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var Transform = require('readable-stream').Transform , inherits = require('util').inherits , xtend = require('xtend')
function DestroyableTransform(opts) { Transform.call(this, opts) this._destroyed = false }
inherits(DestroyableTransform, Transform)
DestroyableTransform.prototype.destroy = function(err) { if (this._destroyed) return this._destroyed = true var self = this process.nextTick(function() { if (err) self.emit('error', err) self.emit('close') }) }
// a noop _transform function
function noop (chunk, enc, callback) { callback(null, chunk) }
// create a new export function, used by both the main export and
// the .ctor export, contains common logic for dealing with arguments
function through2 (construct) { return function (options, transform, flush) { if (typeof options == 'function') { flush = transform transform = options options = {} }
if (typeof transform != 'function') transform = noop
if (typeof flush != 'function') flush = null
return construct(options, transform, flush) } }
// main export, just make me a transform stream!
module.exports = through2(function (options, transform, flush) { var t2 = new DestroyableTransform(options)
t2._transform = transform
if (flush) t2._flush = flush
return t2 })
// make me a reusable prototype that I can `new`, or implicitly `new`
// with a constructor call
module.exports.ctor = through2(function (options, transform, flush) { function Through2 (override) { if (!(this instanceof Through2)) return new Through2(override)
this.options = xtend(options, override)
DestroyableTransform.call(this, this.options) }
inherits(Through2, DestroyableTransform)
Through2.prototype._transform = transform
if (flush) Through2.prototype._flush = flush
return Through2 })
module.exports.obj = through2(function (options, transform, flush) { var t2 = new DestroyableTransform(xtend({ objectMode: true, highWaterMark: 16 }, options))
t2._transform = transform
if (flush) t2._flush = flush
return t2 })
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