dynatrace-cordova-outsystems-plugin/node_modules/stringstream/stringstream.js

This plugin gives you the ability to use the Dynatrace instrumentation in your hybrid application (Cordova, Ionic, ..). It uses the Mobile Agent, the JavaScript Agent and the Javascript Bridge. The Mobile Agent will give you all device specific values con

var util = require('util')
var Stream = require('stream')
var StringDecoder = require('string_decoder').StringDecoder

module.exports = StringStream
module.exports.AlignedStringDecoder = AlignedStringDecoder

function StringStream(from, to) {
  if (!(this instanceof StringStream)) return new StringStream(from, to)

  Stream.call(this)

  if (from == null) from = 'utf8'

  this.readable = this.writable = true
  this.paused = false
  this.toEncoding = (to == null ? from : to)
  this.fromEncoding = (to == null ? '' : from)
  this.decoder = new AlignedStringDecoder(this.toEncoding)
}
util.inherits(StringStream, Stream)

StringStream.prototype.write = function(data) {
  if (!this.writable) {
    var err = new Error('stream not writable')
    err.code = 'EPIPE'
    this.emit('error', err)
    return false
  }
  if (this.fromEncoding) {
    if (Buffer.isBuffer(data) || typeof data === 'number') data = data.toString()
    data = new Buffer(data, this.fromEncoding)
  }
  var string = this.decoder.write(data)
  if (string.length) this.emit('data', string)
  return !this.paused
}

StringStream.prototype.flush = function() {
  if (this.decoder.flush) {
    var string = this.decoder.flush()
    if (string.length) this.emit('data', string)
  }
}

StringStream.prototype.end = function() {
  if (!this.writable && !this.readable) return
  this.flush()
  this.emit('end')
  this.writable = this.readable = false
  this.destroy()
}

StringStream.prototype.destroy = function() {
  this.decoder = null
  this.writable = this.readable = false
  this.emit('close')
}

StringStream.prototype.pause = function() {
  this.paused = true
}

StringStream.prototype.resume = function () {
  if (this.paused) this.emit('drain')
  this.paused = false
}

function AlignedStringDecoder(encoding) {
  StringDecoder.call(this, encoding)

  switch (this.encoding) {
    case 'base64':
      this.write = alignedWrite
      this.alignedBuffer = new Buffer(3)
      this.alignedBytes = 0
      break
  }
}
util.inherits(AlignedStringDecoder, StringDecoder)

AlignedStringDecoder.prototype.flush = function() {
  if (!this.alignedBuffer || !this.alignedBytes) return ''
  var leftover = this.alignedBuffer.toString(this.encoding, 0, this.alignedBytes)
  this.alignedBytes = 0
  return leftover
}

function alignedWrite(buffer) {
  var rem = (this.alignedBytes + buffer.length) % this.alignedBuffer.length
  if (!rem && !this.alignedBytes) return buffer.toString(this.encoding)

  var returnBuffer = new Buffer(this.alignedBytes + buffer.length - rem)

  this.alignedBuffer.copy(returnBuffer, 0, 0, this.alignedBytes)
  buffer.copy(returnBuffer, this.alignedBytes, 0, buffer.length - rem)

  buffer.copy(this.alignedBuffer, 0, buffer.length - rem, buffer.length)
  this.alignedBytes = rem

  return returnBuffer.toString(this.encoding)
}