 | }
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143 |
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144 |
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145 |
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146 | if (typeof chunk === 'string' && !this[OBJECTMODE] &&
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147 |
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148 | !(encoding === this[ENCODING] && !this[DECODER].lastNeed)) {
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149 | chunk = Buffer.from(chunk, encoding)
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150 | }
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151 |
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152 | if (Buffer.isBuffer(chunk) && this[ENCODING])
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153 | chunk = this[DECODER].write(chunk)
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154 |
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155 | if (this.flowing) {
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156 |
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157 |
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158 |
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159 |
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160 | if (this[BUFFERLENGTH] !== 0)
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161 | this[FLUSH](true)
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162 | this.emit('data', chunk)
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163 | } else
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164 | this[BUFFERPUSH](chunk)
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165 |
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166 | if (this[BUFFERLENGTH] !== 0)
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167 | this.emit('readable')
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168 |
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169 | if (cb)
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170 | cb()
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171 |
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172 | return this.flowing
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173 | }
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174 |
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175 | read (n) {
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176 | if (this[DESTROYED])
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177 | return null
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178 |
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179 | try {
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180 | if (this[BUFFERLENGTH] === 0 || n === 0 || n > this[BUFFERLENGTH])
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181 | return null
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182 |
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183 | if (this[OBJECTMODE])
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184 | n = null
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185 |
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186 | if (this.buffer.length > 1 && !this[OBJECTMODE]) {
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187 | if (this.encoding)
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188 | this.buffer = new Yallist([
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189 | Array.from(this.buffer).join('')
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190 | ])
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191 | else
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192 | this.buffer = new Yallist([
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193 | Buffer.concat(Array.from(this.buffer), this[BUFFERLENGTH])
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194 | ])
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195 | }
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196 |
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197 | return this[READ](n || null, this.buffer.head.value)
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198 | } finally {
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199 | this[MAYBE_EMIT_END]()
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200 | }
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201 | }
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202 |
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203 | [READ] (n, chunk) {
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204 | if (n === chunk.length || n === null)
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205 | this[BUFFERSHIFT]()
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206 | else {
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207 | this.buffer.head.value = chunk.slice(n)
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208 | chunk = chunk.slice(0, n)
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209 | this[BUFFERLENGTH] -= n
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210 | }
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211 |
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212 | this.emit('data', chunk)
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213 |
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214 | if (!this.buffer.length && !this[EOF])
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215 | this.emit('drain')
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216 |
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217 | return chunk
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218 | }
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219 |
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220 | end (chunk, encoding, cb) {
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221 | if (typeof chunk === 'function')
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222 | cb = chunk, chunk = null
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223 | if (typeof encoding === 'function')
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224 | cb = encoding, encoding = 'utf8'
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225 | if (chunk)
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226 | this.write(chunk, encoding)
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227 | if (cb)
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228 | this.once('end', cb)
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229 | this[EOF] = true
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230 | this.writable = false
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231 |
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232 |
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233 |
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234 |
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235 |
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236 | if (this.flowing || !this[PAUSED])
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237 | this[MAYBE_EMIT_END]()
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238 | return this
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239 | }
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240 |
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241 |
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242 | [RESUME] () {
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243 | if (this[DESTROYED])
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244 | return
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245 |
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246 | this[PAUSED] = false
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247 | this[FLOWING] = true
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248 | this.emit('resume')
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249 | if (this.buffer.length)
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250 | this[FLUSH]()
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251 | else if (this[EOF])
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252 | this[MAYBE_EMIT_END]()
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253 | else
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254 | this.emit('drain')
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255 | }
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256 |
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257 | resume () {
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258 | return this[RESUME]()
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259 | }
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260 |
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261 | pause () {
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262 | this[FLOWING] = false
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263 | this[PAUSED] = true
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264 | }
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265 |
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266 | get destroyed () {
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267 | return this[DESTROYED]
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268 | }
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269 |
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270 | get flowing () {
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271 | return this[FLOWING]
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272 | }
