node/deps/npm/node_modules/fstream/lib/proxy-writer.js

// A writer for when we don't know what kind of thing
// the thing is.  That is, it's not explicitly set,
// so we're going to make it whatever the thing already
// is, or "File"
//
// Until then, collect all events.

module.exports = ProxyWriter

var Writer = require("./writer.js")
  , getType = require("./get-type.js")
  , inherits = require("inherits")
  , collect = require("./collect.js")
  , fs = require("fs")

inherits(ProxyWriter, Writer)

function ProxyWriter (props) {
  var me = this
  if (!(me instanceof ProxyWriter)) throw new Error(
    "ProxyWriter must be called as constructor.")

  me.props = props
  me._needDrain = false

  Writer.call(me, props)
}

ProxyWriter.prototype._stat = function () {
  var me = this
    , props = me.props
    // stat the thing to see what the proxy should be.
    , stat = props.follow ? "stat" : "lstat"

  fs[stat](props.path, function (er, current) {
    var type
    if (er || !current) {
      type = "File"
    } else {
      type = getType(current)
    }

    props[type] = true
    props.type = me.type = type

    me._old = current
    me._addProxy(Writer(props, current))
  })
}

ProxyWriter.prototype._addProxy = function (proxy) {
  // console.error("~~ set proxy", this.path)
  var me = this
  if (me._proxy) {
    return me.error("proxy already set")
  }

  me._proxy = proxy
  ; [ "ready"
    , "error"
    , "close"
    , "pipe"
    , "drain"
    , "warn"
    ].forEach(function (ev) {
      proxy.on(ev, me.emit.bind(me, ev))
    })

  me.emit("proxy", proxy)

  var calls = me._buffer
  calls.forEach(function (c) {
    // console.error("~~ ~~ proxy buffered call", c[0], c[1])
    proxy[c[0]].apply(proxy, c[1])
  })
  me._buffer.length = 0
  if (me._needsDrain) me.emit("drain")
}

ProxyWriter.prototype.add = function (entry) {
  // console.error("~~ proxy add")
  collect(entry)

  if (!this._proxy) {
    this._buffer.push(["add", [entry]])
    this._needDrain = true
    return false
  }
  return this._proxy.add(entry)
}

ProxyWriter.prototype.write = function (c) {
  // console.error("~~ proxy write")
  if (!this._proxy) {
    this._buffer.push(["write", [c]])
    this._needDrain = true
    return false
  }
  return this._proxy.write(c)
}

ProxyWriter.prototype.end = function (c) {
  // console.error("~~ proxy end")
  if (!this._proxy) {
    this._buffer.push(["end", [c]])
    return false
  }
  return this._proxy.end(c)
}