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273 |
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274 | get paused () {
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275 | return this[PAUSED]
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276 | }
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277 |
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278 | [BUFFERPUSH] (chunk) {
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279 | if (this[OBJECTMODE])
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280 | this[BUFFERLENGTH] += 1
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281 | else
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282 | this[BUFFERLENGTH] += chunk.length
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283 | return this.buffer.push(chunk)
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284 | }
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285 |
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286 | [BUFFERSHIFT] () {
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287 | if (this.buffer.length) {
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288 | if (this[OBJECTMODE])
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289 | this[BUFFERLENGTH] -= 1
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290 | else
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291 | this[BUFFERLENGTH] -= this.buffer.head.value.length
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292 | }
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293 | return this.buffer.shift()
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294 | }
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295 |
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296 | [FLUSH] (noDrain) {
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297 | do {} while (this[FLUSHCHUNK](this[BUFFERSHIFT]()))
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298 |
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299 | if (!noDrain && !this.buffer.length && !this[EOF])
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300 | this.emit('drain')
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301 | }
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302 |
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303 | [FLUSHCHUNK] (chunk) {
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304 | return chunk ? (this.emit('data', chunk), this.flowing) : false
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305 | }
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306 |
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307 | pipe (dest, opts) {
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308 | if (this[DESTROYED])
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309 | return
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310 |
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311 | const ended = this[EMITTED_END]
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312 | opts = opts || {}
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313 | if (dest === process.stdout || dest === process.stderr)
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314 | opts.end = false
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315 | else
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316 | opts.end = opts.end !== false
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317 |
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318 | const p = { dest: dest, opts: opts, ondrain: _ => this[RESUME]() }
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319 | this.pipes.push(p)
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320 |
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321 | dest.on('drain', p.ondrain)
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322 | this[RESUME]()
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323 |
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324 | if (ended && p.opts.end)
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325 | p.dest.end()
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326 | return dest
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327 | }
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328 |
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329 | addListener (ev, fn) {
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330 | return this.on(ev, fn)
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331 | }
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332 |
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333 | on (ev, fn) {
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334 | try {
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335 | return super.on(ev, fn)
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336 | } finally {
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337 | if (ev === 'data' && !this.pipes.length && !this.flowing)
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338 | this[RESUME]()
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339 | else if (isEndish(ev) && this[EMITTED_END]) {
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340 | super.emit(ev)
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341 | this.removeAllListeners(ev)
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342 | }
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343 | }
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344 | }
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345 |
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346 | get emittedEnd () {
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347 | return this[EMITTED_END]
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348 | }
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349 |
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350 | [MAYBE_EMIT_END] () {
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351 | if (!this[EMITTING_END] &&
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352 | !this[EMITTED_END] &&
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353 | !this[DESTROYED] &&
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354 | this.buffer.length === 0 &&
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355 | this[EOF]) {
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356 | this[EMITTING_END] = true
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357 | this.emit('end')
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358 | this.emit('prefinish')
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359 | this.emit('finish')
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360 | if (this[CLOSED])
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361 | this.emit('close')
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362 | this[EMITTING_END] = false
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363 | }
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364 | }
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365 |
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366 | emit (ev, data) {
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367 |
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368 | if (ev !== 'error' && ev !== 'close' && ev !== DESTROYED && this[DESTROYED])
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369 | return
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370 | else if (ev === 'data') {
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371 | if (!data)
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372 | return
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373 |
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374 | if (this.pipes.length)
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375 | this.pipes.forEach(p =>
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376 | p.dest.write(data) === false && this.pause())
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377 | } else if (ev === 'end') {
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378 |
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379 | if (this[EMITTED_END] === true)
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380 | return
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381 |
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382 | this[EMITTED_END] = true
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383 | this.readable = false
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384 |
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385 | if (this[DECODER]) {
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386 | data = this[DECODER].end()
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387 | if (data) {
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388 | this.pipes.forEach(p => p.dest.write(data))
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389 | super.emit('data', data)
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390 | }
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391 | }
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392 |
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393 | this.pipes.forEach(p => {
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394 | p.dest.removeListener('drain', p.ondrain)
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395 | if (p.opts.end)
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396 | p.dest.end()
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397 | })
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398 | } else if (ev === 'close') {
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399 | this[CLOSED] = true
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400 |
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401 | if (!this[EMITTED_END] && !this[DESTROYED])
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402 | return
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403 | }
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404 |
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405 |
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406 | const args = new Array(arguments.length)
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407 | args[0] = ev
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408 | args[1] = data
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409 | if (arguments.length > 2) {
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410 | for (let i = 2; i < arguments.length; i++) {
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411 | args[i] = arguments[i]
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412 | }
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413 | }
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414 |
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415 | try {
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416 | return super.emit.apply(this, args)
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417 | } finally {
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418 | if (!isEndish(ev))
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419 | this[MAYBE_EMIT_END]()
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420 | else
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421 | this.removeAllListeners(ev)
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422 | }
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423 | }
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424 |
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425 |
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426 | collect () {
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427 | const buf = []
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428 | if (!this[OBJECTMODE])
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429 | buf.dataLength = 0
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430 |
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431 |
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432 | const p = this.promise()
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433 | this.on('data', c => {
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434 | buf.push(c)
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435 | if (!this[OBJECTMODE])
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436 | buf.dataLength += c.length
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437 | })
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438 | return p.then(() => buf)
|
439 | }
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440 |
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441 |
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442 | concat () {
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443 | return this[OBJECTMODE]
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444 | ? Promise.reject(new Error('cannot concat in objectMode'))
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445 | : this.collect().then(buf =>
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446 | this[OBJECTMODE]
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447 | ? Promise.reject(new Error('cannot concat in objectMode'))
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448 | : this[ENCODING] ? buf.join('') : Buffer.concat(buf, buf.dataLength))
|
449 | }
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450 |
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451 |
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452 | promise () {
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453 | return new Promise((resolve, reject) => {
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454 | this.on(DESTROYED, () => reject(new Error('stream destroyed')))
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455 | this.on('end', () => resolve())
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456 | this.on('error', er => reject(er))
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457 | })
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458 | }
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459 |
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460 |
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461 | [ASYNCITERATOR] () {
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462 | const next = () => {
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463 | const res = this.read()
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464 | if (res !== null)
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465 | return Promise.resolve({ done: false, value: res })
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466 |
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467 | if (this[EOF])
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468 | return Promise.resolve({ done: true })
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469 |
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470 | let resolve = null
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471 | let reject = null
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472 | const onerr = er => {
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473 | this.removeListener('data', ondata)
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474 | this.removeListener('end', onend)
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475 | reject(er)
|
476 | }
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477 | const ondata = value => {
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478 | this.removeListener('error', onerr)
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479 | this.removeListener('end', onend)
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480 | this.pause()
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481 | resolve({ value: value, done: !!this[EOF] })
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482 | }
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483 | const onend = () => {
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484 | this.removeListener('error', onerr)
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485 | this.removeListener('data', ondata)
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486 | resolve({ done: true })
|
487 | }
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488 | const ondestroy = () => onerr(new Error('stream destroyed'))
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489 | return new Promise((res, rej) => {
|
490 | reject = rej
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491 | resolve = res
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492 | this.once(DESTROYED, ondestroy)
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493 | this.once('error', onerr)
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494 | this.once('end', onend)
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495 | this.once('data', ondata)
|
496 | })
|
497 | }
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498 |
|
499 | return { next }
|
500 | }
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501 |
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502 |
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503 | [ITERATOR] () {
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504 | const next = () => {
|
505 | const value = this.read()
|
506 | const done = value === null
|
507 | return { value, done }
|
508 | }
|
509 | return { next }
|
510 | }
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511 |
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512 | destroy (er) {
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513 | if (this[DESTROYED]) {
|
514 | if (er)
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515 | this.emit('error', er)
|
516 | else
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517 | this.emit(DESTROYED)
|
518 | return this
|
519 | }
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520 |
|
521 | this[DESTROYED] = true
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522 |
|
523 |
|
524 | this.buffer = new Yallist()
|
525 | this[BUFFERLENGTH] = 0
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526 |
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527 | if (typeof this.close === 'function' && !this[CLOSED])
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528 | this.close()
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529 |
|
530 | if (er)
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531 | this.emit('error', er)
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532 | else
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533 | this.emit(DESTROYED)
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534 |
|
535 | return this
|
536 | }
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537 |
|
538 | static isStream (s) {
|
539 | return !!s && (s instanceof Minipass || s instanceof Stream ||
|
540 | s instanceof EE && (
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541 | typeof s.pipe === 'function' ||
|
542 | (typeof s.write === 'function' && typeof s.end === 'function')
|
543 | ))
|
544 | }
|
545 | }
|